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   107234篇
  免费   1859篇
  国内免费   438篇
电工技术   1080篇
综合类   2352篇
化学工业   16844篇
金属工艺   5120篇
机械仪表   3481篇
建筑科学   3428篇
矿业工程   656篇
能源动力   1712篇
轻工业   5418篇
水利工程   1490篇
石油天然气   412篇
无线电   10958篇
一般工业技术   20535篇
冶金工业   7106篇
原子能技术   448篇
自动化技术   28491篇
  2023年   214篇
  2022年   359篇
  2021年   567篇
  2020年   340篇
  2019年   434篇
  2018年   14822篇
  2017年   13714篇
  2016年   10466篇
  2015年   1152篇
  2014年   962篇
  2013年   1596篇
  2012年   4249篇
  2011年   10767篇
  2010年   9257篇
  2009年   6478篇
  2008年   7811篇
  2007年   8753篇
  2006年   1049篇
  2005年   1948篇
  2004年   1854篇
  2003年   1803篇
  2002年   1086篇
  2001年   521篇
  2000年   536篇
  1999年   456篇
  1998年   801篇
  1997年   579篇
  1996年   482篇
  1995年   419篇
  1994年   388篇
  1993年   370篇
  1992年   280篇
  1991年   217篇
  1990年   268篇
  1989年   260篇
  1988年   224篇
  1987年   224篇
  1986年   226篇
  1985年   265篇
  1984年   224篇
  1983年   223篇
  1982年   207篇
  1981年   194篇
  1980年   168篇
  1979年   193篇
  1978年   164篇
  1977年   185篇
  1976年   231篇
  1975年   160篇
  1974年   123篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
Final-offer salary arbitration in major league baseball offers a unique institutional arrangement that creates a naturally occurring, non-equivalent-groups, repeated measures research design. The structural arrangements allow for examination of anticipatory expectancy effects and assessment of behavioral responses consistent with equity theory predictions. In addition, equity theory can be tested without the methodological problems inherent in defining the referent other. Performance and mobility were examined for major league baseball position players who won and lost their arbitration hearings. Prearbitration performance significantly predicted arbitration outcome. A significant relationship was noted between losing arbitration and postarbitration performance decline. Losers were significantly more likely to change teams and leave major league baseball. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
144.
The authors attempt to provide a better understanding of the differences between the normal memory decline characteristic of age-associated memory impairment (AAMI) and the pathological decline typical of mild Alzheimer's disease (AD). Batteries of traditional memory tests and computer-simulated everyday-memory tests discriminated between the 2 groups, which were matched on age, gender, and education, with reasonable degrees of accuracy (87.5% and 88.4%, respectively). False positives were the most frequent classification errors when using either battery. These results indicate that it is possible to use ecologically valid memory assessment paradigms without sacrificing discriminant validity. The clinical significance of discriminating mild AD from AAMI is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
145.
Responds to the points made by R. Cropanzano and K. James (see record 1991-00462-001) concerning the article by R. D. Arvey et al (1989). The authors acknowledge that the Arvey et al study is based on a single design, makes use of a small and special sample, and, as such, is vulnerable to threats of internal and external validity. Nevertheless, after providing a more comprehensive conceptual and empirical context for the study, and after reviewing a number of the issues raised by Cropanzano and James, the authors conclude that it is not premature to accept the idea that work attitudes are partially genetically influenced. Indeed, the authors use behavioral genetic theory, together with data gathered in the Arvey et al study, to make specific point predictions regarding the outcomes of an array of studies that easily can be undertaken. Finally, the authors acknowledge that the comments and issues raised by Cropanzano and James, along with the interchange, can offer directions for future research in this important area. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
146.
147.
Image and geometry processing applications estimate the local geometry of objects using information localized at points. They usually consider information about the tangents as a side product of the points coordinates. This work proposes parabolic polygons as a model for discrete curves, which intrinsically combines points and tangents. This model is naturally affine invariant, which makes it particularly adapted to computer vision applications. As a direct application of this affine invariance, this paper introduces an affine curvature estimator that has a great potential to improve computer vision tasks such as matching and registering. As a proof-of-concept, this work also proposes an affine invariant curve reconstruction from point and tangent data.  相似文献   
148.
149.
Phase-change read-and-write memory (PRAM) is a promising memory that can solve the problems of conventional memory—scalability, read/write speed, and reliability. We will review the opportunities and technical challenges of PRAM. The most important challenge of PRAM is the reduction of the writing current. Various approaches to reduce the writing current will be reviewed and the prospects of PRAM are discussed.  相似文献   
150.
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