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Articles de revues sur le sujet « CH3I »

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Auteur : Grafiati
Publié le 25 mai 2024

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1

Ji, Xiaoyan, et Jing Xie. « Proton transfer-induced competing product channels of microsolvated Y−(H2O)n + CH3I (Y = F, Cl, Br, I) reactions ». Physical Chemistry Chemical Physics 24, no 12 (2022) : 7539–50. http://dx.doi.org/10.1039/d1cp04873b.

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2

Tegtmeier, S., K. Krüger, B. Quack, E. Atlas, D. R. Blake, H. Boenisch, A. Engel et al. « The contribution of oceanic methyl iodide to stratospheric iodine ». Atmospheric Chemistry and Physics 13, no 23 (9 décembre 2013) : 11869–86. http://dx.doi.org/10.5194/acp-13-11869-2013.

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Abstract. We investigate the contribution of oceanic methyl iodide (CH3I) to the stratospheric iodine budget. Based on CH3I measurements from three tropical ship campaigns and the Lagrangian transport model FLEXPART, we provide a detailed analysis of CH3I transport from the ocean surface to the cold point in the upper tropical tropopause layer (TTL). While average oceanic emissions differ by less than 50% from campaign to campaign, the measurements show much stronger variations within each campaign. A positive correlation between the oceanic CH3I emissions and the efficiency of CH3I troposphere–stratosphere transport has been identified for some cruise sections. The mechanism of strong horizontal surface winds triggering large emissions on the one hand and being associated with tropical convective systems, such as developing typhoons, on the other hand, could explain the identified correlations. As a result of the simultaneous occurrence of large CH3I emissions and strong vertical uplift, localized maximum mixing ratios of 0.6 ppt CH3I at the cold point have been determined for observed peak emissions during the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere)-Sonne research vessel campaign in the coastal western Pacific. The other two campaigns give considerably smaller maxima of 0.1 ppt CH3I in the open western Pacific and 0.03 ppt in the coastal eastern Atlantic. In order to assess the representativeness of the large local mixing ratios, we use climatological emission scenarios to derive global upper air estimates of CH3I abundances. The model results are compared with available upper air measurements, including data from the recent ATTREX and HIPPO2 aircraft campaigns. In the eastern Pacific region, the location of the available measurement campaigns in the upper TTL, the comparisons give a good agreement, indicating that around 0.01 to 0.02 ppt of CH3I enter the stratosphere. However, other tropical regions that are subject to stronger convective activity show larger CH3I entrainment, e.g., 0.08 ppt in the western Pacific. Overall our model results give a tropical contribution of 0.04 ppt CH3I to the stratospheric iodine budget. The strong variations in the geographical distribution of CH3I entrainment suggest that currently available upper air measurements are not representative of global estimates and further campaigns will be necessary in order to better understand the CH3I contribution to stratospheric iodine.
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Tegtmeier, S., K. Krüger, B. Quack, E. Atlas, D. R. Blake, H. Boenisch, A. Engel et al. « The contribution of oceanic methyl iodide to stratospheric iodine ». Atmospheric Chemistry and Physics Discussions 13, no 4 (30 avril 2013) : 11427–71. http://dx.doi.org/10.5194/acpd-13-11427-2013.

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Abstract. We investigate the contribution of oceanic methyl iodide (CH3I) to the stratospheric iodine budget. Based on CH3I measurements during three tropical ship campaigns and the Lagrangian transport model FLEXPART we provide a detailed analysis of CH3I transport from the ocean surface to the cold point in the upper tropical tropopause layer (TTL). While average oceanic emissions differ by less than 50% from campaign to campaign, the measurements show much stronger variations within each campaign. A positive correlation between the oceanic CH3I emissions and the efficiency of CH3I troposphere–stratosphere transport has been identified for some cruise sections. The mechanism of strong horizontal surface winds triggering large emissions on the one hand and being associated with tropical convective systems, such as developing typhoons, on the other hand, could explain the identified correlations. As a result of the simultaneous occurrence of large CH3I emissions and strong vertical uplift, localized maximum mixing ratios of 0.6 ppt CH3I at the cold point have been determined for observed peak emissions during the SHIVA-Sonne campaign in the coastal West Pacific. The other two campaigns give considerable smaller maxima of 0.1 ppt CH3I for the TransBrom campaign in the open West Pacific and 0.03 ppt for emissions from the coastal East Atlantic during the DRIVE campaign. In order to assess the representativeness of the large local mixing ratios we use climatological emission scenarios to derive global upper air estimates of CH3I abundances. The model results are compared to available upper air measurements including data from the recent ATTREX and HIPPO2 aircraft campaigns. In the East Pacific region, the location of the available measurement campaigns in the upper TTL, the comparisons give a good agreement indicating that around 0.01 to 0.02 ppt of CH3I enter the stratosphere. However, other tropical regions, which are subject to stronger convective activity show larger CH3I entrainment, e.g., 0.08 ppt in the West Pacific. The strong variations in the geographical distribution of CH3I entrainment suggest that currently available upper air measurements are not representative of global estimates and further campaigns will be necessary in order to better understand the CH3I contribution to stratospheric iodine.
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Caron, Maurice, Takeshi Kawamata, Luc Ruest, Pierre Soucy et Pierre Deslongchamps. « The addition of electrophiles on ester enolates containing an oxygen in the β-position. A stereoelectronically controlled reaction ». Canadian Journal of Chemistry 64, no 9 (1 septembre 1986) : 1781–87. http://dx.doi.org/10.1139/v86-293.

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The enolate anion derived from spiro ketal methyl esters (1, 3, and 4) reacts with various electrophiles (PhSeBr, Ch3I, O2, I2, (CH3S)2, and (PhS)2) to yield as the major product, the isomer resulting from an equatorial approach of the electrophilic reagent. This stereochemically controlled reaction is discussed in terms of stereoelectronic effects that increase the electron density of the α face of the enolate anion.
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5

Zhang, Jiaxu, Jing Xie et William L. Hase. « Dynamics of the F– + CH3I → HF + CH2I– Proton Transfer Reaction ». Journal of Physical Chemistry A 119, no 50 (2 novembre 2015) : 12517–25. http://dx.doi.org/10.1021/acs.jpca.5b08167.

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6

Stemmler, I., M. Rothe, I. Hense et H. Hepach. « Numerical modelling of methyl iodide in the eastern tropical Atlantic ». Biogeosciences 10, no 6 (25 juin 2013) : 4211–25. http://dx.doi.org/10.5194/bg-10-4211-2013.

