全文获取类型
收费全文 | 21396篇 |
免费 | 2714篇 |
国内免费 | 1576篇 |
专业分类
电工技术 | 2791篇 |
技术理论 | 1篇 |
综合类 | 2842篇 |
化学工业 | 2815篇 |
金属工艺 | 513篇 |
机械仪表 | 1070篇 |
建筑科学 | 1771篇 |
矿业工程 | 767篇 |
能源动力 | 505篇 |
轻工业 | 1160篇 |
水利工程 | 1073篇 |
石油天然气 | 1045篇 |
武器工业 | 219篇 |
无线电 | 1898篇 |
一般工业技术 | 1563篇 |
冶金工业 | 1108篇 |
原子能技术 | 157篇 |
自动化技术 | 4388篇 |
出版年
2024年 | 110篇 |
2023年 | 332篇 |
2022年 | 593篇 |
2021年 | 742篇 |
2020年 | 735篇 |
2019年 | 660篇 |
2018年 | 664篇 |
2017年 | 754篇 |
2016年 | 885篇 |
2015年 | 887篇 |
2014年 | 1287篇 |
2013年 | 1343篇 |
2012年 | 1608篇 |
2011年 | 1681篇 |
2010年 | 1240篇 |
2009年 | 1270篇 |
2008年 | 1221篇 |
2007年 | 1317篇 |
2006年 | 1279篇 |
2005年 | 1067篇 |
2004年 | 875篇 |
2003年 | 833篇 |
2002年 | 711篇 |
2001年 | 548篇 |
2000年 | 508篇 |
1999年 | 408篇 |
1998年 | 342篇 |
1997年 | 272篇 |
1996年 | 245篇 |
1995年 | 197篇 |
1994年 | 188篇 |
1993年 | 146篇 |
1992年 | 123篇 |
1991年 | 103篇 |
1990年 | 90篇 |
1989年 | 89篇 |
1988年 | 58篇 |
1987年 | 35篇 |
1986年 | 29篇 |
1985年 | 28篇 |
1984年 | 21篇 |
1983年 | 18篇 |
1982年 | 29篇 |
1981年 | 13篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1977年 | 7篇 |
1964年 | 12篇 |
1961年 | 5篇 |
1955年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
The stability of stochastic functional differential equation with Markovian switching was studied by several authors,but there was almost no work on the stability of the neutral stochastic functional differential equations with Markovian switching.The aim of this article is to close this gap.The authors establish Razumikhin-type theorem of the neutral stochastic functional differential equations with Markovian switching,and those without Markovian switching. 相似文献
22.
RADIOIMMUNOTOXICOLOGICALEFFECTOFENRICHEDURANIUMONCENTRALANDPERIPHERALIMMUNECELLSANDTHEPROTECTIVEACTIONOFIL-1ANDIL-2¥ZhuShoupe... 相似文献
23.
24.
25.
A stochastic differential equation involving both a Wiener process and fractional Brownian motion, with nonhomogeneous coefficients and random initial condition, is considered. The coefficients and initial condition depend on a parameter. The assumptions on the coefficients and the initial condition supplying continuous dependence of the solution on a parameter, with respect to the Besov space norm, are established. 相似文献
26.
In this paper, we shall establish sufficient conditions for the existence of mild solutions for nonlocal impulsive differential inclusions. On the basis of the fixed point theorems for multivalued maps and the technique of approximate solutions, new results are obtained. Examples are also provided to illustrate our results. 相似文献
27.
A simple controller synthesis method is developed for certain classes of linear, time-invariant, multi-input multi-output plants. The number of poles in each entry of these controllers depends on the number of right-half plane plant zeros, and is independent of the number of poles of the plant to be stabilized. Furthermore, these controllers have integral-action so that they achieve asymptotic tracking of step input references with zero steady-state error. The designed controller’s poles and zeros are all in the stable region with the exception of one pole at the origin for the integral-action design requirement. The freedom available in the design parameters may be used for additional performance objectives, although the only goal here is stabilization and tracking of constant references. 相似文献
28.
Marie-Nathalie Contou-Carrere Yiannis N. Kaznessis Prodromos Daoutidis 《Systems & Control Letters》2011,60(1):75-86
This paper addresses the model reduction problem for a class of stiff chemical Langevin equations that arise as models of biomolecular networks with fast and slow reactions and can be described as continuous Markov processes. Initially, a coordinate transformation is sought that allows the decoupling of fast and slow variables in the model equations. Necessary and sufficient conditions are derived for such a linear transformation to exist, along with an explicit change of variables which achieves the desired decoupling. For the systems for which this step is applicable, the method of adiabatic elimination is applied to determine a representation of the slow dynamics. Theoretical concepts and results are illustrated with simple examples. 相似文献
29.
We prove the existence of optimal relaxed controls as well as strict optimal controls for systems governed by non linear forward-backward stochastic differential equations (FBSDEs). Our approach is based on weak convergence techniques for the associated FBSDEs in the Jakubowski S-topology and a suitable Skorokhod representation theorem. 相似文献
30.
针对电力系统经济负荷分配问题,提出一种有效的差分蜂群算法.受差分进化算法的启发,该算法基于差分进化操作改进了雇佣蜂的搜索方式,提高了探索能力和收敛速度.此外,提出一种有效的修复机制以保证新个体的可行性.该算法在带有阀点效应和多燃料特征的典型电力系统经济负荷分配问题上进行了测试.仿真结果验证了所提算法的有效性. 相似文献