全文获取类型
收费全文 | 299篇 |
免费 | 0篇 |
专业分类
化学 | 94篇 |
晶体学 | 19篇 |
力学 | 98篇 |
数学 | 6篇 |
物理学 | 82篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 14篇 |
2011年 | 17篇 |
2010年 | 20篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 10篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 5篇 |
1969年 | 2篇 |
1968年 | 5篇 |
1966年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有299条查询结果,搜索用时 15 毫秒
101.
G. A. Lyubimov 《Journal of Applied Mechanics and Technical Physics》1973,14(3):307-312
An electric discharge in a flow of ionized gas is widely used in many physics and engineering problems. Among them are problems associated with current flow in various magnetohydrodynamic devices (generators, accelerators), arc shunting in a plasmatron, physical experiments in shock tubes, etc. It is known that with cold electrodes providing the contact between the plasma and the external circuit and relatively high pressures, two modes of current flow occur: at low current, the discharge is of a distributed nature; as the applied voltage increases, the discharge abruptly shifts into a discharge with a clearly developed cathode spot at some critical current density (we call this form of discharge an arc discharge). Existing experimental data [1–20] refers to varying experimental conditions. Furthermore, the critical voltage (or current) at which the transition of the discharge from a distributed discharge to an arc discharge occurs varies within very broad limits. From an analysis of the experimental data, a condition is formulated which the discharge parameters satisfy at the time of transition from a distributed discharge to an arc discharge.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 16–23, May–June, 1973.The author thanks Yu. A. Nikuev for invaluable help in the analysis of experimental data. 相似文献
102.
A. I. Rodionov B. V. Zubkov A. P. Kalinin V. N. Lyubimov A. F. Osipov I. D. Rodionov I. P. Rodionova I. B. Shilov 《Technical Physics》2002,47(10):1272-1276
The problems of developing methods for multidimensional (multichannel) data acquisition as applied to the optical study of the surface are considered. Unlike conventional methods of transition to multidimensional measurement, which employ mechanical scanning, the use of new-type instruments that allow for coordinate-sensitive and time measurements are discussed. Both the sensitive elements (detectors) and the instruments (hyperspectrometers) created for multidimensional coordinate-spectrum-time measurements are described. The application of hyperspectrometers makes it possible to increase manyfold the information content of measurements. The fluorescence of dye molecules deposited on the surfaces of germanium and silicon preirradiated by a laser beam is studied. The scattering spectra from these samples are examined. 相似文献
103.
S. E. Lyubimov R. P. Zhuravskii V. I. Rozenberg A. S. Safronov P. V. Petrovskii V. A. Davankov 《Russian Chemical Bulletin》2008,57(1):137-139
First representatives of chiral phosphite ligands derived from 4,5-dihydroxy[2.2]paracyclophane have been synthesized. A possibility
of the use of these compounds in the reactions of asymmetric Pd- and Ir-catalyzed allylic amination of 1,3-diphenylprop-2-enyl
acetate with pyrrolidine and Rh-catalyzed hydrogenation of dimethyl itaconate has been demonstrated.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 132–134, January, 2008. 相似文献
104.
105.
Yu. I. Blokhin K. N. Kornilov A. V. Akilin I. A. Abramov A. M. Bagautdinov I. A. Lyubimov 《Russian Chemical Bulletin》2016,65(4):910-922
The data on the synthesis, structure, and chemical properties of bisphosphorylated dihydric phenols are summarized. All the currently known methods for the synthesis of the systems in question are shown. Specific features of their structure, chemical and complexation properties, as well as areas of application of these compounds were analyzed. 相似文献
106.
A complex study of sodium and potassium halides as catalysts of the addition of CO2 to epoxides to yield organic carbonates was carried out. The activity of these metal iodides was investigated. The conditions allowing achievement of a quantitative conversion of epoxides into carbonates were found by varying the temperature, carbon dioxide pressure, and available co-solvents.
相似文献107.
The effect of the atmosphere composition and the electrode material and design on the discharge shape and variation in the
process of its development and in the steady-state regime is investigated. Graphites of different modifications, tungsten,
and copper were used as electrode materials and air, argon, and helium as baseline atmospheres. It is established that the
discharge shape (the shape of the glow region in the interelectrode gap) considerably depends on the actual composition of
the atmosphere which is determined by the composition of the baseline atmosphere and additions introduced in the interelectrode
gap either upon electrode evaporation or with a special purpose. The electrode material influences the steady discharge shape
via precisely these additions. 相似文献
108.
The paper focuses on the determination of statistical characteristics of photon distributions in a semi-infinite turbid medium, specifically the photon average trajectory and the root-mean-square deviation of photons from the average trajectory, with an approach based on the diffusion approximation to the radiative transfer equation. We show that the Dirichlet and Robin boundary conditions used for this purpose give close results. We derive exact analytical expressions for the case of the Dirichlet boundary condition. To demonstrate the practical value of our results we consider approximate solution of the inverse problem of time-domain diffuse optical tomography with the flat layer transmission geometry. The problem is solved with the method of photon average trajectories which are constructed with analytical expressions derived for a semi-infinite medium. 相似文献
109.
L. L. Gladkov Yu. D. Khamchukov I. Yu. Sychev A. V. Lyubimov 《Journal of Applied Spectroscopy》2012,79(1):31-37
IR absorption spectra of indolinospironaphthooxazine (ISNO) are presented. The geometric structure and normal coordinates
of the ISNO molecule have been calculated using a quantum mechanical DFT method. The IR spectrum of ISNO in its original spiro
form has been interpreted for the first time. Four normal modes in the range 800–1200 cm–1 with the largest amplitudes of Cspiro–O bond change are identified. The excited ISNO molecule spiro form may experience photoconversion to the merocyanine form
through them. 相似文献
110.
D.V. Lyubimov K.V. Kovalevskaya T.P. Lyubimova 《Communications in Nonlinear Science & Numerical Simulation》2012,17(9):3521-3532
Convection of a viscoelastic fluid in a square domain heated from below is investigated for the case of nondeformable free surfaces. To describe the rheological behavior of the fluid the generalized Oldroyd model is used. A weakly nonlinear analysis is performed in order to determine the character of branching for both the monotonic and oscillatory modes. We also perform a reduction of the boundary value-problem to the set of nonlinear amplitude equations. The analysis of this dynamic system demonstrates the onset and competition of five convection modes. 相似文献