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Abstract. Methyl iodide (CH3I) is a volatile organic halogen compound that contributes significantly to the transport of iodine from the ocean to the atmosphere, where it plays an important role in tropospheric chemistry. CH3I is naturally produced and occurs in the global ocean. The processes involved in the formation of CH3I, however, are not fully understood. In fact, there is an ongoing debate whether production by phytoplankton or photochemical degradation of organic matter is the main source term. Here, both the biological and photochemical production mechanisms are considered in a biogeochemical module that is coupled to a one-dimensional water column model for the eastern tropical Atlantic. The model is able to reproduce observed subsurface maxima of CH3I concentrations. But, the dominating source process cannot be clearly identified as subsurface maxima can occur due to both direct biological and photochemical production. However, good agreement between the observed and simulated difference between surface and subsurface methyl iodide concentrations is achieved only when direct biological production is taken into account. Production rates for the biological CH3I source that were derived from published laboratory studies are shown to be inappropriate for explaining CH3I concentrations in the eastern tropical Atlantic.
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Stemmler, I., M. Rothe et I. Hense. « Numerical modelling of methyl iodide in the Eastern Tropical Atlantic ». Biogeosciences Discussions 10, no 1 (24 janvier 2013) : 1111–45. http://dx.doi.org/10.5194/bgd-10-1111-2013.

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Abstract. Methyl iodide (CH3I) is a volatile organic halogen compound that contributes significantly to the transport of iodine from the ocean to the atmosphere, where it plays an important role in tropospheric chemistry. CH3I is naturally produced and occurs in the global ocean. The processes involved in the formation of CH3I, however, are not fully understood. In fact, there is an ongoing debate whether production by phytoplankton or photochemical degradation of organic matter is the main source term. Here, both the biological and photochemical production mechanisms are considered in a biogeochemical module that is coupled to a one-dimensional water column model for the Eastern Tropical Atlantic. The model is able to reproduce observed subsurface maxima of CH3I concentrations. But, the dominating source process cannot be clearly identified as subsurface maxima can occur due to both, direct biological and photochemical production. However, good agreement between the observed and simulated difference between surface and subsurface methyl iodide concentrations is achieved only when direct biological production is taken into account. Published production rates for the biological CH3I source that were derived from laboratory studies are shown to be inappropriate for explaining CH3I concentrations in the Eastern Tropical Atlantic.
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8

Stemmler, I., I. Hense, B. Quack et E. Maier-Reimer. « Methyl iodide production in the open ocean ». Biogeosciences 11, no 16 (22 août 2014) : 4459–76. http://dx.doi.org/10.5194/bg-11-4459-2014.

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Abstract. Production pathways of the prominent volatile organic halogen compound methyl iodide (CH3I) are not fully understood. Based on observations, production of CH3I via photochemical degradation of organic material or via phytoplankton production has been proposed. Additional insights could not be gained from correlations between observed biological and environmental variables or from biogeochemical modeling to identify unambiguously the source of methyl iodide. In this study, we aim to address this question of source mechanisms with a three-dimensional global ocean general circulation model including biogeochemistry (MPIOM–HAMOCC (MPIOM – Max Planck Institute Ocean Model HAMOCC – HAMburg Ocean Carbon Cycle model)) by carrying out a series of sensitivity experiments. The simulated fields are compared with a newly available global data set. Simulated distribution patterns and emissions of CH3I differ largely for the two different production pathways. The evaluation of our model results with observations shows that, on the global scale, observed surface concentrations of CH3I can be best explained by the photochemical production pathway. Our results further emphasize that correlations between CH3I and abiotic or biotic factors do not necessarily provide meaningful insights concerning the source of origin. Overall, we find a net global annual CH3I air–sea flux that ranges between 70 and 260 Gg yr−1. On the global scale, the ocean acts as a net source of methyl iodide for the atmosphere, though in some regions in boreal winter, fluxes are of the opposite direction (from the atmosphere to the ocean).
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9

Stemmler, I., I. Hense, B. Quack et E. Maier-Reimer. « Methyl iodide production in the open ocean ». Biogeosciences Discussions 10, no 11 (8 novembre 2013) : 17549–95. http://dx.doi.org/10.5194/bgd-10-17549-2013.

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Abstract. Production pathways of the prominent volatile organic halogen compound methyl iodide (CH3I) are not fully understood. Previous model studies suggest either production via photochemical degradation of organic material or rather phytoplankton production. Correlations between biological and environmental variables derived from observations also suggest both production pathways. In this study we aim to address this question of source mechanisms with a global three-dimensional ocean general circulation model including biogeochemistry (MPIOM-HAMOCC) by carrying out a series of sensitivity experiments. Simulated distribution patterns and emissions of CH3I differ largely for the different production pathways. However, the evaluation of our model results with observations from a newly available global data set shows that observed surface concentrations of CH3I can be best explained by the photochemical production pathway. Our results further emphasize that correlations between CH3I and abiotic or biotic factors do not necessarily provide meaningful insights concerning the source of origin. Overall, we find a net global annual CH3I air–sea flux that ranges between 70 and 260 Gg yr−1. Hence, at the global scale the ocean is a net source of methyl iodide for the atmosphere, though in some regions in boreal winter fluxes are of opposite direction (from the atmosphere to the ocean).
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10

Buldyreva, J., A. Dudaryonok et N. Lavrentieva. « Temperature-dependence parameters for CH3I-O2 and CH3I-air line-broadening coefficients ». Journal of Quantitative Spectroscopy and Radiative Transfer 284 (juillet 2022) : 108164. http://dx.doi.org/10.1016/j.jqsrt.2022.108164.

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11

Kornweitz, Haya, et R. D. Levine. « Formation of molecular iodine in high-energy four-center CH3I+CH3I collisions ». Chemical Physics Letters 294, no 1-3 (septembre 1998) : 153–61. http://dx.doi.org/10.1016/s0009-2614(98)00849-5.

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12

Hepach, H., B. Quack, F. Ziska, S. Fuhlbrügge, E. L. Atlas, I. Peeken, K. Krüger et D. W. R. Wallace. « Drivers of diel and regional variations of halocarbon emissions from the tropical North East Atlantic ». Atmospheric Chemistry and Physics Discussions 13, no 7 (25 juillet 2013) : 19701–50. http://dx.doi.org/10.5194/acpd-13-19701-2013.

