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   18096篇
  免费   857篇
  国内免费   400篇
  2021年   179篇
  2020年   220篇
  2019年   284篇
  2018年   347篇
  2017年   311篇
  2016年   350篇
  2015年   233篇
  2014年   332篇
  2013年   1420篇
  2012年   541篇
  2011年   649篇
  2010年   420篇
  2009年   462篇
  2008年   587篇
  2007年   639篇
  2006年   620篇
  2005年   507篇
  2004年   458篇
  2003年   402篇
  2002年   368篇
  2001年   474篇
  2000年   539篇
  1999年   371篇
  1998年   230篇
  1997年   172篇
  1996年   188篇
  1995年   176篇
  1992年   286篇
  1991年   289篇
  1990年   302篇
  1989年   280篇
  1988年   270篇
  1987年   236篇
  1986年   246篇
  1985年   265篇
  1984年   197篇
  1983年   213篇
  1982年   167篇
  1979年   251篇
  1978年   216篇
  1975年   216篇
  1974年   242篇
  1973年   269篇
  1972年   226篇
  1971年   212篇
  1970年   162篇
  1969年   195篇
  1968年   250篇
  1967年   239篇
  1966年   212篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
A common criticism of iterative least squares estimates of communality is that method of initial estimation may influence stabilized values. As little systematic research on this topic has been performed, the criticism appears to be based on cumulated experience with empirical data sets. In the present paper, two studies are reported in which four types of initial estimate (unities, squared multiple correlations, highestr, and zeroes) and four levels of convergence criterion were employed using four widely available computer packages (BMDP, SAS, SPSS, and SOUPAC). The results suggest that initial estimates have no effect on stabilized communality estimates when a stringent criterion for convergence is used, whereas initial estimates appear to affect stabilized values employing rather gross convergence criteria. There were no differences among the four computer packages for matrices without Heywood cases.  相似文献   
212.
213.
Fear of death and the concept of extended self   总被引:1,自引:0,他引:1  
  相似文献   
214.
Effects of presentation complexity on rapid-sequential reading   总被引:1,自引:0,他引:1  
  相似文献   
215.
216.
Hemispheric symmetry in contrast and orientation sensitivity   总被引:1,自引:0,他引:1  
  相似文献   
217.
218.
The phases of a patient's struggle to come to terms with a malignant disease and impending death are illustrated by means of W. M. Diggelmann's book "Schatten--Tagebuch einer Krankheit" (Shadow--Diary of an Illness). Their expression, mutual influences and contents are documented by quotations.  相似文献   
219.
220.
This project studied the effects of weather variables and size of the population on minor and major violence rates within six prisons in the Kingston, Ontario, Canada area from January, 1980 through December, 1983. While weather variables have been studied in relation to mood changes within the general population, this study was the first to analyze the impact of weather variables on rates of violence within the prison setting using forward inclusion multiple regression. Analysis showed that population size consistently appeared positively correlated with assaults on other inmates among the male medium-security prisoners during the summer months. In the summer months, temperature tended to be positively related to some minor kinds of offenses, but in the winter months the relationship was negative. Humidity, rain, sunshine hours, snow, and snow on the ground were not consistently related to incidences of minor and major violence. Indices of geomagnetic disturbances had statistically significant inverse relationships with attempted suicide/self-inflicted injury rates among the male prisoners during the summer months. Over 12 months, wind was generally negatively correlated with incidences of major and minor violence among the male inmates. For 6-mo. periods, wind was generally positively correlated with violence rates during the winter months and negatively correlated during the summer months among the male inmates. The findings relating weather variables to violence rates in the women's prison were consistently in opposition to those found for male prisoners during the 4-yr. period.  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