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1
Bebkiewicz, Katarzyna, Zdzisław Chłopek, Hubert Sar, Krystian Szczepański y Magdalena Zimakowska-Laskowska. "Influence of the Thermal State of Vehicle Combustion Engines on the Results of the National Inventory of Pollutant Emissions". Applied Sciences 11, n.º 19 (29 de septiembre de 2021): 9084. http://dx.doi.org/10.3390/app11199084.
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The article presents the results of studies on the influence of the thermal state of vehicle combustion engines on pollutant emissions. This influence was analyzed based on data from Poland’s inventory of pollutant emissions for the years 1990–2017. The results show that during engine warm-up, carbon monoxide emission constitutes the largest share (up to 50%) in the national annual total emission. Volatile organic compounds are next in the ranking, whereas the share of nitrogen oxides is the lowest (less than 5%). Under the model traffic conditions, close to those in Poland’s cities in winter, simulation tests regarding additional pollutant emissions from passenger cars during engine warm-up were also carried out. As a result of the cold-start emissive behavior of internal combustion engines, emissions of carbon monoxide and volatile organic compounds showed a considerably greater impact on national pollutant emission, as compared to carbon dioxide, nitrogen oxides and particulate matter. This is particularly evident for the results of the inventory of pollutant emissions from road transport.
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Guven, Denizhan, M. Özgür Kayalica y Gülgün Kayakutlu. "CO2 emissions analysis for East European countries: the role of underlying emission trend". Environmental Economics 11, n.º 1 (5 de junio de 2020): 67–81. http://dx.doi.org/10.21511/ee.11(1).2020.07.
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This paper aims to analyze the impact of energy consumption, economic structure, and manufacturing output on the CO2 emissions of East European countries by applying the Structural Time Series Model (STSM). Several explanatory factors are used to construct the model using annual data of the 1990–2017 period. The factors are: total primary energy supply, GDP per capita and manufacturing value added, and, finally, a stochastic Underlying Emission Trend (UET). The significant effects of all variables on CO2 emissions are detected. Based on the estimated functions, CO2 emissions of Belarus, Ukraine, Romania, Russia, Serbia, and Hungary will decrease, by 2027, to 53.2 Mt, 103.2 Mt, 36.1 Mt, 1528.2 Mt, 36 Mt, and 36.1 Mt, respectively. Distinct from other countries, CO2 emissions of Poland will extend to 312.2 Mt in 2027 due to the very high share of fossil-based supply (i.e., coal and oil) in Poland. The results also indicate that the most forceful factor in CO2 emissions is the total primary energy supply. Furthermore, for Poland, Romania, Hungary, and Belarus, the long-term impact of economic growth on CO2 emissions is negative, while it is positive for Russia, Ukraine, and Serbia. The highest long-term manufacturing value-added elasticity of CO2 emissions is calculated for Serbia and Belarus.
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Simmonds, Peter G., Matthew Rigby, Alistair J. Manning, Sunyoung Park, Kieran M. Stanley, Archie McCulloch, Stephan Henne et al. "The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF<sub>6</sub>)". Atmospheric Chemistry and Physics 20, n.º 12 (23 de junio de 2020): 7271–90. http://dx.doi.org/10.5194/acp-20-7271-2020.
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Abstract. We report a 40-year history of SF6 atmospheric mole fractions measured at the Advanced Global Atmospheric Gases Experiment (AGAGE) monitoring sites, combined with archived air samples, to determine emission estimates from 1978 to 2018. Previously we reported a global emission rate of 7.3±0.6 Gg yr−1 in 2008 and over the past decade emissions have continued to increase by about 24 % to 9.04±0.35 Gg yr−1 in 2018. We show that changing patterns in SF6 consumption from developed (Kyoto Protocol Annex-1) to developing countries (non-Annex-1) and the rapid global expansion of the electric power industry, mainly in Asia, have increased the demand for SF6-insulated switchgear, circuit breakers, and transformers. The large bank of SF6 sequestered in this electrical equipment provides a substantial source of emissions from maintenance, replacement, and continuous leakage. Other emissive sources of SF6 occur from the magnesium, aluminium, and electronics industries as well as more minor industrial applications. More recently, reported emissions, including those from electrical equipment and metal industries, primarily in the Annex-1 countries, have declined steadily through substitution of alternative blanketing gases and technological improvements in less emissive equipment and more efficient industrial practices. Nevertheless, there are still demands for SF6 in Annex-1 countries due to economic growth, as well as continuing emissions from older equipment and additional emissions from newly installed SF6-insulated electrical equipment, although at low emission rates. In addition, in the non-Annex-1 countries, SF6 emissions have increased due to an expansion in the growth of the electrical power, metal, and electronics industries to support their continuing development. There is an annual difference of 2.5–5 Gg yr−1 (1990–2018) between our modelled top-down emissions and the UNFCCC-reported bottom-up emissions (United Nations Framework Convention on Climate Change), which we attempt to reconcile through analysis of the potential contribution of emissions from the various industrial applications which use SF6. We also investigate regional emissions in East Asia (China, S. Korea) and western Europe and their respective contributions to the global atmospheric SF6 inventory. On an average annual basis, our estimated emissions from the whole of China are approximately 10 times greater than emissions from western Europe. In 2018, our modelled Chinese and western European emissions accounted for ∼36 % and 3.1 %, respectively, of our global SF6 emissions estimate.
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Yang, Ming, Shun An Chen, Qian Ru Lin y Tao Pang. "Temperature Sensing Assists the Understanding of Er3+ Concentration Dependent Anti-Stokes Luminescence in NaYF4:Er3+/Yb3+ Nanophosphors". Materials Science Forum 1003 (julio de 2020): 241–46. http://dx.doi.org/10.4028/www.scientific.net/msf.1003.241.
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In this paper, upcovnerison luminescence in Er3+/Yb3+ co-doped NaYF4 nanophosphors was regulated by changing the Er3+ concentration. With increasing the Er3+ concentration, the green and red emissions increased first and then decreased, but the intensity ratio of red to green emission decreased monotonically. To clarify the role of Er3+ doping, the factors including crystal structure, morphology and size of particle, photon absorption, energy transfer, multi-phonon relaxation, population of emissive levels and emission probability of radiative transitions were considered and analyzed. More importantly, we proposed a simple method for discussing radiation transitions based on luminescence temperature sensing.
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Rao, Longshi, Qing Zhang, Bin Sun, Mingfu Wen, Jiayang Zhang, Guisheng Zhong, Ting Fu y Xiaodong Niu. "Multicolor Luminescent Carbon Dots: Tunable Photoluminescence, Excellent Stability, and their Application in Light-Emitting Diodes". Nanomaterials 12, n.º 18 (9 de septiembre de 2022): 3132. http://dx.doi.org/10.3390/nano12183132.
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Carbon dots (CDs) are attracting much interest due to their excellent photoelectric properties and wide range of potential applications. However, it is still a challenge to regulate their bandgap emissions to achieve full-color CDs with high emissions. Herein, we propose an approach for producing full-color emissive CDs by employing a solvent engineering strategy. By only tuning the volume ratio of water and dimethylformamide (H2O/DMF), the photoluminescence (PL) emission wavelengths of the CDs can be changed from 451 to 654 nm. Different fluorescence features of multicolor CDs were systematically investigated. XRD, SEM, TEM, Abs/PL/PLE, XPS, and PL decay lifetime characterizations provided conclusive evidence supporting the extent to which the solvent controlled the dehydration and carbonization processes of the precursors, leading to a variation in their emission color from red to blue. The as-prepared CDs exhibited excellent and stable fluorescence performance even after being heated at 80 °C for 48 h and with UV light continuously irradiated for 15 h. Based on their excellent fluorescent properties and photothermal stability, bright multicolor light-emitting diodes with a high CRI of up to 91 were obtained. We anticipate that these full-color emissive CDs are beneficial for applications in lighting, display, and other fields.
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Gayton, Jacqueline, Shane Autry, Ryan Fortenberry, Nathan Hammer y Jared Delcamp. "Counter Anion Effect on the Photophysical Properties of Emissive Indolizine-Cyanine Dyes in Solution and Solid State". Molecules 23, n.º 12 (22 de noviembre de 2018): 3051. http://dx.doi.org/10.3390/molecules23123051.
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Near-infrared emissive materials with tunable Stokes shifts and solid-state emissions are needed for several active research areas and applications. To aid in addressing this need, a series of indolizine-cyanine compounds varying only the anions based on size, dipole, and hydrophilicity were prepared. The effect of the non-covalently bound anions on the absorption and emission properties of identical π-system indolizine-cyanine compounds were measured in solution and as thin films. Interestingly, the anion choice has a significant influence on the Stokes shift and molar absorptivities of the dyes in solution. In the solid-state, the anion choice was found to have an effect on the formation of aggregate states with higher energy absorptions than the parent monomer compound. The dyes were found to be emissive in the NIR region, with emissions peaking at near 900 nm for specific solvent and anion selections.
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Khuong Mai, Duy, Joomin Lee, Ilgi Min, Temmy Vales, Kyong-Hoon Choi, Bong Park, Sung Cho y Ho-Joong Kim. "Aggregation-Induced Emission of Tetraphenylethene-Conjugated Phenanthrene Derivatives and Their Bio-Imaging Applications". Nanomaterials 8, n.º 9 (15 de septiembre de 2018): 728. http://dx.doi.org/10.3390/nano8090728.