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Abstract. Methyl iodide (CH3I}, bromoform (CHBr3) and dibromomethane (CH2Br2), which are produced naturally in the oceans, take part in ozone chemistry both in the troposphere and the stratosphere. The significance of oceanic upwelling regions for emissions of these trace gases in the global context is still uncertain although they have been identified as important source regions. To better quantify the role of upwelling areas in current and future climate, this paper analyzes major factors that influenced halocarbon emissions from the tropical North East Atlantic including the Mauritanian upwelling during the DRIVE expedition. Diel and regional variability of oceanic and atmospheric CH3I, CHBr3 and CH2Br2 was determined along with biological and meteorological parameters at six 24 h-stations. Low oceanic concentrations of CH3I from 0.1–5.4 pmol L-1 were equally distributed throughout the investigation area. CHBr3 of 1.0–42.4 pmol L-1 and CH2Br2 of 1.0–9.4 pmol L-1 were measured with maximum concentrations close to the Mauritanian coast. Atmospheric mixing rations of CH3I of up to 3.3, CHBr3 to 8.9 and CH2Br2 to 3.1 ppt above the upwelling and 1.8, 12.8, respectively 2.2 ppt at a Cape Verdean coast were detected during the campaign. While diel variability in CH3I emissions could be mainly ascribed to oceanic non-biological production, no main driver was identified for its emissions in the entire study region. In contrast, oceanic bromocarbons resulted from biogenic sources which were identified as regional drivers of their sea-to-air fluxes. The diel impact of wind speed on bromocarbon emissions increased with decreasing distance to the coast. The height of the marine atmospheric boundary layer (MABL) was determined as an additional factor influencing halocarbon emissions. Oceanic and atmospheric halocarbons correlated well in the study region and in combination with high oceanic CH3I, CHBr3 and CH2Br2 concentrations, local hot spots of atmospheric halocarbons could solely be explained by marine sources. This conclusion is in contrast with previous studies that hypothesized the occurrence of elevated atmospheric halocarbons over the eastern tropical Atlantic mainly originating from the West-African continent.
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Hepach, H., B. Quack, F. Ziska, S. Fuhlbrügge, E. L. Atlas, K. Krüger, I. Peeken et D. W. R. Wallace. « Drivers of diel and regional variations of halocarbon emissions from the tropical North East Atlantic ». Atmospheric Chemistry and Physics 14, no 3 (3 février 2014) : 1255–75. http://dx.doi.org/10.5194/acp-14-1255-2014.

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Abstract. Methyl iodide (CH3I), bromoform (CHBr3) and dibromomethane (CH2Br2), which are produced naturally in the oceans, take part in ozone chemistry both in the troposphere and the stratosphere. The significance of oceanic upwelling regions for emissions of these trace gases in the global context is still uncertain although they have been identified as important source regions. To better quantify the role of upwelling areas in current and future climate, this paper analyzes major factors that influenced halocarbon emissions from the tropical North East Atlantic including the Mauritanian upwelling during the DRIVE expedition. Diel and regional variability of oceanic and atmospheric CH3I, CHBr3 and CH2Br2 was determined along with biological and physical parameters at six 24 h-stations. Low oceanic concentrations of CH3I from 0.1–5.4 pmol L−1 were equally distributed throughout the investigation area. CHBr3 and CH2Br2 from 1.0 to 42.4 pmol L−1 and to 9.4 pmol L−1, respectively were measured with maximum concentrations close to the Mauritanian coast. Atmospheric CH3I, CHBr3, and CH2Br2 of up to 3.3, 8.9, and 3.1 ppt, respectively were detected above the upwelling, as well as up to 1.8, 12.8, and 2.2 ppt at the Cape Verdean coast. While diel variability in CH3I emissions could be mainly ascribed to oceanic non-biological production, no main driver was identified for its emissions over the entire study region. In contrast, biological parameters showed the greatest influence on the regional distribution of sea-to-air fluxes of bromocarbons. The diel impact of wind speed on bromocarbon emissions increased with decreasing distance to the coast. The height of the marine atmospheric boundary layer (MABL) influenced halocarbon emissions via its influence on atmospheric mixing ratios. Oceanic and atmospheric halocarbons correlated well in the study region, and in combination with high oceanic CH3I, CHBr3 and CH2Br2 concentrations, local hot spots of atmospheric halocarbons could solely be explained by marine sources. This conclusion is in contrast to previous studies that hypothesized elevated atmospheric halocarbons above the eastern tropical Atlantic to be mainly originated from the West-African continent.
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Wulan, Praswasti Pembangun Dyah Kencana, Widodo Wahyu Purwanto et Yuswan Muharam. « KINETIKA MIKRO DEKOMPOSISI METANA MENJADI KARBON NANOTUBE PADA PERMUKAAN KATALIS Ni-Cu-Al ». Reaktor 13, no 3 (3 juin 2011) : 148. http://dx.doi.org/10.14710/reaktor.13.3.148-154.

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MICRO KINETICS OF DECOMPOSITION OF METHANE TO CARBON NANOTUBES OVER NI-CU-AL CATALYST. The main focus of this research was to obtain micro kinetics decomposition of methane producing carbon nanotube on the surface of the Ni-Cu-Al catalyst. Experimental kinetics data collected at a temperature range of 650-750oC and pressure of one atmosphere. The preliminary test was conducted to obtain the kinetics are not influenced by external and internal diffusion limitations as well as inter-phase transfer. Kinetics data were tested by micro kinetic model derived from the catalyst surface reaction mechanism. The most appropriate kinetic model becomes the rate-limiting step of methane decomposition reaction. Results of preliminary experiment showed that the kinetics of the external diffusion effect is negligible at flow rates above 150 mL/min. Internal diffusion can be ignored with a catalyst under 0.25 mm in diameter with a weight of 0.04 grams of catalyst and contact time 2.5x10-4. Rate equation analysis shows that the rate-limiting step is the adsorption which indicates that intermediate consumption (CH4I + I Û CH3I + HI) is faster than the formation of intermediate (adsorption of methane, CH4 + I Û CH4I). The activation energy obtained for 34.628 kJ/mol and pre-exponential factor of 6.583x106. Fokus utama penelitian ini adalah memperoleh kinetika mikro dekomposisi metana yang menghasilkan Carbon Nanotube pada permukaan katalis Ni-Cu-Al. Data kinetika eksperimen diambil pada rentang temperatur 650-750oC dan tekanan 1 atmosfer. Percobaan pendahuluan dilakukan untuk memperoleh daerah kinetika yang tidak dipengaruhi oleh limitasi difusi eksternal dan internal serta perpindahan antar fasa. Data kinetika diuji dengan model kinetika mikro yang diturunkan dari mekanisme reaksi permukaan katalis. Model kinetika yang paling sesuai menjadi tahap pembatas laju reaksi dekomposisi metana. Hasil percobaan pendahuluan kinetika menunjukkan bahwa pengaruh difusi eksternal dapat diabaikan pada laju alir di atas 150 mL/menit. Difusi internal dapat diabaikan dengan menggunakan katalis berdiameter di bawah 0,25 mm dengan berat katalis 0,04 gram pada waktu kontak 2,5x10-4. Analisis persamaan laju menunjukkan bahwa tahap pembatas laju adalah tahap adsorpsi yang menunjukkan bahwa konsumsi intermediate (CH4I + I Û CH3I + HI) lebih cepat dari pembentukan intermediate (adsorpsi metana,CH4 + I Û CH4I). Energi aktivasi yang diperoleh sebesar 34,628 kJ/mol dan faktor pre-eksponensial 6,583x106.
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Shi, Qiang, et Douglas Wallace. « A 3-year time series of volatile organic iodocarbons in Bedford Basin, Nova Scotia : a northwestern Atlantic fjord ». Ocean Science 14, no 6 (8 novembre 2018) : 1385–403. http://dx.doi.org/10.5194/os-14-1385-2018.

