全文获取类型
收费全文 | 155篇 |
免费 | 0篇 |
专业分类
化学 | 72篇 |
晶体学 | 9篇 |
力学 | 3篇 |
数学 | 29篇 |
物理学 | 42篇 |
出版年
2022年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 8篇 |
2009年 | 3篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1972年 | 1篇 |
1971年 | 4篇 |
1969年 | 4篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1952年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 0 毫秒
1.
Inverse diffusion problems allow the diffusion coefficients to be determined from experimental concentration profiles. Solutions
of the inverse diffusion problem are unstable toward perturbations of the initial concentration profiles. By the example of
inverse diffusion problem solution for a model binary system it is demonstrated that the use of the production entropy to
minimize the discrepancy functional stabilizes the solution even for significant perturbations of the initial concentration
profile. The choice of the entropy production for the smoothing component of the discrepancy functional is physically adequate
to the formulated problem, and the entropy production can be used to solve inverse problems of heat and mass transfer.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 79–83, June, 2006. 相似文献
2.
Lyashenko G. S. Dmitriev D. V. Yazovtsev I. A. Demina M. M. Albanov A. I. Medvedeva A. S. 《Russian Journal of Organic Chemistry》2003,39(10):1497-1500
Hydrosilylation of 2-(2-propynyl)-2,3-dihydro-1,2-benzothiazol-3-one 1,1-dioxide with 1-alkynyldimethyl- and bis(1-alkynyl)methylsilanes of the general formula Me
n
HSi(C=-CR)3-n (n = 1, 2) in the presence of H2PtCl6 (Speier's catalyst) occurs in a nonregioselective but stereoselective fashion, yielding mixtures of the corresponding trans-- and -adducts. The fraction of the latter ranges from 50 to 70%, depending mainly on the substrate nature rather than on the nature of substituent at the triple bond of the reagent. 相似文献
3.
A. A. Konstantinchenko P. I. Lyashenko A. F. Pozharskii 《Chemistry of Heterocyclic Compounds》1981,17(8):832-835
2-Azidoperimidine and its 1-methyl, 1-benzyl, and 1-phenyl derivatives were synthesized by the action of sodium azide on the corresponding 2-chloroperimidines. The IR spectra constitute evidence for the existence of all of these compounds in both the solid state and in solution in exclusively the tetrazolo [1,5-a]perimidine form.See [1] for Communication 54.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1114–1117, August, 1981. 相似文献
4.
5.
N. E. Zhukhlistova V. V. Balaev A. V. Lyashenko A. A. Lashkov 《Crystallography Reports》2012,57(3):337-359
Endonucleases (EC 3.1) are enzymes of the hydrolase class that catalyze the hydrolytic cleavage of deoxyribonucleic and ribonucleic acids at any region of the polynucleotide chain. Endonucleases are widely used both in biotechnological processes and in veterinary medicine as antiviral agents. Medical applications of endonucleases in human cancer therapy hold promise. The results of X-ray diffraction studies of the spatial organization of endonucleases and their complexes and the mechanism of their action are analyzed and generalized. An analysis of the structural studies of this class of enzymes showed that the specific binding of enzymes to nucleic acids is characterized by interactions with nitrogen bases and the nucleotide backbone, whereas the nonspecific binding of enzymes is generally characterized by interactions only with the nucleic-acid backbone. It should be taken into account that the specificity can be modulated by metal ions and certain low-molecular-weight organic compounds. To test the hypotheses about specific and nonspecific nucleic-acid-binding proteins, it is necessary to perform additional studies of atomic-resolution three-dimensional structures of enzyme-nucleic-acid complexes by methods of structural biology. 相似文献
6.
Physics of the Solid State - The problem of normal collision of a spherical particle with a half-space is considered with allowance for nonlocal plastic deformation in the case where the strength... 相似文献
7.
Lyashenko G. S. Medvedeva A. S. Yazovtsev I. A. Albanov A. I. Demina M. M. 《Russian Journal of Organic Chemistry》2002,38(2):147-149
The hydrosilylation of a number of acetylenes RCCH (R, R' = Ph, CH2OPh, CH2SPh) with -ethynylhydrosilanes Me2SiHCHCR' in the presence of H2PtCl6 was investigated. The addition did not occur regioselectively, but was stereospecific and afforded a mixture of - and trans--adducts. The replacement of phenyl substituent by phenoxymethyl both in the molecule of ethynylsilane and the acetylene substrate resulted in growing proportion of the -adduct in the reaction mixture up to 10-60%. 相似文献
8.
9.
V. P. Veleshchuk O. V. Lyashenko Yu. A. Myagchenko R. G. Chuprina 《Journal of Applied Spectroscopy》2004,71(4):553-557
The dependence of the spectral position of the electroluminescence bands of epitaxial light-emitting diode n
+–n–p structures (GaAs0.15P0.85) on the density of a direct heterojunction current at different successive instants of time — before an acoustic emission and after it — has been revealed. The shifts of the electroluminescence bands accompanied by acoustic emission can be divided into three types according to the density of the current: (1) short-term shifts due to relaxation of the defect structure of a sample — at relatively low currents, (2) the magnitude of the reverse shift being determined by the current density — at large currents, and (3) formation of an IR band (1.5–1.1 eV) with irreversible degradation changing in the red (1.75 eV) and green (2.19 eV) bands of the electroluminescence spectrum — at ultrahigh currents (100–200 A/cm2). 相似文献
10.
Melting of an ultrathin lubricant film during friction between atomically smooth surfaces is studied. Additive noise of shear stress and strain as well as of film temperature is introduced and the phase diagram is constructed. On the diagram, the noise intensity for this temperature and the temperature of friction surfaces determine the regions of sliding, dry, and stick-slip friction. As a result of numerical analysis of the Langevin equation for various regions of the diagram, time series of stresses are constructed, which make it possible to explain the experiment on friction, in which intermittent motion is observed. Lubricant melting due to dissipative heating of friction surface is considered and the experimental time dependences of friction force are interpreted. 相似文献