Search results for "ELECTRONS"
showing 10 items of 1325 documents
Enhanced orbital magnetic moments in the Heusler compounds ,,
2004
Abstract Using the magnetic circular dichroism in X-ray absorption at the L2,3-edges of the 3d-transition metals, we determined the element specific ratio between orbital and spin magnetic moment of the Heusler compounds Co 2 CrAl , Co 2 Cr 0.6 Fe 0.4 Al and Co2FeAl. The orbital magnetic moment per spin is large (0.1–0.2) compared to bulk values of Fe and Co metals.
Local Berry curvature signatures in dichroic angle-resolved photoelectron spectroscopy from two-dimensional materials
2020
Orbital polarization and Berry curvature signatures are mapped out by circular dichroism in angle-resolved photoemission.
From attraction to repulsion : anion–π interactions between bromide and fluorinated phenyl groups
2011
Anion–π interactions in crystals of fluorobenzyl ammonium salts depend on the degree of fluorination at the aromatics.
Detection of mitochondrial electron chain carrier redox status by transhepatic light intensity during rat liver reperfusion.
2003
The aim of the study was to investigate mitochondrial electron transfer during rat liver reperfusion after cold storage and hypothermic machine perfusion. Livers from male Brown Norway rats were preserved (UW) for 10h either by cold storage (CS) or by hypothermic oxygenated perfusion extracorporal (HOPE). Transhepatic photometric analysis allowed determination of the redox status of mitochondrial cytochromes during preservation, rewarming and reperfusion. Mitochondrial electron chain carriers were inhibited at different sites with rotenone and cyanide in some experiments. reversed transcriptional polymerase chain reaction (RT-PCR) was performed after reperfusion concerning transcription of …
Intramolecular electronic excitation energy transfer in donor∕acceptor dyads studied by time and frequency resolved single molecule spectroscopy
2008
Electronic excitation energy transfer has been studied by single molecule spectroscopy in donor/acceptor dyads composed of a perylenediimide donor and a terrylenediimide acceptor linked by oligo(phenylene) bridges of two different lengths. For the shorter bridge (three phenylene units) energy is transferred almost quantitatively from the donor to the acceptor, while for the longer bridge (seven phenylene units) energy transfer is less efficient as indicated by the occurrence of donor and acceptor emission. To determine energy transfer rates and efficiencies at the single molecule level, several methods have been employed. These comprise time-correlated single photon counting techniques at r…
Use of electron spectroscopic imaging to determine element composition of the melanin granules in the stria vascularis of the guinea pig.
1998
Electron spectroscopic imaging (ESI) was used to analyze the element content of melanin granules in the stria vascularis seen in ultrathin sections of Spurr-embedded cochleae of the guinea pig. To determine element composition, ESI images were taken at different ionization edges, and non-specific background signals were subtracted digitally by an image processing system. The presence of calcium and nitrogen in the melanin granules could be demonstrated clearly. The calcium identified in the melanin granules was then compared with the spatial distributions of calcium binding sites after the application of an antimonate precipitation method, which was used to localize loosely bound calcium. D…
Masstodon : a tool for assigning peaks and modeling electron transfer reactions in top-down mass spectrometry
2019
Abstract: Top-down mass spectrometry methods are becoming continuously more popular in the effort to describe the proteome. They rely on the fragmentation of intact protein ions inside the mass spectrometer. Among the existing fragmentation methods, electron transfer dissociation is known for its precision and wide coverage of different cleavage sites. However, several side reactions can occur under electron transfer dissociation (ETD) conditions, including nondissociative electron transfer and proton transfer reaction. Evaluating their extent can provide more insight into reaction kinetics as well as instrument operation. Furthermore, preferential formation of certain reaction products can…
Microheterogeneous electrocatalytic chiral recognition at monoclinic vanadium-doped zirconias: enantioselective detection of glucose.
2007
Synthetic tetragonal and monoclinic vanadium-doped zirconias (t- and m-VxZr1-xO2, 0.005x0.150) exert an effective catalytic effect toward the electrochemical oxidation of glucose in aqueous alkaline media. The catalytic effect of monoclinic specimens attached to carbon and fluorine-doped tin oxide electrodes exhibits a remarkable enantioselectivity, so that catalytic currents for the oxidation of L-glucose at +0.92 V vs AgCl/Ag are considerably larger than those obtained for the oxidation of D-glucose. This enantioselectivity can be associated with the existence of a noncentrosymmetric coordination of vanadium centers in the monoclinic crystalline form of zirconia. From the electrochemical …
Rational enantioselective design of chiral heterobimetallic single-chain magnets: synthesis, crystal structures and magnetic properties of oxamato-br…
2011
A new series of neutral oxamato-bridged M(II)Cu(II) chiral chains of general formula [MCuL(x)(S)(m)(H(2)O)(n)]·aS·bH(2)O [L(1)=(M)-1,1'-binaphthalene-2,2'-bis(oxamate) with M=Mn (1a) and Co (1b); L(2)=(P)-1,1'-binaphthalene-2,2'-bis(oxamate) with M=Mn (2a) and Co (2b)] and the analogous racemic chains of formula [MCuL(3)(S)(m)(H(2)O)(n)]·aS·bH(2)O [L(3)=1,1'-binaphthalene-2,2'-bis(oxamate) with M=Mn (3a) and Co (3b)] have been prepared by reaction of the corresponding dianionic oxamatocopper(II) complex [Cu(L(x))](2-) with Mn(2+) or Co(2+) cations in either dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). Solid circular dichroism (CD) spectra of the bimetallic chain compounds were reco…
Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
2017
High energy cosmic ray electrons plus positrons (CREs), which lose energy quickly during their propagation, provide an ideal probe of Galactic high-energy processes and may enable the observation of phenomena such as dark-matter particle annihilation or decay. The CRE spectrum has been directly measured up to $\sim 2$ TeV in previous balloon- or space-borne experiments, and indirectly up to $\sim 5$ TeV by ground-based Cherenkov $\gamma$-ray telescope arrays. Evidence for a spectral break in the TeV energy range has been provided by indirect measurements of H.E.S.S., although the results were qualified by sizeable systematic uncertainties. Here we report a direct measurement of CREs in the …