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排序方式: 共有199条查询结果,搜索用时 46 毫秒
1.
It is found that, when a bismuth crystal is subjected simultaneously to concentrated loading and a dc magnetic field, the magnetoplastic effect manifests itself as an abrupt decrease in the average length of wedge twins on the (111) cleavage plane (and, hence, as a decrease in the total twinned volume of the crystal) as a threshold value of the magnetic field is reached. However, the magnetic field stimulates glide deformation, which is indicated by an increase in the size of dislocation rosettes. The microhardness of a crystal varies smoothly and tends to increase with increasing magnetic field. The last phenomenon is accounted for by hardening of the crystal under the indenter in the presence of a magnetic field, because several slip systems become operative. 相似文献
2.
The modifying action of chloroform on photochemical reactions induced in the eye lenses of rats by UVB radiation is revealed. In anesthetic concentrations, halogenmethane increases the quantum yield of photodisintegration of protein tryptophanyls with formation of a new photochemical product that absorbs radiation in the UVA range and possesses the photosensitizing activity. 相似文献
3.
Investigation of anode and cathode jets influence on electric arc properties with current up to 500 kA 总被引:1,自引:0,他引:1
Rutberg P.G. Bogomaz A.A. Budin A.V. Kolikov V.A. Pinchuk M.E. Pozubenkov A.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2003,31(2):201-206
A number of phenomena connected with the formation of electrode jets in discharges in hydrogen at a current of 10/sup 5/-10/sup 6/ A, a current growth rate of 10/sup 10/ A/s, an initial pressure 0.1-4.0 MPa, and a discharge gap length of 5-40 mm were studied. After the secondary breakdown, the jets are observed through a discharge semitransparent channel, widening with velocity (4-7) /spl middot/ 10/sup 2/ m/s. Shockwave formation was detected at the interaction of jets with the surrounding gas and the opposite electrode. Plasma vapor pressure of metal near the end of the tungsten cathode 70 /spl mu/s after initiation of a discharge was 180 MPa. Thus, magnitude of brightness temperature was 59 /spl middot/ 10/sup 3/ K, with an average charge of ions-m~=3.1, and a concentration of metal vapors n=5.3/spl middot/10/sup 19/ cm/sup -3/. While those at the end of the anode 90 /spl mu/s after initiation of discharge: m~=2.6, n=7.4/spl middot/10/sup 19/ cm/sup -3/. Probable reasons of high-voltage drops near the electrodes (the summarized magnitude of which is /spl sim/1 kV) are discussed on the basis of experimental data. For the first time, the shadow method registered symmetric ejection of material from the all-cathode surface the maximum discharge current was observed. 相似文献
4.
In this paper, we study Steinberg unitary Lie conformal algebras, which are universal central extensions of unitary Lie conformal
algebras. We describe the kernels of these extensions by means of skew-dihedral homology.
__________
Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 11, No. 2, pp. 135–155, 2005. 相似文献
5.
V. M. Pinchuk E. S. Kotlyarova N. V. Parkhomenko P. N. Tsybulev 《Journal of Structural Chemistry》1996,37(4):544-556
The studies concerned with the oxidation of carbon monoxide on the nickel surface are reviewed. The Eley-Rideal (ER) collision
and Langmuir-Hinshelwood (LH) adsorption mechanisms of the oxidation are analyzed. Calculations of the activation barriers
of the oxidation of carbon monoxide on the Ni (111), (100), and (110) faces were performed for the first time and involved
optimization of the reaction paths by the collision and adsorption mechanisms. It is shown that on the Ni (111) and (110)
faces the ER collision mechanism of the reaction is preferable with the activation barriers ΔE
dis
O
2=62 kJ/mole and ΔE
trans
O
A21F50012x=25 kJ/mole for Ni (111) and ΔE
dis
O
2=72 kJ/mole and ΔE
trans
O
2=20 kJ/mole for Ni (110); on the Ni (100) face, the LH adsorption mechanism with the activation barriers ΔE
dis
O
2=75 kJ/mole and ΔE
trans
O
2=42 kJ/mole is favored. Analysis of the potential barriers for the catalytic oxidation of carbon monoxide on the Ni surfaces
suggests the LH mechanism to be preferential, although insignificant differences in the activation barries can lead to the
oscillatory reaction mechanism, which is confirmed experimentally. The calculations were performed by the LCAO MO SCF method
in the MINDO/3 approximation.
Kiev Polytechnical Institute. Translated fromZhurnal Struktumoi Khimii, Vol. 37, No. 4, pp. 628–645, July–August, 1996.
Translated by I. Izvekova 相似文献
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Technical Physics - We propose a method for measuring the harmonic vibration amplitude of a reflector using a coherent radar station. A mathematical model describing the dependence of the Doppler... 相似文献
10.