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981.
Bourne LS 《Canadian journal of urban research》1992,1(1):66-89
"The paper begins with a brief review of the theoretical arguments and empirical evidence that might be used to explain the emergence, sources and spatial variations of inner-city repopulation. The discussion then examines the various forms of property development that underlie the process of repopulation and the possible origins and potential impacts of each form. Examples are introduced to illustrate the trends and relationships involved, drawing on selective references from North American and European cities, but with special emphasis on Canadian cities and the recent Toronto experience. The paper concludes with a brief assessment of the significance of these processes for understanding the changing residential functions and social environments of the inner city." 相似文献
982.
The influence of polyvitamin compounds on the course and outcome of experimental hypercoagulemia was studied. "Hendevitum", "Aerovitum" and "Undevitum" proved to be most effective in reducing negative results of thromboplastemia. "Glutamevitum" was insignificantly effective, while "Quadevitum" and "Complevitum" did not reduce animals' death rate after intravascular injection of thromboplastin in LD50. Positive effects of polyvitamin compounds might be associated with their capacity for stimulating anticoagulation potential, especially, in accelerated continuous intravascular blood coagulation. 相似文献
983.
A full profile X-ray powder diffraction structure refinement has been carried out on a sample of synthesized CuGaTe2 using graphite monocromatized CuK step-scan data and a profile shape of the Pearson VII type. The most satisfactory convergence was achieved at R
p = 0.0666, R
wp = 0.0884, R
B = 0.0106 and R
F = 0.0102. The derived structural parameters at 26.5°C are: a = 0.602348(7), c = 1.193979(2) nm and x(Te) = 0.256(6). The ratio between lattice parameters, = c/2a = 0.9911 (0), differs from 1.0, indicating a tetragonal distortion, and non-ideal anion displacements, x(Te)1/4, is manifested by the existence of bond alternation of Cu-Te and Ga-Te with interatomic distances of 0.262(5) and 0.2578(5) nm, respectively. These results show a light tetrahedral deformation produced by four-fold tetrahedra of the copper cation in the CuGaTe2 chalcopyrite-type structure. 相似文献
984.
Monolayer isotherms were measured for 15, 18, and 20 K for para-hydrogen adsorbed on exfoliated graphite foam, and for the second, third, and fourth layers in the temperature interval of 8 to 20 K, using the standard volumetric method. From the data, the isosteric heat of adsorption, molar entropies and internal energies were obtained as a function of coverage. The values for coverages above the third layer were compared to those at the p-H2 bulk triple point, showing that, within our experimental uncertainty, the results are closer to the values of bulk solid para-hydrogen. Critical temperatures for the second and third layers and the triple point temperature for the second layer, were determined, yielding values of Tc2 = (10.0±0.1) K, Tc3 = (11.0±0.5) K and Tt2 = (6.5±0.1) K respectively. Features occurring along the monolayer coverages are compared to transitions which occur in the para-hydrogen phase diagrams adsorbed on graphite, obtained from heat capacity measurements by other authors. From the isotherms, compressibilities were calculated as a function of coverage for several temperatures. Whenever possible the obtained results were compared to existing data in the literature. 相似文献
985.
V. S. Grebneva V. A. Ermishkin D. L. Krasavin S. Ya. Misevra R. D. Strokatov 《Strength of Materials》1992,24(10):593-598
The commercial alloy 36NKhTYu in various structural conditions differing in the type of decomposition, grain size, and degree of dispersion of Y'- and -phase hardening particles was investigated by high-voltage electron microscopy and determination of the mechanical properties in tension in fatigue tests. It was established that in the alloy with the original coarse grain size regardless of the type of structure being formed and the form of loading, fracture is primarily ductile, occurring by a dislocation-shear mechanism. The comparison of structures of different type that was made showed that the structure with interrupted precipitation of -phase has the highest fracture energy requirement as the result of the presence of plastic interlamellar layers, providing effective dissipation of the energy supplied in loading. Deformation and fracture of the fragmented and ultradispersed structures is controlled by collective rotational processes.Translated from Problemy Prochnosti, No. 10, pp. 23–28, October, 1992. 相似文献
986.
The article presents a method of processing the recorded diagram of deformations vs time t for the purpose of determining the time-dependent change of strain rate and acceleration. The method is based on the utilization of data of statistical tests (the Monte Carlo method) and the least squares method applied to the deviations of the functions (t) from the experimental curve at the specified number of points.Translated from Problemy Prochnosti, No. 8, pp. 20–22, August, 1992. 相似文献
987.
L. P. Pitaevskii 《Journal of Low Temperature Physics》1992,87(3-4):445-451
The elementary theory of threshold phenomena in the excitation spectrum of superfluid 4He is presented. The multiphonon threshold in the initial part of the spectrum and the two-roton threshold at energy 2 are discussed. 相似文献
988.
R. V. Vasil'eva V. L. Goryachev 《Journal of Engineering Physics and Thermophysics》1992,63(2):775-777
The main results of theoretical and experimental studies of low-temperature magnetized (>1) nonequilibrium-ionization plasma properties are reported. Such plasma is found to be more stable as compared to the equilibrium-ionization one. Development of ionization instability in such plasma results in the formation of striae oriented perpendicularly to the plasma velocity and not decreasing its effective electric conductivity. Thus, the possibility exists of designing an effective MHD-generator operating with the inert-gas plasma without admixtures in closed-cycle installations.Reported at the VIIIth All-Union Conference on Physics of Low-Temperature Plasma (Minsk, September 1991).St. Petersburg Branch of the All-Union Research Institute for Electromechanical Engineering. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 63, No. 2, pp. 161–164, August, 1992. 相似文献
989.
Laughlin ML 《Computers in healthcare》1992,13(3):28-30
Courts have cleared the way for regional Bell operating companies to sell electronic information. Although critics are fearful of the Baby Bells' power, others say the decision will open a myriad of possibilities that could have far-reaching effects on the healthcare industry. 相似文献
990.
T. S. Barnitskaya V. B. Zelyavskii A. V. Kurdyumov N. F. Ostrovskaya L. L. Sukhikh 《Powder Metallurgy and Metal Ceramics》1992,31(10):817-821
A study has been made on how the structural state of the silicon affects the nitriding at 1200–1400C. As the initial powder becomes more defective, the nitriding accelerates, and there is an increase in the importance of reactions in the gas phase, with an increase in the proportion of the a modification of silicon nitride, and a tendency for elongated crystals to form.Translated from Poroshkovaya Metallurgiya, No. 10, pp. 1–7, October, 1992. 相似文献