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71.
W. Hempel C. Paal W. Hartmann G. A. Burrell G. G. Oberfell O. Brunck Mathers J. E. Lee J. W. Robertson F. M. Seibert P. Lebeau A. Damiens O. Brunck L. A. Levy F. St. Sinnatt B. J. Cramer E. H. Weiskopf J. I. Graham Th. F. Winmill F. Haber F. Löwe O. Mohr R. L. von Klemperer O. Wolft E. Müller E. Reinhardt J. N. Pring Juan Calafat y Leon M. Guichard R. Nowicki John J. Griffin A. Sons L. Hamburger H. Filippo Izn Ch. Moureau G. Lunge und A. Rittener 《Fresenius' Journal of Analytical Chemistry》1915,54(10):504-509
Ohne Zusammenfassung 相似文献
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The kinetics of the oxygen exchange reaction and the reduction of NO at La0.8Sr0.2CoO3−, La0.8Sr0.2MnO3− and Ag-electrodes on stabilized zirconia (8mol% Y203=YSZ) has been studied by means of electrochemical methods (impedance, I-U characteristics). For La0.8Sr0.2CoO3 electrodes the oxygen exchange was found to proceed via the bulk of the electrode with a rate limiting oxygen exchange at
the electrode surface. Electrodes based on La0.8Sr0.2MnO3 change their electrode characteristics with the applied potential. At low cathodic polarization the electrode reaction is
limited to the three-phase boundary electrode/YSZ/gas. At high cathodic potentials oxygen vacancies are created and consequently
additional oxygen is exchanged via the electrode bulk. Furthermore, a significant NO reduction was observed which indicate
a reaction with the oxygen vacancies at the electrode surface. For Ag a rate limiting transport of oxygen atoms through the
bulk of the electrode was found. As a consequence the oxygen concentration at the electrode surface remains nearly constant.
In this context, the observed inactivity for the NO reduction of Ag-electrodes may be explained.
Paper presented at the 2nd Euroconference on Solid State Ionics, Funchal, Madeira, Portugal, Sept. 10–16, 1995 相似文献
74.
An x-ray analysis of two natural compounds isolated fromPiper sanctum confirmed thetrans configuration for 5-(8-methoxy)cinnamyliden-4-methoxy-but-3-enolide [piperolide (I)] and for 5-[trans-(z)-,-epoxy--methoxycinnamyliden]-4-methoxy-2(5H)-furanon [epoxypiperolide (II)]. The space groups arePbca [a = 44.174(3),b = 8.056(3),c = 7.515(4) Å] for (I) andP21/c [a = 11.351(4),b = 8.292(5),c = 14.292(2) Å, = 96.28(2) °] for (II). The structures were solved by direct methods and refined by least-squares techniques toR = 4.8% (I) andR = 7.5% (II). The stereochemistry of the semicyclic double bond is in favor of theZ-isomers. 相似文献
75.
H. v. Baeyer F. Kochinke G. Klopp R. Mohnhaupt H.W. Reinhardt M. Kessel R. Schnabel 《Journal of membrane science》1982,11(3):275-288
Modules of surface-modified porous glass capillaries with a hydraulic conductivity of 0.25-0.70 ml min-1 mmHg-1 m-2 were tested for suitability for clinical haemofiltration by ex vivo dog experiments and by in vitro perfusion. The results show that (1) the construction of reusable haemofilters based on porous glass capillaries is possible; (2) operational data of testmodules are comparable with hollow-fiber high-flux haemofilters based on asymmetric cellulose acetate membranes; and (3) blood-surface interaction of porous glass capillaries is characterized by protein deposition which entails very low protein cutoff. 相似文献
76.
H. Reinhardt 《Nuclear Physics A》1982,390(1):70-116
By using the path integral approach to many-body systems, we formulate a time-dependent mean field S-matrix theory of nuclear reactions. Many-body channel eigenstates are constructed by using projection techniques. In this way the S-matrix between the channel eigenstates is expressed as a superposition of S-matrix elements between wave-packet-like states localized in space and time. A field operator representation of the interaction picture S-matrix is derived which enables one to apply the path integral approach. Applying the stationary phase approximation to the path integral representation of the interaction picture S-matrix between the localized states an asymptotically constant time-dependent mean field approximation to this S-matrix is obtained. Finally, the S-matrix between the projected channel eigenstates is obtained by evaluating the integral, arising from the projections, over the space-time positions of the localized states in the stationary phase approximation. The stationary phase conditions select those localized states from the projected channel states for which the mean field values of energy and momentum coincide with their corresponding channel eigenvalues. 相似文献
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Gerhard Soff Joachim Reinhardt Berndt Müller Walter Greiner 《Zeitschrift für Physik A Hadrons and Nuclei》1980,294(2):137-147
We calculate the ionization probability of the quasimolecular 1sσ-state in collisions of very heavy ions with (Z 1+Z 2) α?1. Multistep excitation processes between bound and continuum states are investigated. Due to the multistep processes the number of created 1sσ-vacancies is typically increased by a factor 2–5 over that obtained within time-dependent perturbation theory (i.e. the one-step processes). Some implications of the many-electron problem and the Pauli principle are discussed. The δ-electron distribution is compared with recent experimental data. 相似文献