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   96849篇
  免费   3350篇
  国内免费   178篇
化学   59731篇
晶体学   507篇
力学   2385篇
综合类   5篇
数学   17102篇
物理学   20647篇
  2023年   666篇
  2022年   557篇
  2021年   1142篇
  2020年   1360篇
  2019年   1375篇
  2018年   1862篇
  2017年   1631篇
  2016年   3137篇
  2015年   2707篇
  2014年   2756篇
  2013年   5937篇
  2012年   6178篇
  2011年   6285篇
  2010年   3995篇
  2009年   3426篇
  2008年   5456篇
  2007年   5329篇
  2006年   4771篇
  2005年   4555篇
  2004年   3888篇
  2003年   3160篇
  2002年   2768篇
  2001年   1907篇
  2000年   1735篇
  1999年   1227篇
  1998年   944篇
  1997年   880篇
  1996年   1101篇
  1995年   800篇
  1994年   907篇
  1993年   865篇
  1992年   900篇
  1991年   764篇
  1990年   788篇
  1989年   694篇
  1988年   650篇
  1987年   627篇
  1986年   575篇
  1985年   841篇
  1984年   781篇
  1983年   586篇
  1982年   674篇
  1981年   666篇
  1980年   587篇
  1979年   550篇
  1978年   530篇
  1977年   480篇
  1976年   551篇
  1974年   494篇
  1973年   505篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Applications of Mathematics - Proper traffic simulation of electric vehicles, which draw energy from overhead wires, requires adequate modeling of traction infrastructure. Such vehicles include...  相似文献   
2.
3.
Set-Valued and Variational Analysis - In a Hilbert framework ℌ, we study the convergence properties of a Newton-like inertial dynamical system governed by a general maximally monotone...  相似文献   
4.
5.
Set-Valued and Variational Analysis - R. Tyrell Rockafellar and his collaborators introduced, in a series of works, new regression modeling methods based on the notion of superquantile (or...  相似文献   
6.

In this paper, we design a Branch and Bound algorithm based on interval arithmetic to address nonconvex robust optimization problems. This algorithm provides the exact global solution of such difficult problems arising in many real life applications. A code was developed in MatLab and was used to solve some robust nonconvex problems with few variables. This first numerical study shows the interest of this approach providing the global solution of such difficult robust nonconvex optimization problems.

  相似文献   
7.
Archiv der Mathematik - In this note, we introduce a criterion to detect vanishing of essential algebras of a Green biset functor by means of morphisms. We introduce the inflation morphism and...  相似文献   
8.
Set-Valued and Variational Analysis - The production correspondence associated with a technology maps every input vector into the set of output vectors that may be obtained by means of those...  相似文献   
9.
10.
A temperature control unit was implemented to vary the temperature of samples studied on a commercial Mobile Universal Surface Explorer nuclear magnetic resonance (MOUSE-NMR) apparatus. The device was miniaturized to fit the maximum MOUSE sampling depth (25 mm). It was constituted by a sample holder sandwiched between two heat exchangers placed below and above the sample. Air was chosen as the fluid to control the temperature at the bottom of the sample, at the interface between the NMR probe and the sample holder, in order to gain space. The upper surface of the sample was regulated by the circulation of water inside a second heat exchanger placed above the sample holder. The feasibility of using such a device was demonstrated first on pure water and then on several samples of bread dough with different water contents. For this, T1 relaxation times were measured at various temperatures and depths and were then compared with those acquired with a conventional compact closed-magnet spectrometer. Discussion of results was based on biochemical transformations in bread dough (starch gelatinization and gluten heat denaturation). It was demonstrated that, within a certain water level range, and because of the low magnetic field strength of the MOUSE, a linear relationship could be established between T1 relaxation times and the local temperature in the dough sample.  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