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   170515篇
  免费   7774篇
  国内免费   155篇
  2021年   1498篇
  2020年   2767篇
  2019年   3428篇
  2018年   3520篇
  2017年   3931篇
  2016年   4599篇
  2015年   3911篇
  2014年   4783篇
  2013年   23373篇
  2012年   4556篇
  2011年   3633篇
  2010年   3846篇
  2009年   4749篇
  2008年   3842篇
  2007年   3358篇
  2006年   3967篇
  2005年   3928篇
  2004年   3451篇
  2003年   3079篇
  2002年   2879篇
  2001年   3345篇
  2000年   3214篇
  1999年   3190篇
  1998年   2809篇
  1997年   2644篇
  1996年   2332篇
  1995年   2347篇
  1994年   2313篇
  1993年   2280篇
  1992年   2552篇
  1991年   2433篇
  1990年   2268篇
  1989年   2195篇
  1988年   2157篇
  1987年   2118篇
  1986年   2095篇
  1985年   2348篇
  1984年   2442篇
  1983年   2240篇
  1982年   2268篇
  1981年   2249篇
  1980年   2114篇
  1979年   2166篇
  1978年   2114篇
  1977年   2106篇
  1976年   1900篇
  1975年   1945篇
  1974年   2025篇
  1973年   1887篇
  1972年   1507篇
排序方式: 共有10000条查询结果,搜索用时 625 毫秒
1.
2.
3.
The present study tested gender as a moderator of the relationship between race-related stress and mental health symptoms among African American adults. Because African American women are exposed to stressors associated with race and gender, we hypothesized that African American women would have higher levels of race-related stress and more severe mental health outcomes related to experiences of race-related stress compared to African American men. Multivariate analyses revealed that African American men had higher stress appraisals for institutional racism than did women. No significant gender differences were found for cultural and individual racism. Moderated regression analyses revealed that increases in stress appraisals for individual racism were associated with increases in anxiety and obsessive-compulsive symptoms for African American women. Race-related stress had no significant effects on mental health symptoms for African American men. The findings suggest that gender is an important factor in determining the impact of race-related stress on mental health.  相似文献   
4.
5.
6.
7.
8.
The special composition question asks, roughly, under what conditions composition occurs. The common sense view is that composition only occurs among some things and that all and only ‘ordinary objects’ exist. Peter van Inwagen has marshaled a devastating argument against this view. The common sense view appears to commit one to giving what van Inwagen calls a ‘series‐style answer’ to the special composition question, but van Inwagen argues that series‐style answers are impossible because they are inconsistent with the transitivity of parthood. In what follows I answer this objection in addition to other, less troubling objections raised by van Inwagen.  相似文献   
9.
Two studies are reported examining academic procrastination and motivation in 1,145 university students from Canada and Singapore. In Study 1, relationships between procrastination and motivation variables were found to be similar across contexts, with self‐efficacy for self‐regulated learning most strongly associated with procrastination in both contexts. In Study 2, patterns of procrastinating behavior and the negative impact of procrastination were examined and compared in Canadian and Singaporean undergraduates. Participants in both contexts reported writing to be the academic task most prone to procrastination. More Singaporeans than Canadians were classified as negative procrastinators (i.e. rated procrastination as a negative influence on academic functioning). In both contexts, negative procrastinators spent more time procrastinating than neutral procrastinators and displayed lower self‐efficacy for self‐regulated learning. On décrit deux recherches portant sur la motivation et la procrastination universitaire (tendance à remettre au lendemain) de 1145 étudiants du Canada et de Singapour. Dans la première étude, les relations entre la motivation et la procrastination sont apparues être analogues dans les deux pays, la variable la plus fortement associéà la procrastination étant l'auto‐efficience pour l'apprentissage autorégulé. Dans la deuxième étude, les schémas comportementaux de procrastination et son impact négatif ont été analysés et comparés chez les étudiants de 1° cycle canadiens et singapouriens. Les sujets des deux pays ont mentionné la rédaction comme étant la tâche universitaire la plus soumise à la procrastination. Davantage de Singapouriens que de Canadiens été classés en procrastinateurs négatifs (c'est‐à‐dire que la procrastination est considérée comme étant un handicap pour les études). Dans les deux cas, les procrastinateurs négatifs gaspillaient plus de temps que les procrastinateurs neutres et manifestaient une moindre auto‐efficience pour l'apprentissage autorégulé.  相似文献   
10.
Rats received Pavlovian conditioning in which food was signalled by a visual stimulus, A+, an auditory stimulus, B+, and a compound composed of different visual and auditory stimuli, CD+. Test trials were then given with the compound AB. Experiments 1 and 2A revealed stronger responding during AB than during CD. In Experiment 2B, there was no evidence of a summation of responding during AB when A+ B+ training was conducted in the absence of CD+ trials. A further failure to observe abnormally strong responding during ABwas found in Experiment 3 for which the training trials with A+ B+ CD+ were accompanied by trials in which C and D were separately paired with food. The results are explained in terms of a configural theory of conditioning, which assumes that responding during a compound is determined by generalization from its components, as well as from other compounds to which it is similar.  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