全文获取类型
收费全文 | 794篇 |
免费 | 5篇 |
专业分类
化学 | 307篇 |
晶体学 | 96篇 |
力学 | 32篇 |
数学 | 57篇 |
物理学 | 307篇 |
出版年
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 22篇 |
2018年 | 22篇 |
2017年 | 22篇 |
2016年 | 13篇 |
2015年 | 12篇 |
2014年 | 25篇 |
2013年 | 29篇 |
2012年 | 31篇 |
2011年 | 24篇 |
2010年 | 18篇 |
2009年 | 27篇 |
2008年 | 31篇 |
2007年 | 27篇 |
2006年 | 24篇 |
2005年 | 27篇 |
2004年 | 16篇 |
2003年 | 27篇 |
2002年 | 30篇 |
2001年 | 28篇 |
2000年 | 26篇 |
1999年 | 9篇 |
1998年 | 10篇 |
1996年 | 11篇 |
1995年 | 7篇 |
1994年 | 14篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 14篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 10篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1974年 | 9篇 |
1973年 | 6篇 |
1970年 | 7篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1963年 | 6篇 |
排序方式: 共有799条查询结果,搜索用时 335 毫秒
1.
2.
Crystallography Reports - Nd1 – yEuyF3 – y crystals (y is the molar fraction of EuF2; 0 ≤ y ≤ 0.15) with a tysonite (LaF3) structure have... 相似文献
3.
4.
D. N. Karimov E. A. Krivandina Z. I. Zhmurova B. P. Sobolev V. A. Bezhanov S. P. Chernov G. M. Shapochkin 《Crystallography Reports》2006,51(6):1009-1015
Crystalline materials that are transparent in the vacuum UV spectral region and currently used have been reviewed. Transmission of crystals of solid solutions with the fluorite structure Ca1?x R xF2+x (R = Sc, Y, La, Yb, Lu) in the UV and vacuum UV spectral regions has been investigated. It is shown that application of different methods of purification of fluorides from some impurities can significantly improve the optical quality of fluoride multicomponent crystals in the short-wavelength spectral region. 相似文献
5.
The results of investigations of the rheological characteristics and electrical resistance of the suspensions of carbon black in vaseline oil under the effects of shear and vibration were presented. The investigations are carried out on an original unit that allowed one to simultaneously subject the suspensions to shear deformation and orthogonal vibration. The electrical resistance was also measured in an ac pulsed low-voltage mode. Possible mechanisms of the suspension conductivity were considered depending on the regime of dynamic action. 相似文献
6.
For either of the two reflection spectra of cadmium difluoride that are known from experiments, a complete set of the fundamental
optical functions is calculated in the energy range 4–45 eV with the Kramers-Kronig relationships. The basic features of the
optical spectra are established, and a hypothesis for their origin is suggested based on the known theoretical results for
the band structure. 相似文献
7.
V. P. Koshelets S. V. Shitov L. V. Filippenko P. N. Dmitriev A. N. Ermakov A. S. Sobolev M. Yu. Torgashin 《Radiophysics and Quantum Electronics》2003,46(8-9):618-630
We overview recent achievements in the field of cryogenic submillimeter-wave receivers based on superconductor–insulator–superconductor (SIS) tunnel junctions. The main attention is paid to the novel superconducting integrated receivers (SIRs) with an on-chip superconducting local oscillator. The single-chip microcircuit of the receiver, which integrates a quantum mixer based on the nonlinearity of a quasi-particle current in the SIS junction, a planar superconducting receiving antenna, and a cryogenic local oscillator, is described. Being dc-powered only by batteries, such a microcircuit operates as a submillimeter-wave superheterodyne receiver without any additional microwave equipment. Such receivers are very attractive for radioastronomical research, space communication systems, and monitoring of the environment from satellites, balloons, and special aircraft. A breadboard of a superconducting spectrometer with a phase-locked flux-flow oscillator (FFO) has been developed and tested. A frequency resolution better than 10 kHz was reached at a frequency of 365 GHz. We describe a balloon-borne 500-650 GHz integrated spectrometer for oblique atmospheric sounding, developed for the international Terahertz Limb Sounder (TELIS) project. The first flight is scheduled for 2005. 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.
L. A. Chetkina V. E. Zavodnik A. N. Sobolev V. K. Bel'skii B. P. Bespalov A. G. Abolin 《Journal of Structural Chemistry》1991,32(3):442-445
L. Ya. Karpov Physical Chemical Research Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 3, pp. 141–144, May–June, 1991. 相似文献
10.