Artículos de revistas: "Electron spectroscopie"

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MIKI, Hideho, Tamio KAMIDATE, Hiroto WATANABE, Mamoru TAMURA y Isao YAMAZAKI. "Electron spin resonance spectroscopie method for the identification animal meats." Analytical Sciences 6, n.º 3 (1990): 459–60. http://dx.doi.org/10.2116/analsci.6.459.

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Reuther, H. "Conversion Electron Moessbauer Spectroscopie Studies on Ion Implanted Iron Layers". Isotopenpraxis Isotopes in Environmental and Health Studies 24, n.º 11-12 (enero de 1988): 419–22. http://dx.doi.org/10.1080/10256018808624018.

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Marmet, Paul y Hamid K. Nasrallah. "Spectroscopie d'électroionisation de HBr et DBr entre 11 et 25 eV". Canadian Journal of Physics 63, n.º 8 (1 de agosto de 1985): 1015–21. http://dx.doi.org/10.1139/p85-167.

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Electroionization spectra of HBr and DBr are measured and analyzed between the ionization threshold and 25 eV. Several negative-ion states having configurations (4pσ) (4pπ)4 5s2, 5p2, and 4d2, associated with Rydberg states converging to the 2Σ+ limit, have been identified. Other structures result from the excitation of the inner 4sσ electron. Finally, data on DBr are used to confirm the interpretation.

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Zhang, Ying, Dongdong Qi, Jianzhuang Jiang y Xuan Sun. "A novel photochromic and electrochromic europium tetraazaporphyrinato and phthalocyaninato heteroleptic double-decker for information storage". Journal of Porphyrins and Phthalocyanines 13, n.º 12 (diciembre de 2009): 1197–205. http://dx.doi.org/10.1142/s1088424609001558.

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A novel tetraazaporphyrinato and phthalocyaninato mixed heteroleptic double-decker sandwich rare-earth compound with photochromic and electrochromic features has been facilely synthesized by one-pot reaction using Eu(acac)3 ·n H2O , metal-free phthalocyanine H2Pc′ ( Pc′ = 2,3,9,10,16,17,23,24-octakis(decyloxy)phthalocyanine), and the photochromic precursor 1,2-dicyano-l,2-bis(2,3,5-trimethyl-3-thienyl)ethane as starting materials. The compound was well characterized by elemental analysis and various spectroscopic methods including UV-vis, IR, 1H NMR, and mass spectroscopies. The electrochemical behavior of this compound was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods, which showed up to three one-electron oxidation and four one-electron reduction processes, demonstrating an electro-active compound for high-density information storage. The photochromic performance of the compound was detected by electronic absorption spectra, suggesting the compound to be a good candidate for non-destructive readout by means of UV-vis spectroscopy.

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Menningen, K. L., M. A. Childs, H. Toyoda, L. W. Anderson y J. E. Lawler. "Evaluation of a substrate pretreatment for hot filament CVD of diamond". Journal of Materials Research 9, n.º 4 (abril de 1994): 915–20. http://dx.doi.org/10.1557/jmr.1994.0915.

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The absolute concentration of methyl radicals (CH3) and the mole fraction of acetylene (C2H2) are measured in a hot filament chemical vapor deposition (CVD) system both during and after an initial pretreatment that has been used successfully in microwave plasma and oxyacetylene torch CVD systems to produce more uniform and higher density crystal nucleation. The pretreatment technique, which consists of deposition for a relatively short time with a high input concentration of hydrocarbon in the feed gas, was studied for both methane (CH4) and C2H2 as the input hydrocarbon diluted in H2. Scanning electron micrographs of diamond films deposited under the conditions studied indicate that the pretreatment using CH4 is not effective in increasing the crystal nucleation density, but is moderately effective in increasing the crystal size. The C2H2 pretreatment has no apparent effect upon either the crystal size or nucleation density. The spectroscopie measurements suggest that the surface condition of the filament is the prominent factor affecting the gas phase chemistry both during and after the pretreatment stage.

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DEY, S. C. y S. S. NATH. "SIZE-DEPENDENT PHOTOLUMINESCENCE AND ELECTROLUMINESCENCE OF COLLOIDAL CdSe QUANTUM DOTS". International Journal of Nanoscience 12, n.º 02 (abril de 2013): 1350013. http://dx.doi.org/10.1142/s0219581x13500130.

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Here we adopt a convenient green chemical route for synthesis of CdSe quantum dots, their characterization by UV/Vis absorption spectroscopy, X-ray diffraction study and transmission electron microscopy. We carry out photoluminescence and electroluminescence spectroscopy to investigate the variation in electro-optical property with size. By UV/Vis spectroscopy, blue shift is revealed and bandgap is also calculated. X-ray diffraction spectrum reveals cubic structure and transmission electron micrographs show quantum dots of different size distributions (in the range 2–8 nm). Both the luminescence spectroscopies reveal green-orange luminescence depending upon the size distribution and indicate the possibility of using CdSe quantum dots as light emitting devices with better compatibility and faster response.

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Christopher, Joshua, Masoud Taleb, Achyut Maity, Mario Hentschel, Harald Giessen y Nahid Talebi. "Electron-driven photon sources for correlative electron-photon spectroscopy with electron microscopes". Nanophotonics 9, n.º 15 (18 de septiembre de 2020): 4381–406. http://dx.doi.org/10.1515/nanoph-2020-0263.

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AbstractElectron beams in electron microscopes are efficient probes of optical near-fields, thanks to spectroscopy tools like electron energy-loss spectroscopy and cathodoluminescence spectroscopy. Nowadays, we can acquire multitudes of information about nanophotonic systems by applying space-resolved diffraction and time-resolved spectroscopy techniques. In addition, moving electrons interacting with metallic materials and optical gratings appear as coherent sources of radiation. A swift electron traversing metallic nanostructures induces polarization density waves in the form of electronic collective excitations, i.e., the so-called plasmon polariton. Propagating plasmon polariton waves normally do not contribute to the radiation; nevertheless, they diffract from natural and engineered defects and cause radiation. Additionally, electrons can emit coherent light waves due to transition radiation, diffraction radiation, and Smith-Purcell radiation. Some of the mechanisms of radiation from electron beams have so far been employed for designing tunable radiation sources, particularly in those energy ranges not easily accessible by the state-of-the-art laser technology, such as the THz regime. Here, we review various approaches for the design of coherent electron-driven photon sources. In particular, we introduce the theory and nanofabrication techniques and discuss the possibilities for designing and realizing electron-driven photon sources for on-demand radiation beam shaping in an ultrabroadband spectral range to be able to realize ultrafast few-photon sources. We also discuss our recent attempts for generating structured light from precisely fabricated nanostructures. Our outlook for the realization of a correlative electron-photon microscope/spectroscope, which utilizes the above-mentioned radiation sources, is also described.

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SCHEIPERS, A. y H. MERZ. "CORRELATION EFFECTS IN NiO: COMPARISON OF NEAR THRESHOLD EXCITATION SPECTROSCOPIES". International Journal of Modern Physics B 07, n.º 01n03 (enero de 1993): 337–40. http://dx.doi.org/10.1142/s0217979293000706.