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Abstract. We report weekly observations of volatile organic iodocarbons (CH3I, CH2ClI and CH2I2) over the time period May 2015 to December 2017 from four depths in Bedford Basin, a coastal fjord (70 m deep) on the Atlantic coast of Canada. The fjord is subject to wintertime mixing, seasonal stratification and bloom dynamics, subsurface oxygen depletion, local input of freshwater, and occasional intrusions of higher-density water from the adjacent continental shelf. Near-surface concentrations showed strong seasonal and sub-seasonal variability, which is compared with other coastal time series. The vertical variation of CH2I2 and CH2ClI within the upper 10 m is consistent with rapid photolysis of CH2I2. Average annual sea-to-air fluxes (46.7 nmol m−2 day−1) of total volatile organic iodine were similar to those observed in other coastal and shelf time series, and polyiodinated compounds contributed 80 % of the total flux. Fluxes were subject to strong interannual variability (a factor of 2) mainly due to wind speed variability. Near-surface net production of CH3I averaged 1 pmol L−1 day−1 and was similar to rates in the English Channel but an order of magnitude higher than in shallow waters of the Kiel Fjord, Germany, possibly due to higher microbial degradation in the latter. The near-bottom (60 m) time series showed evidence of CH3I production associated with organic matter degradation and a possible “switch” from the production of CH3I via an alkylation pathway to the production of CH2I2 by a haloform-type reaction. Near-bottom CH3I production varied strongly between years but was generally ca. 20 times lower than near-surface production.
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Ito, Fumiyuki. « Infrared studies of the CH3I–H2O complex and large CH3I clusters in Ar matrices ». Journal of Molecular Structure 1035 (mars 2013) : 54–60. http://dx.doi.org/10.1016/j.molstruc.2012.09.027.

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An, Hyejin, Sungjoon Kweon, Sanggil Park, Jaeyoung Lee, Hyung-Ki Min et Min Bum Park. « Immobilization of Radioiodine via an Interzeolite Transformation to Iodosodalite ». Nanomaterials 10, no 11 (29 octobre 2020) : 2157. http://dx.doi.org/10.3390/nano10112157.

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We described a technology for immobilizing radioiodine in the sod-cages by the interzeolite transformation of iodine-containing LTA (zeolite A) and FAU (zeolites X and Y) into a sodalite (SOD) structure. The immobilization of iodine in the sod-cage was confirmed using diverse characterization methods including powder XRD, elemental analysis, SEM–EDS, 127I MAS NMR, and I 3d XPS. Although both zeolites A (Na-A) and X (Na-X) were well converted into SOD structure in the presence of NaI and AgI, the iodide anions were fixed in the sod-cages only when NaI was used. The ability to adsorb methyl iodide (CH3I) was evaluated for zeolites A and X in which Na+ and/or Ag+ ions were exchanged, and Ag+ and zeolite X showed better adsorption properties than Na+ and zeolite A, respectively. However, when both CH3I adsorption ability and the successive immobilization of iodine by interzeolite transformation were considered, Na-X was determined to be the best candidate of adsorbent among the studied zeolites. More than 98% of the iodine was successfully immobilized in the sod-cage in the SOD structure by the interconversion of Na-X following CH3I adsorption, although the Na-X zeolite exhibited half the CH3I adsorption capacity of Ag-X.
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Chandrasekar MJN, Raman Rajeshkumar et Arivukkarasi Varadharajan. « In vitro bioassessment of novel δ- carboline derivatives as an antiproliferative agent ». International Journal of Research in Pharmaceutical Sciences 11, no 3 (17 juillet 2020) : 3563–68. http://dx.doi.org/10.26452/ijrps.v11i3.2512.

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Several carboline derivatives are anticancer agents and studied for antiproliferative action against various cancer cells. Based on the preliminary analysis using insilico strategies, we have selected eight compounds for the study. All compounds have been synthesised and characterised for their purity and chemical composition. Antiproliferative activity was assessed by insilico Carcinogenicity assay, Cytotoxicity analysis by sulphorhodamine B, Antiproliferation assay and DNA damage analysis. The cytotoxic effects of the CH5, CH17, CH29, CH34, CH37, CH39, CH42 and CH47 on Vero, HeLa, A549, BRL3A, HCT116, and MCF7 were determined using the SRB assay. CH5, CH34, CH37 and CH42 was the most potent cytotoxic towards HCT116 cells with CTC50 value of 62.1±0.19, 47.1±0.41, 78.5±1.26 and 32.1±1.11 µg/ml respectively. The assay revealed a noticeable reduction in cell number for CH5 and CH37 tested except CH34 and CH42. CH5 and CH37 observed cytotoxic effects were found to destroy the cells according to time, and cell viability decreased with that time length. To learn their role in cell death, CH5 and CH37 were therefore taken up for a further screening. This study suggested that CH5 and CH37 had a separate mechanism of action to kill and that in the cell line. Such results will provide enrichment of scientific knowledge on the molecular mechanism and target therapies of CH5 and CH37, thereby potentially helpful for patients with Colon cancer.
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Zhang, Sheng-Hui, Juan Yu, Qiong-Yao Ding, Gui-Peng Yang, Kun-Shan Gao, Hong-Hai Zhang et Da-Wei Pan. « Effect of elevated <i>p</i>CO<sub>2</sub> ; on trace gas production during an ocean acidification mesocosm experiment ». Biogeosciences 15, no 21 (9 novembre 2018) : 6649–58. http://dx.doi.org/10.5194/bg-15-6649-2018.

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Abstract. A mesocosm experiment was conducted in Wuyuan Bay (Xiamen), China, to investigate the effects of elevated pCO2 on the phytoplankton species Phaeodactylum tricornutum (P. tricornutum), Thalassiosira weissflogii (T. weissflogii) and Emiliania huxleyi (E. huxleyi) and their production ability of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), as well as four halocarbon compounds, bromodichloromethane (CHBrCl2), methyl bromide (CH3Br), dibromomethane (CH2Br2) and iodomethane (CH3I). Over a period of 5 weeks, P. tricornuntum outcompeted T. weissflogii and E. huxleyi, comprising more than 99 % of the final biomass. During the logarithmic growth phase (phase I), mean DMS concentration in high pCO2 mesocosms (1000 µatm) was 28 % lower than that in low pCO2 mesocosms (400 µatm). Elevated pCO2 led to a delay in DMSP-consuming bacteria concentrations attached to T. weissflogii and P. tricornutum and finally resulted in the delay of DMS concentration in the high pCO2 treatment. Unlike DMS, the elevated pCO2 did not affect DMSP production ability of T. weissflogii or P. tricornuntum throughout the 5-week culture. A positive relationship was detected between CH3I and T. weissflogii and P. tricornuntum during the experiment, and there was a 40 % reduction in mean CH3I concentration in the high pCO2 mesocosms. CHBrCl2, CH3Br, and CH2Br2 concentrations did not increase with elevated chlorophyll a (Chl a) concentrations compared with DMS(P) and CH3I, and there were no major peaks both in the high pCO2 or low pCO2 mesocosms. In addition, no effect of elevated pCO2 was identified for any of the three bromocarbons.
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Ferreira, Hendrik, Marrigje Marianne Conradie et Jeanet Conradie. « Kinetic Study of the Oxidative Addition Reaction between Methyl Iodide and [Rh(imino-β-diketonato)(CO)(PPh)3] Complexes, Utilizing UV–Vis, IR Spectrophotometry, NMR Spectroscopy and DFT Calculations ». Molecules 27, no 6 (16 mars 2022) : 1931. http://dx.doi.org/10.3390/molecules27061931.