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In this study, a series of rationally designed emissive phenanthrene derivatives were synthesized and their aggregation-induced emission (AIE) properties in tetrahydrofuran (THF)/water mixtures were investigated. Two tetraphenylethene (TPE) segments were conjugated to both ends of the phenanthrene core at the para-positions and meta-positions, resulting in pTPEP and mTPEP derivatives, respectively. While the TPE-conjugated phenanthrene derivatives did not show any emission when dissolved in pure THF, they showed strong sky-blue emissions in water-THF mixtures, which is attributed to the restriction of intramolecular motions of TPE segments by aggregation. Furthermore, silica nanoparticles loaded with these AIE-active compounds were prepared and proved to be promising intracellular imaging agents.
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Hu, Lei, Stephen A. Montzka, Ben R. Miller, Arlyn E. Andrews, John B. Miller, Scott J. Lehman, Colm Sweeney et al. "Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses". Proceedings of the National Academy of Sciences 113, n.º 11 (29 de febrero de 2016): 2880–85. http://dx.doi.org/10.1073/pnas.1522284113.
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National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration’s flask air sampling network. We estimate an annual average US emission of 4.0 (2.0–6.5) Gg CCl4 y−1 during 2008–2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y−1) but only 8% (3–22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008–2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).
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Gavalas, Spyridon y Antonios Kelarakis. "Towards Red Emissive Systems Based on Carbon Dots". Nanomaterials 11, n.º 8 (17 de agosto de 2021): 2089. http://dx.doi.org/10.3390/nano11082089.
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Carbon dots (C-dots) represent an emerging class of nontoxic nanoemitters that show excitation wavelength-dependent photoluminescence (PL) with high quantum yield (QY) and minimal photobleaching. The vast majority of studies focus on C-dots that exhibit the strongest PL emissions in the blue/green region of the spectrum, while longer wavelength emissions are ideal for applications such as bioimaging, photothermal and photodynamic therapy and light-emitting diodes. Effective strategies to modulate the PL emission of C-dot-based systems towards the red end of the spectrum rely on extensive conjugation of sp2 domains, heteroatom doping, solvatochromism, surface functionalization and passivation. Those approaches are systematically presented in this review, while emphasis is given on important applications of red-emissive suspensions, nanopowders and polymer nanocomposites.
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Walaa, Al Masri, Mumtaz Ali, Al-Hartomy Omar y S. Wageh. "Solid-State Emissive Carbon Quantum Dots (CQDs) with a Long Wavelength Emission". Journal of Nanoelectronics and Optoelectronics 18, n.º 8 (1 de agosto de 2023): 881–87. http://dx.doi.org/10.1166/jno.2023.3476.
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Carbon quantum dots (CQDs)—growing stars of the nanocarbon family—have received attention owing to their intriguing photoluminescence (PL), stability, and biocompatibility. However, CQDs may suffer from serious aggregation-caused quenching (ACQ) of PL, specifically in powder or thin film form. Moreover, most engineering applications are solid-state; therefore, it is important to design solid-state emissive CQDs, potentially defeating ACQ. Previous reviews highlighted the strategies for solid-state emissive CQDs; however, less focus has been given to CQDs with emissions at longer wavelengths. This review summarizes recent advances (specifically in the last two years), focusing on long wavelengths, including yellow-, orange-, and red-emissive fluorescence. Furthermore, the synthesis method, quantum yield, and mechanism of fluorescence are explained. In addition, a detailed summary of synthesis parameters and their role in emission tuning is highlighted. Finally, the future directions and potential applications of solid-state CQDs for emerging applications were discussed.
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Herrington, T. y K. Zickfeld. "Path independence of climate and carbon cycle response over a broad range of cumulative carbon emissions". Earth System Dynamics 5, n.º 2 (24 de noviembre de 2014): 409–22. http://dx.doi.org/10.5194/esd-5-409-2014.
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Abstract. Recent studies have identified an approximately proportional relationship between global warming and cumulative carbon emissions, yet the robustness of this relationship has not been tested over a broad range of cumulative emissions and emission rates. This study explores the path dependence of the climate and carbon cycle response using an Earth system model of intermediate complexity forced with 24 idealized emissions scenarios across five cumulative emission groups (1275–5275 Gt C) with varying rates of emission. We find the century-scale climate and carbon cycle response after cessation of emissions to be approximately independent of emission pathway for all cumulative emission levels considered. The ratio of global mean temperature change to cumulative emissions – referred to as the transient climate response to cumulative carbon emissions (TCRE) – is found to be constant for cumulative emissions lower than ∼1500 Gt C but to decline with higher cumulative emissions. The TCRE is also found to decrease with increasing emission rate. The response of Arctic sea ice is found to be approximately proportional to cumulative emissions, while the response of the Atlantic Meridional Overturning Circulation does not scale linearly with cumulative emissions, as its peak response is strongly dependent on emission rate. Ocean carbon uptake weakens with increasing cumulative emissions, while land carbon uptake displays non-monotonic behavior, increasing up to a cumulative emission threshold of ∼2000 Gt C and then declining.
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Herrington, T. y K. Zickfeld. "Path dependence of climate and carbon cycle response over a broad range of cumulative carbon emissions". Earth System Dynamics Discussions 5, n.º 1 (17 de junio de 2014): 747–78. http://dx.doi.org/10.5194/esdd-5-747-2014.
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Abstract. Recent studies have demonstrated the proportional relationship between global warming and cumulative carbon emissions, yet the robustness of this relationship has not been tested over a broad range of cumulative emissions and emission rates. This study explores the path dependence of the climate and carbon cycle response using an Earth System model of intermediate complexity forced with 24 idealized emissions scenarios across five cumulative emission groups (1275–5275 GtC) with varying rates of emission. We find the century-scale climate and carbon cycle response after cessation of emissions to be approximately independent of emission pathway for all cumulative emission levels considered. The ratio of global mean temperature change to cumulative emissions – referred to as the transient climate response to cumulative emissions (TCRE) – is found to be constant for cumulative emissions lower than ~1500 GtC, but to decline with higher cumulative emissions. The TCRE is also found to decrease with increasing emission rate. The response of Arctic sea ice is found to be approximately proportional to cumulative emissions, while the response of the Atlantic meridional overturning circulation (AMOC) does not scale linearly with cumulative emissions, as its peak response is strongly dependent on emission rate. Ocean carbon uptake weakens with increasing cumulative emissions, while land carbon uptake displays non-monotonic behavior, increasing up to a cumulative emission threshold of ~2000 GtC and then declining.
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Domena, Justin B., Ermin Celebic, Braulio C. L. B. Ferreira, Yiqun Zhou, Wei Zhang, Jiuyan Chen, M. Bartoli et al. "Investigation into Red Emission and Its Applications: Solvatochromic N-Doped Red Emissive Carbon Dots with Solvent Polarity Sensing and Solid-State Fluorescent Nanocomposite Thin Films". Molecules 28, n.º 4 (12 de febrero de 2023): 1755. http://dx.doi.org/10.3390/molecules28041755.
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In this work, a NIR emitting dye, p-toluenesulfonate (IR-813) was explored as a model precursor to develop red emissive carbon dots (813-CD) with solvatochromic behavior with a red-shift observed with increasing solvent polarity. The 813-CDs produced had emission peaks at 610 and 698 nm, respectively, in water with blue shifts of emission as solvent polarity decreased. Subsequently, 813-CD was synthesized with increasing nitrogen content with polyethyleneimine (PEI) to elucidate the change in band gap energy. With increased nitrogen content, the CDs produced emissions as far as 776 nm. Additionally, a CD nanocomposite polyvinylpyrrolidone (PVP) film was synthesized to assess the phenomenon of solid-state fluorescence. Furthermore, the CDs were found to have electrochemical properties to be used as an additive doping agent for PVP film coatings.
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Tsuji, Takashi, T. Tawara, Ryohei Tanuma, Yoshiyuki Yonezawa, Noriyuki Iwamuro, K. Kosaka, H. Yurimoto et al. "Analyses of High Leakage Currents in Al+ Implanted 4H SiC pn Diodes Caused by Threading Screw Dislocations". Materials Science Forum 645-648 (abril de 2010): 913–16. http://dx.doi.org/10.4028/www.scientific.net/msf.645-648.913.
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The authors fabricated pn diodes with Al+ implantation in p-type epitaxial layers, and investigated the influence of the implantation dose on reverse leakage currents. Only in the highest dose with the Al concentration of 2x1020cm-3, more than 90% of the devices showed high leakage currents above 10-4A at the maximum electric field of 3MV/cm. In such devices, almost all of the emissive spots corresponded to threading screw dislocations (TSDs) by the analysis of emission microscopy and X-ray topography. These TSDs were defined as killer defects with the estimated density of 500cm-2 in the case of the highest dose. The emissions were supposed to be due to microplasmas, since the spectra of the emissions were different from those of heat radiation. Condensation of Al atoms, nitrogen atoms and DI defects were excluded as the origin of the emissions by secondary ion mass spectrometry and low temperature photoluminescence analyses.
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Liu, Shiwen, Hongxiong Li, Wen Kun, Zhen Zhang y Haotian Wu. "How Do Transportation Influencing Factors Affect Air Pollutants from Vehicles in China? Evidence from Threshold Effect". Sustainability 14, n.º 15 (1 de agosto de 2022): 9402. http://dx.doi.org/10.3390/su14159402.
