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   8736篇
  免费   24篇
  国内免费   4篇
化学   5504篇
晶体学   116篇
力学   282篇
数学   1135篇
物理学   1727篇
  2019年   100篇
  2018年   163篇
  2017年   164篇
  2016年   198篇
  2015年   82篇
  2014年   198篇
  2013年   243篇
  2012年   249篇
  2011年   259篇
  2010年   249篇
  2009年   229篇
  2008年   229篇
  2007年   230篇
  2006年   169篇
  2005年   151篇
  2004年   145篇
  2003年   148篇
  2002年   154篇
  2001年   117篇
  2000年   84篇
  1998年   111篇
  1997年   109篇
  1995年   112篇
  1994年   105篇
  1993年   105篇
  1992年   119篇
  1991年   132篇
  1990年   122篇
  1989年   123篇
  1988年   118篇
  1987年   148篇
  1986年   154篇
  1985年   135篇
  1984年   129篇
  1983年   142篇
  1982年   137篇
  1981年   136篇
  1980年   129篇
  1979年   160篇
  1978年   192篇
  1977年   247篇
  1976年   273篇
  1975年   192篇
  1974年   188篇
  1973年   193篇
  1972年   189篇
  1971年   150篇
  1970年   129篇
  1969年   110篇
  1968年   119篇
排序方式: 共有8764条查询结果,搜索用时 15 毫秒
51.
Novosibirsk. Translated fromSibirskiî Matematicheskiî Zhurnal, Vol. 33, No. 6, pp. 195–198, November–December, 1992.  相似文献   
52.
Universidade de Beira Interior, Portugal: and S. P. Timoshenko Institute of Mechanics, National Academy of Sciences of the Ukraine, Kiev. Translated from Prikladnaya Mekhanika, Vol. 31. No. 11, pp. 3–10, November, 1995.  相似文献   
53.
54.
A scheme of magnetic calorimeter for registration of rare events characterized by small energy release (cosmic rays, WIMPs, solitary X-ray quanta) is proposed. The calorimeter is brought to operation by adiabatic demagnetization, and its magnetic response is measured by a quantum interferometer (SQUID, A. Barone and G. Paterno, Physics and applications of Josephson Effect). Special consideration is given to the specific features of calorimeter operation in the ferromagnetic transition region. The trigger registration of ultrasmall energy release by a ferromagnetic system in the metastable state is described.  相似文献   
55.
We carry out a detailed analysis of the existence, asymptotics, and stability problems for periodic solutions that bifurcate from the zero equilibrium state in systems with large delay. The account is based on a specific meaningful example given by a certain scalar nonlinear second-order differential-difference equation that is a mathematical model of a single-circuit RCL oscillator with delay in a feedback loop. Original Russian Text ? A.Yu. Kolesov, E.F. Mishchenko, N.Kh. Rozov, 2007, published in Trudy Matematicheskogo Instituta imeni V.A. Steklova, 2007, Vol. 259, pp. 106–133.  相似文献   
56.
It is shown that the coneigenvalues of a matrix, when properly defined (in a way different from the one commonly used in the literature), obey relations similar to the classical inequalities between the (ordinary) eigenvalues and singular values. Several interesting spectral properties of conjugate-normal matrices are indicated. This matrix class plays the same role in the theory of unitary congruences as the class of normal matrices plays in the theory of unitary similarities. Bibliography: 5 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 334, 2006, pp. 111–120.  相似文献   
57.
58.
The temperature and concentration dependences of the electron work function (EWF) of rubidium, cesium, and nine Rb-Cs alloys are studied by the Fowler photoelectric method under the conditions of an ultra-high vacuum. It is shown that the polytherms of the electron work function for the pure components and alloys decrease by a linear law with increasing temperature. Based on the experimental data obtained, it is concluded that the concentration dependence of the EWF for the binary Rb-Cs system has a linear (additive) character within the limits of experimental error (about 1%). The presence of the azeotropic point on the state diagram of the system is not visualized in the concentration dependence of the work function.  相似文献   
59.
The features of structural phase transitions that occur under high pressure are studied. The density functional theory is used to calculate the B1–B2 phase transition pressure as a function of the crystal size for small-sized alkali halide crystals. A size effect (an increase in the phase transition pressure as the crystal grain radius decreases) is revealed for the B1–B2 transitions in all halogen compounds except for lithium fluoride, for which the dependence is inverse.  相似文献   
60.
The molecular crystal structure of 4-phenyl-3,5-diethoxycarbonyl-1,2,6-trimethyl-1,2-dihydropyridine has been investigated by x-ray structural analysis. The three-dimensional structural properties of the molecule have been compared against the large observed reactivity of the 3-ethoxycarbonyl group with respect to nucleophilic substitution reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1236–1239, September, 1991.  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