全文获取类型
收费全文 | 400篇 |
免费 | 2篇 |
专业分类
化学 | 154篇 |
晶体学 | 9篇 |
力学 | 29篇 |
数学 | 53篇 |
物理学 | 157篇 |
出版年
2021年 | 6篇 |
2020年 | 8篇 |
2018年 | 13篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 12篇 |
2013年 | 17篇 |
2012年 | 16篇 |
2011年 | 16篇 |
2010年 | 20篇 |
2009年 | 15篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 12篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1972年 | 7篇 |
1971年 | 6篇 |
1970年 | 3篇 |
1967年 | 4篇 |
1966年 | 3篇 |
排序方式: 共有402条查询结果,搜索用时 15 毫秒
1.
The diffraction of plane surface gravitational waves by the edge of an ice cover lying on the surface of an incompressible fluid of infinitely great depth is considered. The ice cover is simulated by a thin elastic plate. The wave reflection and transmission coefficients are determined when it interacts with the ice cover. A wave field is constructed in the fluid under the conditions that a periodic lumped force and a lumped moment act on the edge of the ice cover. It is shown that as the incident wavelength increases the reflection coefficient tends to zero and the transmission coefficient tends to unity. 相似文献
2.
A. N. Bandura V. V. Chebotarev I. E. Garkusha V. A. Makhlay A. K. Marchenko D. G. Solyakov V. I. Tereshin S. A. Trubchaninov A. V. Tsarenko I. Landman 《Czechoslovak Journal of Physics》2004,54(3):C53
The paper presents experimental investigation of energy characteristics of the plasma streams generated with quasi—steady—state plasma accelerator QSPA Kh-50 and adjustment of plasma paramenters from the point of view its applicability for simulation of transient plasma heat loads expected for ITER disruptions and type I ELMs. Possibility of generation of high-power magnetized plasma streams with ion impact energy up to 0.6 keV, pulse length 0.25 ms and heat loads varied in wide range from 0.5 to 30 MJ/m2 has been demonstrated and some features of plasma interaction with tungsten targets in dependence on plasma heat loads are discussed. 相似文献
3.
A direct central collision of two identical bodies of revolution is studied. A nonstationary mixed boundary-value problem with an unknown moving boundary is formulated. Its solution is represented by a series in term of Bessel functions. An infinite system of Volterra equations of the second kind for the unknown expansion coefficients is derived by satisfying the boundary conditions. The basic characteristics of the collision process are determined depending on the curvature of the frontal surface of the bodies 相似文献
4.
5.
Yu. M. Berezanskii B. Ya. Levin V. A. Marchenko Yu. A. Mitropol''skii I. V. Ostrovskii 《Functional Analysis and Its Applications》1990,24(2):85-85
Obituary
Mark Grigor'evich Krein 相似文献6.
7.
Piot L Marchenko A Wu J Müllen K Fichou D 《Journal of the American Chemical Society》2005,127(46):16245-16250
The growth and structure of self-assembled adlayers of hexakis(n-dodecyl)-peri-hexabenzocoronene (HBC-C12) adsorbed on highly ordered pyrolitic graphite (HOPG) decorated by an n-pentacontane (n-C50H102) monolayer have been investigated by scanning tunneling microscopy (STM). Whereas on HOPG the HBC-C12 molecules readily self-assemble into a unique stable 2D structure, on the [n-C50H102 monolayer/graphite] system we observe morphological phase transitions with formation of time dependent alpha, beta, and gamma phases (alpha-->beta-->gamma). The initial alpha-phase is similar to that obtained on bare graphite, while intermediate beta- and final gamma-structures present molecular dimers and rows, respectively. The observed two-dimensional polymorphism is due to weak interaction between HBC-C12 molecules and n-C50H102-modified graphite substrate. Our results constitute an important step toward the control of the growth and structure of highly ordered monolayers of functional conjugated molecules by modifying the graphite surface with an n-alkane monolayer of appropriate chain length. 相似文献
8.
E. M. Belova N. G. Vais V. F. Sopin A. I. Kazakov Yu. I. Rubtsov G. B. Manelis G. N. Marchenko 《Russian Chemical Bulletin》1989,38(11):2244-2249
Complexing in the HNO3-CH2Cl2 system was confirmed tensimetrically. The kinetics of nitration of wood cellulose by the HNO3-CH2Cl2 mixture were investigated. A large part of the cellulose is nitrated in a first fast reaction in comparison to the HNO3-H2SO4 mixture with the same concentration of HNO3. The rate of the process is determined by the rate of diffusion of the HNO3, the rate of the process decreases more rapidly in the case of HNO3-CH2Cl2 than in the HNO3-H2SO4 mixture, which is probably due to the effect of CH2Cl2 on the diffusion coefficient of HNO3.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2445–2450, November, 1989. 相似文献
9.
The results of the oxidation of a number of 4-substituted 1,2-dimethyldecahydro-4-quinolones with hydrogen peroxide in methanol are in conformity with the results obtained by us earlier and confirm that the stereochemistry of the oxidation of nitrogen depends on the configuration of the methyl substituent in the 2 position of the decahydroquinoline ring. Under these conditions, the epimeric 1,2-dimethyl-trans-decahydro-4-quinolones undergo partial interisomerization at the 2 position to give a mixture of three N-oxides that correspond to both amino ketones. The oxidation of the corresponding ketals proceeds like the oxidation of amino alcohols without epimerization. It is thereby shown that the epimerization of the C2 center during the formation of the N-oxides from epimeric 1,2-dimethyl-trans-decahydro-4-quinolones occurs with the participation of the carbonyl group. 相似文献
10.
V. G. Beshenkov A. G. Znamenskii A. V. Irzhak V. A. Marchenko 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2018,12(5):861-865
The problem concerning the diagnostics of the phase composition of lead-zirconate-titanate (PZT) films under conditions of overlapping Raman spectra is solved via applied mathematical statistics. The proposed phase-identification method based on reference spectra is implemented using different Raman-spectrum regions measured on the surface of multiphase PZT films. It is demonstrated that the identification of phases, as well as determination of their concentration, must be performed using the spectral range in which the calculated first principal components of the set of Raman spectra differ to the greatest extent from each other. 相似文献