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   72569篇
  免费   2157篇
  国内免费   30篇
  2020年   602篇
  2019年   766篇
  2018年   4258篇
  2017年   3596篇
  2016年   3195篇
  2015年   957篇
  2014年   1026篇
  2013年   4821篇
  2012年   2227篇
  2011年   4074篇
  2010年   3437篇
  2009年   2464篇
  2008年   3258篇
  2007年   3624篇
  2006年   1501篇
  2005年   1568篇
  2004年   1471篇
  2003年   1303篇
  2002年   1290篇
  2001年   1805篇
  2000年   1718篇
  1999年   1305篇
  1998年   716篇
  1997年   615篇
  1996年   546篇
  1995年   538篇
  1994年   524篇
  1993年   533篇
  1992年   1037篇
  1991年   977篇
  1990年   972篇
  1989年   870篇
  1988年   832篇
  1987年   820篇
  1986年   820篇
  1985年   873篇
  1984年   686篇
  1983年   597篇
  1982年   495篇
  1979年   680篇
  1978年   503篇
  1976年   461篇
  1975年   602篇
  1974年   629篇
  1973年   609篇
  1972年   545篇
  1971年   482篇
  1968年   549篇
  1967年   546篇
  1966年   484篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
This study investigated the effect of television food commercials on children's self-control within a resistance to temptation paradigm. Commercial type, food stimulus type, and the child's sex provided the three independent variables in a 4 × 4 × 2 factorial design. Behavioral and self-report indices of temptation and control were measured. Children were significantly more tempted to transgress for the low-nutrition food, regardless of the commercial shown. Sex differences in reported degree of temptation were found. However, the television commercials did not affect the children's latency to transgress.  相似文献   
182.
Celiac-Sprue Disease, also referred to as Non-Tropical Sprue, is a dietary disease. Celiac-Sprue patients were asked to complete a questionnaire regarding the effect of dietary restrictions on participation in the Passover meal and reception of Communion. A pilot study suggested that subjects made changes in their religious practices because of dietary restrictions. A second, more detailed survey, was performed in which 58 subjects participated and 14 religions were represented. The results indicated that many subjects made changes in their religious practices (p less than .01), made changes on their own initiative (p less than .01), or violated diet prescribed for the disease under the religious setting versus other settings (p less than .05).  相似文献   
183.
In this study I explored whether the degree of anticipation/habituation (undershooting/overshooting) varies with the dimension to be localized, when the method of adjustment is used in space localization. In this study, undershooting occurred for both the vertical (Group 1) and the horizontal (Group 2) dimensions, but was significant only for verticality. The magnitude of undershooting observed for verticality was significantly greater than that for horizontality. A secondary issue regarding the possible relationship between spatial category width and undershooting/overshooting was examined. It was hypothesized that greater degree of spatial category width would be associated with greater undershooting. The opposite was found: Spatial category width was negatively related to undershooting. Finally, within each group, very high consistency of magnitude of spatial category width was observed (rs greater than .90), despite the fact that spatial category width showed shrinkage over the course of the study.  相似文献   
184.
Tobacco, alcohol, and drug use are problems for American-Indian people. We reviewed these problems and the explanations for them and described a bicultural competence skills approach for preventing substance abuse with American-Indian adolescents. Data from a study of that approach suggest its efficacy with American-Indian youth. At posttest and a 6-month follow-up, American-Indian subjects who received preventive intervention based on bicultural competence skills concepts improved more than did American-Indian subjects in a no-intervention control condition on measures of substance-use knowledge, attitudes, and interactive skills, and on self-reported rates of tobacco, alcohol, and drug use. Our findings have implications for future substance-abuse prevention research with American-Indian people.  相似文献   
185.
186.
187.
This paper combines the results of two studies across different cultures which included an investigation into the relationship between field-dependence-independence and vocational orientations within the framework of Holland's theory of career choice and Witkin's theory of psychological differentiation. The samples included 179 Canadian senior high school students and 376 Pakistani college and university students. Both samples were administered Self-Directed Search and Group Embedded Figures Test. The results indicated a significant relationship between cognitive styles and vocational orientations. It was evident from the findings of these two studies that the theories of Holland and Witkin dove-tail nicely with each other.  相似文献   
188.
The structure of the covariance matrix of sample covariances under the class of linear latent variate models is derived using properties of cumulants. This is employed to provide a general framework for robustness of statistical inference in the analysis of covariance structures arising from linear latent variate models. Conditions for normal theory estimators and test statistics to retain each of their usual asymptotic properties under non-normality of latent variates are given. Factor analysis, LISREL and other models are discussed as examples.  相似文献   
189.
190.
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