全文获取类型
收费全文 | 300篇 |
免费 | 1篇 |
专业分类
化学 | 180篇 |
晶体学 | 2篇 |
力学 | 12篇 |
数学 | 19篇 |
物理学 | 88篇 |
出版年
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 41篇 |
2012年 | 5篇 |
2011年 | 13篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 10篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 13篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1973年 | 8篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1965年 | 2篇 |
1961年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有301条查询结果,搜索用时 937 毫秒
211.
N. E. Britikova L. A. Belova K. A. Chkhikvadze O. Yu. Magidson 《Chemistry of Heterocyclic Compounds》1973,9(2):253-255
The possibility of nucleophilic substitution of bromine in 5-bromoorotic acid by aromatic amines was studied. 5-Phenylamino derivatives of uracil and 5-phenylamino derivatives of orotic acid were synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 273–275, February, 1973.Deceased. 相似文献
212.
L. O. Belova M. V. Pletneva M. G. Shamina N. A. Golub A. A. Korlyukov A. D. Kirilin 《Russian Journal of General Chemistry》2014,84(6):1115-1120
The behavior of organic and organosilicon nitrogen—containing compounds-hydrazine, aminopyridine, 2-furylamine, and diazole derivatives — in the synthesis of O-silylurethanes, semicarbazides, and ureas was studied. The structure of the synthesized N,N′-bis(furan-2-ylmethyl)ureas was studied by X-ray diffraction analysis. 相似文献
213.
In this paper, we address the enhancement of solute diffusion by solute addition. We focus on the little studied kinetic effect leading to solute enhancement arising from the kinetics of the encounter of a solute atom with a vacancy in the presence of other solute atoms. The study complements an earlier study by two of the present authors of the enhancement of the solvent diffusivity. In the present paper, the fcc random alloy model is employed at the dilute limit. We employ Monte Carlo techniques to calculate the solute diffusion enhancement factors B 1 and B 2. Solute correlation factors, upon which the enhancement factors rely in this model, are calculated to a very high precision using long runs and averaging over a very large number of atoms. There is fair agreement with the kinetic treatments of Manning and of Holdsworth and Elliott, and excellent agreement with the self-consistent theory of Moleko et al. 相似文献
214.
In this paper we address the problem of enhancement of the solvent diffusivity by the addition of very small amounts of solute. The random alloy model is employed at the dilute limit. No Monte Carlo calculations have been available for evaluating the available theoretical treatments. In the present study we report on very-high-precision results of the solvent correlation factors as obtained from Monte Carlo calculations with averaging over 6 210 7 atoms and very long runs (2000 jumps per atom). The results are expressed in terms of the usual solvent enhancement factors b 1 and b 2 . There is good agreement with the theory of Holdsworth and Elliott and excellent agreement with the theory of Moleko et al . but not with other available theories. 相似文献
215.
Belova EI Lopatkova GY Pismenskaya ND Nikonenko VV Larchet C Pourcelly G 《The journal of physical chemistry. B》2006,110(27):13458-13469
Four effects providing overlimiting current transfer in ion-exchange membrane systems are examined. Two of them are related to water splitting: the appearance of additional current carriers (H+ and OH- ions) and exaltation effect. Two others are due to coupled convection partially destroying the diffusion boundary layer: gravitational convection and electroconvection. Three anion-exchange membranes, which differ in surface morphology and the nature of ion-exchange sites within a surface layer, are examined. The ion transfer across these membranes in NaCl solutions is studied by voltammetry, chronopotentiometry, and pH-metry. By excluding the effects of water splitting and gravitational convection, it is shown that the main mechanism of overlimiting mass transfer in narrow membrane cells at low salt concentrations is electroconvection. The reasons explaining why water splitting suppresses electroconvection are discussed. The scenario of development of potential oscillations with growing current and time is compared with that described theoretically by Rubinstein and Zaltzman. 相似文献
216.
T. I. Zhidkova V. V. Belova Yu. Yu. Brenno L. L. Zhidkov A. I. Khol’kin 《Russian Journal of Inorganic Chemistry》2009,54(9):1502-1506
We studied the extraction of chloropalladium complexes by solutions of trioctylmethylammonium di(2,4,4-trimethylpentyl)dithiophosphinate
in toluene over a wide range of aqueous acidities. Distribution factors and spectroscopic studies of extraction products showed
that (R4N)[Pd2Cl4A] complexes are formed in the organic phase during extraction under near-saturation conditions. As the concentration of the
binary extractant or dialkyldithiophosphinic acid increases, palladium di(2,4,4-trimethylpentyl)dithiophosphinate is formed
in the organic phase. 相似文献
217.
Inomoto M Gerhardt SP Yamada M Ji H Belova E Kuritsyn A Ren Y 《Physical review letters》2006,97(13):135002
The coupling between the global reconnection geometry and the local microphysics, caused by the Hall effect, is studied during counterhelicity plasma merging in the magnetic reconnection experiment. The structure of the reconnection layer is significantly modified by reversing the sign of the toroidal fields, which affects the manifestation of the Hall effect in the collisionless regime. The local two-fluids physics changes the global boundary conditions, and this combination effect consequently provides different reconnection rates, magnetic field structure, and plasma flow patterns for two different counterhelicity merging cases in the collisionless regime. 相似文献
218.
219.
A. A. Kraevskii P. P. Purygin L. N. Rudzite Z. S. Belova B. P. Gottikh 《Russian Chemical Bulletin》1968,17(2):364-367
Conclusions A new method was developed for the synthesis of 3(2)-O-(amino-acyl)nucleotides by the condensation of nucleotides with 1-[(t-butoxycarbonylamino)acyl]imidazoles with subsequent removal of the t-butoxycarbonyl protection by treatment with hydrogen chloride in dry ether.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 378–382, February, 1968. 相似文献
220.
R. V. Belova 《Mathematical Notes》1973,13(6):503-507
If is a bounded open set of a Banach space (B), is a completely continuous mapping of into the same space (B), and E- , where E is the identity transformation, is a uniformly fading mapping of into the Banach space, then the order of on equals ± 1 at every point y of .Translated from Matematicheskii Zametki, Vol. 13, No. 6, pp. 838–848, June, 1973.In conclusion, the author wishes to express her gratitude to her supervisor, K. A. Sitnikov. 相似文献