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The oxidative addition of methyl iodide to [Rh(β-diketonato)(CO)(PPh)3] complexes, as modal catalysts of the first step during the Monsanto process, are well-studied. The β-diketonato ligand is a bidentate (BID) ligand that bonds, through two O donor atoms (O,O-BID ligand), to rhodium. Imino-β-diketones are similar to β-diketones, though the donor atoms are N and O, referred to as an N,O-BID ligand. In this study, the oxidative addition of methyl iodide to [Rh(imino-β-diketonato)(CO)(PPh)3] complexes, as observed on UV–Vis spectrophotometry, IR spectrophotometry and NMR spectrometry, are presented. Experimentally, one isomer of [Rh(CH3COCHCNPhCH3)(CO)(PPh3)] and two isomers of [Rh(CH3COCHCNHCH3)(CO)(PPh3)] are observed—in agreement with density functional theory (DFT) calculations. Experimentally the [Rh(CH3COCHCNPhCH3)(CO)(PPh3)] + CH3I reaction proceeds through one reaction step, with a rhodium(III)-alkyl as the final reaction product. However, the [Rh(CH3COCHCNHCH3)(CO)(PPh3)] + CH3I reaction proceeds through two reaction steps, with a rhodium(III)-acyl as the final reaction product. DFT calculations of all the possible reaction products and transition states agree with experimental findings. Due to the smaller electronegativity of N, compared to O, the oxidative addition reaction rate of CH3I to the two [Rh(imino-β-diketonato)(CO)(PPh)3] complexes of this study was 7–11 times faster than the oxidative addition reaction rate of CH3I to [Rh(CH3COCHCOCH3)(CO)(PPh3)].
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21

Speck, T., T. Mostefaoui, C. Rebrion-Rowe, J. B. A. Mitchell et B. R. Rowe. « Low-temperature electron attachment to CH3I ». Journal of Physics B : Atomic, Molecular and Optical Physics 33, no 18 (1 septembre 2000) : 3575–82. http://dx.doi.org/10.1088/0953-4075/33/18/307.

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Eden, S., P. Limão-Vieira, S. V. Hoffmann et N. J. Mason. « VUV spectroscopy of CH3Cl and CH3I ». Chemical Physics 331, no 2-3 (janvier 2007) : 232–44. http://dx.doi.org/10.1016/j.chemphys.2006.10.021.

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23

Asher, Elizabeth, Rebecca S. Hornbrook, Britton B. Stephens, Doug Kinnison, Eric J. Morgan, Ralph F. Keeling, Elliot L. Atlas et al. « Novel approaches to improve estimates of short-lived halocarbon emissions during summer from the Southern Ocean using airborne observations ». Atmospheric Chemistry and Physics 19, no 22 (22 novembre 2019) : 14071–90. http://dx.doi.org/10.5194/acp-19-14071-2019.

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Abstract. Fluxes of halogenated volatile organic compounds (VOCs) over the Southern Ocean remain poorly understood, and few atmospheric measurements exist to constrain modeled emissions of these compounds. We present observations of CHBr3, CH2Br2, CH3I, CHClBr2, CHBrCl2, and CH3Br during the O2∕N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) study and the second Atmospheric Tomography mission (ATom-2) in January and February of 2016 and 2017. Good model–measurement correlations were obtained between these observations and simulations from the Community Earth System Model (CESM) atmospheric component with chemistry (CAM-Chem) for CHBr3, CH2Br2, CH3I, and CHClBr2 but all showed significant differences in model : measurement ratios. The model : measurement comparison for CH3Br was satisfactory and for CHBrCl2 the low levels present precluded us from making a complete assessment. Thereafter, we demonstrate two novel approaches to estimate halogenated VOC fluxes; the first approach takes advantage of the robust relationships that were found between airborne observations of O2 and CHBr3, CH2Br2, and CHClBr2. We use these linear regressions with O2 and modeled O2 distributions to infer a biological flux of halogenated VOCs. The second approach uses the Stochastic Time-Inverted Lagrangian Transport (STILT) particle dispersion model to explore the relationships between observed mixing ratios and the product of the upstream surface influence of sea ice, chl a, absorption due to detritus, and downward shortwave radiation at the surface, which in turn relate to various regional hypothesized sources of halogenated VOCs such as marine phytoplankton, phytoplankton in sea-ice brines, and decomposing organic matter in surface seawater. These relationships can help evaluate the likelihood of particular halogenated VOC sources and in the case of statistically significant correlations, such as was found for CH3I, may be used to derive an estimated flux field. Our results are consistent with a biogenic regional source of CHBr3 and both nonbiological and biological sources of CH3I over these regions.
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24

Youn, D., K. O. Patten, D. J. Wuebbles, H. Lee et C. W. So. « Potential impact of iodinated replacement compounds CF<sub>3</sub>I and CH<sub>3</sub>I on atmospheric ozone : a three-dimensional modeling study ». Atmospheric Chemistry and Physics 10, no 20 (29 octobre 2010) : 10129–44. http://dx.doi.org/10.5194/acp-10-10129-2010.