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In recent years, China has promoted a series of legal norms to reduce the environmental impact of air pollutants from vehicles. The three main vehicle emission species (carbon monoxide, hydrocarbons, nitrogen oxides) contribute significantly to air pollution. In this study, the emission factor method was used to estimate air pollutants from vehicles in 31 provinces from 2006 to 2016. The results show a trend of total vehicle carbon monoxide (CO) and hydrocarbons (HC) emissions decreasing with time; the vehicle nitrogen oxides (NOx) emission trend is divided into two stages: an upward trend between 2006 and 2012 and a downward trend after 2012. Based on a panel threshold, a regression method was used to divide the vehicle NOx and CO emissions in China into four emission zones: low emissions, medium emissions, high emissions, and extra-high emissions. Vehicle HC emissions were divided into three emission zones, which corresponded to low emissions, medium emissions, and high emissions. Overall, vehicle pollution emission efficiency and per capita GDP have a significant inhibitory effect on the three main air pollutants from vehicles (NOx, HC, CO). Both passenger and freight turnover have significant roles in promoting the three air pollutants from vehicles (NOx, HC, CO). Road density and road carrying capacity have a significant role in promoting vehicle HC and CO emissions. Increasing truck proportion inhibits vehicle CO emissions and promotes vehicle NOx emissions. The urbanization rate has a positive effect on vehicle HC and CO emissions. Moreover, there is obvious heterogeneity in different emission zones of the three air pollutants from vehicles (NOx, HC, CO).
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Arifin, Ilham Zainul, Wirawan Wirawan y Hari Rarindo. "The Effect of Sodium Hydroxide Absorbent on The Exhaust Emissions From Internal Combustion Engine". Logic : Jurnal Rancang Bangun dan Teknologi 22, n.º 1 (30 de marzo de 2022): 27–34. http://dx.doi.org/10.31940/logic.v22i1.27-34.
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Exhaust emissions are the residue from burning fuel which can cause air pollution. To overcome this problem, it is necessary to design a system for reducing exhaust emissions of internal combustion engine. This study aims to determine the effect of absorbent concentration on the exhaust emission from internal combustion engine. The research was carried out in 2 stages, namely designing a system for reducing exhaust emissions from internal combustion engines and processing exhaust emissions by channeling exhaust emissions into an exhaust emission reduction system. The internal combustion engine used pertalite. The exhaust emissions consisted of CO, CO2 and HC. The absorbent concentrations were 0.05 M, 0.1 M and 0.15 M. The engine speeds were 800, 1000, 1500 and 2000 rpm. The paired-t test showed that the exhaust emission reduction system in this study can reduce exhaust emission. The one-way Anova test resulted the absorbent concentration affect the exhaust gas emissions, both CO, CO2 and HC which are expressed in the efficiency of reducing exhaust emission.. The greatest efficiency in reducing exhaust emission is CO2 of 67.95%. The lowest efficiency of reducing exhaust emission is CO, which is 46.92%, while the efficiency of reducing HC emission is 62.47%.
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Oliveira, Patrícia Perondi Anchão. "Gases de efeito estufa em sistemas de produção animal brasileiros e a importância do balanço de carbono para a preservação ambiental (Greenhouse gases in brazilian livestock production systems and the importance of the carbon balance for environmental)". Revista Brasileira de Geografia Física 8 (15 de diciembre de 2015): 623. http://dx.doi.org/10.26848/rbgf.v8.0.p623-634.
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O aquecimento global, acentuado por ações antrópicas de emissão de gases de efeito estufa, tem como consequência as mudanças climáticas, que causam muitos transtornos ambientais para a humanidade. A atividade pecuária produz gases de efeito estufa na forma de metano (CH4) e óxido nitroso (N2O) principalmente, com tendência de aumento de emissão atrelado ao aumento da produção pecuária. A degradação de pastagens, o mais importante problema ambiental da pecuária, também pode contribuir para a emissão desses gases e pode levar à desertificação. Ações de mitigação dessas emissões podem amenizar o problema e devem ser observadas considerando-se o balanço de carbono dos sistemas de produção pecuários, onde, além da emissão de gases de efeito estufa, o sequestro de carbono é também considerado. Na pecuária, existe possibilidade de mitigação das emissões pela redução da emissão do CH4 e do N2O, entretanto, o maior potencial de mitigação das emissões está no sequestro de carbono devido à recuperação das pastagens. Apesar disso, grande ênfase é dada aos aspectos envolvendo a emissão de CH4 entérico pelos ruminantes e suas formas de mitigação. Também é importante ressaltar que a adoção das tecnologias que promovem a mitigação das emissões de gases de efeito estufa depende mais de questões econômicas do que da viabilidade técnica das ações de mitigação propostas. Global warming is intensified by greenhouse gases emissions from human activities, resulting in climate change and causing many environmental disorders for humanity. The livestock produces greenhouse gases such as methane (CH4) and nitrous oxide (N2O) mainly and the increasing in emissions is linked to increased livestock production. The degradation of pastures had been the most important issue of livestock contributing to the greenhouse gases emissions and leading the desertification. Mitigation actions can reduce these emissions and the carbon balance of livestock production systems, which also considerate carbon sequestration besides the emission of greenhouse gases. Mitigating emissions of CH4 and N2O are possible in livestock but the carbon sequestration that occurs during the recovery of pasture is the greatest potential for mitigating greenhouse. Nevertheless, great emphasis can be found in literature related to the aspects involving the issue of enteric methane by ruminants and its methods of mitigation. Importantly, the adoption of technologies that promote mitigation of greenhouse gases emissions is most dependent of economic issues than technical feasibility of the mitigation actions proposed. Keywords: livestock, desertification, degradation, methane, nitrous oxide.
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Wang, Chao, Xianhao Zhao, Kaiyu Wu, Shuyi Lv y Chunlei Zhu. "A Ratiometric Organic Fluorescent Nanogel Thermometer for Highly Sensitive Temperature Sensing". Biosensors 12, n.º 9 (1 de septiembre de 2022): 702. http://dx.doi.org/10.3390/bios12090702.
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Sensing temperature in biological systems is of great importance, as it is constructive to understanding various physiological and pathological processes. However, the realization of highly sensitive temperature sensing with organic fluorescent nanothermometers remains challenging. In this study, we report a ratiometric fluorescent nanogel thermometer and study its application in the determination of bactericidal temperature. The nanogel is composed of a polarity-sensitive aggregation-induced emission luminogen with dual emissions, a thermoresponsive polymer with a phase transition function, and an ionic surface with net positive charges. During temperature-induced phase transition, the nanogel exhibits a reversible and sensitive spectral change between a red-emissive state and a blue-emissive state by responding to the hydrophilic-to-hydrophobic change in the local environment. The correlation between the emission intensity ratio of the two states and the external temperature is delicately established, and the maximum relative thermal sensitivities of the optimal nanogel are determined to be 128.42 and 68.39% °C−1 in water and a simulated physiological environment, respectively. The nanogel is further applied to indicate the bactericidal temperature in both visual and ratiometric ways, holding great promise in the rapid prediction of photothermal antibacterial effects and other temperature-related biological events.
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Zhang, Rongshuo, Hongfei Chen, Peiyuan Xie, Lei Zu, Yangbing Wei, Menglei Wang, Yunjing Wang y Rencheng Zhu. "Exhaust Emissions from Gasoline Vehicles with Different Fuel Detergency and the Prediction Model Using Deep Learning". Sensors 23, n.º 17 (4 de septiembre de 2023): 7655. http://dx.doi.org/10.3390/s23177655.
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Enhancing gasoline detergency is pivotal for enhancing fuel efficiency and mitigating exhaust emissions in gasoline vehicles. This study investigated gasoline vehicle emission characteristics with different gasoline detergency, explored synergistic emission reduction potentials, and developed versatile emission prediction models. The results indicate that improved fuel detergency leads to a reduction of 5.1% in fuel consumption, along with decreases of 3.2% in total CO2, 55.4% in CO, and 15.4% in HC emissions. However, during low-speed driving, CO2 and CO emissions reductions are limited, and HC emissions worsen. A synergistic emission reduction was observed, particularly with CO exhibiting a pronounced reduction compared to HC. The developed deep-learning-based vehicle emission model for different gasoline detergency (DPVEM-DGD) enables accurate emission predictions under various fuel detergency conditions. The Pearson correlation coefficients (Pearson’s r) between predicted and measured values of CO2, CO, and HC emissions before and after adding detergency agents are 0.913 and 0.934, 0.895 and 0.915, and 0.931 and 0.969, respectively. The predictive performance improves due to reduced peak emissions resulting from improved fuel detergency. Elevated gasoline detergency not only reduces exhaust emissions but also facilitates more refined emission management to a certain extent.
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Jiang, Kai, Xiangyu Feng, Xiaolu Gao, Yuhui Wang, Congzhong Cai, Zhongjun Li y Hengwei Lin. "Preparation of Multicolor Photoluminescent Carbon Dots by Tuning Surface States". Nanomaterials 9, n.º 4 (3 de abril de 2019): 529. http://dx.doi.org/10.3390/nano9040529.
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The achievements of multicolor photoluminescent (PL)-emissive carbon dots (CDs), particularly red to near infrared (NIR), are critical for their applications in optoelectronic devices and bioimaging, but it still faces great challenges to date. In this study, PL emission red-shifts were observed when tartaric acid (TA) was added into m-phenylenediamine (mPD) or o-phenylenediamine (oPD) solutions as carbon sources to prepare CDs, i.e., from blue to green for mPD and from yellow-green to red for oPD. Morphology and structure analyses revealed that the increased surface oxidation and carboxylation were responsible for the red-shifts of emission, indicating that TA played a key role in tuning the surface state of CDs. These factors could be employed as effective strategies to adjust PL emissions of CDs. Consequently, multicolor PL CDs (i.e., blue-, green-, yellow-green- and red-emissive CDs) can be facilely prepared using mPD and oPD in the absence and presence of TA. Particularly, the obtained red-emissive CDs showed a high PL quantum yield up to 22.0% and an emission covering red to NIR regions, demonstrating great potentials in optoelectronic devices and bioimaging. Moreover, multicolor phosphors were further prepared by mixing corresponding CDs with polyvinylpyrrolidone (PVP), among which the blue, green, and red ones could serve as three primary color phosphors for fabricating multicolor and white light-emitting diodes (LEDs). The white LED was measured to show a Commission Internationale de L’Eclairage (CIE) 1931 chromaticity coordinate of (0.34, 0.32), a high color rendering index (CRI) of 89, and a correlated color temperature (CCT) of 5850 K, representing one of the best performances of white LEDs based on CDs.
