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1.
The photochlorination of methyl fluoride has been studied at low pressures. Excited (2P1/2) chlorine atoms have been found to participate in the reaction. The ratio of the excited and ground state rate constants has been estimated at room temperature.
. (2P1/2) . .相似文献
2.
V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Y. Pomjakushin S. N. Shilov D. T. Bezhitadze I. I. Gurevich B. F. Kirillov E. P. Krasnoperov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin G. F. Tavadze I. P. Borovinskaya M. D. Nersesyan A. G. Peresada Y. F. Eltzev V. R. Karasik O. E. Omelyanovsky 《Hyperfine Interactions》1990,61(1-4):1093-1096
We report the results of μSR investigations of the ceramic samples La2-xSrxCuO4-σ (x=0.1, 0.15, 0.25) and ReBa2Cu3O7-σ (Re=Er, Ho, Y0.5Ho0.5) in the external magnetic field 0–800 Oe. The measurements were performed by the ZFC and FC methods. The irreversibility effects were studied at several temperatures by measuring the mean value and the width of the magnetic field distribution on the muon in the step by step procedure of increasing and subsequent decreasing of the external field. The temperature dependences of the magnetic penetration depth perpendicular to the basal plane λ⊥ were obtained. For the lanthanum sample with 0.15 of Sr its value at the zero temperature is λ⊥ (0)=2400 Å, for Er-Ba-Cu-O λ⊥ (0)=1600 Å. 相似文献
3.
E. P. Krasnoperov 《Hyperfine Interactions》1990,61(1-4):1155-1158
Effect of pinning on muon spin relaxation is discussed. The application of μSR to study of the second type superconductors
are considered. 相似文献
4.
K. Bohmhammel G. Wolf N.E. Alekseevskii E.P. Krasnoperov 《Solid State Communications》1977,21(6):519-520
Heat capacity of the Nb3Al0.8Ge0.2 samples have been measured in the temperature range 14–25K. It has been shown that the electron part of the heat capacity (γ) and the Debye temperature undergo only a small change after thermal treatment leading to significant increase of superconducting Tc. Such an increase of the band density of states N(EF)band may be caused by appropriate changes of phonon spectrum. The character of these changes is determined, to a great extent, by localization of the d-electrons in the niobium chains. 相似文献
5.
I. V. Bondarenko A. V. Krasnoperov A. I. Frank S. N. Balashov S. V. Masalovich V. G. Nosov P. Geltenbort P. Hoghoj A. G. Klein A. Cimmino 《JETP Letters》1998,67(10):786-792
An experiment to check the standard dispersion law for ultracold neutrons is described. The experiment is based on searching
for a shift of the resonance line of a neutron interference filter as the neutron velocity component parallel to the filter
surface is varied. The first results attest to a statistically significant effect. No mimicking effects were found in a control
experiment, but their possible existence cannot be completely ruled out at present.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 10, 746–751 (25 May 1998) 相似文献
6.
V. Yu. Aleksakhin V. M. Bystritskii N. I. Zamyatin E. V. Zubarev A. V. Krasnoperov V. L. Rapatskii A. V. Rogachev Yu. N. Rogov A. B. Sadovskii A. V. Salamatin M. G. Sapozhnikov V. M. Slepnev 《Physics of Particles and Nuclei Letters》2013,10(7):860-867
The tagged neutron technique (TNT) is analyzed in terms of its application for detecting dangerous substances hidden in underwater objects. The use of the technique for solving these problems is justified theoretically. The main characteristics of a prototype detector aimed at detecting explosives in a water environment are determined. 相似文献
7.
