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   6650篇
  免费   235篇
  国内免费   24篇
电工技术   82篇
综合类   10篇
化学工业   1333篇
金属工艺   233篇
机械仪表   196篇
建筑科学   148篇
矿业工程   7篇
能源动力   493篇
轻工业   572篇
水利工程   74篇
石油天然气   92篇
武器工业   2篇
无线电   724篇
一般工业技术   1403篇
冶金工业   788篇
原子能技术   64篇
自动化技术   688篇
  2023年   110篇
  2022年   221篇
  2021年   254篇
  2020年   232篇
  2019年   207篇
  2018年   302篇
  2017年   250篇
  2016年   238篇
  2015年   162篇
  2014年   235篇
  2013年   496篇
  2012年   280篇
  2011年   332篇
  2010年   254篇
  2009年   265篇
  2008年   255篇
  2007年   188篇
  2006年   184篇
  2005年   106篇
  2004年   94篇
  2003年   98篇
  2002年   82篇
  2001年   61篇
  2000年   81篇
  1999年   92篇
  1998年   222篇
  1997年   149篇
  1996年   136篇
  1995年   99篇
  1994年   85篇
  1993年   84篇
  1992年   69篇
  1991年   62篇
  1990年   51篇
  1989年   66篇
  1988年   50篇
  1987年   48篇
  1986年   59篇
  1985年   70篇
  1984年   53篇
  1983年   57篇
  1982年   59篇
  1981年   57篇
  1980年   53篇
  1979年   49篇
  1978年   29篇
  1977年   41篇
  1976年   46篇
  1974年   30篇
  1973年   26篇
排序方式: 共有6909条查询结果,搜索用时 734 毫秒
91.
Sharma  Shalini  Chou  Jerry 《The Journal of supercomputing》2021,77(10):10896-10920
The Journal of Supercomputing - Travelling salesman problem (TSP) is a graph problem that has been widely used in many applications, especially for transportation and logistics. Because TSP is a NP...  相似文献   
92.
Neural Computing and Applications - This work presents an efficient hybridized approach for the classification of electrocardiogram (ECG) samples into crucial arrhythmia classes to detect heartbeat...  相似文献   
93.
We propose a novel pose-invariant face recognition approach which we call Discriminant Multiple Coupled Latent Subspace framework. It finds the sets of projection directions for different poses such that the projected images of the same subject in different poses are maximally correlated in the latent space. Discriminant analysis with artificially simulated pose errors in the latent space makes it robust to small pose errors caused due to a subject’s incorrect pose estimation. We do a comparative analysis of three popular latent space learning approaches: Partial Least Squares (PLSs), Bilinear Model (BLM) and Canonical Correlational Analysis (CCA) in the proposed coupled latent subspace framework. We experimentally demonstrate that using more than two poses simultaneously with CCA results in better performance. We report state-of-the-art results for pose-invariant face recognition on CMU PIE and FERET and comparable results on MultiPIE when using only four fiducial points for alignment and intensity features.  相似文献   
94.
95.
An attempt is made to develop the hydrophilic grafting of polyether urethane urea with hydroxyethyl methacrylate (hema) using60Coγ-irradiation for achieving optimum hydrophilic/hydrophobic property needed towards blood compatibility. Contact angle method and platelet adhesion from calf’s blood are used to determine the suitability of these modified surfaces.  相似文献   
96.
The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel (2)+1-alkanols (C_3 or C_4)(3) and ternary Jatropha curcas biodiesel (1)+diesel (2)+1-alkanols (C_3or C_4)(3) blends have been reported over full range of composition at temperatures within range 288.15 to 313.15 K.Also densities of Jatropha curcas biodiesel (1)+diesel or 1-alkanols (C_3 or C_4)(2) blends have been measured at 313.15 K.Excess molar volumes,V~E,V~E_(123)of binary and ternary blends were calculated from the measured data and the derived properties were correlated to composition using Redlich–Kister equation.A reasonable agreement was found between the measured and estimated values.Further,densities and excess molar volumes data were reasoned to discuss molecular interactions taking into consideration effect of composition and temperature.  相似文献   
97.
98.
R. Sharma  L.V. Sud  P.K.C. Pillai 《Polymer》1980,21(8):925-928
The depolarization currents in poly(vinyl alcohol) thermoelectrets have been measured by thermally stimulated discharge (t.s.d.) current techniques. The polarization is found to be uniform. The activation energy and the relaxation time have been calculated under different polarizing conditions. The formation of heterocharge is explained by dipole alignment and migration of charge over microscopic distances with trapping.  相似文献   
99.
100.
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