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Pang, Kaili, Xiangrui Meng, Shuai Ma y Ziyuan Yin. "Characterization of Pollutant Emissions from Typical Material Handling Equipment Using a Portable Emission Measurement System". Atmosphere 12, n.º 5 (5 de mayo de 2021): 598. http://dx.doi.org/10.3390/atmos12050598.
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Non-road equipment has been an important source of pollutants that negatively affect air quality in China. An accurate emission inventory for non-road equipment is therefore required to improve air quality. The objective of this paper was to characterize emissions from typical diesel-fueled material handling equipment (loaders and cranes) using a portable emission measurement system. Instantaneous, modal, and composite emissions were quantified in this study. Three duty modes (idling, moving, and working) were used. Composite emission factors were estimated using modal emissions and time-fractions for typical duty cycles. Results showed that emissions from loaders and cranes were higher and more variable for the moving and working modes than the idling mode. The estimated fuel-based CO, HC, NO, and PM2.5 composite emission factors were 21.7, 2.7, 38.2, and 3.6 g/(kg-fuel), respectively, for loaders, and 8.7, 2.4, 28.3, and 0.3 g/(kg-fuel), respectively, for cranes. NO emissions were highest and should be the main focus for emission controls. CO, HC, NO, and PM2.5 emissions measured were different from emission factors in the US Environmental Protection Agency NONROAD model and the Chinese National Guideline for Emission Inventory Development for Non-Road Equipment. This indicates that improving emission inventory accuracy for non-road equipment requires more real-world emission measurements.
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Shen, Zijie y Liguo Xin. "Characterizing Carbon Emissions and the Associations with Socio-Economic Development in Chinese Cities". International Journal of Environmental Research and Public Health 19, n.º 21 (23 de octubre de 2022): 13786. http://dx.doi.org/10.3390/ijerph192113786.
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Reducing carbon emissions in cities is crucial for addressing climate change, while the city-level emissions of different compositions and their relationships with socio-economic features remain largely unknown in China. Here, we explored the city-level emission pattern from the industrial, transportation, and household sectors and the emission intensity, as well as their associations with socio-economic features in China, using the up-to-date (2020) CO2 emissions based on 0.1° grid (10 × 10 km) emission data. The results show that: (1) CO2 emissions from the industrial sector were considerably dominant (78%), followed by indirect (10%), transportation (8%), and household (2%) emissions on the national scale; (2) combining total emissions with emission intensity, high emission–high intensity cities, which are the most noteworthy regions, were concentrated in the North, while low emission–low intensity types mainly occurred in the South-West; (3) cities with a higher GDP tend to emit more CO2, while higher-income cities tend to emit less CO2, especially from the household sector. Cities with a developed economy, as indicated by GDP and income, would have low emissions per GDP, representing a high emission efficiency. Reducing the proportion of the secondary sector of the economy could significantly decrease CO2 emissions, especially for industrial cities. Therefore, the carbon reduction policy in China should focus on the industrial cities in the North with high emission–high intensity performance. Increasing the income and proportion of the tertiary industry and encouraging compact cities can effectively reduce the total emissions during the economic development and urbanization process.
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Guo, Rong, Xiaochen Wu, Tong Wu y Chao Dai. "Spatial–Temporal Pattern Characteristics and Impact Factors of Carbon Emissions in Production–Living–Ecological Spaces in Heilongjiang Province, China". Land 12, n.º 6 (30 de mayo de 2023): 1153. http://dx.doi.org/10.3390/land12061153.
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Under the threat of global climate change, China has proposed a dual carbon goal of peak carbon and carbon neutrality. As the vital carrier for territorial spatial planning, production–living–ecological (PLE) spaces drive carbon emissions and are important to the dual carbon goals. In this study, carbon emissions and sinks of PLE spaces in cities in Heilongjiang Province from 2005 to 2020 were calculated and spatial–temporal changes were analyzed. The carbon emission structure was analyzed in segmentation sectors. The land use changes and socioeconomic factors on carbon emissions were analyzed, and emission reduction strategies were implemented. The results show the following: (1) Carbon emissions from production and living spaces increased yearly. Carbon sinks were smaller than emissions, but capacity was stable. (2) Higher-emission cities were concentrated in southwest Heilongjiang, and carbon emission differences between regions gradually increased. (3) Among carbon emission sectors, agricultural and household made up smaller proportions, while animal husbandry, industrial, transportation, and traffic travel contributed most. Carbon emission structures were transformed by adjusting urban development and industrial structure. (4) For most cities, industrial space was the main emission space, but agricultural production and urban–rural living spaces dominated in some cities. (5) GDP, urbanization rate, and area of city paved roads suppressed emissions in cities with decreased carbon emission grades. The industrial structure and coal consumption inhibited emissions in cities with maintaining and increasing carbon emissions grades.
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Aamaas, Borgar, Terje K. Berntsen, Jan S. Fuglestvedt, Keith P. Shine y Nicolas Bellouin. "Regional emission metrics for short-lived climate forcers from multiple models". Atmospheric Chemistry and Physics 16, n.º 11 (15 de junio de 2016): 7451–68. http://dx.doi.org/10.5194/acp-16-7451-2016.
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Abstract. For short-lived climate forcers (SLCFs), the impact of emissions depends on where and when the emissions take place. Comprehensive new calculations of various emission metrics for SLCFs are presented based on radiative forcing (RF) values calculated in four different (chemical-transport or coupled chemistry–climate) models. We distinguish between emissions during summer (May–October) and winter (November–April) for emissions in Europe and East Asia, as well as from the global shipping sector and global emissions. The species included in this study are aerosols and aerosol precursors (BC, OC, SO2, NH3), as well as ozone precursors (NOx, CO, VOCs), which also influence aerosols to a lesser degree. Emission metrics for global climate responses of these emissions, as well as for CH4, have been calculated using global warming potential (GWP) and global temperature change potential (GTP), based on dedicated RF simulations by four global models. The emission metrics include indirect cloud effects of aerosols and the semi-direct forcing for BC. In addition to the standard emission metrics for pulse and sustained emissions, we have also calculated a new emission metric designed for an emission profile consisting of a ramping period of 15 years followed by sustained emissions, which is more appropriate for a gradual implementation of mitigation policies.For the aerosols, the emission metric values are larger in magnitude for emissions in Europe than East Asia and for summer than winter. A variation is also observed for the ozone precursors, with largest values for emissions in East Asia and winter for CO and in Europe and summer for VOCs. In general, the variations between the emission metrics derived from different models are larger than the variations between regions and seasons, but the regional and seasonal variations for the best estimate also hold for most of the models individually. Further, the estimated climate impact of an illustrative mitigation policy package is robust even when accounting for the fact that the magnitude of emission metrics for different species in a given model is correlated. For the ramping emission metrics, the values are generally larger than for pulse or sustained emissions, which holds for all SLCFs. For SLCFs mitigation policies, the dependency of metric values on the region and season of emission should be considered.
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Li, Jing, Weibin Zeng y Xiaoming Wan. "Management and Reduction Techniques Strategies of Ammonia Emission in Agricultural Sectors in China". Agronomy 13, n.º 10 (4 de octubre de 2023): 2555. http://dx.doi.org/10.3390/agronomy13102555.
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Agricultural ammonia (NH3) emissions (including farmland, livestock and poultry) are China’s main sources of NH3 emissions. China’s government has proposed a national strategic goal to reduce NH3 emissions. Excessive protein feeds, unreasonable manure treatments and agricultural fertilizer applications result in large emissions of NH3. Agricultural activities such as the breeding of livestock and fertilization in farmlands are the main sources of atmospheric NH3 emissions. This article discussed the progress and characteristics of typical NH3 emission inventory, calculated the nationwide NH3 emissions and analyzed the NH3 emission control strategy in the past 40 years in China. There was also an integration analysis of national documents on emission reduction technologies (including government reports) in China. The results showed that there existed single calculation methods and insufficient localization of emission factors in the estimation of domestic NH3 emissions. NH3 emission inventories varied greatly influenced by meteorology, planting structure and breeding pattern. The control strategy of NH3 emission in China has transformed from emission standards to technical guidelines to national strategic control, and it involves the coordination and cooperation of the Ministry of Agriculture and Rural Affairs departments. Current domestic NH3 emission management strategy needs scientific emission verification specification, multi-department and inter-provincial regional coordination mechanisms, and suggestions for further improvement have been put forward. It is urgent to evaluate precise NH3 emission inventories at different regional scales, followed by intensive NH3 emission controls in the key regions (such as North China). Government, agriculture, and breeding industries should vigorously promote low-protein feeds, large-scale livestock farming (including poultry), and pilot projects on closed negative pressure farming. Also, agriculture-related NH3 emission reduction measures should be fully implemented by providing technical support for NH3 emission control in domestic agricultural farms.