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At UHV-cleaved single-crystal NiO(100) surfaces core electron energy loss spectra (CEELS) at low primary energy and soft x-ray appearance potential spectra (SXAPS) have been measured at the oxygen K-threshold: the near-edge fine-structures have been investigated up to 40 eV above the threshold. Both spectroscopic methods probe in different ways the structure of the lowest empty states. CEELS is closely related to x-ray absorption spectroscopy (XAS), in both cases the excited final configuration consists of one core hole and one additional electron near the Fermi level E F. In APS we can study correlation effects very directly because the excited system consists of one core hole and two additional interacting electrons in localized resp. delocalized states near E F. The interpretation of the CEELS and SXAPS spectra at the oxygen K-edge is in agreement with a description of NiO as an intermediate valence system, where the charge-transfer gap is smaller than the Hubbard correlation energy. The comparison of our measured spectra with the experimental XAS of NiO shows the dominance of optically allowed channels in both spectroscopies.

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Shimizu, Ryuichi y Hideki Yoshikawa. "Monte Carlo Simulation of Background in electron spectroscopies". Proceedings, annual meeting, Electron Microscopy Society of America 50, n.º 2 (agosto de 1992): 1664–65. http://dx.doi.org/10.1017/s0424820100132959.

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Recent progress in getting precise knowledge on inelastic scattering, particularly, on dielectric functions for various types of material has been enabling the electron spectroscopic spectra obtained by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS) to be reproduced theoretically with considerable success. For this Monte Carlo simulation is probably most powerful tool, leading to more comprehensive understanding of not only the signal generation but also the background formation.In this paper we present a Monte Carlo simulation approach based on the uses of Mott-scattering cross section and appropriate dielectric function for describing elastic scattering and inelastic scatterings, respectively. With respect to the dielectric function one can use, to good approximation in general, the optical dielectric constants from the data base provided by synchrotron radiation facilities.As typical examples of the Monte Carlo simulation the applications to the AES, XPS, and REELS are shown in Figs. 1, 2, and 3, respectively. The N(E)-spectrum in Fig.l demonstrates how the Monte Carlo simulation describes the energy loss spectrum due to plasmon excitation near at primary energy, general shape of energy distributions of backscattered electrons and secondary electrons.

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Orosz, Gábor Tamás, György Gergely, Sándor Gurbán, Miklós Menyhard y Aleksander Jablonski. "Inelastic Mean Free Path Data for Si Corrected for Surface Excitation". Microscopy and Microanalysis 11, n.º 6 (15 de noviembre de 2005): 581–85. http://dx.doi.org/10.1017/s1431927605050713.

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Surface-sensitive electron spectroscopies, like Auger electron spectroscopy, X-ray photoelectron spectroscopy and elastic peak electron spectroscopy (EPES) are suitable techniques to investigate surfaces and thin layers. A theoretical model for electron transport is needed to process the observed electron spectra. Electron transport descriptions are based on the differential elastic cross sections for the sample atoms and the inelastic mean free path (IMFP) of backscattered electrons. An electron impinging on the sample can lose energy either due to surface or volume excitations. In the present work a Monte Carlo (MC) simulation of the elastic peak of Si, Ag, Ni, Cu, and Au for surface analysis is presented. The IMFP of Si was determined applying the EPES method. The integrated elastic peak ratio of Si with the standard metal reference samples corrected for surface excitation provided IMFP values of Si in the energy range E = 0.2–2.0 keV. Experiments were made with the ESA 31 HSA (ATOMKI) and with the DESA-100 (Staib) spectrometers. Surface correction was based on the application of Chen's model and material parameters. The Monte Carlo simulations of elastically backscattered electron trajectories were made using new EPESWIN software of Jablonski. An improvement of IMFP experimental results was achieved applying the presented procedure.

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11

Na, M. X., A. K. Mills, F. Boschini, M. Michiardi, B. Nosarzewski, R. P. Day, E. Razzoli et al. "Direct determination of mode-projected electron-phonon coupling in the time domain". Science 366, n.º 6470 (5 de diciembre de 2019): 1231–36. http://dx.doi.org/10.1126/science.aaw1662.

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Ultrafast spectroscopies have become an important tool for elucidating the microscopic description and dynamical properties of quantum materials. In particular, by tracking the dynamics of nonthermal electrons, a material’s dominant scattering processes can be revealed. Here, we present a method for extracting the electron-phonon coupling strength in the time domain, using time- and angle-resolved photoemission spectroscopy (TR-ARPES). This method is demonstrated in graphite, where we investigate the dynamics of photoinjected electrons at the K¯ point, detecting quantized energy-loss processes that correspond to the emission of strongly coupled optical phonons. We show that the observed characteristic time scale for spectral weight transfer mediated by phonon-scattering processes allows for the direct quantitative extraction of electron-phonon matrix elements for specific modes.

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Lee, Geon-Woo, Young-Bok Lee, Dong-Hyun Baek, Jung-Gon Kim y Ho-Seob Kim. "Raman Scattering Study on the Influence of E-Beam Bombardment on Si Electron Lens". Molecules 26, n.º 9 (8 de mayo de 2021): 2766. http://dx.doi.org/10.3390/molecules26092766.

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Microcolumns have a stacked structure composed of an electron emitter, electron lens (source lens), einzel lens, and a deflector manufactured using a micro electro-mechanical system process. The electrons emitted from the tungsten field emitter mostly pass through the aperture holes. However, other electrons fail to pass through because of collisions around the aperture hole. We used Raman scattering measurements and X-ray photoelectron spectroscopy analyses to investigate the influence of electron beam bombardment on a Si electron lens irradiated by acceleration voltages of 0, 20, and 30 keV. We confirmed that the crystallinity was degraded, and carbon-related contamination was detected at the surface and edge of the aperture hole of the Si electron lens after electron bombardment for 24 h. Carbon-related contamination on the surface of the Si electron lens was verified by analyzing the Raman spectra of the carbon-deposited Si substrate using DC sputtering and a carbon rod sample. We report the crystallinity and the origin of the carbon-related contamination of electron Si lenses after electron beam bombardment by non-destructive Raman scattering and XPS analysis methods.

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13

Al-Masoud, May Ahmed, Mai M. Khalaf, Fakiha El-Taib Heakal, Mohamed Gouda, Ibrahim M. A. Mohamed, Kamal Shalabi y Hany M. Abd El-Lateef. "Advanced Protective Films Based on Binary ZnO-NiO@polyaniline Nanocomposite for Acidic Chloride Steel Corrosion: An Integrated Study of Theoretical and Practical Investigations". Polymers 14, n.º 21 (4 de noviembre de 2022): 4734. http://dx.doi.org/10.3390/polym14214734.

