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   16937篇
  免费   806篇
  国内免费   15篇
  17758篇
  2021年   132篇
  2020年   230篇
  2019年   243篇
  2018年   357篇
  2017年   364篇
  2016年   366篇
  2015年   282篇
  2014年   309篇
  2013年   1320篇
  2012年   570篇
  2011年   650篇
  2010年   375篇
  2009年   351篇
  2008年   474篇
  2007年   452篇
  2006年   399篇
  2005年   336篇
  2004年   339篇
  2003年   324篇
  2002年   327篇
  2001年   702篇
  2000年   700篇
  1999年   461篇
  1998年   181篇
  1997年   174篇
  1996年   138篇
  1995年   135篇
  1993年   138篇
  1992年   361篇
  1991年   321篇
  1990年   345篇
  1989年   335篇
  1988年   317篇
  1987年   288篇
  1986年   311篇
  1985年   298篇
  1984年   235篇
  1983年   200篇
  1979年   190篇
  1978年   161篇
  1975年   187篇
  1974年   241篇
  1973年   197篇
  1972年   203篇
  1971年   167篇
  1970年   149篇
  1969年   198篇
  1968年   202篇
  1967年   161篇
  1966年   182篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
In an 18-month prospective study, community-dwelling older adults, including both spousal caregivers of dementia patients and noncaregiving controls, were examined. Participants were selected on the basis of the presence or absence of chronic depressive symptoms that exceeded a cutoff score for clinically relevant depressive symptoms on a self-report symptom measure. Compared with nondepressed older adults, those with chronic, mild depressive symptoms had poorer T cell responses to 2 mitogens from baseline to follow-up. Additionally, among individuals with depressive symptoms, older age was associated with the poorest blastogenic response to the mitogens at follow-up. These findings extend the association between depression and immune function to community-dwelling older adults with chronic, mild depressive symptoms.  相似文献   
892.
The authors examined the impact of 2 hybrid dispute resolution procedures (mediation-arbitration [med-arb] and arbitration-mediation [arb-med]) and 3 disputant dyadic structures (individual vs. individual, individual vs. team, and team vs. team) on various dispute outcomes. Consistent with W. H. Ross and D. E. Conlon (2000), the authors found that disputants in the arb-med procedure (a) settled in the mediation phase of their procedure more frequently and (b) achieved settlements of higher joint benefit than did disputants in the med-arb procedure. These results suggest that arb-med may be a dispute resolution procedure with broader applicability than originally imagined.  相似文献   
893.
Five-factor model of personality and job satisfaction: a meta-analysis   总被引:16,自引:0,他引:16  
This study reports results of a meta-analysis linking traits from the 5-factor model of personality to overall job satisfaction. Using the model as an organizing framework, 334 correlations from 163 independent samples were classified according to the model. The estimated true score correlations with job satisfaction were -.29 for Neuroticism, .25 for Extraversion, .02 for Openness to Experience, .17 for Agreeableness, and .26 for Conscientiousness. Results further indicated that only the relations of Neuroticism and Extraversion with job satisfaction generalized across studies. As a set, the Big Five traits had a multiple correlation of .41 with job satisfaction, indicating support for the validity of the dispositional source of job satisfaction when traits are organized according to the 5-factor model.  相似文献   
894.
895.
896.
The authors investigated whether behavior of fielders pursuing uncatchable fly balls supported either (a) maintenance of a linear optical trajectory (LOT) with monotonic increases in optical ball height or (b) maintenance of optical acceleration cancellation (OAC) with simultaneous lateral alignment with the ball. Past work supports usage of both LOT and OAC strategies in the pursuit of catchable balls headed to the side. When balls are uncatchable, fielders must choose either optical linearity or alignment at the expense of the other. Fielders maintained the LOT strategy more often and for a longer period of time than they did the OAC alignment strategy. Findings support the LOT strategy as primary when pursuing balls headed to the side, whether catchable or not.  相似文献   
897.
The authors explored the phenomenon that knowledge is not always integrated and consistent but may be partitioned into independent parcels that may contain mutually contradictory information. In 4 experiments, using a function learning paradigm, a binary context variable was paired with the continuous stimulus variable of a to-be-learned function. In the first 2 experiments, when context predicted the slope of a quadratic function, generalization was context specific. Because context did not predict function values, it is suggested that people use context to gate separate learning of simpler partial functions. The 3rd experiment showed that partitioning also occurs with a decreasing linear function, whereas the 4th study showed that partitioning is absent for a linearly increasing function. The results support the notion that people simplify complex learning tasks by acquiring independent parcels of knowledge.  相似文献   
898.
Figure-ground assignment is an important visual process; humans recognize, attend to, and act on figures, not backgrounds. There are many visual cues for figure-ground assignment. A new cue to figure-ground assignment, called lower region, is presented: Regions in the lower portion of a stimulus array appear more figurelike than regions in the upper portion of the display. This phenomenon was explored, and it was demonstrated that the lower-region preference is not influenced by contrast, eye movements, or voluntary spatial attention. It was found that the lower region is defined relative to the stimulus display, linking the lower-region preference to pictorial depth perception cues. The results are discussed in terms of the environmental regularities that this new figure-ground cue may reflect.  相似文献   
899.
In this study, the clinical profile of Hindi-speaking stroke patients with aphasia from northern India has been investigated. We examined the interactional effect between age and gender with aphasia type in 97 Hindi-speaking right-handed individuals, the majority of them with a confirmed diagnosis of a cerebrovascular accident. The subjects included in the study ranged from 3 weeks to two years post-onset with a diagnosis of a common classical aphasia (Broca's, Wernicke's, anomic, global, conduction, and transcortical) types involving both males and females. Also examined was the interaction between literacy and aphasia type since the subjects had varied exposures to education (total illiteracy to professional/university education). While the data reported here about Hindi-speaking aphasics are relatively in agreement with the age-aphasia type patterns discussed in western countries, nonetheless some differences were also observed. The mean age of Indian patients with aphasia was significantly lower. Also, in addition to some gender and literacy related differences, an outstanding difference was that many clinical symptoms that are known to co-occur with aphasia were not readily reported by subjects with stroke.  相似文献   
900.
To study the relationship of stages of smoking acquisition and environmental factors, 757 Japanese junior high school students (390 boys and 367 girls) anonymously answered a questionnaire regarding the four stages of smoking acquisition (precontemplation, contemplation, preparation, and action stages) and environmental factors of smoking behavior. Analysis showed that the influence of advertising and students' interpersonal situations on smoking behavior increased from the precontemplation stage to the action stage.  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