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Tu, Ran, Islam Kamel, Baher Abdulhai y Marianne Hatzopoulou. "Reducing Transportation Greenhouse Gas Emissions Through the Development of Policies Targeting High-Emitting Trips". Transportation Research Record: Journal of the Transportation Research Board 2672, n.º 25 (18 de abril de 2018): 11–20. http://dx.doi.org/10.1177/0361198118755714.
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Traffic emission inventories have been under development for decades, often relying on data from traffic assignment models, ranging from macroscopic models generating average link speeds, to more detailed microscopic models with instantaneous speed profiles. Policy testing within such frameworks has often focused on identifying changes in total emissions, or in emissions aggregated at a zonal or street level. Emissions from specific trips or trajectories are seldom analyzed, although reductions in greenhouse gas (GHG) emissions can be achieved more efficiently when targeting high emitters. In this paper, we propose a different approach to reducing transportation GHG emissions, by catering policies to specific trips based on their emission burden. We focus on the City of Toronto downtown. Using second-by-second speed data for entire trajectories, GHGs (in CO2eq) and nitrogen oxides (NOx) emissions were estimated. We observe that the destinations attracting the highest trip emissions tend to be in the hospital and financial districts. Trips originating and ending in the downtown area are responsible for a small share of total emissions, although they have high emission intensity. Removing trips with high total emissions and high emission intensity led to significant reductions in CO2eq and NOx emissions, whereas removing shorter trips, did not have a significant influence on total emissions nor emission intensities.
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Shao, Cheng-Tsung, Wen-Hsi Cheng, Yuan-Chung Lin, Ken-Lin Chang, Kang-Shin Chen y Chung-Shin Yuan. "Qualifying and Quantifying the Emissions of Volatile Organic Compounds from the Coking Process in a Steel Plant Using an Innovative Sampling Technique". Atmosphere 13, n.º 9 (26 de agosto de 2022): 1363. http://dx.doi.org/10.3390/atmos13091363.
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The aim of this paper is to quantify the amounts of volatile organic compounds (VOCs) emitted from a coke oven in a steel plant in Taiwan and estimate the emission factors of VOCs using an innovative sampling technique. The identification of VOCs emissions was referred to in the AP-42 report issued by the USEPA and the field measurement data of fugitive emissions. VOCs were sampled using a self-designed closed sampling system. A total of six emission points, including quenching emissions, charge lid emissions, combustion stack emissions, door emissions, charging emissions, and coke pushing emissions, were identified in the coking process after comparing with the report of AP-42, and the emission factor of VOCs was 0.030 kg/ton-coke. It showed that the emission factor of VOCs via field measurement was approximately 56% of that reported by Taiwan EPA. Therefore, VOCs emissions estimated by the Taiwan EPA would be highly overestimated than those from the coke oven in the site.
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Wu, Qiong, Kanittha Tambunlertchai y Pongsa Pornchaiwiseskul. "Examining the Impact and Influencing Channels of Carbon Emission Trading Pilot Markets in China". Sustainability 13, n.º 10 (18 de mayo de 2021): 5664. http://dx.doi.org/10.3390/su13105664.
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As China has an important role in global climate change, the Chinese government has set goals to improve its environmental efficiency and performance and launched carbon emission trading pilot markets in 2013, aiming to reduce CO2 emissions. Based on panel data of 30 provinces from 2005 to 2017, this paper uses the difference-in-difference method to study the impact of China’s carbon emission trading pilot markets on carbon emissions and regional green development. The paper also explores possible influencing channels. The main conclusions are as follows: (1) China’s carbon emission trading policy has promoted a reduction in CO2 emissions and carbon emission intensity and has increased green development in the pilot areas. (2) The main path for China’s carbon emission trading policy to achieve carbon emission reduction and regional green development is to promote technology adoption. (3) China’s carbon emission trading policy achieves green development through synergistic SO2 emission reduction. The pilot carbon markets have reduced both the amount of SO2 emissions and SO2 emission intensity.
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Li, Sen, Yanwen Lan y Lijun Guo. "Analysis of Carbon Emission and Its Temporal and Spatial Distribution in County-Level: A Case Study of Henan Province, China". Nature Environment and Pollution Technology 21, n.º 2 (1 de junio de 2022): 447–56. http://dx.doi.org/10.46488/nept.2022.v21i02.003.
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Estimating carbon emissions and assessing their contribution are critical steps toward China’s objective of reaching a “carbon peak” in 2030 and “carbon neutrality” in 2060. This paper selects relevant statistical data on carbon emissions from 2000 to 2018, combines the emission coefficient method and the Logarithmic Mean Divisia Index model (LMDI) to calculate carbon emissions, and analyses the driving force of carbon emission growth using Henan Province as a case study. Based on the partial least squares regression analysis model (PLS), the contributions of inter-provincial factors of carbon emission are analyzed. Finally, a county-level downscaling estimation model of carbon emission is further formulated to analyze the temporal and spatial distribution of carbon emissions and their evolution. The research results show that: 1) The effect of energy intensity is responsible for 82 percent of the increase in carbon emissions, whereas the effect of industrial structure is responsible for -8 percent of the increase in carbon emissions. 2) The proportion of secondary industry and energy intensity, which are 1.64 and 0.82, respectively, have the most evident explanatory effect on total carbon emissions; 3). Carbon emissions vary widely among counties, with high emissions in the central and northern regions and low emissions in the southern. However, their carbon emissions have constantly decreased over time. 4) The number of high-emission counties, their carbon emissions, and the degree of their discrepancies are gradually reduced. The findings serve as a foundation for relevant agencies to gain a macro-level understanding of the industrial landscape and to investigate the feasibility of carbon emission reduction programs.
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Guo, Xixuan, Kaixiang Huang, Lanyu Li y Xiaonan Wang. "Renewable Energy for Balancing Carbon Emissions and Reducing Carbon Transfer under Global Value Chains: A Way Forward". Sustainability 15, n.º 1 (23 de diciembre de 2022): 234. http://dx.doi.org/10.3390/su15010234.
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Research on the relationship between a country’s renewable energy consumption and carbon emissions is of great significance for reducing carbon emissions embodied in international trade. There always exists a gap between production-based and consumption-based carbon emissions. Accordingly, this paper investigates the influence of renewable energy consumption on carbon emission balance, the ratio of production-based emissions to consumption-based emissions, in various countries using the ordinary least square (OLS) method and generalized method of moments (GMM) method. We found that a 1% increase in renewable energy consumption can decrease the carbon emission balance by 5.8%. Furthermore, renewable energy consumption can help narrow the gap between production-based and consumption-based carbon emissions in net emission exporters. In addition, renewable energy consumption can also weaken the negative impact of the global value chains (GVCs) division system on the carbon emission balance. The findings in this study fill the research gap by analyzing the heterogeneous impacts of renewable energy consumption on carbon emission balance embodied within a GVC division system in various countries and provide policy suggestions that renewable energy consumption should be encouraged in net emission exporters to reduce the carbon emission transfers.
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Castellanos, P., K. F. Boersma y G. R. van der Werf. "Satellite observations indicate substantial spatiotemporal variability in biomass burning NO<sub>x</sub> emission factors for South America". Atmospheric Chemistry and Physics Discussions 13, n.º 8 (30 de agosto de 2013): 22757–93. http://dx.doi.org/10.5194/acpd-13-22757-2013.
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Abstract. Biomass burning is an important contributor to global total emissions of NOx (NO + NO2). Generally bottom-up fire emissions models calculate NOx emissions by multiplying fuel consumption estimates with static biome specific emission factors, defined in units of grams of NO per kilogram of dry matter consumed. Emission factors are a significant source of uncertainty in bottom-up fire emissions modeling because relatively few observations are available to characterize the large spatial and temporal variability of burning conditions. In this paper we use NO2 tropospheric column observations from the Ozone Monitoring Instrument (OMI) from the year 2005 over South America to calculate monthly NOx emission factors for four fire types: deforestation, savanna/grassland, woodland, and agricultural waste burning. In general, the spatial trends in NOx emission factors calculated in this work are consistent with emission factors derived from in situ measurements from the region, but are more variable than published biome specific global average emission factors widely used in bottom up fire emissions inventories such as the Global Fire Emissions Database (GFED) v3. Satellite based NOx emission factors also indicate substantial temporal variability in burning conditions. Overall, we found that deforestation fires have the lowest NOx emission factors, on average 30 % lower than the emission factors used in GFED v3. Agricultural fire NOx emission factors were the highest, on average a factor of 2 higher than GFED v3 values. For savanna, woodland, and deforestation fires early dry season NOx emission factors were a factor of ~1.5–2.0 higher than late dry season emission factors. A minimum in the NOx emission factor seasonal cycle for deforestation fires occurred in August, the time period of severe drought in South America in 2005. Our results support the hypothesis that prolonged dry spells may lead to an increase in the contribution of smoldering combustion from large diameter fuels to total fire emissions, which would lower the overall modified combustion efficiency (MCE) and NOx emission factor, and offset the higher combustion efficiency of dryer fine fuels. We evaluated the OMI derived NOx emission factors with SCIAMACHY NO2 tropospheric column observations and found improved model performance in regions dominated by fire emissions.
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WANG, Xingmin, Jing WU, Zheng WANG, Xiaoting JIA y Bing BAI. "Accounting and Characteristics Analysis of CO2 Emissions in Chinese Cities". Chinese Journal of Urban and Environmental Studies 08, n.º 01 (marzo de 2020): 2050004. http://dx.doi.org/10.1142/s2345748120500049.