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Due to their thermal stability characteristics, polymer/composite materials have typically been employed as corrosion inhibitors in a variety of industries, including the maritime, oil, and engineering sectors. Herein, protective films based on binary ZnO-NiO@polyaniline (ZnNiO@PANE) nanocomposite were intended with a respectable yield. The produced nanocomposite was described using a variety of spectroscopic characterization methods, including dynamic light scattering (DLS), ultraviolet–visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) approaches, in addition to other physicochemical methods, including X-ray powder diffraction (XRD), transmission Electron Microscopy (TEM), field emission scanning electron microscopy (FESEM), and selected area electron diffraction (SAED). By using open-circuit potentials (OCP) vs. time, electrochemical impedance spectroscopic (EIS), and potentiodynamic polarization (PDP) methods, the inhibitory effects of individual PANE and ZnNiO@PANE on the mild steel alloy corrosion in HCl/NaCl solution were assessed. The ZnNiO@PANE composite performed as mixed-type inhibitors, according to PDP findings. PANE polymer and ZnNiO@PANE composite at an optimal dose of 200 mg/L each produced protective abilities of 84.64% and 97.89%, respectively. The Langmuir isotherm model is used to explain the adsorption of ZnNiO@PANE onto MS alloy. DFT calculations showed that the prepared materials’ efficiency accurately reflects their ability to contribute electrons, whereas Monte Carlo (MC) simulations showed that the suitability and extent of adsorption of the ZnNiO@PANE molecule at the metal interface determine the materials’ corrosion protection process.

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14

Webster, Richard D. "Electrochemical and Spectroscopic Characterization of Oxidized Intermediate Forms of Vitamin E". Molecules 27, n.º 19 (21 de septiembre de 2022): 6194. http://dx.doi.org/10.3390/molecules27196194.

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Vitamin E, a collection of lipophilic phenolic compounds based on chroman-6-ol, has a rich and fascinating oxidative chemistry involving a range of intermediate forms, some of which are proposed to be important in its biological functions. In this review, the available electrochemical and spectroscopic data on these oxidized intermediates are summarized, along with a discussion on how their lifetimes and chemical stability are either typical of similar phenolic and chroman-6-ol derived compounds, or atypical and unique to the specific oxidized isomeric form of vitamin E. The overall electrochemical oxidation mechanism for vitamin E can be summarized as involving the loss of two-electrons and one-proton, although the electron transfer and chemical steps can be controlled to progress along different pathways to prolong the lifetimes of discreet intermediates by modifying the experimental conditions (applied electrochemical potential, aqueous or non-aqueous solvent, and pH). Depending on the environment, the electrochemical reactions can involve single electron transfer (SET), proton-coupled electron transfer (PCET), as well as homogeneous disproportionation and comproportionation steps. The intermediate species produced via chemical or electrochemical oxidation include phenolates, phenol cation radicals, phenoxyl neutral radicals, dications, diamagnetic cations (phenoxeniums) and para–quinone methides. The cation radicals of all the tocopherols are atypically long-lived compared to the cation radicals of other phenols, due to their relatively weak acidity. The diamagnetic cation derived from α–tocopherol is exceptionally long-lived compared to the diamagnetic cations from the other β–, γ– and δ–isomers of vitamin E and compared with other phenoxenium cations derived from phenolic compounds. In contrast, the lifetime of the phenoxyl radical derived from α–tocopherol, which is considered to be critical in biological reactions, is typical for what is expected for a compound with its structural features. Over longer times via hydrolysis reactions, hydroxy para–quinone hemiketals and quinones can be formed from the oxidized intermediates, which can themselves undergo reduction processes to form intermediate anion radicals and dianions. Methods for generating the oxidized intermediates by chemical, photochemical and electrochemical methods are discussed, along with a summary of how the final products vary depending on the method used for oxidation. Since the intermediates mainly only survive in solution, they are most often monitored using UV-vis spectroscopy, FTIR or Raman spectroscopies, and EPR spectroscopy, with the spectroscopic techniques sometimes combined with fast photoinitiated excitation and time-resolved spectroscopy for detection of short-lived species.

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Sahu, Sumit Ranjan, Mayanglambam Manolata Devi, Puspal Mukherjee, Pratik Sen y Krishanu Biswas. "Optical Property Characterization of Novel Graphene-X (X=Ag, Au and Cu) Nanoparticle Hybrids". Journal of Nanomaterials 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/232409.

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The present investigation reports new results on optical properties of graphene-metal nanocomposites. These composites were prepared by a solution-based chemical approach. Graphene has been prepared by thermal reduction of graphene oxide (GO) at 90°C by hydrazine hydrate in an ammoniacal medium. This ammoniacal solution acts as a solvent as well as a basic medium where agglomeration of graphene can be prevented. This graphene solution has further been used for functionalization with Ag, Au, and Cu nanoparticles (NPs). The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, UV-Vis spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to reveal the nature and type of interaction of metal nanoparticles with graphene. The results indicate distinct shift of graphene bands both in Raman and UV-Vis spectroscopies due to the presence of the metal nanoparticles. Raman spectroscopic analysis indicates blue shift of D and G bands in Raman spectra of graphene due to the presence of metal nanoparticles except for the G band of Cu-G, which undergoes red shift, reflecting the charge transfer interaction between graphene sheets and metal nanoparticles. UV-Vis spectroscopic analysis also indicates blue shift of graphene absorption peak in the hybrids. The plasmon peak position undergoes blue shift in Ag-G, whereas red shift is observed in Au-G and Cu-G.

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Reimer, L. "Electron Spectroscopic Imaging and Diffraction in TEM". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 2 (12 de agosto de 1990): 66–67. http://dx.doi.org/10.1017/s0424820100133928.

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Energy-filtering electron microscopy at 80 keV (ZEISS EM902) offers the combination of electron spectroscopic imaging (ESI) and diffraction (ESD) and electron energy-loss spectroscopy (EELS). For details the reader is referred to a description of the different modes, applications of ESI to biological and crystalline specimens and of ESD. The very important mode of elemental mapping with the difference of ESI below and beyond an edge will not be discussed in this review.The ESI mode increases scattering contrast of stained and unstained biological sections and avoids chromatic aberration by zero-loss filtering. Filtering at ΔE=250 eV below the C edge increases the (structure-sensitive) contrast by non-carbon atoms of unstained sections (Fig.1). Phase contrast is also increased but inelastically scattered electrons show a faint phase contrast which can be explained by treating partial inelastic waves with different q as incoherent. Bragg contrast of crystalline specimens is enhanced due to avoiding chromatic aberration and a blurring by the spectrum of excitation errors of inelastically scattered electrons (Fig.2).

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ATWATER, HARRY A., C. C. AHN, S. S. WONG, G. HE, H. YOSHINO y S. NIKZAD. "ENERGY-FILTERED RHEED AND REELS FOR IN SITU REAL TIME ANALYSIS DURING FILM GROWTH". Surface Review and Letters 04, n.º 03 (junio de 1997): 525–34. http://dx.doi.org/10.1142/s0218625x9700050x.