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Abstract. The concept of Ozone Depletion Potentials (ODPs) is extensively used in policy considerations related to concerns about the effects of various halocarbons and other gases on stratospheric ozone. Many of the recent candidate replacement compounds have atmospheric lifetimes shorter than one year in order to limit their environmental effects, especially on stratospheric ozone. Using a three-dimensional global chemistry-transport model (CTM) of the troposphere and the stratosphere, the purpose of this study is to evaluate the potential effects of several very short-lived iodinated substances, namely iodotrifluoromethane (CF3I) and methyl iodide (CH3I), on atmospheric ozone. Like other chemicals with extremely short lifetimes, the stratospheric halogen loading and resulting ozone effects from these compounds are strongly dependent on the location of emissions. For CF3I, a possible replacement candidate for bromotrifluoromethane (CF3Br), ODPs derived by the three-dimensional model are 0.008 with chemical lifetime of 5.03 days and 0.016 with a lifetime of 1.13 days for emissions assumed to be evenly distributed over land surfaces at mid-latitudes and the tropics, respectively. While this is the first time the ODPs have been evaluated with a three-dimensional model, these values are in good agreement with those derived previously. The model calculations suggest that tropical convection could deliver a larger portion of the gas and their breakdown products to the upper troposphere and lower stratosphere if emission source is located in the tropics. The resulting ODP for CH3I, emitted from mid-latitudes, is 0.017 with lifetime of 13.59 days. Valid simulations of convective transport, vertical mixing and degradation chemistry of CH3I are shown that have good qualitative agreement between the model derived distribution of background CH3I, based on global source emission fluxes from previous studies, and available observations especially in vertical profiles.
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25

Campbell, Mark L., Nick Furio et Paul J. Dagdigian. « The Reaction of Spin–Orbit State-Selected Ca(PJ03) With CH3I, CH2I2, and SF6 ». Laser Chemistry 6, no 6 (1 janvier 1986) : 391–402. http://dx.doi.org/10.1155/lc.6.391.

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Chemiluminescence cross sections for reaction of the individual spin–orbit states of metastable Ca(PJ03) with CH3I, CH2I2, and SF6 have been determined by the use of optical pumping state selection. This technique was also used to separate the chemiluminescence arising from the two excited metastable Ca 3P0 and 1D states. The spin–orbit dependence of the chemiluminescence pathway was found to be substantial for the CH3I and CH2I2 reactions and similar to that previously observed for halogen diatom and alkyl bromide reagents. By contrast, no spin–orbit effect was observed for Ca(3P0)+SF6. These results are discussed in terms of our previously presented model for the origin of spin–orbit effects in chemical reactions.
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26

Pothoczki, Szilvia, László Pusztai et Shinji Kohara. « The structure of liquid iodomethane, CH3I/CD3I ». Journal of Physics : Condensed Matter 19, no 33 (4 juillet 2007) : 335204. http://dx.doi.org/10.1088/0953-8984/19/33/335204.

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27

Kleiman, Valeria D., Langchi Zhu, Jeanette Allen et Robert J. Gordon. « Coherent control over the photodissociation of CH3I ». Journal of Chemical Physics 103, no 24 (22 décembre 1995) : 10800–10803. http://dx.doi.org/10.1063/1.469865.

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Nishimura, S. Y., D. N. Aldrich, M. T. Hoerth, C. J. Ralston et N. J. Tro. « Photochemistry of CH3I Adsorbed on Al2O3(0001) ». Journal of Physical Chemistry B 103, no 44 (novembre 1999) : 9717–20. http://dx.doi.org/10.1021/jp9922864.

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Tamassia, F., R. Danieli et F. Scappini. « Collision-induced radio-frequency transitions in CH3I ». Chemical Physics Letters 300, no 3-4 (février 1999) : 478–82. http://dx.doi.org/10.1016/s0009-2614(98)01358-x.

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Garrett, Simon J., D. Howard Fairbrother, Victor P. Holbert, Eric Weitz et Peter C. Stair. « Multiphoton ionization mechanisms in CH3I and CD3I ». Chemical Physics Letters 219, no 5-6 (mars 1994) : 409–15. http://dx.doi.org/10.1016/0009-2614(94)00120-0.

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31

Paso, R., R. Anttila et G. Guelachvili. « Perturbations in the ν1 band of CH3I ». Journal of Molecular Spectroscopy 140, no 1 (mars 1990) : 46–53. http://dx.doi.org/10.1016/0022-2852(90)90005-b.

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32

Bastian, Björn, Tim Michaelsen, Milan Ončák, Jennifer Meyer et Roland Wester. « F−(H2O)+CH3I ligand exchange reaction dynamics ». Chinese Journal of Chemical Physics 33, no 2 (avril 2020) : 210–16. http://dx.doi.org/10.1063/1674-0068/cjcp2002018.

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33

He, Lanhai, Jaap Bulthuis, Sizuo Luo, Jia Wang, Chunjing Lu, Steven Stolte, Dajun Ding et Wim G. Roeterdink. « Laser induced alignment of state-selected CH3I ». Physical Chemistry Chemical Physics 17, no 37 (2015) : 24121–28. http://dx.doi.org/10.1039/c5cp02997j.

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34

Wang, C. A., C. W. Krueger, M. Flytzani-Stephanopoulos et R. A. Brown. « OMVPE regrowth of CH3I-vapor-etched GaAs ». Journal of Electronic Materials 21, no 3 (mars 1992) : 299–304. http://dx.doi.org/10.1007/bf02660458.

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35

Minkwitz, Rolf, et Detlef Konikowski. « Über verbesserte Darstellungsmethoden für CF3OCH3 / Improved Methods to Prepare CF3OCH3 ». Zeitschrift für Naturforschung B 51, no 1 (1 janvier 1996) : 147–48. http://dx.doi.org/10.1515/znb-1996-0127.

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36

Eger, Philipp G., Frank Helleis, Gerhard Schuster, Gavin J. Phillips, Jos Lelieveld et John N. Crowley. « Chemical ionization quadrupole mass spectrometer with an electrical discharge ion source for atmospheric trace gas measurement ». Atmospheric Measurement Techniques 12, no 3 (26 mars 2019) : 1935–54. http://dx.doi.org/10.5194/amt-12-1935-2019.

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Abstract. We present a chemical ionization quadrupole mass spectrometer (CI-QMS) with a radio-frequency (RF) discharge ion source through N2∕CH3I as a source of primary ions. In addition to the expected detection of PAN, peracetic acid (PAA) and ClNO2 through well-established ion–molecule reactions with I− and its water cluster, the instrument is also sensitive to SO2, HCl and acetic acid (CH3C(O)OH) through additional ion chemistry unique to our ion source. We present ionization schemes for detection of SO2, HCl and acetic acid along with illustrative datasets from three different field campaigns underlining the potential of the CI-QMS with an RF discharge ion source as an alternative to 210Po. The additional sensitivity to SO2 and HCl makes the CI-QMS suitable for investigating the role of sulfur and chlorine chemistry in the polluted marine and coastal boundary layer.
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37

Huang, Guangtuan, et Li Huang. « Particulate copper electrodeposited on carbon felt for degradation of low concentration of methyl iodide in liquid radioactive wastes ». Water Science and Technology 80, no 3 (1 août 2019) : 397–407. http://dx.doi.org/10.2166/wst.2019.298.