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Accurate estimation of CO2 emissions is a prerequisite for scientific low-carbon emission policymaking. Based on 20 types of energy consumption data at the prefecture level in China, this paper re-estimates the CO2 emissions of 198 prefecture-level cities in 2016 by using the method of carbon emission coefficient. The spatial pattern and scale characteristics are analyzed, and the conclusions are as follows: (1) Overall, China’s urban CO2 emissions show a certain degree of spatial separation in terms of the total amount, per capita emissions, and emission intensity. Cities with the highest CO2 emissions in China are mainly concentrated in North China, East China and Chongqing, while cities with the highest per capita CO2 emissions and emission intensity are mainly concentrated in Northwest and North China. (2) Different types of cities have different CO2 emission characteristics. Resource-based cities have a higher total amount and emission intensity; tourism and underdeveloped cities both have lower values; while super-large-sized cities and many very-large-sized cities have higher CO2 emissions, but their emission intensities are usually lower; and no obvious rules are found in other cities. (3) Spatial analysis shows that cities with higher CO2 emissions are clustered. The Beijing–Tianjin–Hebei region, the Yangtze River Delta region, Shandong Province, and Shanxi–Henan–Anhui resource-producing areas are the agglomeration areas of high-emission cities. (4) Scale analysis shows that the characteristics of CO2 emissions at different scales are different. Provincial-level research can help to identify the environmental impact and total effect of carbon emissions, while urban-scale research is helpful to explore the diversity and phases of cities. Finally, based on the main conclusions of this study, the corresponding urban low-carbon policy implications are drawn.
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Zhang, Xiufan y Decheng Fan. "The Spatial-Temporal Evolution of China’s Carbon Emission Intensity and the Analysis of Regional Emission Reduction Potential under the Carbon Emissions Trading Mechanism". Sustainability 14, n.º 12 (17 de junio de 2022): 7442. http://dx.doi.org/10.3390/su14127442.
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It is of great significance to study the regional differences and temporal and spatial evolution of China’s carbon emission intensity under the carbon emissions trading mechanism, and to explore the potential for regional emission reduction. This paper uses the Theil index and Moran index to analyze the regional differences and temporal and spatial evolution trend of carbon emission intensity in China from 2010 to 2019, further constructs the emission reduction effect standard of carbon emissions trading mechanisms, discusses the emission reduction effect of the trading mechanisms, and measures the regional emission reduction potential according to the environmental learning curve. The results showed that: (1) China’s overall carbon emissions continued to increase, but the carbon emission intensity showed an overall decreasing trend. There are strong regional differences in China’s carbon emission intensity. The carbon emission intensity in the western region is higher, and the overall regional difference is decreasing year by year. (2) China’s carbon emissions trading mechanism has a significant reduction effect, but the total quota slack of the Tianjin, Beijing, and Chongqing carbon emissions trading pilot markets is loose. (3) Shanghai, Shanxi, Jiangxi, Guizhou, Inner Mongolia, and Beijing are high-efficiency carbon emission reduction provinces (more than 35%), and Fujian and Xinjiang are low-efficiency carbon emission reduction provinces (less than 15%). It is necessary to further develop the demonstration effect of high emission reduction potential areas and increase the emission reduction efforts in low emission reduction potential areas.
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Liu, Mo Ru y Hua Yu Wang. "A Theoretical Analysis of Carbon Emission Trading System in China and the Perfection of its Rules and Regulations". Applied Mechanics and Materials 448-453 (octubre de 2013): 4530–35. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.4530.
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The Carbon emission trading mechanism is an important tool to tackle climate change, promote low-carbon economic development, and facilitate ecological civilization construction. The Carbon emission trading system is set up based on the overall amount control. It controls the greenhouse gas emissions through the marketing mechanism, and reduces the cost of carbon emission control. Through theoretical analyses of the property rights of carbon emission right and the legal relationship of carbon emissions trading ,the theoretical basis for the carbon emissions trading mechanism is established. Currently, the measures to improve the carbon emissions trading mechanisms in China mainly consist of perfecting the trading platform, improving the marketing regulation system, promoting legislations of the total amount control of carbon emissions and the initial allocation of carbon emissions right so as to realize the optimal environmental capacity allocation of carbon emissions.
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Li, Yanbin, Zhen Li, Min Wu, Feng Zhang y Gejirifu De. "Regional-Level Allocation of CO2 Emission Permits in China: Evidence from the Boltzmann Distribution Method". Sustainability 10, n.º 8 (25 de julio de 2018): 2612. http://dx.doi.org/10.3390/su10082612.
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To achieve the commitment of carbon emission reduction in 2030 at the climate conference in Paris, it is an important task for China to decompose the carbon emission target among regions. In this paper, entropy maximization is brought to inter-provincial carbon emissions allocation via the Boltzmann distribution method, which provides guidelines for allocating carbon emissions permits among provinces. The research is mainly divided into three parts: (1) We develop the CO2 influence factor, including per capita GDP, per capita carbon emissions, carbon emission intensity and carbon emissions of per unit industrial added value; the proportion of the second industry; and the urbanization rate, to optimize the Boltzmann distribution model. (2) The probability of carbon emission reduction allocation in each province was calculated by the Boltzmann distribution model, and then the absolute emission reduction target was allocated among different provinces. (3) Comparing the distribution results with the actual carbon emission data in 2015, we then put forward the targeted development strategies for different provinces. Finally, suggestions were provided for CO2 emission permits allocation to optimize the national carbon emissions trading market in China.
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Zhang, Caiqing, Mi Zhang y Nan Zhang. "Identifying the Determinants of CO2 Emission Change in China’s Power Sector". Discrete Dynamics in Nature and Society 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/2626418.
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Power sector is significantly important for China to achieve the CO2 emission reduction targets. In this study, we analyze the features of CO2 emissions and environment effect in China’s power sector, investigate the driving factors of CO2 emission change based on the logarithmic mean Divisia index (LMDI) method, and evaluate the mitigation potential of CO2 emissions in China’s power sector. Results show that CO2 emissions in China’s power sector increased rapidly from 492.00 Mt in 1990 to 3049.88 Mt in 2014 while CO2 emission intensity experienced an unsteady downward trend during the study period. Industrial scale effect is the key contributor to CO2 emission growth in China’s power sector, and its contribution degree reaches 123.97%. Energy intensity effect contributes most to the decrease in CO2 emissions, with a contribution degree of −20.01%. Capital productivity effect is another important factor leading to CO2 emissions increase. The aggregate CO2 emission reduction would reach 17973.86 million tons (Mt) during 2015–2030 in the ideal emission reduction scenario. Finally, policy recommendations are made for future energy-saving and CO2 emission reduction in China’s power sector.
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Nababan, Meliani y Sylvia Veronica Nalurita Purnama Siregar. "The Impact of Emission GHG Performance on Financial Performance: Moderating by Financial Constraints and COVID-19". Indonesian Journal of Economics and Management 3, n.º 3 (31 de julio de 2023): 535–50. http://dx.doi.org/10.35313/ijem.v3i3.4946.
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Previous studies on the relationship between GHG emissions and financial performance presented two competing points of view: either reducing GHG emissions can cause firms to diverge from their corporate goals, or, reducing GHG emissions can raise firm value in line with the resource-based view theory. This study examines 105 non-financial industry in Indonesia that produce significant amounts of emissions GHG between 2019 and 2021, with a total of 315 data observations. This study analyzes the financial performance using ROA and firm value, and the performance of GHG emissions using two constructs: the quantity of emissions and disclosure of GHG emissions. The Global Initiative Report (GRI) guidelines are used to conduct content analysis on disclosure of GHG emission. This study shows that GHG emission performance is considered as a firm's competitive advantage, there is a positive relationship between GHG emission performance and firm value, financial constraints negatively impact the relationships between GHG emission performance, and COVID-19 had no impact on the relationship between emission performance and financial performance.
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Castellanos, P., K. F. Boersma y G. R. van der Werf. "Satellite observations indicate substantial spatiotemporal variability in biomass burning NO<sub>x</sub> emission factors for South America". Atmospheric Chemistry and Physics 14, n.º 8 (17 de abril de 2014): 3929–43. http://dx.doi.org/10.5194/acp-14-3929-2014.
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Abstract. Biomass burning is an important contributor to global total emissions of NOx (NO+NO2). Generally bottom-up fire emissions models calculate NOx emissions by multiplying fuel consumption estimates with static biome-specific emission factors, defined in units of grams of NO per kilogram of dry matter consumed. Emission factors are a significant source of uncertainty in bottom-up fire emissions modeling because relatively few observations are available to characterize the large spatial and temporal variability of burning conditions. In this paper we use NO2 tropospheric column observations from the Ozone Monitoring Instrument (OMI) from the year 2005 over South America to calculate monthly NOx emission factors for four fire types: deforestation, savanna/grassland, woodland, and agricultural waste burning. In general, the spatial patterns in NOx emission factors calculated in this work are consistent with emission factors derived from in situ measurements from the region but are more variable than published biome-specific global average emission factors widely used in bottom-up fire emissions inventories such as the Global Fire Emissions Database (GFED). Satellite-based NOx emission factors also indicate substantial temporal variability in burning conditions. Overall, we found that deforestation fires have the lowest NOx emission factors, on average 30% lower than the emission factors used in GFED v3. Agricultural fire NOx emission factors were the highest, on average a factor of 1.8 higher than GFED v3 values. For savanna, woodland, and deforestation fires, early dry season NOx emission factors were a factor of ~1.5–2 higher than late dry season emission factors. A minimum in the NOx emission factor seasonal cycle for deforestation fires occurred in August, the time period of severe drought in South America in 2005, supporting the hypothesis that prolonged dry spells may lead to an increase in the contribution of smoldering combustion from large-diameter fuels, offsetting the higher combustion efficiency of dryer fine fuels. We evaluated the OMI-derived NOx emission factors with SCIAMACHY NO2 tropospheric column observations and found improved model performance in regions dominated by fire emissions.