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Energy-filtered reflection high energy electron diffraction and reflection electron energy loss spectroscopy expand the usefulness of reflection high energy electron diffraction for quantitative structure determination and surface spectroscopy during film growth. Several implementations of energy-filtered reflection high energy electron diffraction are discussed, along with the progress and prospects for structure determination. New developments in parallel detection reflection electron energy loss spectroscopy (PREELS) enable the use of this method to obtain surface-spectroscopic information in real time during thin film growth, greatly expanding the range of surface information available during growth.

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Wagner, R. C. y S. C. Chen. "Ultrastructural distribution of terbium across capillary endothelium: detection by electron spectroscopic imaging and electron energy loss spectroscopy." Journal of Histochemistry & Cytochemistry 38, n.º 2 (febrero de 1990): 275–82. http://dx.doi.org/10.1177/38.2.2299181.

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We used terbium as an intravital tracer of permeability pathways across the walls of capillaries in the rete mirabile of the eel swimbladder and in frog mesentery. Terbium was detected in unstained ultra-thin sections by electron density using electron spectroscopic imaging (ESI) and by electron energy loss spectroscopy (EELS). Enhancement of intrinsic contrast in zero loss images (elastically scattered electrons) permitted imaging of membrane-bound compartments and terbium within them which might otherwise have been undetected in counterstained sections. Element-selective imaging with EELS indicated that terbium was associated with heavy electron-dense deposits, but the terbium mass:volume of sections in areas of lighter deposition was insufficient to obtain a terbium signal. In the rete capillaries, terbium was deposited on the luminal surface, throughout vesicular profiles, and in the interstitium, but could not be traced through interendothelial junctions. Fine terbium deposits were detectable throughout apparent vesicular connections across the endothelium. In the frog mesentery, terbium penetrated some but not all interendothelial clefts, and was detectable in small quantities within luminal and abluminal vesicular profiles and in the interstitium. The results indicate that in the rete capillaries, terbium permeates the capillary via a transcellular route. This route may be provided by transient fusions of luminal and abluminal vesicular compartments.

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Sulyok, A. y G. Gergely. "Electron spectroscopic studies on FeNi alloys using ionization loss spectroscopy (ILS), Auger electron spectroscopy (AES) and elastic peak electron spectroscopy (EPES)". Surface Science 213, n.º 2-3 (abril de 1989): 327–35. http://dx.doi.org/10.1016/0039-6028(89)90294-x.

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Sulyok, A. y G. Gergely. "Electron spectroscopic studies on FeNi alloys using ionization loss spectroscopy (ILS), Auger Electron Spectroscopy (AES) and Elastic Peak Electron Spectroscopy (EPES)". Surface Science Letters 213, n.º 2-3 (abril de 1989): A222. http://dx.doi.org/10.1016/0167-2584(89)90459-3.

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NAGATOMI, Takaharu y Shigeo TANUMA. "Surface Excitations in Surface Electron Spectroscopies Studied by Reflection Electron Energy-Loss Spectroscopy and Elastic Peak Electron Spectroscopy". Analytical Sciences 26, n.º 2 (2010): 165–76. http://dx.doi.org/10.2116/analsci.26.165.

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Ingrin, Jannick, Khellil Latrous, Jean-Claude Doukhan y Nicole Doukhan. "Water in diopside: an electron microscopy and infrared spectroscopy study". European Journal of Mineralogy 1, n.º 3 (27 de julio de 1989): 327–42. http://dx.doi.org/10.1127/ejm/1/3/0327.

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Joy, David C., Suichu Luo, John R. Dunlap, Dick Williams y Siqi Cao. "Stopping-power determination for compound by EELS". Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 948–49. http://dx.doi.org/10.1017/s0424820100172474.

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In Physics, Chemistry, Materials Science, Biology and Medicine, it is very important to have accurate information about the stopping power of various media for electrons, that is the average energy loss per unit pathlength due to inelastic Coulomb collisions with atomic electrons of the specimen along their trajectories. Techniques such as photoemission spectroscopy, Auger electron spectroscopy, and electron energy loss spectroscopy have been used in the measurements of electron-solid interaction. In this paper we present a comprehensive technique which combines experimental and theoretical work to determine the electron stopping power for various materials by electron energy loss spectroscopy (EELS ). As an example, we measured stopping power for Si, C, and their compound SiC. The method, results and discussion are described briefly as below.The stopping power calculation is based on the modified Bethe formula at low energy:where Neff and Ieff are the effective values of the mean ionization potential, and the number of electrons participating in the process respectively. Neff and Ieff can be obtained from the sum rule relations as we discussed before3 using the energy loss function Im(−1/ε).

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Hunt, J. A., G. Kothleitner y R. Harmon. "Comparison of STEM EELS Spectrum Imaging vs EFTEM Spectrum Imaging". Microscopy and Microanalysis 5, S2 (agosto de 1999): 616–17. http://dx.doi.org/10.1017/s1431927600016408.

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Electron energy-loss spectroscopy (EELS) in the transmission electron microscope (TEM) analyzes the energy distribution of the probe electrons after they have lost energy within the sample. The resultant energy-losses are characteristic of elemental, chemical, and dielectric properties and are typically measured in one of two ways. Parallel-detection EELS spectrometers (PEELS) acquire large energy ranges of the energy-loss spectrum simultaneously for rapid acquisition of spectral data at a single area. In contrast, the energy filtering TEM (EFTEM) acquires only a single energy band at once, but does so for thousands or even millions of image pixels simultaneously.Spectrum imaging (SI) involves acquisition of detailed spectroscopic data sufficient for rigorous analysis at each pixel in a digital image. (Fig. la) A STEM EELS spectrum image “data cube” can be acquired by stepping a focused electron probe to each pixel and filling the spectrum image one spectrum at a time.

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Hu, Kaiyue, Luigi Brambilla, Patrizia Sartori, Claudia Moscheni, Cristiana Perrotta, Lucia Zema, Chiara Bertarelli y Chiara Castiglioni. "Development of Tailored Graphene Nanoparticles: Preparation, Sorting and Structure Assessment by Complementary Techniques". Molecules 28, n.º 2 (5 de enero de 2023): 565. http://dx.doi.org/10.3390/molecules28020565.

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We present a thorough structural characterization of Graphene Nano Particles (GNPs) prepared by means of physical procedures, i.e., ball milling and ultra-sonication of high-purity synthetic graphite. UV-vis absorption/extinction spectroscopy, Dynamic Light Scattering, Transmission Electron Microscopy, IR and Raman spectroscopies were performed. Particles with small size were obtained, with an average lateral size <L> = 70–120 nm, formed by few <N> = 1–10 stacked layers, and with a small number of carboxylic groups on the edges. GNPs relatively more functionalized were separated by centrifugation, which formed stable water dispersions without the need for any surfactant. A critical reading and unified interpretation of a wide set of spectroscopic data was provided, which demonstrated the potential of Specular Reflectance Infrared Spectroscopy for the diagnosis and quantification of chemical functionalization of GNPs. Raman parameters commonly adopted for the characterization of graphitic materials do not always follow a monotonic trend, e.g., with the particle size and shape, thus unveiling some limitations of the available spectroscopic metrics. This issue was overcome thanks to a comparative spectra analysis, including spectra deconvolution by means of curve fitting procedures, experiments on reference materials and the exploitation of complementary characterization techniques.

