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   34577篇
  免费   1405篇
  国内免费   24篇
  2020年   391篇
  2019年   500篇
  2018年   708篇
  2017年   728篇
  2016年   766篇
  2015年   564篇
  2014年   675篇
  2013年   3194篇
  2012年   1182篇
  2011年   1248篇
  2010年   751篇
  2009年   753篇
  2008年   1019篇
  2007年   1070篇
  2006年   998篇
  2005年   927篇
  2004年   858篇
  2003年   877篇
  2002年   883篇
  2001年   971篇
  2000年   918篇
  1999年   746篇
  1998年   403篇
  1997年   399篇
  1996年   398篇
  1995年   352篇
  1994年   330篇
  1993年   319篇
  1992年   576篇
  1991年   587篇
  1990年   553篇
  1989年   507篇
  1988年   495篇
  1987年   486篇
  1986年   501篇
  1985年   538篇
  1984年   455篇
  1983年   397篇
  1982年   321篇
  1981年   331篇
  1979年   450篇
  1978年   359篇
  1975年   364篇
  1974年   450篇
  1973年   446篇
  1972年   341篇
  1971年   328篇
  1970年   315篇
  1968年   374篇
  1967年   324篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
This study examined information communication technologies and workplace friendship dynamics. Employees reported factors that influenced their initiation of friendship with a coworker and reported patterns and perceptions of communication with their workplace friend via different communication methods. Results indicated that personality, shared tasks, and perceived similarity are the most important factors to coworker friendship initiation, and the importance of physical proximity to workplace friendship is diminishing in the electronically connected workplace. Results confirm the primacy of face‐to‐face interaction for workplace friendship initiation and maintenance. E‐mail, phone, and texting were also central to communication among workplace friends. The amount of time spent telecommuting affected workplace friendship initiation and communication. Finally, generational differences were identified with respect to Internet‐based communication methods.  相似文献   
42.
Cancellation tests are commonly used in the clinical assessment of visuospatial function, but there has been little study of task characteristics influencing performance. This study was designed to assess factors which affect cancellation performance. Sixteen healthy subjects sequentially performed four random-array letter cancellation tasks. The forms contained 50 and 100 stimuli and target:distractor (T/D) ratios of 1:4 and 1:9 with target letter “A” and randomly selected letter distractors. The primary performance measure was calculated as the number of correctly cancelled targets divided by the time to complete the task, corrected for accuracy. This measure revealed a strong effect of T/D ratio (p< .0001), with performance adversely affected by higher proportion of distractors. There was no effect of stimulus number. This suggests that T/D ratio should be considered in cancellation test design and interpretation.  相似文献   
43.
44.
45.
46.
47.
48.
49.
The purpose of this paper is to study the convergent validity of the four most widely used burnout measures in a sample of Chinese nurses (N= 717). First, Structural Equation Modeling was used to investigate the factor structure of scores produced by the Maslach Burnout Inventory‐General Survey (MBI‐GS), the Burnout Measure (BM), the Shirom‐Melamed Burnout Measure (SMBM), and the Oldenburg Burnout Inventory (OLBI). Next, several competing models were tested to investigate the convergent validity of these four burnout instruments. The final results suggest that burnout is best conceived of as a multidimensional construct consisting of exhaustion and withdrawal, which are two related but conceptually distinct aspects. In addition, positively phrased items should be dropped from burnout measures for they constitute a separate factor that is considered to be an artifact.  相似文献   
50.
In Experiment 1, rats were trained on a discrimination between rubber- and sandpaper-covered arms of a maze after one group had been pre-exposed to these intra-maze cues. Pre-exposure facilitated subsequent discrimination learning, unless the discrimination was made easier by adding further discriminative stimuli, when it now significantly retarded learning. In Experiment 2, rats were trained on an extra-maze spatial discrimination, again after one group, but not another, had been pre-exposed to the extra-maze landmarks. Here too, pre-exposure facilitated subsequent discrimination learning, unless the discrimination was made substantially easier by arranging that the two arms between which rats had to choose were always separated by 135°. The results of both experiments can be explained by supposing that perceptual learning depends on the presence of features common to S+ and S-.  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