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QIFENG, LI, ZHANG JIANLEI, QIAN DAKE y HE LIN. "The impact of heterogeneous environmental regulations on China's textile industry CO2 emissions". Industria Textila 74, n.º 04 (30 de agosto de 2023): 419–25. http://dx.doi.org/10.35530/it.074.04.202299.
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Environmental regulation is an important tool to reduce CO2 emissions. To investigate the relationship between heterogeneous environmental regulations and CO2 emissions of China's textile industry (CTI), this paper uses the threshold model and panel model to study the impacts of command-based, market-based and public-based environmental regulations (CER, MER and PER) on the total carbon emissions and carbon emission intensity of CTI from 2004 to 2019. Then it further explores their regional heterogeneity. The results show that: at the national level, CER has a forced emission reduction effect and a green paradox effect on CTI’s total carbon emissions and carbon emission intensity, respectively. And MER shows a forced emission reduction effect on carbon emission intensity. But the coefficients of PER are not significant. At the regional level, the result verifies a U-shaped relationship between CER and CO2 emissions in the eastern textile industry. And CER shows a forced emission reduction effect in the central and western regions. The impact of MER on the carbon emission intensity of the eastern textile industry is N-shaped, which means MER can lower carbon emission intensity only within a certain range. And its impacts on the central and western regions are also the forced emission reduction effect. There is an inverted U-shaped relationship between PER and the total carbon emission in the eastern textile industry. While PER has always had a green paradox effect on carbon emission intensity in the eastern region. Other coefficients are not significant. Finally, this paper puts forward the policy suggestions to mitigate the CO2 emissions of CTI.
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Yuan, Yongke, Yixing Wang, Yuanying Chi y Feng Jin. "Identification of Key Carbon Emission Sectors and Analysis of Emission Effects in China". Sustainability 12, n.º 20 (19 de octubre de 2020): 8673. http://dx.doi.org/10.3390/su12208673.
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Analysis of sectors’ emission effects is crucial for identifying key emission sectors and reducing carbon. Current literature for calculating sectors’ emission effects in China ignore intermediate demand. This might introduce inaccuracy into the analyzed results. To solve this gap, this paper used an alternative input–output method to analyze sectors’ emission effects in China. Firstly, it identifies the key emission sectors and their emission effect characteristics from 2005 to 2017. Then, the reasons for the changes in these sectors’ emission effects are analyzed. Lastly, emission effects were further decomposed so that the driving relationships of emissions among these sectors can be sorted out. The results show that the overall key emission sectors were metal smelting and processing and nonmetal mineral products. The backward-emission-dominant sectors were construction, chemical products, other services (such as finance, health and education), metal products, and so on. The forward-emission-dominant sectors were production and supply of electricity and heat, transportation, storage, postal, and telecommunications services. In 2017, transportation, storage, postal, and telecommunications services’ own final demand emissions and forward emissions accounted for 41.7% and 58.3%, respectively, of this sector’s direct emissions. Moreover, from 2005 to 2017, the main sector emission paths affecting the growth of China’s emissions shifted from manufacturing and construction industries to service industries. Accordingly, strategies for emission reduction, such as substituting pollution inputs, were proposed and analyzed. The research provides an important reference for the Chinese government to adopt appropriate measures to reduce carbon.
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Huang, Junfeng, Jianbing Gao, Yufeng Wang, Ce Yang y Chaochen Ma. "Real-World Pipe-Out Emissions from Gasoline Direct Injection Passenger Cars". Processes 11, n.º 1 (27 de diciembre de 2022): 66. http://dx.doi.org/10.3390/pr11010066.
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The analysis of real-world emissions is necessary to reduce the emissions of vehicles during on-road driving. In this paper, the matrix of gasoline direct injection passenger cars is applied to analyze the real-world emissions. The results show that high acceleration and high speed conditions are major conditions for the particulate number emissions, and the particulate number emissions are positively correlated with torque and throttle opening. The catalyst temperature and saturation are important factors that affect nitrogen oxide emission. The nitrogen oxide emissions of low speed and low torque conditions cannot be ignored in real-world driving. The carbon dioxide emissions are positively correlated with acceleration, torque and throttle opening. Once the vehicles are in the acceleration condition, the carbon dioxide emissions increase rapidly. The vehicles with higher average emission factors are more susceptible to driving behaviors, and the differences in the emission factors are more obvious, leading to an increase in the difficulty of emission control.
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Jauhiainen, J., A. Hooijer y S. E. Page. "Carbon dioxide emissions from an <i>Acacia</i> plantation on peatland in Sumatra, Indonesia". Biogeosciences Discussions 8, n.º 4 (12 de agosto de 2011): 8269–302. http://dx.doi.org/10.5194/bgd-8-8269-2011.
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Abstract. Peat surface CO2 emission, groundwater table depth and peat temperature were monitored for two years along transects in an Acacia plantation on thick tropical peat (>4 m) in Sumatra, Indonesia. A total of 2300 emission measurements were taken at 144 locations. The autotrophic root respiration component of the CO2 emission was separated from heterotrophic emissions caused by peat oxidation in three ways: (i) by comparing CO2 emissions within and beyond the tree rooting zone, (ii) by comparing CO2 emissions with and without peat trenching (i.e. cutting any roots remaining in the peat beyond the tree rooting zone), and (iii) by comparing CO2 emissions before and after Acacia tree harvesting. On average, the contribution of root respiration to daytime CO2 emission is 21 % along transects in mature tree stands. At locations 0.5 m from trees this is up to 80 % of the total emissions, but it is negligible at locations more than 1.3 m away. This means that CO2 emission measurements well away from trees are free of any root respiration contribution and thus represent only peat oxidation emission. We find daytime mean annual CO2 emission from peat oxidation alone of 94 t ha−1 yr−1 at a mean water table depth of 0.8 m, and a minimum emission value of 80 t ha−1 yr−1 after correction for the effect of diurnal temperature fluctuations, which resulted in a 14.5 % reduction of the daytime emission. There is a positive correlation between mean long-term water table depths and peat oxidation CO2 emission. However, no such relation is found for instantaneous emission/water table depth within transects and it is clear that factors other than water table depth also affect peat oxidation and total CO2 emissions. The increase in the temperature of the surface peat due to plantation development may explain over 50 % of peat oxidation emissions.
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Ju, Liping y Yibin Zhu. "CO2 Emission Accounting Model in Nonferrous Mining Industry". E3S Web of Conferences 358 (2022): 02019. http://dx.doi.org/10.1051/e3sconf/202235802019.
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The policy of carbon peak in 2030 address the question of how to account CO2 emissions of Nonferrous Mining. The aim of this study is to establish CO2 emissions accounting model, focused on usual activities, e.g. fuel combustion emission, process emission, emission from purchased and exported electricity and heat. And also to discuss explosive and urea emission sources to identify the significant process that contribute the most to climate change. Moreover, the accounting model is chosen to evaluate emissions of one mine in china, and explosive explosion and urea use of CO2 emissions accounting for 4.61% and 3.97%, respectively.
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Guo, Mengjie, Miao Ning, Shida Sun, Chenxi Xu, Gaige Zhang, Luyao Zhang, Runcao Zhang et al. "Estimation and Analysis of Air Pollutant Emissions from On-Road Vehicles in Changzhou, China". Atmosphere 15, n.º 2 (1 de febrero de 2024): 192. http://dx.doi.org/10.3390/atmos15020192.
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Vehicle emissions have become a significant contributor to urban air pollution. However, studies specific to city-level vehicle emission inventories are still scarce and tend to be outdated. This study introduces a methodology for developing high-resolution monthly vehicle emission inventories. We applied this methodology to Changzhou in 2022 to analyze emission characteristics and generate gridded emission data with a resolution of 0.01° × 0.01°. The results show that the total vehicle emissions of carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOx), and fine particulate matters (PM2.5) in Changzhou are 39.69, 8.68, 18.6, and 0.56 Gg, respectively. Light-duty passenger vehicles are the main contributors to CO (74.3%) and VOCs (86.1%) emissions, while heavy-duty trucks play a significant role in NOx (50.7%) and PM2.5 (34.7%) emissions. Gasoline vehicles are mainly responsible for CO (78.6%) and VOCs (91.4%) emissions, while diesel vehicles are the primary source of NOx (81.1%) and PM2.5 (70.6%) emissions. Notably, China IV vehicles have the highest emission contribution rates (ranging from 32.5% to 44.9%). Seasonally, emissions peak in winter and are lowest in April. Spatially, emission intensity is higher in the northeast of Changzhou compared to the west and south. The methodology presented in this study offers a valuable tool for developing comprehensive city-level emission inventories, and the results provide critical insights that can inform the formulation of effective environmental policies.
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Basu, Sourish, John Bharat Miller y Scott Lehman. "Separation of biospheric and fossil fuel fluxes of CO<sub>2</sub> by atmospheric inversion of CO<sub>2</sub> and <sup>14</sup>CO<sub>2</sub> measurements: Observation System Simulations". Atmospheric Chemistry and Physics 16, n.º 9 (10 de mayo de 2016): 5665–83. http://dx.doi.org/10.5194/acp-16-5665-2016.
