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排序方式: 共有3123条查询结果,搜索用时 140 毫秒
1.
Journal of Materials Science - Phase separation is a relevant mode of transformation for microstructure development in multicomponent alloys. Its occurrence can drastically alter the composition... 相似文献
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V. N. Petrov V. V. Grebenshikov B. D. Grachev A. S. Kamochkin M. K. Yarmarkin 《Technical Physics Letters》2004,30(2):157-160
A compact electron polarimeter employing the classical Mott scheme has been developed and tested. The device has an efficiency
of about 5.6×10−4, a maximum count rate of 5×105 cps, dimensions 15 cm (diameter) × 25 cm (length), and a working voltage of 40 kV. The polarimeter can operate for a long
time under arbitrary vacuum conditions without maintenance, exhibiting no changes in the main working characteristics, and
obeys all requirements to the electron spin polarization studies on the modern level. 相似文献
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A method of measuring and identifying the static parameters of a bipolar transistor is considered. The characteristic of the transistor, from which the parameters of the model are determined, is chosen depending on what group the calculated parameters belong to. The characteristics are measured in such a way that the equations of the model describing them can be reduced to the simplest form. 相似文献
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N. A. Sheikina L. V. Petrov B. L. Psikha V. V. Kharitonov V. A. Tyshchenko T. N. Shabalina 《Petroleum Chemistry》2006,46(1):34-40
The mechanism of the inhibiting effect of diphenylamine during the oxidation of two base stocks of hydraulic oils were studied at 120, 130, and 140°C. The key reactions in the mechanism of the action of the inhibitor were identified, and the values of the kinetic parameters and their activation energies were determined. The kinetic parameters were calculated, and the salient kinetic features of the inhibited oxidation of the two specimens were compared at 70°C, the temperature of accelerated testing of hydraulic oils. The results of this prediction were analyzed, and the reasons for differences in the oxidation stability of the samples examined were established. 相似文献
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Vladimir Rozenshtein Alexander Berg Haim Levanon Uwe Krueger Dietmar Stehlik Yuri Kandrashkin Art Van Der Est 《Israel journal of chemistry》2003,43(3-4):373-381
Light-induced spin-polarized transient EPR spectra are reported for several water-soluble copper porphyrins. The spectra are assigned to the doublet ground state, with emissive spin polarization resulting from photoexcitation and subsequent electronic relaxation. In contrast to other systems for which polarization of a doublet ground state has been observed, the exchange interactions in the copper porphyrins are strong and the geometry is fixed. It is proposed that intersystem crossing from the photoexcited trip-doublet to the trip-quartet state can lead to net polarization of the spin system and that this polarization is maintained during electronic decay, possibly via charge-transfer and exciplex states. The intensity of the observed spin polarization is essentially independent of the molecular orientation in the external field, but is strongly dependent on the nature of the charged peripheral groups. Possible reasons for this behavior are discussed. 相似文献
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The properties of a spinel copper cobaltite obtained by thermal decomposition of mixed nitrates of both metals at 350°C and normal pressure are described. It has been shown that the maximum copper content (x) in the spinel CuxCo3?xO4 does not exceed 0.9. When the copper amount in the initial mixture is higher a second phase CuO is formed. The copper ions are distributed over the A- and the B-sites of the spinel lattice, i.e. the spinel is partially inverted. Such a model explains well the data obtained about the lattice parameter, IR-absorption and the magnetic susceptibility of the samples with different x. 相似文献