全文获取类型
收费全文 | 1193篇 |
免费 | 5篇 |
专业分类
化学 | 475篇 |
晶体学 | 13篇 |
力学 | 20篇 |
数学 | 161篇 |
物理学 | 529篇 |
出版年
2021年 | 12篇 |
2020年 | 16篇 |
2019年 | 20篇 |
2018年 | 30篇 |
2017年 | 41篇 |
2016年 | 29篇 |
2015年 | 21篇 |
2014年 | 45篇 |
2013年 | 38篇 |
2012年 | 37篇 |
2011年 | 50篇 |
2010年 | 49篇 |
2009年 | 35篇 |
2008年 | 32篇 |
2007年 | 43篇 |
2006年 | 39篇 |
2005年 | 28篇 |
2004年 | 25篇 |
2003年 | 32篇 |
2002年 | 28篇 |
2001年 | 37篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 19篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 18篇 |
1987年 | 15篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 14篇 |
1981年 | 20篇 |
1980年 | 14篇 |
1979年 | 11篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1974年 | 20篇 |
1973年 | 14篇 |
1972年 | 17篇 |
1969年 | 13篇 |
1968年 | 11篇 |
1966年 | 10篇 |
排序方式: 共有1198条查询结果,搜索用时 31 毫秒
1.
2.
V. D. Orlov Z. Kaluski N. P. Borob'eva E. Figas A. A. Tishchenko F. G. Yaremko 《Chemistry of Heterocyclic Compounds》1994,30(8):964-971
We have measured the PMR spectra of 5, 7-diaryl-1, 4-diazabicyclo[4. ].O]hept-4-enes. We have studied the structure of the 5-(4-nitrophenyl)-7-phenyl derivative by x-ray diffraction. We show that the six-membered heterocycle has the half-chair form. The 6-H and 7-H protons of the aziridine ring are trans, while the 7-aryl is exo relative to the six-membered ring. Introduction of substituents into the aromatic ring has practically no effect on the geometry of the bicycle.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1117–1124, August, 1994.For Communication 11, see [1]. 相似文献
3.
V. V. Orlov 《Optics and Spectroscopy》2002,92(4):619-631
The wave field arising at reconstruction of volume volume-superimposed holograms was studied taking into account the multiple wave diffraction at hologram gratings. The theory is based on the wave field concept in the form of a superposition of hologram modes. Superimposed hologram modes were found. 相似文献
4.
5.
6.
We present the results of a study and substantiation of the method of polygaussian approximation of an electrocardiographic (ECG) signal against interference background during computer analysis of that signal. It is proposed to use adaptive processing of ECG signals, which allows one to increase the signal-to-interference ratio by over 7 dB. 相似文献
7.
N. B. Voznesensky E. V. Gavrilov A. P. Zhevlakov V. K. Kirillovskiĭ P. V. Orlov 《Technical Physics》2007,52(2):271-275
Methods and schemes to inspect the EUV mirror shape are developed on the basis of a point diffraction interferometer with computer processing of interferograms. A measurement accuracy to within 0.001 of a wavelength in the visual range is achieved. 相似文献
8.
A. S. Boreysho S. L. Druzhinin V. M. Malkov I. A. Kiselev A. V. Morozov A. E. Orlov A. V. Savin I. V. Shatalov V. I. Zapryagaev A. V. Sobolev 《Thermophysics and Aeromechanics》2007,14(4):561-576
The matter of development of a high-performance pressure recovery system (PRS) for a high-power HF/DF laser is discussed.
A sequence of design steps is proposed, which involves estimation of basic characteristics of PRS components with the help
of one-dimensional integral and semi-empirical procedures; simulation, to be performed using three-dimensional non-stationary
Navier — Stokes equations; experimental modelling aimed at verification of the calculation procedures and at refinement of
obtained parameters; and a fullscale experiment. An ejector-type system providing for recovery of pressure from 12 Torr to
atmospheric pressure in the gas-dynamic system of an HF/DF laser of several-tens-kilowatt power is developed. Matching conditions
for parameters of individual PRS components as well as joint functioning of the PRS with a continuous chemical laser in an
integral complex are analysed. Conditions for minimization of mass-dimensional characteristics of the laser-PRS complex necessary
for the development of ground-based mobile systems are identified. 相似文献
9.
The mean busy period of an infinite multilinear queue with a doubly stochastic flow of incoming queries having two intensities and exponential server is calculated. 相似文献
10.