首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   455篇
  免费   1篇
化学   222篇
晶体学   3篇
力学   17篇
数学   50篇
物理学   164篇
  2022年   3篇
  2020年   4篇
  2019年   7篇
  2018年   12篇
  2017年   12篇
  2016年   12篇
  2014年   11篇
  2013年   12篇
  2012年   12篇
  2011年   16篇
  2010年   17篇
  2009年   25篇
  2008年   21篇
  2007年   20篇
  2006年   16篇
  2005年   12篇
  2004年   15篇
  2003年   8篇
  2002年   12篇
  2001年   8篇
  2000年   12篇
  1999年   5篇
  1998年   8篇
  1997年   8篇
  1996年   9篇
  1994年   8篇
  1993年   9篇
  1992年   6篇
  1990年   2篇
  1989年   5篇
  1988年   6篇
  1987年   5篇
  1986年   9篇
  1985年   6篇
  1984年   13篇
  1983年   8篇
  1982年   3篇
  1981年   6篇
  1980年   4篇
  1979年   3篇
  1978年   5篇
  1977年   9篇
  1976年   3篇
  1975年   4篇
  1974年   5篇
  1973年   5篇
  1972年   12篇
  1971年   8篇
  1970年   2篇
  1967年   3篇
排序方式: 共有456条查询结果,搜索用时 15 毫秒
1.
New lower bounds for probabilities of large deviations of tests and estimators are proposed. These bounds cover the cases of moderate and Cramér-type large deviations. Bibliography: 12 titles. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 216, 1994, pp. 52–61. Translated by the author.  相似文献   
2.
The influence exerted by the nature and concentration of a number of organic and mineral acids on the composition of products formed in electric-spark dispersion of aluminum was studied.  相似文献   
3.
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   
4.
The impedance spectra of Pb5Ge3O11 single crystals are measured in the frequency range from 5 Hz to 13 MHz at temperatures of 600 to 800 K in dry air and in a dry or wet nitrogen gas. It is found that the temperature and the gas composition significantly affect the electrical properties of the compound. The data obtained are used to discuss the origin of crystal lattice defects and their influence on charge transfer. It is concluded that the conduction is mixed in character (p-type electronic and ionic due to oxygen ions). The proton conduction is shown experimentally to be feasible. The possible mechanisms of proton transport in Pb5Ge3O11 are discussed.  相似文献   
5.
6.
We consider the problem of signal detection in the heteroscedastic Gaussian white noise when the set of alternatives is essentially nonparametric. In this setting, we find a family of asymptotically minimax tests. The results are extended to the case of testing a parametric hypothesis against nonparametric sets of alternatives. Bibliography: 8 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 320, 2004, pp. 54–68.  相似文献   
7.
8.
9.
Reactions of 3-(ω-haloalkoxy)-2-hydroxypropyl sulfamates with amines or ammonia followed by acid hydrolysis give the corresponding diaminohydroxyethers. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1663–1665, August, 1998.  相似文献   
10.
We study the asymptotic behavior of Bayesian and maximum likelihood estimators of the parameter when the density function f(x, ) for each fixed x has discontinuities in on some surface.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 74, pp. 83–107, 1977.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号