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Wu, Kejun, Pankaj Koinkar y Akihiro Furube. "Preparation of WS2–TiO2–Au using hydrothermal synthesis for photocatalysis under visible light". International Journal of Modern Physics B 35, n.º 14n16 (19 de junio de 2021): 2140046. http://dx.doi.org/10.1142/s0217979221400464.

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In this study, the preparation of ternary photocatalyst using a simple hydrothermal method is shown with high performance. A ternary composite consisting of tungsten sulfide (WS[Formula: see text] nanosheets, titanium oxide (TiO[Formula: see text] and gold (Au) nanoparticles is used to the extend the visible-light absorption region of TiO2. The morphological and spectroscopic natures of the prepared sample were analyzed using scanning electron microscopy (SEM), Raman spectroscopy and ultraviolet–visible (UV–vis) photospectroscopy. The photocatalysis measurement for photodegradation of methylene blue dye was performed under the visible light. The photocatalytic studies suggest that in the ternary composite, consisting of three materials with different energy levels, the electrons excited form a cycle to lower the probability for the recombination of electron–hole pairs enhancing the property of photocatalytic activity of TiO2.

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Taha, Amel y Hanaa A. Hassanin. "Facile Green Synthesis of Ni(OH)2@Mn3O4 Cactus-Type Nanocomposite: Characterization and Cytotoxicity Properties". Molecules 27, n.º 24 (8 de diciembre de 2022): 8703. http://dx.doi.org/10.3390/molecules27248703.

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In the present work, the facile eco-friendly synthesis and evaluation of the anti-tumor activity of Ni(OH)2@Mn3O4 nanocomposite were carried out. The synthesis of Ni(OH)2@Mn3O4 nanocomposite from chia-seed extract was mediated by sonication. The obtained materials were characterized by different spectroscopic techniques such as transmission electron microscopy (TEM), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis), and Fourier transform infrared (FT-IR) spectroscopies. The results of XRD, SEM, EDS, TEM, FT-IR, and UV-Vis analysis indicate the successful manufacturing of a crystalline, cactus-type Ni(OH)2@Mn3O4 nanocomposite of 10.10 nm average particle size. XPS analysis confirms that the synthesized materials consist mainly of Ni2+, Mn2+, and Mn3+. The antitumor activity of the nanocomposite was tested against a breast cancer (MCF-7) cell line. The results showed Ni(OH)2@Mn3O4 nanocomposite possesses insignificant cytotoxicity. The cell-death percentage was 34% at a 100 ppm concentration of Ni(OH)2@Mn3O4 nanocomposite. The obtained results imply that the synthesized nanocomposite could be suitable and safe for drug delivery and water treatment.

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Sharma, Shubham, Swarna Jaiswal, Brendan Duffy y Amit Jaiswal. "Nanostructured Materials for Food Applications: Spectroscopy, Microscopy and Physical Properties". Bioengineering 6, n.º 1 (19 de marzo de 2019): 26. http://dx.doi.org/10.3390/bioengineering6010026.

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Nanotechnology deals with matter of atomic or molecular scale. Other factors that define the character of a nanoparticle are its physical and chemical properties, such as surface area, surface charge, hydrophobicity of the surface, thermal stability of the nanoparticle and its antimicrobial activity. A nanoparticle is usually characterized by using microscopic and spectroscopic techniques. Microscopic techniques are used to characterise the size, shape and location of the nanoparticle by producing an image of the individual nanoparticle. Several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy/high resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM) and scanning tunnelling microscopy (STM) have been developed to observe and characterise the surface and structural properties of nanostructured material. Spectroscopic techniques are used to study the interaction of a nanoparticle with electromagnetic radiations as the function of wavelength, such as Raman spectroscopy, UV–Visible spectroscopy, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), dynamic light scattering spectroscopy (DLS), Zeta potential spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray photon correlation spectroscopy. Nanostructured materials have a wide application in the food industry as nanofood, nano-encapsulated probiotics, edible nano-coatings and in active and smart packaging.

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Ray, Sekhar C. y W. F. Pong. "Possible Ferro-electro-magnetic performance of “reduced graphene oxide” deposited on “ZnO-nanorod (NR) decorated with nanocrystalline (nc) Au particles”". AIP Advances 12, n.º 5 (1 de mayo de 2022): 055008. http://dx.doi.org/10.1063/5.0091852.

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Possible ferro-electromagnetic performance of “ reduced graphene oxide ( r-GO)” deposited on the surface of “ ZnO-nanorod ( NR) decorated with nanocrystalline ( nc) Au particles” is studied using different spectroscopies and magnetic measurements. The presence of carbon/zinc-interstitials (Zn i), nc-Au, and oxygen vacancies are established through electronic property studies using different spectroscopic measurements. The magnetic moment (M) applied magnetic field (H) curve and electrical measurement current (I)–voltage (V) loops show that nc-Au/ZnO-NRs:r-GO is ferromagnetic and partial ferroelectric, respectively. The work functions are obtained from the lower kinetic energy of ultraviolet photoelectron spectroscopy, which is correlated with the enhancement of ferro-electro-magnetic performance. Both ferroelectric and ferromagnetic performance of nc-Au/ZnO-NRs:r-GO nanocomposite material could be useful for ferro-electro-magnetic technological applications.

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30

Xiao Changtao, 肖常涛, 宋寅 Song Yin y 赵维谦 Zhao Weiqian. "超快二维电子光谱（特邀）". Laser & Optoelectronics Progress 61, n.º 1 (2024): 0130002. http://dx.doi.org/10.3788/lop232753.

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31

Caciuffo, R., E. C. Buck, D. L. Clark y G. van der Laan. "Spectroscopic characterization of actinide materials". MRS Bulletin 35, n.º 11 (noviembre de 2010): 889–95. http://dx.doi.org/10.1557/mrs2010.716.

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Advanced spectroscopic techniques provide new and unique tools for unraveling the nature of the electronic structure of actinide materials. Inelastic neutron scattering experiments, which address temporal aspects of lattice and magnetic fluctuations, probe electromagnetic multipole interactions and the coupling between electronic and vibrational degrees of freedom. Nuclear magnetic resonance clearly demonstrates different magnetic ground states at low temperature. Photoemission spectroscopy provides information on the occupied part of the electronic density of states and has been used to investigate the momentum-resolved electronic structure and the topology of the Fermi surface in a variety of actinide compounds. Furthermore, x-ray absorption and electron energy-loss spectroscopy have been used to probe the relativistic nature, occupation number, and degree of localization of 5f electrons across the actinide series. More recently, element- and edge-specific resonant and non-resonant inelastic x-ray scattering experiments have provided the opportunity of measuring elementary electronic excitations with higher resolution than traditional absorption techniques. Here, we will discuss results from these spectroscopic techniques and what they tell us of the electronic and magnetic properties of selected actinide materials.

