全文获取类型
收费全文 | 91篇 |
免费 | 0篇 |
专业分类
化学 | 8篇 |
力学 | 13篇 |
数学 | 15篇 |
物理学 | 55篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2004年 | 4篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有91条查询结果,搜索用时 31 毫秒
51.
Ab initio calculations were used to study the properties of a series of hexagonal (Fe2N-like) subcarbides M2C, where M = Tc, Ru, Rh, Pd, Re, Os, Ir, and Pt, and to calculate their equilibrium structural parameters, electronic properties, phase stability, elastic constants, compression modulus, shear modulus, Young’s modulus, compressibility, Pugh’s indicator, Poisson ratio, elastic anisotropy indices, and also hardness, Debye temperature, sound velocity, and low-temperature heat capacity. It is found based on these results that all the subcarbides are mechanically stable; however, their formation energies Eform are positive with respect to a mixture of d-metal and graphite. In addition, the calculation of the phonon spectra of these subcarbides shows the existence of negative modes, which indicates their dynamical instability. Thus, a successful synthesis of these subcarbides at normal conditions is highly improbable. 相似文献
52.
D.V. Suetin 《Physica B: Condensed Matter》2009,404(20):3544-3549
First-principles FLAPW-GGA calculations have been performed with the purpose to determine the peculiarities of the structural, electronic, magnetic properties and stability for a family of related η carbides M3W3C and M6W6C (where M=Fe and Co). The geometries of all phases were optimized and their structural parameters, theoretical density, cohesive and formation energies, total and partial densities of states, atomic magnetic moments have been obtained and analyzed in comparison with available theoretical and experimental data. 相似文献
53.
D. V. Suetin I. R. Shein A. S. Kurlov A. I. Gusev A. L. Ivanovskiĭ 《Physics of the Solid State》2008,50(8):1420-1426
The structural and electronic properties are investigated and the relative stabilities of all the known polymorphic modifications (α, β, γ, ?) of the lower tungsten carbide W2C are numerically estimated using the ab initio full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA) of the local spin density. The equilibrium parameters of the crystal lattices, the band structures, and the total and partial densities of states are determined for the first time within a unified approach. The energies of formation of the α, β, γ, and ? polymorphic modifications of the lower tungsten carbide [in the reactions W2C ? 2W + C (graphite)] are calculated and used to discuss their relative stabilities. 相似文献
54.
55.
56.
57.
V. A. Krivchenko D. V. Lopaev P. V. Minakov V. G. Pirogov A. T. Rakhimov N. V. Suetin 《Technical Physics》2007,52(11):1471-1474
The effect of the degree of doping polycrystalline diamond films by boron on their Raman and absorption spectra has been studied in the visible region (from 200 to 1000 nm). As the boron concentration increases in a polycrystalline diamond film, its Raman spectrum exhibits a number of new specific features caused by the effect of boron atoms on the diamond lattice. The dependences that relate these features to the boron concentration in the films are given. Moreover, the absorption spectra of the films have revealed a peak whose maximum corresponds to photons with an energy near 2 eV. 相似文献
58.
V. D. Akin'shin S. F. Borisov B. T. Porodnov P. E. Suetin 《Journal of Applied Mechanics and Technical Physics》1974,15(2):183-186
An experimental study was made of the flow of the gases He, Ne, Ar, Kr, Xe, H2, D2, N2, CO2, and CH4 in the range of Knudsen numbers of 104–10?1 at room temperature in a capillary screen. A study was also made of the flow of a number of inert and diatomic gases at temperatures of 77.2 and 194.7 °K in an orifice and in a capillary screen. The relative flow rates were determined in the free-molecular mode of flow. The coefficients of accomodation of tangential momentum are calculated for the gases studied at different temperatures. 相似文献
59.
V. V. Ivanov T. V. Rakhimova A. O. Serov N. V. Suetin A. F. Pal’ 《Journal of Experimental and Theoretical Physics》1999,88(6):1105-1114
Elementary processes in dusty, beam-driven plasma discharges are studied experimentally and theoretically for the first time.
A theoretical model is constructed for a beam-driven plasma containing macroscopic particles. The effect of macroscopic particles
on the electron energy distribution function is estimated assuming a Coulomb field for the particles. The resulting rate of
electron-ion recombination on the macroscopic particles is compared with the electron loss constant calculated from the electron
energy distribution function with an electron absorption constant in the orbital-motion approximation. This approximation,
which is valid in the collisionless case, is found to work satisfactorily beyond its range of applicability. The distributions
of the charged particles and electric fields created by macroscopic particles in a helium plasma are determined. The experimental
data demonstrate the importance of secondary emission by high-energy electrons.
Zh. éksp. Teor. Fiz. 115, 2020–2036 (June 1999) 相似文献
60.
We have performed ab initio total energy calculations using the full-potential linearized augmented plane wave method (FP-LAPW) with the generalized gradient approximation (GGA) for the exchange-correlation potential to predict the structural, elastic, cohesive, electronic and magnetic properties of perovskite-like phases Co3WC, Rh3WC and Ir3WC. The optimized lattice parameters, density, independent elastic constants (Cij), bulk moduli, shear moduli, tetragonal shear moduli, compressibility, and Cauchy pressure, as well as electronic densities of states, cohesive and formation energies, atomic magnetic moments have been obtained and analyzed for the first time. 相似文献