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31.
Tanskanen H Khriachtchev L Räsänen M Feldman VI Sukhov FF Orlov AY Tyurin DA 《The Journal of chemical physics》2005,123(6):64318
Vinyl radicals produced by annealing-induced reaction of mobilized hydrogen atoms with acetylene molecules in solid noble-gas matrices (Ar, Kr, and Xe) were characterized by Fourier transform infrared and electron paramagnetic resonance (EPR) spectroscopies. The hydrogen atoms were generated from acetylene by UV photolysis or fast electron irradiation. Two vibrational modes of the vinyl radical (nu7 and nu5) were assigned in IR absorption studies. The assignment is based on data for various isotopic substitutions (D and 13C) and confirmed by comparison with the EPR measurements and density-functional theory calculations. The data on the nu7 mode is in agreement with previous experimental and theoretical results whereas the nu5 frequency agrees well with the computational data but conflicts with the gas-phase IR emission results. 相似文献
32.
Frey GL Reynolds KJ Friend RH Cohen H Feldman Y 《Journal of the American Chemical Society》2003,125(19):5998-6007
The development of low-cost, large-area electronic applications requires the deposition of active materials in simple and inexpensive techniques at room temperature, properties usually associated with polymer films. In this study, we demonstrate the integration of solution-processed inorganic films in light-emitting diodes. The layered transition metal dichalcogenide (LTMDC) films are deposited through Li intercalation and exfoliation in aqueous solution and partially oxidized in an oxygen plasma generator. The chemical composition and thickness of the LTMDC and corresponding transition metal oxide (TMO) films are investigated by X-ray photoelectron spectroscopy. The morphology and topography of the films are studied by atomic force microscopy. X-ray powder diffraction is used to determine the orientation of the LTMDC film. Finally, the LTMDC and their corresponding oxides are utilized as hole-injecting and electron-blocking materials in polymer light-emitting diodes with the general structure ITO/LTMDC/TMO/polyfluorene/Ca/Al. Efficient hole injection and electron blocking by the inorganic layers result in outstanding device performance and high efficiency. 相似文献
33.
A helium glow discharge is employed as a gas Chromatographie detector which is selective for silicon. Operated with spectral background compensation at 251.6 nm or 288.2 nm, the detector shows a lower limit of detection of 5 ng of silicon per injection. The detector is applied to the rapid screening of trimethylsilylated fractions of shale-derived liquids being prepared for biossay. 相似文献
34.
D. Feldman M. Chervenka E. Stokh M. Shimanska E. Khaber 《Chemistry of Heterocyclic Compounds》1995,31(1):80-85
Methyl derivatives of several nitrogen-containing heterocyclic compounds were converted into the corresponding carboxylic acids by means of electrochemical oxidation at the nickel oxohydroxide anode in alkaline medium, using a nondiaphragm electrolyzer. The oxidation of 2,5-dimethylpyrazine was used to demonstrate the effect of adding chromium (III) and cobalt (II) compounds to the reaction mixture. The composition and electronics state of the anode surface were studied usign x-ray diffraction and XPS methods. 相似文献
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Schumm BA Koetke DS Adolphsen CE Alexander JP Averill D Barish BC Barklow T Barnett BA Blockus D Boyarski A Brabson B Breakstone A Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Cords D Coupal DP Dauncey P DeStaebler HC Dorfan JM Drell PS Drewer DC Durrett D Elia R Feldman GJ Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gero E Gidal G Glanzman T Goldhaber G Gomez Cadenas JJ Gratta G Hanson G Harr R Harral B Harris FA Hayes K Hearty C Heusch CA Hildreth MD Himel T Hinshaw DA 《Physical review D: Particles and fields》1992,46(1):453-456
38.
A health insurance market is examined in which individuals with a history of high utilization of health care services tend to select fee-for-service (FFS) insurance when offered a choice between FFS and health maintenance organizations (HMOs). In addition, HMOs are assumed to practice community rating of employee groups. Based on these observations and health plan enrollment and premium data from Minneapolis-St. Paul, a deterministic simulation model is constructed to predict equilibrium market shares and premiums for HMO and FFS insurers within a firm. Despite the fact that favorable selection enhances their ability to compete with FFS insurers, the model predicts that HMOs maximize profits at less than 100% market share, and at a lower share than they could conceivably capture. That is, HMOs would not find it to their advantage to drive FFS insurers from the market even if they could. In all cases, however, the profit-maximizing HMO premium is greater than the experience-rated premium and, thus, the average health insurance premium per employee in firms offering both HMOs and FFS insurance is predicted to be greater than in firms offering one experience-rated plan. The model may be used to simulate the effects of varying the employer's method of contributing to health insurance premiums. Several contribution methods are compared. Employers who offer FFS and HMO insurance and pay the full cost of the lowest-cost plan are predicted to have lower average total premiums (employer plus employee contributions) than employers who pay any level percent of the cost of each plan. 相似文献
39.
Molecular complexes of aromatic hydrocarbons and carbonium ions are described according to Mulliken's donor — acceptor theory. Estimations of electron affinities of several cations are deduced from charge-transfer transition energies and the indepently measured electron affinity of the tropylium ion. 相似文献
40.