首页 | 官方网站   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   1515篇
  免费   58篇
  国内免费   2篇
工业技术   1575篇
  2023年   17篇
  2022年   31篇
  2021年   48篇
  2020年   42篇
  2019年   54篇
  2018年   51篇
  2017年   53篇
  2016年   43篇
  2015年   33篇
  2014年   46篇
  2013年   154篇
  2012年   65篇
  2011年   75篇
  2010年   74篇
  2009年   54篇
  2008年   54篇
  2007年   50篇
  2006年   44篇
  2005年   31篇
  2004年   21篇
  2003年   21篇
  2002年   17篇
  2001年   10篇
  2000年   20篇
  1999年   27篇
  1998年   29篇
  1997年   36篇
  1996年   25篇
  1995年   24篇
  1994年   28篇
  1993年   27篇
  1992年   22篇
  1991年   26篇
  1990年   14篇
  1989年   21篇
  1988年   16篇
  1987年   19篇
  1986年   14篇
  1985年   23篇
  1984年   22篇
  1983年   10篇
  1982年   8篇
  1981年   11篇
  1980年   10篇
  1979年   7篇
  1978年   9篇
  1977年   6篇
  1976年   8篇
  1975年   5篇
  1973年   5篇
排序方式: 共有1575条查询结果,搜索用时 15 毫秒
21.
22.
A compression moulded Kevlar-phenolic resin composite consisting of 30 wt% continuous fibres was slid against a steel disc such that the fibre axis was normal to the sliding plane. The sliding experiments were conducted in a normal pressure range of 0.47–4.27 MPa and at a sliding speed of 0.5 ms–1. The initial sliding interaction is abrasive. With further sliding, as patches of polymer transfer film develop on the polymer pin and counterface, the interaction becomes adhesive and steady-state friction is established. The wear resistance of the polymer was found to be related to the stability of this film.  相似文献   
23.
Model-Based Diagnosis of Hybrid Systems   总被引:3,自引:0,他引:3  
Techniques for diagnosing faults in hybrid systems that combine digital (discrete) supervisory controllers with analog (continuous) plants need to be different from those used for discrete or continuous systems. This paper presents a methodology for online tracking and diagnosis of hybrid systems. We demonstrate the effectiveness of the approach with experiments conducted on the fuel-transfer system of fighter aircraft  相似文献   
24.
Reports the nearly ideal electrical characteristics of p-Ge/N-GaAs heterojunction diodes grown by molecular beam epitaxy. The temperature and device size dependencies of the current-voltage characteristics have been investigated. At room temperature, unity ideality factor has been demonstrated over almost six decades of current.<>  相似文献   
25.
Calmodulin (CaM) has been reported to have affinity for the estrogen receptor (ER). Observations reported here reveal a direct physical interaction between purified CaM and ER. This direct ER-CaM interaction may be an initial event preceding the assembly of ER plus auxiliary proteins into the active ER complex with its DNA motif, the estrogen response element. We demonstrate that CaM is an integral component of this complex by using a system reconstituted from purified ER and nuclear extract from ER-negative breast cancer cells and also with ER-depleted nuclear extract of an ER-positive breast cancer cell line. Although CaM is essential for formation of this complex, it is not sufficient, suggesting roles also of auxiliary proteins. CaM also is functionally required for activation of an ER-responsive promoter, in the 17beta-estradiol-ER pathway of hormone action and regulation of 17beta-estradiol-responsive gene expression that is associated with proliferation of mammary epithelial cells.  相似文献   
26.
27.
Water Resources Management - Reference evapotranspiration (ET0) is a crucial element for deriving irrigation scheduling of major crops. Thus, precise projection of ET0 is essential for better...  相似文献   
28.
It is shown that if the root-mean-square of the gradient of the phase fluctuation of either of the components exceeds the corresponding inverse of the coherence length or if the chemical potential exceeds 1 0 or 2 0 , where is the volume integrals of the interaction function between the components, and 1 0 , 2 0 are the densities of the two components, the mixture of two rotating superfluids has an instability.  相似文献   
29.
The Journal of Supercomputing - In this article, the authors suggested a rotation-invariant local binary pattern-based weighted generalized closest neighbor (RILBP-WGCN) method for HSI...  相似文献   
30.
Microsystem Technologies - Single-Walled Carbon Nanotubes (SWCNTs) are widely used as potential carriers in drug delivery systems. The objective of this work was to observe the effects of pristine,...  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-23

京公网安备 11010802026262号