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   184594篇
  免费   8149篇
  国内免费   155篇
  192898篇
  2020年   2788篇
  2019年   3456篇
  2018年   3763篇
  2017年   4129篇
  2016年   4789篇
  2015年   3937篇
  2014年   4804篇
  2013年   23485篇
  2012年   5116篇
  2011年   4375篇
  2010年   4114篇
  2009年   4901篇
  2008年   4473篇
  2007年   4032篇
  2006年   4471篇
  2005年   4342篇
  2004年   3896篇
  2003年   3487篇
  2002年   3280篇
  2001年   4039篇
  2000年   3788篇
  1999年   3561篇
  1998年   2891篇
  1997年   2701篇
  1996年   2622篇
  1995年   2451篇
  1994年   2415篇
  1993年   2372篇
  1992年   2921篇
  1991年   2729篇
  1990年   2572篇
  1989年   2484篇
  1988年   2440篇
  1987年   2409篇
  1986年   2429篇
  1985年   2669篇
  1984年   2652篇
  1983年   2409篇
  1982年   2405篇
  1981年   2370篇
  1980年   2215篇
  1979年   2362篇
  1978年   2265篇
  1977年   2210篇
  1976年   2021篇
  1975年   2101篇
  1974年   2189篇
  1973年   2071篇
  1972年   1663篇
  1971年   1599篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
192.
193.
194.
195.
Recent studies demonstrating that multiple meanings of an ambiguous word are initially accessed even when only one reading is syntactically appropriate with the preceding context can be criticized on at least two grounds. First, many of the syntactic contexts used were not truly restrictive, and, secondly, subjects may not have had time to integrate the context before processing the ambiguous word. In the present study, subjects listened to a sentence ending in an ambiguous word and then made a lexical decision to a target related to either the appropriate or inappropriate reading. Contexts were completely restrictive, and a pause was introduced between the context and the ambiguous word. Multiple access still obtained, providing further support for the claim that lexical access is not guided by syntactic context.  相似文献   
196.
Suicides among older adults in the United States and Canada in the last decade have accounted for an increasing share of all suicides. In both countries the use of firearms among older adults has steadily increased. Despite these trends, little is known about the extent to which crisis centers are prepared to prevent elder suicide. A survey of AAS-listed crisis prevention centers examined the training, knowledge, and current practices relevant to elder suicide among personnel in 321 crisis prevention centers in both countries. Results revealed insufficient training, a lack of familiarity with recent suicide trends, and limited outreach to older adults.  相似文献   
197.
198.
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   
199.
200.
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