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Abstract In this work, the study of copper particles deposition on to carbon felt was presented by pulse electrodeposition method to electrochemically degrade methyl iodide (CH3I, 1 mg L−1) in aqueous solution. In order to solve the problems linked to the heterogeneous potential distribution in the 3-D porous structure, which lead to the so-called ‘black core’, we successfully used low concentration of copper salt (1 mM) and negative deposition potential (−2.5 V) to obtain Cu-nanoparticles/carbon felt (Cu-nano/CF) electrode, the copper coating improved the specific surface area of carbon felt from ∼0.07 to 0.7 m2 g−1 with high catalytic activity. Results show that 98.1% of CH3I can be removed with the Cu-nano/CF electrode in 120 min.
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38

Shechner, Moshe, Alex Guenther, Robert Rhew, Asher Wishkerman, Qian Li, Donald Blake, Gil Lerner et Eran Tas. « Emission of volatile halogenated organic compounds over various Dead Sea landscapes ». Atmospheric Chemistry and Physics 19, no 11 (7 juin 2019) : 7667–90. http://dx.doi.org/10.5194/acp-19-7667-2019.

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Abstract. Volatile halogenated organic compounds (VHOCs), such as methyl halides (CH3X; X is Br, Cl and I) and very short-lived halogenated substances (VSLSs; bromoform – CHBr3, dibromomethane – CH2Br2, bromodichloromethane – CHBrCl2, trichloroethylene – C2HCl3, chloroform – CHCl3 – and dibromochloromethane – CHBr2Cl) are well known for their significant influence on ozone concentrations and oxidation capacity of the troposphere and stratosphere and for their key role in aerosol formation. Insufficient characterization of the sources and the emission rate of VHOCs limits our ability to understand and assess their impact in both the troposphere and stratosphere. Over the last two decades, several natural terrestrial sources for VHOCs, including soil and vegetation, have been identified, but our knowledge of emission rates from these sources and their responses to changes in ambient conditions remains limited. Here we report measurements of the mixing ratios and fluxes of several chlorinated and brominated VHOCs from different landscapes and natural and agricultural vegetated sites at the Dead Sea during different seasons. Fluxes were generally positive (emission into the atmosphere), corresponding to elevated mixing ratios, but were highly variable. Fluxes (and mixing ratios) for the investigated VHOCs ranged as follows: CHBr3 from −79 to 187 nmol m−2 d−1 (1.9 to 22.6 pptv), CH2Br2 from −55 to 71 nmol m−2 d−1 (0.7 to 19 pptv), CHBr2Cl from −408 to 768 nmol m−2 d−1 (0.4 to 11 pptv), CHBrCl2 from −29 to 45 nmol m−2 d−1 (0.5 to 9.6 pptv), CHCl3 from −577 to 883 nmol m−2 d−1 (15 to 57 pptv), C2HCl3 from −74 to 884 nmol m−2 d−1 (0.4 to 11 pptv), methyl chloride (CH3Cl) from -5300 to 10,800 nmol m−2 d−1 (530 to 730 pptv), methyl bromide (CH3Br) from −111 to 118 nmol m−2 d−1 (7.5 to 14 pptv) and methyl iodide (CH3I) from −25 to 17 nmol m−2 d−1 (0.4 to 2.8 pptv). Taking into account statistical uncertainties, the coastal sites (particularly those where soil is mixed with salt deposits) were identified as sources of all VHOCs, but this was not statistically significant for CHCl3. Further away from the coastal area, the bare soil sites were sources for CHBrCl2, CHBr2Cl, CHCl3, and probably also for CH2Br2 and CH3I, and the agricultural sites were sources for CHBr3, CHBr2Cl and CHBrCl2. In contrast to previous reports, we also observed emissions of brominated trihalomethanes, with net molar fluxes ordered as follows: CHBr2Cl > CHCl3 > CHBr3 > CHBrCl2 and lowest positive flux incidence for CHCl3 among all trihalomethanes; this finding can be explained by the soil's enrichment with Br. Correlation analysis, in agreement with recent studies, indicated common controls for the emission of CHBr2Cl and CHBrCl2 and likely also for CHBr3. There were no indications for correlation of the brominated trihalomethanes with CHCl3. Also in line with previous reports, we observed elevated emissions of CHCl3 and C2HCl3 from mixtures of soil and different salt-deposited structures; the flux correlations between these compounds and methyl halides (particularly CH3I) suggested that at least CH3I is also emitted via similar mechanisms or is subjected to similar controls. Overall, our results indicate elevated emission of VHOCs from bare soil under semiarid conditions. Along with other recent studies, our findings point to the strong emission potential of a suite of VHOCs from saline soils and salt lakes and call for additional studies of emission rates and mechanisms of VHOCs from saline soils and salt lakes.
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Filus, Michal T., Elliot L. Atlas, Maria A. Navarro, Elena Meneguz, David Thomson, Matthew J. Ashfold, Lucy J. Carpenter, Stephen J. Andrews et Neil R. P. Harris. « Transport of short-lived halocarbons to the stratosphere over the Pacific Ocean ». Atmospheric Chemistry and Physics 20, no 2 (31 janvier 2020) : 1163–81. http://dx.doi.org/10.5194/acp-20-1163-2020.

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Abstract. The effectiveness of transport of short-lived halocarbons to the upper troposphere and lower stratosphere remains an important uncertainty in quantifying the supply of ozone-depleting substances to the stratosphere. In early 2014, a major field campaign in Guam in the western Pacific, involving UK and US research aircraft, sampled the tropical troposphere and lower stratosphere. The resulting measurements of CH3I, CHBr3 and CH2Br2 are compared here with calculations from a Lagrangian model. This methodology benefits from an updated convection scheme that improves simulation of the effect of deep convective motions on particle distribution within the tropical troposphere. We find that the observed CH3I, CHBr3 and CH2Br2 mixing ratios in the tropical tropopause layer (TTL) are consistent with those in the boundary layer when the new convection scheme is used to account for convective transport. More specifically, comparisons between modelled estimates and observations of short-lived CH3I indicate that the updated convection scheme is realistic up to the lower TTL but is less good at reproducing the small number of extreme convective events in the upper TTL. This study consolidates our understanding of the transport of short-lived halocarbons to the upper troposphere and lower stratosphere by using improved model calculations to confirm consistency between observations in the boundary layer, observations in the TTL and atmospheric transport processes. Our results support recent estimates of the contribution of short-lived bromocarbons to the stratospheric bromine budget.
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40

Mead, M. I., M. A. H. Khan, G. Nickless, B. R. Greally, D. Tainton, T. Pitman et D. E. Shallcross. « Leaf cutter ants : a possible missing source of biogenic halocarbons ». Environmental Chemistry 5, no 1 (2008) : 5. http://dx.doi.org/10.1071/en07068.