A complete thermodynamically consistent elementary reaction kinetic model of particle nucleation and growth from supersaturated vapor was developed and numerically evaluated to determine the conditions for the steady-state regime. The model treats all processes recognized in the aerosol science (such as nucleation, condensation, evaporation, agglomerationcoagulation, etc.) as reversible elementary reactions. It includes all possible forward reactions (i.e., of monomers, dimers, trimers, etc.) together with the thermodynamically consistent reverse processes. The model is built based on the Kelvin approximation, and has two dimensionless parameters: S0-the initial supersaturation and Theta-the dimensionless surface tension. The time evolution of the size distribution function was obtained over the ranges of parameters S0 and Theta. At low initial supersaturations, S0, the steady state is established after a delay, and the steady-state distribution function corresponds to the predictions of the classical nucleation theory. At high initial supersaturations, the depletion of monomers due to condensation on large clusters starts before the establishing of the steady state. The steady state is never reached, and the classical nucleation theory is not applicable. The boundary that separates these two regimes in the two dimensionless parameter space, S0 and Theta, was determined. The model was applied to several experiments on water nucleation in an expansion chamber [J. Wolk and R. Strey, J. Phys. Chem. B 105, 11683 (2001)] and in Laval nozzle [Y. J. Kim et al., J. Phys. Chem. A 108, 4365 (2004)]. The conditions of the experiments performed using Laval nozzle (S0=40-120) were found to be close to the boundary of the non-steady-state regime. Additional calculations have shown that in the non-steady-state regime the nucleation rate is sensitive to the rate constants of the initial steps of the nucleation process, such as the monomer-monomer, monomer-dimer, etc., reactions. This conclusion is particularly important for nucleation from supersaturated water vapor, since these processes for water molecules at and below the atmospheric pressure are in the low pressure limit, and the rate constants can be several orders of magnitude lower than the gas kinetic. In addition, the impact of the thermodynamic inconsistency of the previously developed partially reversible kinetic numerical models was assessed. At typical experimental conditions for water nucleation, S0=10 and Theta=10 (T=250 K), the error in the particle nucleation rate introduced by the thermodynamic inconsistency exceeds one order of magnitude. 相似文献
8.
V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Yu. Pomjakushin S. N. Shilov I. I. Gurevich B. F. Kirillov E. P. Krasnoperov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin A. I. Morozov 《Hyperfine Interactions》1991,63(1-4):241-247
High temperature superconductors HoBa2Cu3O7−δ (T
c
≅93 K), Ho0.5Y0.5Ba2Cu3O7−δ (T
c
≅93 K) and ErBa2Cu3O7−δ (T
c
≅95 K) were investigated by the zero-field μSR-technique. The muon spin depolarisation rate connected with the fluctuation
frequency of rare-earth ion magnetic moments was measured. It was found that the samples with holmium show a fast increase
of the muon spin depolarisation rate at temperatures below 20 K, while in ErBa2Cu3O7−δ the depolarisation rate remains low in the whole temperature region studied (4.2 K-270 K). The sharp difference between the
behaviours of the muon spin depolarisation rate may be explained by the difference between the ground state of Ho3+ and Er3+ ions in the crystalline field of the lattice. 相似文献
9.
Evgenji Krasnoperov Evgenji E. Meilikhov Dimitrji Eschenko Dierk Herlach Elvezio Morenzoni Ulrich Zimmermann Fredy N. Gygax Alexander Schenck 《Hyperfine Interactions》1994,87(1):1011-1016
The influence of electric fields on the formation of muonium in liquid helium (4He,3He, and mixture of4He + 0.2%3He) has been studied. It was found that the relative distribution of muon-electron pairs is anisotropic. The maximum muon density is shifted with respect to the electrons in the direction of the initial muon momentum. Due to the anisotropy the muonium asymmetry in normal liquid helium is enhanced by a factor of 3 in an electric fieldE=1 kV/cm. 相似文献
10.
G. Solt C. Baines V.S. Egorov D. Herlach E.P. Krasnoperov U. Zimmermann 《Hyperfine Interactions》1997,104(1-4):257-263
The first spectroscopic evidence for dia‐ and paramagnetic domains (Condon domains) in beryllium metal is presented. The domains,
detected by the splitting of the μSR line, arise and disappear periodically in each de Haas–van Alphen cycle as the field
\bf H, normal to the single crystal Be plate and parallel to its [0001] axis, is tuned near \bf H_0\approx 2.7\ T. The intensity
of the lines in the doublet reflect the ratio of dia‐ to paramagnetic regions. For the difference in induction within the
domains we obtain \Delta B\approx 30\mbox--40\ G in the investigated field range at T=0.8 K.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献