全文获取类型
收费全文 | 40463篇 |
免费 | 4622篇 |
国内免费 | 3768篇 |
专业分类
电工技术 | 3306篇 |
技术理论 | 2篇 |
综合类 | 7022篇 |
化学工业 | 1792篇 |
金属工艺 | 845篇 |
机械仪表 | 2741篇 |
建筑科学 | 2833篇 |
矿业工程 | 830篇 |
能源动力 | 814篇 |
轻工业 | 2532篇 |
水利工程 | 1061篇 |
石油天然气 | 885篇 |
武器工业 | 500篇 |
无线电 | 5378篇 |
一般工业技术 | 4001篇 |
冶金工业 | 910篇 |
原子能技术 | 531篇 |
自动化技术 | 12870篇 |
出版年
2024年 | 171篇 |
2023年 | 530篇 |
2022年 | 937篇 |
2021年 | 1023篇 |
2020年 | 1080篇 |
2019年 | 1010篇 |
2018年 | 1020篇 |
2017年 | 1232篇 |
2016年 | 1354篇 |
2015年 | 1432篇 |
2014年 | 2156篇 |
2013年 | 2429篇 |
2012年 | 2825篇 |
2011年 | 3045篇 |
2010年 | 2397篇 |
2009年 | 2595篇 |
2008年 | 2703篇 |
2007年 | 3098篇 |
2006年 | 2745篇 |
2005年 | 2434篇 |
2004年 | 2054篇 |
2003年 | 1699篇 |
2002年 | 1413篇 |
2001年 | 1189篇 |
2000年 | 1052篇 |
1999年 | 871篇 |
1998年 | 705篇 |
1997年 | 608篇 |
1996年 | 548篇 |
1995年 | 492篇 |
1994年 | 417篇 |
1993年 | 294篇 |
1992年 | 266篇 |
1991年 | 218篇 |
1990年 | 199篇 |
1989年 | 178篇 |
1988年 | 117篇 |
1987年 | 71篇 |
1986年 | 39篇 |
1985年 | 36篇 |
1984年 | 27篇 |
1983年 | 34篇 |
1982年 | 25篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1964年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
71.
The structure of a canalizing function is discussed. Using a new matrix product, namely semitensor product,
the logical function is expressed in its matrix form. From its matrix expression, a criterion is obtained to test whether a
logical function is a canalizing function. Then a formula is obtained to calculate the number of canalizing functions. Moreover,
an algorithm is presented to generate canalizing functions. Finally, some results obtained are extended to seminested
canalizing functions. 相似文献
72.
73.
Sangmun Shin Nguyen Khoa Viet Truong Byung Rae Cho Sung Hoon Hong 《Computers & Industrial Engineering》2011
Robust design (RD) and tolerance design (TD) have received much attention from researchers and practitioners for more than two decades, and a number of methodologies for modeling and optimizing the RD and TD processes have been studied. However, there is ample room for improvement. Because most existing research considers RD and TD as separate research fields, the primary objective of this paper is to develop a sequential robust–tolerance design method to jointly determine the best factor settings and the closed-form solutions for the optimal specification limits. We then apply the proposed method to a destructive quality characteristic. Finally, a case study and sensitivity analyses are performed for verification purposes, and further studies are discussed. 相似文献
74.
Joan Goh Ahmad Abd. MajidAhmad Izani Md. Ismail 《Computers & Mathematics with Applications》2011,62(12):4492-4498
In the present paper, the cubic B-splines method is considered for solving one-dimensional heat and wave equations. A typical finite difference approach had been used to discretize the time derivative while the cubic B-spline is applied as an interpolation function in the space dimension. The accuracy of the method for both equations is discussed. The efficiency of the method is illustrated by some test problems. The numerical results are found to be in good agreement with the exact solution. 相似文献
75.
We introduce a machine learning-based classifier that identifies free radio channels for cognitive radio. The architecture is designed for nanoscale implementation, under nanoscale implementation constraints; we do not describe all physical details but believe future physical implementation to be feasible. The system uses analog computation and consists of cyclostationary feature extraction and a radial basis function network for classification. We describe a model for nanoscale faults in the system, and simulate experimental performance and fault tolerance in recognizing WLAN signals, under different levels of noise and computational errors. The system performs well under expected non-ideal manufacturing and operating conditions. 相似文献
76.
This paper presents a systematic approach for decreasing conservativeness in stability analysis and control design for Takagi-Sugeno (TS) systems. This approach is based on the idea of multiple Lyapunov functions together with simple techniques for introducing slack matrices. Unlike some previous approaches based on multiple Lyapunov functions, both the stability and the stabilization conditions are written as linear matrix inequality (LMI) problems. The proposed approach reduces the number of inequalities and guarantees extra degrees of freedom to the LMI problems. Numeric examples illustrate the effectiveness of this method. 相似文献
77.
78.
79.
梁锡坤 《计算机应用与软件》2009,26(4)
从B样条基函数出发,通过参数变换,导出B样条函数类的概念,讨论了它们的性质.给出B样条类曲线和附加权因子的B样条类曲线的理论,研究了它们与B样条曲线的关系.提出B样条曲线重新参数化因子的概念,探讨通过基函数的重新参数化实现B样条曲线的重新参数化的方法.结果表明,该方法具有较好的通用性以及计算简单、便于操作等特点. 相似文献
80.