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Environmental context. With large reductions in anthropogenic emissions of many ozone-depleting gases in response to the Montreal Protocol, gases with biogenic sources have become relatively more important in recent years. The global budgets of the biogenic halocarbons are unbalanced with known sinks outweighing sources, suggesting that additional natural sources are required to balance the budgets. In the present study, an investigation has been carried out to determine the importance of leaf cutter ants as a missing source of the biogenic halocarbons, which will reduce the discrepancy of the global budget of the halocarbons. Abstract. Leaf cutter ant colonies are shown to be a potentially significant new source of biogenic halocarbons. Fungus cultivated by these ant species may emit CH3Br, CH3I, CH3Cl, CH2Cl2 and CHCl3 in significant quantities, contributing to their respective global atmospheric budgets. The study suggests that the mixing ratios of CH3Br, CH3I, CH3Cl, CH2Cl2 and CHCl3 in the ant colony under test were significantly higher than background levels, by on average a factor of 1.5–5.0. Sampling was carried out during three stages of ant colony development (new, moderately active and highly active) and it was found that levels of these halocarbons were elevated during the active phases of the ant colony life cycle. A very rough estimate of the possible emission of CH3Br, CH3I, CH3Cl, CH2Cl2 and CHCl3 from ant colonies globally are 0.50, 0.02, 0.80, 0.15 and 0.22 Gg year–1.
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41

Fiehn, Alina, Birgit Quack, Helmke Hepach, Steffen Fuhlbrügge, Susann Tegtmeier, Matthew Toohey, Elliot Atlas et Kirstin Krüger. « Delivery of halogenated very short-lived substances from the west Indian Ocean to the stratosphere during the Asian summer monsoon ». Atmospheric Chemistry and Physics 17, no 11 (8 juin 2017) : 6723–41. http://dx.doi.org/10.5194/acp-17-6723-2017.

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Abstract. Halogenated very short-lived substances (VSLSs) are naturally produced in the ocean and emitted to the atmosphere. When transported to the stratosphere, these compounds can have a significant influence on the ozone layer and climate. During a research cruise on RV Sonne in the subtropical and tropical west Indian Ocean in July and August 2014, we measured the VSLSs, methyl iodide (CH3I) and for the first time bromoform (CHBr3) and dibromomethane (CH2Br2), in surface seawater and the marine atmosphere to derive their emission strengths. Using the Lagrangian particle dispersion model FLEXPART with ERA-Interim meteorological fields, we calculated the direct contribution of observed VSLS emissions to the stratospheric halogen burden during the Asian summer monsoon. Furthermore, we compare the in situ calculations with the interannual variability of transport from a larger area of the west Indian Ocean surface to the stratosphere for July 2000–2015. We found that the west Indian Ocean is a strong source for CHBr3 (910 pmol m−2 h−1), very strong source for CH2Br2 (930 pmol m−2 h−1), and an average source for CH3I (460 pmol m−2 h−1). The atmospheric transport from the tropical west Indian Ocean surface to the stratosphere experiences two main pathways. On very short timescales, especially relevant for the shortest-lived compound CH3I (3.5 days lifetime), convection above the Indian Ocean lifts oceanic air masses and VSLSs towards the tropopause. On a longer timescale, the Asian summer monsoon circulation transports oceanic VSLSs towards India and the Bay of Bengal, where they are lifted with the monsoon convection and reach stratospheric levels in the southeastern part of the Asian monsoon anticyclone. This transport pathway is more important for the longer-lived brominated compounds (17 and 150 days lifetime for CHBr3 and CH2Br2). The entrainment of CHBr3 and CH3I from the west Indian Ocean to the stratosphere during the Asian summer monsoon is lower than from previous cruises in the tropical west Pacific Ocean during boreal autumn and early winter but higher than from the tropical Atlantic during boreal summer. In contrast, the projected CH2Br2 entrainment was very high because of the high emissions during the west Indian Ocean cruise. The 16-year July time series shows highest interannual variability for the shortest-lived CH3I and lowest for the longest-lived CH2Br2. During this time period, a small increase in VSLS entrainment from the west Indian Ocean through the Asian monsoon to the stratosphere is found. Overall, this study confirms that the subtropical and tropical west Indian Ocean is an important source region of halogenated VSLSs, especially CH2Br2, to the troposphere and stratosphere during the Asian summer monsoon.
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42

Inhester, Ludger, Kota Hanasaki, Koudai Toyota, Yajiang Hao, Oriol Vendrell, Sang-Kil Son et Robin Santra. « Molecular ionization enhancement by charge rearrangement at high X-ray intensity ». EPJ Web of Conferences 205 (2019) : 06009. http://dx.doi.org/10.1051/epjconf/201920506009.

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We simulated the multi-photon multi-ionization dynamics of an iodomethane molecule, CH3I, exposed to ultraintense and ultrashort x-ray pulses. The strong ionization causes electronic charge rearrangement in the molecule that leads to an enhanced total charge.
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43

Balerdi, G., M. E. Corrales, G. Gitzinger, J. González-Vázquez, I. R. Solá, V. Loriot, R. de Nalda et L. Bañares. « Dynamic Stark shift of the3R1Rydberg state of CH3I ». EPJ Web of Conferences 41 (2013) : 02035. http://dx.doi.org/10.1051/epjconf/20134102035.

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Kutzner, J., G. Lindeke, K. H. Welge et D. Feldmann. « Dissociative desorption from CH3I by ultraviolet‐laser radiation ». Journal of Chemical Physics 90, no 1 (janvier 1989) : 548–55. http://dx.doi.org/10.1063/1.456506.

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45

Krueger, C. W., C. A. Wang et M. Flytzani‐Stephanopoulos. « Vapor etching of GaAs and AlGaAs by CH3I ». Applied Physics Letters 60, no 12 (23 mars 1992) : 1459–61. http://dx.doi.org/10.1063/1.107270.

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Li, Ya-Min. « Quasiclassical calculation of the chemical reaction Ba+CH3I ». Molecular Physics 106, no 5 (10 mars 2008) : 717–22. http://dx.doi.org/10.1080/00268970801941809.

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Vindel-Zandbergen, Patricia, Ji Jiang, Marius Lewerenz, Christoph Meier, Manuel Barranco, Martí Pi et Nadine Halberstadt. « Impulsive alignment of 4He–CH3I : A theoretical study ». Journal of Chemical Physics 149, no 12 (28 septembre 2018) : 124301. http://dx.doi.org/10.1063/1.5048338.

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Chandler, David W., John W. Thoman, Maurice H. M. Janssen et David H. Parker. « Photofragment imaging : The 266 nm photodissociation of CH3I ». Chemical Physics Letters 156, no 2-3 (mars 1989) : 151–58. http://dx.doi.org/10.1016/s0009-2614(89)87111-8.

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Szmytkowski, Czesław, et Andrzej M. Krzysztofowicz. « Electron scattering from CH3I. Total cross section measurements ». Chemical Physics Letters 209, no 5-6 (juillet 1993) : 474–78. http://dx.doi.org/10.1016/0009-2614(93)80120-e.

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Nagesha, K., V. R. Marathe et E. Krishnakumar. « Negative ion formation from CH3I by electron impact ». International Journal of Mass Spectrometry and Ion Processes 145, no 1-2 (juillet 1995) : 89–96. http://dx.doi.org/10.1016/0168-1176(95)04170-p.

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