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   7974篇
  免费   249篇
  国内免费   4篇
  8227篇
  2019年   91篇
  2018年   137篇
  2017年   130篇
  2016年   120篇
  2015年   90篇
  2014年   115篇
  2013年   653篇
  2012年   239篇
  2011年   239篇
  2010年   119篇
  2009年   145篇
  2008年   233篇
  2007年   226篇
  2006年   213篇
  2005年   190篇
  2004年   191篇
  2003年   154篇
  2002年   200篇
  2001年   232篇
  2000年   237篇
  1999年   175篇
  1998年   93篇
  1997年   83篇
  1996年   84篇
  1993年   80篇
  1992年   146篇
  1991年   148篇
  1990年   134篇
  1989年   128篇
  1988年   107篇
  1987年   126篇
  1986年   128篇
  1985年   131篇
  1984年   117篇
  1983年   114篇
  1981年   84篇
  1979年   114篇
  1978年   103篇
  1977年   101篇
  1976年   80篇
  1975年   97篇
  1974年   116篇
  1973年   122篇
  1972年   85篇
  1971年   82篇
  1970年   97篇
  1969年   86篇
  1968年   120篇
  1967年   98篇
  1966年   110篇
排序方式: 共有8227条查询结果,搜索用时 15 毫秒
161.
Critical Flicker Fusion Thresholds (CFFTs) were measured in 644 elderly people identified from community-based general practice records, and the relationship of CFFT with age was investigated. The CFFT was measured using the method of limits with mean scores for three ascending (flicker/fusion) and three descending (fusion/flicker) presentations being recorded. The difference between the ascending and descending means was found to be significantly correlated with age (r=−0.131,P<0.001) and may reflect a reduced sensitivity of the Central Nervous System to suprathreshold flicker with increasing age. The results suggest that CFFT measurement has an important role to play in gerontological research as an objective measure of cognitive aspects of the ageing process.  相似文献   
162.
Kenneth Vaux 《Zygon》1990,25(3):317-322
Abstract. Once Queen of the Medieval court of sciences, dethroned theology may be able in our time to play a strategic servant role in rightly humiliating, elevating, and ordering the disciplines, in gadflying like a mutant honeybee, generating surprise and serendipity through the intermediacy of social science, and in offering ethical homing direction to the disciplines in their applied endeavors.  相似文献   
163.
In this article the perspective shifts to the “upstream” end of the agricultural knowledge and information system (AKIS). Because knowledge policy and strategic decision-making are not the prerogative of the public sector, organizations such as cooperative unions and multinational companies are included. After considering the influence of the changing environment on the nature of the AKIS, the role of knowledge management and policy in the emerging knowledge and information market is examined. Special attention is given to public and private R&D. The article then looks where information technology (IT) fits in and what considerations determine strategic investment in IT projects and sustained services. Some of the European experiences with this strategic investment are evaluated.  相似文献   
164.
165.
Abstract— In our discussion of the articles in this Special Section, we ask how well the various methods employed in these investigations can be made to converge on a common issue. We review how current evidence from positron emission tomography, studies of event-related potentials, cognitive methods, lesion studies, and network models relates to the mental processing of an ambiguous word. While many puzzles remain, we are impressed by the promising possibility of bringing these different methods together to deal with an issue central to cognition.  相似文献   
166.
Private and public sector managers were compared regarding their job characteristics and organizational commitment. We hypothesized that job characteristics would be positively related to commitment and that sector would moderate that relationship. Moderated regression analyses revealed partial support for both hypotheses. The existence of clarity and challenge were positively related to commitment. Job characteristics demonstrated a stronger relationship with commitment among private sector managers. Explanations for these findings and directions for future research are discussed.  相似文献   
167.
168.
This article asserts that the family therapy field is approaching an epistemological shift from structuralism and positivism to postmodernism and relativism. The confluence of these movements: feminism, constructivism/constructionism, and cultural relativism is cited as a major impetus for the shift. Live supervision is examined within the context of this transformation, with a discussion of implications for the future.  相似文献   
169.
Sexpert, an expert computer program designed to counsel couples on their sexual relationships, was evaluated. Eighty-one heterosexual couples were assigned to one of three experimental manipulations (Sexpert, video, and self-help book) or a control condition. Daily sexual behavior monitoring forms and structured retrospective reports served as measures of baseline and post-manipulation behavior. Daily monitoring of sexual behavior failed to show significant changes occurring after the manipulations. However, retrospective data concerning the postmanipulation period show that compared with the control, the Sexpert, video, and book manipulations had a significant positive impact on couples’ sexual behavior, communication, and learning about sexuality. Sexpert, video, and book were similarly evaluated, except that Sexpert was evaluated as more engaging. In addition, subjects retrospectively reported positive changes in communication, relationship satisfaction, and sexual behavior during the baseline period. This suggests that daily behavioral monitoring is intrusive and may confound the variables measured by it.  相似文献   
170.
Commercial database programs such as dBase and Paradox, although developed originally for business applications, are versatile and powerful tools that can be used for an academic purpose such as evaluating student performance. They can be used to write and store test questions, assemble and print classroom or on-line laboratory tests, and calculate grades, test statistics, and so forth. Databases are flexible, unlike textbook “ancillary” test bank programs that are inextricably bound to the strictly linear format and brief shelf life of specific textbook editions. A prototypical relational database program is described, with which an instructor can produce tests based on generic terms adapted from Boneau’s (1990) study of psychological literacy, as well as on behavioral learning objectives adapted from Bloom’s (1956) taxonomy of educational objectives. As a relational database, the program integrates terms, objectives, questions, tests, and test scores, and avoids unnecessary data duplication and waste of computer storage space.  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