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32

Hembree, Gary G., Frank C. H. Luo y John A. Venables. "Auger electron spectroscopy and microscopy in STEM". Proceedings, annual meeting, Electron Microscopy Society of America 49 (agosto de 1991): 464–65. http://dx.doi.org/10.1017/s0424820100086623.

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Spatial resolution in Auger electron spectroscopy (AES) is primarily a function of the excitation beam current distribution. For highest resolution the question of how to produce such a small probe of electrons is coupled with how to extract the secondary electrons efficiently from the sample. Kniit and Venables have shown the optimum configuration for highest resolution AES is a combination of a magnetic immersion lens, additional solenoids (“parallelizers“) to shape the weak magnetic field in the low energy electron transport region and a concentric hemispherical analyzer (CHA) to disperse and detect the secondary electrons. This combination has been incorporated into a new ultra-high vacuum STEM at ASU, along with the low energy electron optics required to interface the magnetic collection system with the CHA.

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33

Reimer, L., R. Rennekamp y A. Bakenfelder. "Electron spectroscopic imaging of thick crystalline specimens". Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 de agosto de 1989): 412–13. http://dx.doi.org/10.1017/s0424820100154032.

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Electron spectroscopic imaging (ESI) by an energy-filtering electron microscope (EFEM, Zeiss EM902) shows the following advantages when compared with the unfiltered bright-field mode:1.The zero-loss image does not contain the contribution of inelastically scattered electrons. Though plasmon scattering shows a conversation of Bragg contrast - edge and bent contours and lattice defect images -, the angular distribution of inelastically scattered electrons results in a broader spectrum of excitation errors and a blurring of Bragg contrast.2.The zero-loss image avoids the chromatic aberration of inelastically scattered electrons for medium specimen thicknesses and can be applied so long as the intensity of the zero-loss peak in the electron energy-loss spectrum (EELS) is high enough for an exposure in a reasonable time (<100 s).3.Thick specimens with negligible zero-loss intensity can be imaged with an energy window at the highest multiple plasmon loss of the Poisson distribution or at the most probable energy of a Landau distribution. The angular distribution of electrons with these energy losses is so broad that the Bragg contrast is blurred, and the contrast is only caused by anomalous absorption effects similar to multi-beam images in the STEM mode when using a large probe aperture.

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34

Mayer, J. "Electron spectroscopic imaging and diffraction: applications II materials science". Proceedings, annual meeting, Electron Microscopy Society of America 50, n.º 2 (agosto de 1992): 1198–99. http://dx.doi.org/10.1017/s0424820100130626.

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With imaging energy filters becoming commercially available in transmission electron microscopy many of the limitations of conventional TEM instruments can be overcome. Energy filtered images of diffraction patterns can now be recorded without scanning using efficient parallel (2-dimensional detection. We have evaluated a prototype of the Zeiss EM 912 Omega, the first commercially available electron microscope with integrated imaging Omega energy filter. Combining the capabilities of the imaging spectrometer with the principal operation modes of a TEM gives access to many new qualitative and quantitative techniques in electron microscopy. The basis for all of them is that the filter selecte electrons within a certain energy loss range ΔE1 <ΔE < ΔE2 and images their contribution to an image (electron spectroscopic imaging, ESI) or a diffraction pattern (electron spectroscopic diffraction, ESD) In many applications the filter is only used to remove the inelastically scattered electrons (elastic or zero loss filtering). Furthermore, the electron energy loss spectrum can be magnified and recorded with serial or parallel detection.

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35

Cantow, H. J., M. Kunz y M. Möller. "Electron spectroscopic imaging (ESI) on multiphase polymer materials". Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 de agosto de 1989): 348–49. http://dx.doi.org/10.1017/s0424820100153713.

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In transmission electron microscopy the natural contrast of polymers is very low. Thus the contrast has to be enhanced by staining with heavy metals. The resolution is limited by the size of the staining particles and by the fact that electrons with different energy are focused in different image planes due to the chromatic aberration of the magnetic lenses. The integration of an electron energy loss spectrometer into the optical coloumn of a transmission electron microscope offers the possibility to use monoenergetic electrons and to select electrons with a certain energy for imaging. Thus contrast and resolution are enhanced. By imaging only electrons with an element specific energy loss the element distribution in the sample can be obtained. In addition, elastic bright field images and diffraction patterns yield excellent resolution. Some applications of the method on multicomponent polymer materials are discussed.Bulk polymer samples were prepared by ultramicrotoming at room temperature or well below the glass transition temperature. Very thin films for the direct observation of the structure in semicrystalline polymers were obtained by melt-spinning. Specimens were examined with a ZEISS CEM 902 operated at 80 kV.

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36

Tampieri, Francesco, Matteo Tommasini, Stefano Agnoli, Marco Favaro y Antonio Barbon. "N-Doped Graphene Oxide Nanoparticles Studied by EPR". Applied Magnetic Resonance 51, n.º 11 (25 de octubre de 2020): 1481–95. http://dx.doi.org/10.1007/s00723-020-01276-0.

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AbstractGraphene-derived materials attract a great deal of attention because of the peculiar properties that make them suitable for a wide range of applications. Among such materials, nano-sized systems show very interesting behaviour and high reactivity. Often such materials have unpaired electrons that make them suitable for electron paramagnetic resonance (EPR) spectroscopy. In this work we study by continuous wave and pulse EPR spectroscopy undoped and nitrogen-doped graphene quantum dots (GQD) with a size of about 2 nm. The analysis of the spectra allows identifying different types of paramagnetic centers related to electrons localized on large graphenic flakes and molecular-like radicals. By hyperfine spectroscopies on nitrogen-doped samples, we determine the hyperfine coupling constant of paramagnetic centers (limited-size π-delocalized unpaired electrons) with dopant nitrogen atoms. The comparison of the experimental data with models obtained by density functional theory (DFT) calculations supports the interpretation of doping as due to the insertion of nitrogen atoms in the graphene lattice. The dimension of the delocalized regions in the flakes observed by pulse EPR is of about 20–25 carbon atoms; the nitrogen dopant can be classified as pyridinic or graphitic.

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37

Hunt, J. A. y R. H. Harmon. "EFTEM and STEM EELS Spectrum Imaging". Microscopy and Microanalysis 4, S2 (julio de 1998): 152–53. http://dx.doi.org/10.1017/s1431927600020882.

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Electron energy-loss spectroscopy (EELS) in the transmission electron microscope (TEM) is a powerful technique that analyzes the inelastic scattering distribution of the fast TEM electrons after they have lost energy within the sample. The resultant energy-losses are characteristic of elemental, chemical, and dielectric properties and are typically measured in one of two ways. Parallel-detection EELS spectrometers (PEELS) acquire spectral data over a large range of energy-loss simultaneously for rapid acquisition of spectral data at a single point. In contrast, the energy filtering TEM (EFTEM) acquires only a single energy band at once, but does so for thousands or even millions of image pixels simultaneously.Spectrum-imaging concerns the acquisition of spectroscopic data of sufficient detail for rigorous analysis at each pixel in a digital image. (Fig. 1) A STEM EELS spectrum image “data cube” can be acquired by stepping a focused electron probe to each pixel and filling the spectrum image one spectrum at a time.

