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   191906篇
  免费   31250篇
  国内免费   22915篇
化学   116121篇
晶体学   2357篇
力学   12221篇
综合类   630篇
数学   24284篇
物理学   90458篇
  2023年   1834篇
  2022年   2300篇
  2021年   3103篇
  2020年   4062篇
  2019年   4717篇
  2018年   4925篇
  2017年   5337篇
  2016年   6564篇
  2015年   5590篇
  2014年   6813篇
  2013年   10389篇
  2012年   11284篇
  2011年   13063篇
  2010年   14008篇
  2009年   14261篇
  2008年   9047篇
  2007年   8236篇
  2006年   7468篇
  2005年   7141篇
  2004年   7353篇
  2003年   6203篇
  2002年   5881篇
  2001年   5849篇
  2000年   4572篇
  1999年   4524篇
  1998年   3984篇
  1997年   3640篇
  1996年   3971篇
  1995年   4124篇
  1994年   4225篇
  1993年   4141篇
  1992年   3697篇
  1991年   3386篇
  1990年   2993篇
  1989年   2971篇
  1988年   2796篇
  1987年   2094篇
  1986年   2098篇
  1985年   1817篇
  1984年   1905篇
  1983年   1209篇
  1982年   1672篇
  1981年   1433篇
  1980年   1396篇
  1979年   1305篇
  1978年   1309篇
  1977年   1376篇
  1976年   1869篇
  1973年   1221篇
  1972年   1234篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
Crystallography Reports - The review presents the important unique results of the cycle of research led by M.V. Kovalchuk on the fundamental patterns of protein interactions and the protein...  相似文献   
2.
Journal of Applied Mechanics and Technical Physics - A method for determining the empirical dependence of the rheological properties of rocks on stresses has been developed and tested in...  相似文献   
3.
The surface charge is a key concept in electrochemistry. Mathematically, the surface charge is obtained from a spatial integration of the volume charge along a particular direction. Ambiguities thus arise in choosing the starting and ending points of the integration. As for electrocatalytic interfaces, the presence of chemisorbates further complicates the situation. In this minireview, I adopt a definition of the surface charge within a continuum picture of the electric double layer. I will introduce surface charging behaviors of firstly ordinary electrochemical interfaces and then electrocatalytic interfaces featuring partially charged chemisorbates. Particularly, the origin of nonmonotonic surface charging behaviors of electrocatalytic interfaces is explained using a primitive model. Finally, a brief account of previous studies on the nonmonotonic surface charging behavior is presented, as a subline of the spectacular history of electric double layer.  相似文献   
4.
In this paper,we consider the deformed Hermitian-Yang-Mills equation on closed almost Hermitian manifolds.In the case of the hypercritical phase,we derive a priori estimates under the existence of an admissible C-subsolution.As an application,we prove the existence of solutions for the deformed Hermitian-Yang-Mills equation under the condition of existence of a supersolution.  相似文献   
5.
Journal of Analytical Chemistry - A review of works in developing optical multisensor systems, a new class of specialized spectroscopic analyzers, is presented. The development and use of such...  相似文献   
6.
Bo  Luo  Gao  Wei  Yu  Yuguo  Chen  Xiaojun 《Nonlinear dynamics》2022,110(1):281-311
Nonlinear Dynamics - The perovskite solar cell (PSC) is one of the most promising photovoltaic candidates along with the highly increasing demand for green electricity. One of the main concerns...  相似文献   
7.
Acta Mathematica Sinica, English Series - We are interested in the existence and asymptotic behavior for the least energy solutions of the following fractional eigenvalue problem $$\left({\rm{P}}...  相似文献   
8.
9.
10.
In this paper, the problem of the uniform stability for a class of fuzzy fractional-order genetic regulatory networks with random discrete delays, distributed delays, and parameter uncertainties is studied. Although there is a portion of literature on using fixed point theorems to study the stability of fractional neural networks, most of them required the fractional order to be in 1 2 , 1 . However, the case of the fractional-order belonging to ( 0 , 1 2 ) has not been discussed. To solve it, this work proposes a novel idea of using fixed point theory to study the stability of fuzzy (0,1) order neural networks, the problem of the uniqueness of the solution of the considered genetic regulatory networks is resolved, and a novel sufficient condition to guarantee the uniform stability of above genetic regulatory networks is also derived. Eventually, an example is given to demonstrate that the obtained result is effective.  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