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Abstract. National annual total CO2 emissions from combustion of fossil fuels are likely known to within 5–10 % for most developed countries. However, uncertainties are inevitably larger (by unknown amounts) for emission estimates at regional and monthly scales, or for developing countries. Given recent international efforts to establish emission reduction targets, independent determination and verification of regional and national scale fossil fuel CO2 emissions are likely to become increasingly important. Here, we take advantage of the fact that precise measurements of 14C in CO2 provide a largely unbiased tracer for recently added fossil-fuel-derived CO2 in the atmosphere and present an atmospheric inversion technique to jointly assimilate observations of CO2 and 14CO2 in order to simultaneously estimate fossil fuel emissions and biospheric exchange fluxes of CO2. Using this method in a set of Observation System Simulation Experiments (OSSEs), we show that given the coverage of 14CO2 measurements available in 2010 (969 over North America, 1063 globally), we can recover the US national total fossil fuel emission to better than 1 % for the year and to within 5 % for most months. Increasing the number of 14CO2 observations to ∼ 5000 per year over North America, as recently recommended by the National Academy of Science (NAS) (Pacala et al., 2010), we recover monthly emissions to within 5 % for all months for the US as a whole and also for smaller, highly emissive regions over which the specified data coverage is relatively dense, such as for the New England states or the NY-NJ-PA tri-state area. This result suggests that, given continued improvement in state-of-the art transport models, a measurement program similar in scale to that recommended by the NAS can provide for independent verification of bottom-up inventories of fossil fuel CO2 at the regional and national scale. In addition, we show that the dual tracer inversion framework can detect and minimize biases in estimates of the biospheric flux that would otherwise arise in a traditional CO2-only inversion when prescribing fixed but inaccurate fossil fuel fluxes.
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Hong, Yuning, Jacky Wing Yip Lam, Sijie Chen y Ben Zhong Tang. "Aggregation-Induced Emission and Biological Application of Tetraphenylethene Luminogens". Australian Journal of Chemistry 64, n.º 9 (2011): 1203. http://dx.doi.org/10.1071/ch11170.
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Tetraphenylethene derivatives [Ph(PhCH=CHPhR)C=C(PhCH=CHPhR)Ph, R=H, CN, NO2, NPh2] with green, yellow-green, and orange emission colours were designed and synthesized. These molecules are practically non-emissive in their dilute solutions but emit intensely as nanoaggregates in poor solvents, demonstrating a novel phenomenon of aggregation-induced emission. Their blended films with poly(methyl methacrylate) also display bright emissions. Restriction of intramolecular motion in the condensed phase may be responsible for such unusual behaviour. Multilayer electroluminescence devices with a configuration of indium tin oxide/N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine/emitter/tris(8-hydroxyquinolinolato)aluminum (Alq3)/LiF/Al were constructed, which gave green light with a maximum luminance and current efficiency of 12930 cd cm–2 and 3.04 cd A–1 respectively. The tetraphenylethenes can serve as excellent cell staining agents for selectively illuminating the cytoplasm and vesicles of living cells.
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Lei, Y., Q. Zhang, K. B. He y D. G. Streets. "Primary anthropogenic aerosol emission trends for China, 1990–2005". Atmospheric Chemistry and Physics 11, n.º 3 (2 de febrero de 2011): 931–54. http://dx.doi.org/10.5194/acp-11-931-2011.
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Abstract. An inventory of anthropogenic primary aerosol emissions in China was developed for 1990–2005 using a technology-based approach. Taking into account changes in the technology penetration within industry sectors and improvements in emission controls driven by stricter emission standards, a dynamic methodology was derived and implemented to estimate inter-annual emission factors. Emission factors of PM2.5 decreased by 7%–69% from 1990 to 2005 in different industry sectors of China, and emission factors of TSP decreased by 18%–80% as well, with the measures of controlling PM emissions implemented. As a result, emissions of PM2.5 and TSP in 2005 were 11.0 Tg and 29.7 Tg, respectively, less than what they would have been without the adoption of these measures. Emissions of PM2.5, PM10 and TSP presented similar trends: they increased in the first six years of 1990s and decreased until 2000, then increased again in the following years. Emissions of TSP peaked (35.5 Tg) in 1996, while the peak of PM10 (18.8 Tg) and PM2.5 (12.7 Tg) emissions occurred in 2005. Although various emission trends were identified across sectors, the cement industry and biofuel combustion in the residential sector were consistently the largest sources of PM2.5 emissions, accounting for 53%–62% of emissions over the study period. The non-metallic mineral product industry, including the cement, lime and brick industries, accounted for 54%–63% of national TSP emissions. There were no significant trends of BC and OC emissions until 2000, but the increase after 2000 brought the peaks of BC (1.51 Tg) and OC (3.19 Tg) emissions in 2005. Although significant improvements in the estimation of primary aerosols are presented here, there still exist large uncertainties. More accurate and detailed activity information and emission factors based on local tests are essential to further improve emission estimates, this especially being so for the brick and coke industries, as well as for coal-burning stoves and biofuel usage in the residential sector.
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Lei, Y., Q. Zhang, K. B. He y D. G. Streets. "Primary aerosol emission trends for China, 1990–2005". Atmospheric Chemistry and Physics Discussions 10, n.º 7 (12 de julio de 2010): 17153–212. http://dx.doi.org/10.5194/acpd-10-17153-2010.
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Abstract. An inventory of anthropogenic primary aerosol emissions in China was developed for 1990–2005 using a technology-based approach. Taking into account changes in the technology penetration within industry sectors and improvements in emission controls driven by stricter emission standards, a dynamic methodology was derived and implemented to estimate inter-annual emission factors. Emission factors of PM2.5 decreased by 7%–69% from 1990 to 2005 in different industry sectors of China, and emission factors of TSP decreased by 18%–80% as well. Emissions of PM2.5, PM10 and TSP presented similar trends: increased in the first six years of 1990s and decreased until 2000, then increased again in the following years. Emissions of TSP reached a historical high (35.5 Tg) in 1996, while the peak of PM10 (18.8 Tg) and PM2.5 (12.7 Tg) emissions occurred in 2005. Although various emission trends were identified across sectors, the cement industry and biofuel combustion in the residential sector were consistently the largest sources of PM2.5 emissions, accounting for 53%–62% of emission over the study period. The non-metallic mineral product industry, including the cement, lime and brick industries, accounted for 54%–63% of national TSP emissions. There were no significant trends of BC and OC emissions until 2000, but the increase after 2000 brought the historical high of BC (1.51 Tg) and OC (3.19 Tg) emissions in 2005. Although significant improvements in the estimation of primary aerosols are presented, there still exist large uncertainties. More accurate and detailed activity information and emission factors based on local tests are essential to further improve emission estimates, this especially being so for the brick and coke industries, as well as for coal-burning stoves and biofuel usage in the residential sector.
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Zhuang, Peifeng, Chang Yuan, Yunhao Bai, Changcheng He, Jiayu Long, Hongwei Tan y Huiliang Wang. "Effects of Through-Bond and Through-Space Conjugations on the Photoluminescence of Small Aromatic and Aliphatic Aldimines". Molecules 27, n.º 22 (19 de noviembre de 2022): 8046. http://dx.doi.org/10.3390/molecules27228046.
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Through-bond conjugation (TBC) and/or through-space conjugation (TSC) determine the photophysical properties of organic luminescent compounds. No systematic studies have been carried out to understand the transition from aromatic TBC to non-aromatic TSC on the photoluminescence of organic luminescent compounds. In this work, a series of small aromatic and aliphatic aldimines were synthesized. For the aromatic imines, surprisingly, N,1-diphenylmethanimine with the highest TBC is non-emissive, while N-benzyl-1-phenylmethanimine and N-cyclohexyl-1-phenylmethanimine emit bright fluorescence in aggregate states. The aliphatic imines are all emissive, and their maximum emission wavelength decreases while the quantum yield increases with a decrease in steric hindrance. The imines show concentration-dependent and excitation-dependent emissions. Theoretical calculations show that the TBC extents in the aromatic imines are not strong enough to induce photoluminescence in a single molecule state, while the intermolecular TSC becomes dominant for the fluorescence emissions of both aromatic and aliphatic imines in aggregate states, and the configurations and spatial conformations of the molecules in aggregate states play a key role in the formation of effective TSC. This study provides an understanding of how chemical and spatial structures affect the formation of TBC and TSC and their functions on the photoluminescence of organic luminescent materials.
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Gao, Ting Ting, Hai Yi Li y Yan Xia Su. "The Prediction Research of COD Emissions in Jilin Province Based on the Environment of the 12th Five-Year Plan". Advanced Materials Research 765-767 (septiembre de 2013): 2980–83. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.2980.
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Based on Jilin province and nine cities COD emissions data of 2010, this paper is an attempt to quantitatively analyze the area distribution patterns of two indices (COD emissions per capita and COD emissions per unit production value) as well as their causes. The COD emissions from 2000-2010 and the per capita GDP to establish the environmental learning curve of Jilin province are constructed, in order to analyze the load of emission and potential mitigation. And prediction of the COD emissions discharge trend during the 12th Five-Year plan, the potential mitigation to make sure the direction of emission reduction is analyzed.The chemical oxygen demand (COD) emissions of Jilin province were 352200 tons in 2010. It was declined by 2.4% over the previous year. These emissions were accomplished 130.5% of the "11th five-year plan" emission reduction task[1]. However, in the process of urbanization, they continue to accelerate and high-speed economic growth. The task of the COD emission reduction at 8.8% is hard to achieve by 2015. Predictions can be made by using the environment learning curve on the relationship between the COD emissions and Jilin province economic development through environmental statistics. We analysed the potential reduction of COD emission of "twelfth five-year" in Jilin province and determined the direction of emission reduction.