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38

Alexander, Jessica A., Frank J. Scheltens, Lawrence F. Drummy, Michael F. Durstock, James B. Gilchrist, Sandrine E. M. Heutz y David W. McComb. "Variable Angle Spectroscopic Ellipsometry and Electron Energy-Loss Spectroscopy". Microscopy and Microanalysis 21, S3 (agosto de 2015): 1471–72. http://dx.doi.org/10.1017/s1431927615008132.

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39

Iwami, M., Y. Watanabe, H. Kato, M. Nakayama y N. Sano. "Structure of GaAs-In0.2Ga0.8As heterojunction interface studied by electron spectroscopies: X-ray photoelectron spectroscopy, tunable electron energy loss spectroscopy and Auger electron spectroscopy". Thin Solid Films 146, n.º 3 (febrero de 1987): 291–97. http://dx.doi.org/10.1016/0040-6090(87)90436-6.

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40

Venables, J. A., G. G. Hembree y C. J. Harland. "Electron spectroscopy in SEM and STEM". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 2 (12 de agosto de 1990): 378–79. http://dx.doi.org/10.1017/s0424820100135496.

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Low energy electrons, in the energy range 0-2 keV, are very useful in surface science. Both secondary (0-100 eV nominally) and Auger (50-2 keV) electrons can be used as analytic signals in ultra-high vacuum (UHV) scanning (SEM) and scanning transmission (STEM) electron microscopes. This paper briefly reviews some ongoing projects, which are aimed at improving the spatial resolution and information content of these signals.Both secondary electron imaging (SEI) and Auger electrons spectroscopy (AES) have a long history. Reviews of AES and its microscopic counterpart scanning Auger microscopy (SAM) have been given previously in this International Conference Series; over the intervening period AES/SAM instruments have become widely available commercially. Simply biassing the sample up to a few hundred volts (-ve) has lead to a new technique (biassed-SEI) which is sensitive at the sub-monolayer level. In general biassing the sample is a useful additional experimental variable. It can be used to visualize thin films and surface topography, including steps; it can also be used to distinguish spectral features (eg Auger peaks) from the sample from those due to stray electrons, and to place such features in the best energy region for the electron spectrometer.

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41

Bruley, John. "ELNES: An Electron Spectroscopic Tool to Study Complex Microstructures". Microscopy Today 2, n.º 1 (febrero de 1994): 19–20. http://dx.doi.org/10.1017/s155192950006212x.

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The presence of internal boundaries can significantly influence many important properties of materials, such as fracture toughness, creep, electrical conductivity and magnetic behavior. Interfacial structure, chemical composition and bonding, on a nanometer length scale, are often controlling and sought after factors influencing these properties. An electron spectroscopic technique, known as energy-loss near edge structure (ELNES) analysis, can be utilized to probe compositional and bonding variations with a spatial resolution less than 1 nm and is therefore well suited to this endeavor.When a fast electron passes through a material in an electron microscope, it collides with the electrons bound to the atoms in that sample. As a result, the fast electron often gives up a small fraction of its kinetic energy to the bound electrons. The laws of quantum mechanics dictate that these so-called inelastic scattering events will only take place if the bound electron can gain enough energy to enter an empty energy level.

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42

Ji, Zhurun, Rucheng Dai y Zengming Zhang. "Characterization of fine particulate matter in ambient air by combining TEM and multiple spectroscopic techniques – NMR, FTIR and Raman spectroscopy". Environmental Science: Processes & Impacts 17, n.º 3 (2015): 552–60. http://dx.doi.org/10.1039/c4em00678j.

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We report a study of the microstructures and spectroscopic characteristics of PM_2.5and its potential sources in Beijing by combining transmission electron microscopy and multiple spectroscopic techniques: nuclear magnetic resonance, Fourier transform infrared and Raman spectroscopy.

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43

Barckhaus, R. H., I. Fromm, H. J. Höhling y L. Reimer. "Advantage of Electron Spectroscopic Diffraction on Calcified Tissue Sections". Proceedings, annual meeting, Electron Microscopy Society of America 48, n.º 2 (12 de agosto de 1990): 362–63. http://dx.doi.org/10.1017/s0424820100135411.

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Different stages in the mineralization of calcified tissues can be investigated by electron diffraction. A disadvantage is the strong background below the Debye—Scherrer rings caused by the large massthickness of calcified products and the high ratio (≃ 3) of the inelastic—to—elastic scattering cross—sections of the embedding material. Therefore, a large fraction of the background consists of inelastically scattered electrons with energy losses. The electron spectroscopic diffraction (ESD) mode of an energy—filtering microscope (ZEISS EM902) allows to record diffraction patterns using only the zero—loss electrons which consist of the primary beam, Bragg diffracted electrons and a smaller fraction of elastically scattered electrons between the Debye—Scherrer rings by thermal—diffuse scattering. Small—area diffraction patterns with different camera lengths are generated at the filter—entrance plane and the zero—loss electrons are selected by a slit in the energy—dispersive plane behind the Castaing—Henry filter lens.

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44

Yamada, Kiyotaka, Junji Ikeda y Giuseppe Pezzotti. "Development of Piezo-Spectroscopic Techniques for Nano-Scale Stress Analysis in the Scanning Electron Microscope of Zirconia Bioceramics Based on Rare-Earth Fluorescence". Key Engineering Materials 309-311 (mayo de 2006): 1215–18. http://dx.doi.org/10.4028/www.scientific.net/kem.309-311.1215.

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The electro-stimulated luminescence spectrum of a rare-earth ion added to zirconia (ZrO2) lattice was investigated with the aim of using it as a sensor for nano-scale stress (fluorescence piezo-spectroscopy) and phase transformation assessments in a field emission scanning electron microscope (FE-SEM). In this paper, the selected rare-earth fluorescent ion Eu, added to ZrO2 as a raw oxide powder (Eu2O3) before sintering (in the amount of 1.0 wt. %). Spectroscopic results indicated that the spectral shift of some fluorescent band of the selected rare-earth ion was sensitive to residual stress and that the electron-stimulated spectra of Eu2O3-doped ZrO2 in its tetragonal and monoclinic polymorphs were different to each other. Based on these findings, the luminescent substance can be useful as a “stress and phase transformation sensor”, in order to clarify the elementary mechanisms behind synthetic ZrO2.

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45

Siangchaew, K. y M. Libera. "Effects of Fast Secondary Electrons on Spatiallyresolved Low-Loss Eels of Polystyrene". Microscopy and Microanalysis 4, S2 (julio de 1998): 804–5. http://dx.doi.org/10.1017/s1431927600024144.

