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   37933篇
  免费   1424篇
  国内免费   12篇
  2019年   436篇
  2018年   608篇
  2017年   586篇
  2016年   676篇
  2015年   490篇
  2014年   572篇
  2013年   3621篇
  2012年   992篇
  2011年   1006篇
  2010年   656篇
  2009年   616篇
  2008年   948篇
  2007年   843篇
  2006年   795篇
  2005年   658篇
  2004年   626篇
  2003年   654篇
  2002年   622篇
  2001年   1187篇
  2000年   1138篇
  1999年   877篇
  1998年   393篇
  1996年   497篇
  1995年   475篇
  1994年   469篇
  1993年   444篇
  1992年   907篇
  1991年   809篇
  1990年   812篇
  1989年   715篇
  1988年   715篇
  1987年   699篇
  1986年   705篇
  1985年   679篇
  1984年   607篇
  1983年   504篇
  1982年   396篇
  1981年   418篇
  1979年   570篇
  1978年   436篇
  1975年   528篇
  1974年   518篇
  1973年   586篇
  1972年   558篇
  1971年   498篇
  1970年   439篇
  1969年   424篇
  1968年   535篇
  1967年   454篇
  1966年   442篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
A meta-analysis of published studies with adult human participants was conducted to evaluate whether physical fitness attenuates cardiovascular reactivity and improves recovery from acute psychological stressors. Thirty-three studies met selection criteria; 18 were included in recovery analyses. Effect sizes and moderator influences were calculated by using meta-analysis software. A fixed effects model was fit initially; however, between-studies heterogeneity could not be explained even after inclusion of moderators. Therefore, to account for residual heterogeneity, a random effects model was estimated. Under this model, fit individuals showed significantly attenuated heart rate and systolic blood pressure reactivity and a trend toward attenuated diastolic blood pressure reactivity. Fit individuals also showed faster heart rate recovery, but there were no significant differences in systolic blood pressure or diastolic blood pressure recovery. No significant moderators emerged. Results have important implications for elucidating mechanisms underlying effects of fitness on cardiovascular disease and suggest that fitness may be an important confound in studies of stress reactivity.  相似文献   
56.
Self‐explaining is an effective metacognitive strategy that can help learners develop deeper understanding of the material they study. This experiment explored if the format of material (i.e., text or diagrams) influences the self‐explanation effect. Twenty subjects were presented with information about the human circulatory system and prompted to self‐explain; 10 received this information in text and 10 in diagrams. Results showed that students given diagrams performed significantly better on post‐tests than students given text. Diagrams students also generated significantly more self‐explanations that text students. Furthermore, the benefits of self‐explaining were much greater in the diagrams condition. To discover why diagrams can promote the self‐explanation effect, results are interpreted with reference to the multiple differences in the semantic, cognitive and affective properties of the texts and diagrams studied.  相似文献   
57.
Book reviews     
  相似文献   
58.
59.
60.
Indiana statute allows police to seize firearms without a warrant if the officer believes a person meets the law's definition of “dangerous.” Review of the use of this law in Marion County (Indianapolis), Indiana, showed that prosecutors filed petitions in court to retain weapons seized by police under this law 404 times between 2006 and 2013. Police removed weapons from people due to identification of a risk of suicide (68%) or violence (21%), or the presence of psychosis (16%). The firearm seizures occurred in the context of domestic disputes in 28% of cases and intoxication was noted in 26% of cases. There were significant demographic differences in the circumstances of firearm seizures and the firearms seized. The seized firearms were retained by the court at the initial hearing in 63% of cases; this retention was closely linked to the defendant's failure to appear at the hearing. The court dismissed 29% of cases at the initial hearing, closely linked to the defendant's presence at the hearing. In subsequent hearings of cases not dismissed, the court ordered the destruction of the firearms in 72% of cases, all when the individual did not appear in court, and dismissed 24% of the cases, all when the individual was present at the hearing. Overall, the Indiana law removed weapons from a small number of people, most of whom did not seek return of their weapons. The firearm seizure law thus functioned as a months-long cooling-off period for those who did seek the return of their guns. Copyright © 2015 John Wiley & Sons, Ltd.  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