全文获取类型
收费全文 | 321篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 278篇 |
力学 | 1篇 |
数学 | 2篇 |
物理学 | 42篇 |
出版年
2022年 | 2篇 |
2021年 | 10篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 25篇 |
2017年 | 19篇 |
2016年 | 24篇 |
2015年 | 14篇 |
2014年 | 7篇 |
2013年 | 16篇 |
2012年 | 9篇 |
2011年 | 25篇 |
2010年 | 15篇 |
2009年 | 14篇 |
2008年 | 22篇 |
2007年 | 25篇 |
2006年 | 15篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 11篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有323条查询结果,搜索用时 15 毫秒
1.
Ganina O. G. Bondarenko G. N. Isaeva V. I. Kustov L. M. Beletskaya I. P. 《Russian Journal of Organic Chemistry》2019,55(12):1813-1820
The catalytic activity of copper-containing heterogeneous catalysts, in particular metal-organic frameworks, zeolites, and alumina-supported nanoparticles, in the carboxylation of terminal alkynes and oxiranes has been evaluated. Temperature dependences of these reactions have been studied.
相似文献2.
Russian Chemical Bulletin - The use of the low-power (up to 10 W) microwave activation to heat the reaction mixture in the catalytic oxidative conversion of lignin to synthesis gas results in a... 相似文献
3.
4.
L. M. Kustov O. K. Lebedeva D. Yu. Kultin N. V. Root V. B. Kazansky 《Doklady Chemistry》2016,470(2):297-301
The aim of this study was to synthesize low-concentration catalysts with a highly developed surface based on nanodispersed platinum deposited onto the steel surface electrochemically modified with the use of an ionic liquid. Sintered fibers of austenitic steel without pretreatment (steel 1) and etched with hydrochloric acid to remove surface oxides (steel 2) were used as substrates. 1-Butyl-4-methylimidazolium acetate [BMIM][Ac] ionic liquid was used. Variation of the current intensity and anodic treatment time leads to the formation of different structures at the steel surface. For steel 2, optimal conditions leading to self-organization, namely, formation of hexagonal structures, have been selected. It has been demonstrated that formation of nanostructures at the steel surface can occur without the participation of fluoride ions. Low-concentration (Pt/steel 2) catalysts with a uniform distribution of platinum nanoparticles over the surface were prepared via galvanostatic deposition from an aqueous solution of H2PtCl6. 相似文献
5.
6.
7.
E. F. Kustov V. M. Novotortsev E. O. Goncharov M. E. Kustov 《Russian Journal of Inorganic Chemistry》2012,57(14):1723-1736
General theory of matrix interactions of dimers of iron group ions is considered. Equations for calculation of matrix elements of the exchange energy of dimers and equations for calculation of the magnetic moments of dimers of different d n configurations and different exchange parameters are reported. The energies of the spin states of dimers are calculated with inclusion of exchange interactions of the first J 0 and second J 2 orders, and energy state diagrams for dimers with different spins and exchange energies are reported. For heterospin dimers, equations for calculation of the magnetic moment ?? and magnetic susceptibility ?? are introduced, and for homospin dimers, analytical formulas of calculation are presented. The tables of magnetic moments are calculated and their diagrams as a function of J 0 for homospin dimers with spins S = 5/2, 2, 3/2, 1, and 1/2 are given. The experimental data are interpreted for Co2+ dimers as an example: the experimental and theoretical dependences of ?? and ?? on temperature are considered. 相似文献
8.
T. M. Roshchina N. K. Shoniya O. Ya. Tayakina O. P. Tkachenko L. M. Kustov F. Bernardoni A. Y. Fadeev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(3):437-446
The role of the grafting density of monofunctional polyfluoroalkylsilanes of the C
n
F2n − 1(CH2)
m
Si(CH3)2Cl general formula (where n = 3, 4, and 6; and m = 2 and 3) and their composition in intermolecular interactions of the molecules of saturated and aromatic hydrocarbons with
a surface of chemically modified silica is studied by means of IR spectroscopy and adsorption-static and gas chromatography.
It is shown that the higher the concentration and the shorter the length of the grafted chain, the greater (by a factor of
2 to 25) the drop in the adsorption values of hydrocarbons as a result of modifications, due to an increase in the degree
of oleophobization of surface upon the formation of polyorganofluorine coatings. The high specificity of the surface with
respect to benzene, which is due to the active participation of the polar fragment of a grafted chain in adsorption process,
is related to the features of a relatively low-density sample with a concentration of grafted perfluorobutyl groups of 1.7
nm−2. It is shown that the thermodestruction of polyfluoroalkyl silica remains virtually unobserved upon heating to 523 K in an
argon flow. 相似文献
9.
A. V. Kustov N. L. Smirnova D. B. Berezin M. B. Berezin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(11):1903-1907
The thermal effects of ethyl acetate (EtOAc), 1-octanol (OctOH), and N,N-dimethylformamide (DMF) solution in a OctOH-DMF model
system were measured using a calorimeter of variable temperature with an isothermal shell at 298 K. The standard enthalpies
of solution and ester transfer from an alcohol to a binary mixture, and partial mole enthalpies of mixed solvent components
were determined. The state of non-electrolyte molecules in OctOH-DMF and OctOH-DMF-EtOAc systems were studied using extended
coordination model. It was found that the binary solvent is subjected to microclusterization, since the fraction of the single-type
molecules in the solvation sphere of both components of a mixture is significantly higher than in the liquid phase volume.
The conclusion was drawn that in the triple system, the ethyl acetate solvation sphere in the whole range of compositions
is significantly enriched with amide owing to stronger esteramide dipole-dipole interaction. 相似文献
10.
Tarasenko E. A. Isaeva V. I. Beletskaya I. P. Kustov L. M. 《Russian Chemical Bulletin》2011,60(1):179-181
A possibility of using a ionic liquid, 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), as a reaction medium in the liquid-phase hydrogenation of 1,4-diacetoxybut-2-yne was examined. Two types of catalysts were
studied: Pd(10%)/C and the palladium-containing catalytic system based on the biopolymer chitosan supported on silica gel
(Pd(1%)/chitosan/SiO2). The data obtained indicate high selectivity of hydrogenation of 1,4-diacetoxybut-2-yne to cis-1,4-diacetoxybut-2-ene under selected conditions. 相似文献