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A good understanding of the effect of electron irradiation on polymers is necessary in order to optimally utilize the spectroscopic information and resolution of spatially-resolved electron energy-loss spectroscopy (EELS). This investigation studies the effect of electron irradiation on the low-loss spectroscopic signal and spatial resolution obtainable from polystyrene (PS) homopolymer. Because of the conjugated valence electron distribution associated with its pendant phenyl ring, polystyrene is relatively stable under electron irradiation and has well characterized spectroscopic fingerprints including a notable π—π* transition circa 7eV (1). In addition, polystyrene is used as a positive photoresist because it can cross-link effectively when exposed to an electron irradiation (2).The critical dose characterizing degradation of aromatic polymers is of the order 1-10 C/cm2 (3). In practice, the dose delivered to a specimen is determined both by electron probe size and probe current.

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46

Delledonne, Chiara, Michela Albano, Tommaso Rovetta, Gianmarco Borghi, Mario Gentile, Anna Denia Marvelli, Piero Mezzabotta et al. "Rediscovering the Painting Technique of the 15th Century Panel Painting Depicting the Coronation of the Virgin by Michele di Matteo". Heritage 7, n.º 1 (10 de enero de 2024): 324–37. http://dx.doi.org/10.3390/heritage7010016.

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The study concerned a diagnostic spectroscopic campaign carried out on the panel painting depicting the Coronation of the Virgin (first half of the 15th century) by the late-Gothic Italian painter Michele di Matteo. The main aims were the identification of the original painting materials and the characterization of the painter’s artistic technique. A combined approach based on non- and micro-invasive techniques was employed. Visible and ultraviolet-induced fluorescence photography was used to select the areas of interest for spectroscopic analyses; X-ray radiography assessed the state of conservation of the support, while X-ray fluorescence and external reflection Fourier transform infrared spectroscopies allowed the chemical identification of pigments, binders, and varnishes. Attenuated total reflection infrared spectroscopy, optical microscopy, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy were used to visualize and characterize the materials in the pictorial layers. The results highlighted the presence of pigments, possibly applied with an egg binder, consistent with the period of the production of the painting, as well as modern pigments used during subsequent restorations: an imprimitura with lead white and a gypsum-based ground layer. Concerning the gilding, the guazzo technique was confirmed by identifying a red bolo substrate and gold leaf.

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47

Silveira, Célia M., Lidia Zuccarello, Catarina Barbosa, Giorgio Caserta, Ingo Zebger, Peter Hildebrandt y Smilja Todorovic. "Molecular Details on Multiple Cofactor Containing Redox Metalloproteins Revealed by Infrared and Resonance Raman Spectroscopies". Molecules 26, n.º 16 (11 de agosto de 2021): 4852. http://dx.doi.org/10.3390/molecules26164852.

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Vibrational spectroscopy and in particular, resonance Raman (RR) spectroscopy, can provide molecular details on metalloproteins containing multiple cofactors, which are often challenging for other spectroscopies. Due to distinct spectroscopic fingerprints, RR spectroscopy has a unique capacity to monitor simultaneously and independently different metal cofactors that can have particular roles in metalloproteins. These include e.g., (i) different types of hemes, for instance hemes c, a and a3 in caa3-type oxygen reductases, (ii) distinct spin populations, such as electron transfer (ET) low-spin (LS) and catalytic high-spin (HS) hemes in nitrite reductases, (iii) different types of Fe-S clusters, such as 3Fe-4S and 4Fe-4S centers in di-cluster ferredoxins, and (iv) bi-metallic center and ET Fe-S clusters in hydrogenases. IR spectroscopy can provide unmatched molecular details on specific enzymes like hydrogenases that possess catalytic centers coordinated by CO and CN− ligands, which exhibit spectrally well separated IR bands. This article reviews the work on metalloproteins for which vibrational spectroscopy has ensured advances in understanding structural and mechanistic properties, including multiple heme-containing proteins, such as nitrite reductases that house a notable total of 28 hemes in a functional unit, respiratory chain complexes, and hydrogenases that carry out the most fundamental functions in cells.

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48

Timofeev, Ivan O., Larisa V. Politanskaya, Evgeny V. Tretyakov, Yuliya F. Polienko, Victor M. Tormyshev, Elena G. Bagryanskaya, Olesya A. Krumkacheva y Matvey V. Fedin. "Fullerene-based triplet spin labels: methodology aspects for pulsed dipolar EPR spectroscopy". Physical Chemistry Chemical Physics 24, n.º 7 (2022): 4475–84. http://dx.doi.org/10.1039/d1cp05545c.

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49

Hussain, Ali A.-K. "Spectroscopic analysis of magnesium-aluminum alloys by laser induced breakdown spectroscopy". Iraqi Journal of Physics (IJP) 16, n.º 36 (1 de octubre de 2018): 113–22. http://dx.doi.org/10.30723/ijp.v16i36.36.

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In this work, the spectra of plasma glow produced by Nd:YAG laser operated at 1.064 μm on Al-Mg alloys with same molar ratio samples in air were analyzed by comparing the atomic lines of aluminum and magnesium with that of strong standard lines. The effect of laser energies on spectral lines, produced by laser ablation, were investigated using optical spectroscopy, the electron density was measured utilizing the Stark broadening of magnesium-aluminum lines and the electron temperature was calculated from the standard Boltzmann plot method. The results that show the electron temperature increases in magnesium and aluminum targets but decreases in magnesium: aluminum alloy target, also show the electron density increase all the aluminum, magnesium and mix both them, It was found that the lines intensities at different laser peak powers increase when the laser peak power increases then decreases when the power continues to increase.

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50

Hlava, Paul F. y William F. Chambers. "Electron microprobe analysis: The upper limit of submicron spectroscopy". Proceedings, annual meeting, Electron Microscopy Society of America 44 (agosto de 1986): 744–47. http://dx.doi.org/10.1017/s0424820100145091.

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In the electron microprobe, a beam of high energy electrons is focussed to a fine point on the surface of a fairly thick specimen and the x rays produced are analyzed to determine the chemistry of the "point". The spa- cial resolution of this instrument for chemical analysis, then, is defined by the volume of material from which the x ray signal originates. This, in turn, is related to factors such as the diameter of the electron beam, the spreading of the electron beam as it penetrates into the sample and interacts with the atoms of the sample to generate x rays, and the extent to which these primary x rays penetrate beyond the region of electron beam interaction and generate secondary x rays by the process of fluorescence. Beam voltage, current, and diameter can all be easily controlled by the analyst. Once the electrons enter the specimen, however, the analyst loses control of their density. Each individual electron follows a unique, erratic path as it passes near, passes through, or collides with parts of the atoms in the specimen. Monte Carlo calculations are a means by which many investigators have tried to model the paths of individual electrons and the interation volume that large numbers of such electrons define.3 “* It is well known that the size and shape of the region into which the electron beam penetrates and expends its energy is controlled primarily by the average atomic number, atomic weight, and density of the specimen in the region of interest and the beam voltage.

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