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   13489篇
  免费   241篇
  国内免费   1篇
  13731篇
  2021年   80篇
  2020年   143篇
  2019年   174篇
  2018年   245篇
  2017年   272篇
  2016年   281篇
  2015年   210篇
  2014年   271篇
  2013年   1458篇
  2012年   476篇
  2011年   508篇
  2010年   331篇
  2009年   334篇
  2008年   496篇
  2007年   456篇
  2006年   444篇
  2005年   448篇
  2004年   445篇
  2003年   430篇
  2002年   461篇
  2001年   231篇
  2000年   190篇
  1999年   207篇
  1998年   217篇
  1997年   217篇
  1996年   175篇
  1995年   180篇
  1994年   161篇
  1993年   182篇
  1992年   172篇
  1991年   146篇
  1990年   149篇
  1989年   136篇
  1988年   123篇
  1987年   136篇
  1986年   122篇
  1985年   152篇
  1984年   190篇
  1983年   196篇
  1982年   196篇
  1981年   183篇
  1980年   142篇
  1979年   139篇
  1978年   181篇
  1977年   164篇
  1976年   165篇
  1975年   145篇
  1974年   157篇
  1973年   110篇
  1972年   79篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
This article examines the effects of social support on the receipt of adequate prenatal care. A study was conducted to test the hypotheses that social support helps women overcome obstacles to obtaining such care, and that social support has greater effects on women facing the most obstacles. Survey data were gathered for more than 90% of the women who gave birth in Oklahoma hospitals during specific periods in the summer of 1986. The authors found only weak support for the first hypothesis, and for the second hypothesis found only support that must be qualified according to the measure of social support. Strong evidence indicates, however, that difficulty in paying for prenatal care, personal inconveniences, and unwanted pregnancies are obstacles to obtaining such care. The findings account for some of the frequently observed demographic differences associated with receipt of adequate prenatal care, although such differences persisted even after the obstacles were considered. The authors present implications for policy makers seeking to improve women's receipt of adequate prenatal care.  相似文献   
144.
Hagen JD 《America》1996,175(2):4-6
  相似文献   
145.
Cognitive therapy techniques are applied to an ever-increasing range of psychological disorders. However, both basic methods and general theory of therapy have evolved more slowly. Although cognitive therapy is based on experimentally testable concepts derived from cognitive psychology, an integration of these areas capable of explaining cognitive-attentional phenomena and offering treatment Implications remains to be achieved. In this paper, we outline the Self-Regulatory Executive Function (S-REF) model of emotional disorder, which integrates information processing research with Beck's schema theory. The model advances understanding of the roles of stimulus-driven and voluntary control of cognition, procedural knowledge (beliefs), and of the interactions between different levels of information-processing. It also accounts for cognitive bias effects demonstrated in the experimental psychopathology literature. The model presents implications concerning not only what should be done in cognitive therapy, but how cognitive change may be most effectively accomplished.  相似文献   
146.
The efficacy of three different schedules of reinforcement for promoting and sustaining drug abstinence was compared in this study. Cigarette smoking was studied as an exemplar of stimulant drug self-administration. Sixty cigarette smokers were assigned to one of three groups (progressive rate of reinforcement, fixed rate of reinforcement, and yoked control). Participants in all three groups were asked to refrain from smoking for 1 week. Participants in the progressive and fixed groups achieved greater mean levels of abstinence than those in the control group. Participants in the progressive group were significantly less likely to resume smoking when they became abstinent than participants in the other groups.  相似文献   
147.
John F. Horty 《Synthese》1996,108(2):269-307
The purpose of this paper is to explore a new deontic operator for representing what an agent ought to do; the operator is cast against the background of a modal treatment of action developed by Nuel Belnap and Michael Perloff, which itself relies on Arthur Prior's indeterministic tense logic. The analysis developed here of what an agent ought to do is based on a dominance ordering adapted from the decision theoretic study of choice under uncertainty to the present account of action. It is shown that this analysis gives rise to a normal deontic operator, and that the result is superior to an analysis that identifies what an agent ought to do with what it ought to be that the agent does.  相似文献   
148.
A contrived play group procedure was utilized to examine the behavioral and social-cognitive correlates of reactive aggression, proactive aggression, and victimization via peers. Eleven play groups, each of which consisted of six familiar African-American 8-year-old boys, met for 45-min sessions on five consecutive days. Social-cognitive interviews were conducted following the second and fourth sessions. Play group interactions were videotaped and examined by trained observers. High rates of proactive aggression were associated with positive outcome expectancies for aggression/assertion, frequent displays of assertive social behavior, and low rates of submissive behavior. Reactive aggression was associated with hostile attributional tendencies and frequent victimization by peers. Victimization was associated with submissive behavior, hostile attributional bias, reactive aggression, and negative outcome expectations for aggression/assertion. These results demonstrate that there is a theoretically coherent and empirically distinct set of correlates associated with each of the examined aggression subtypes, and with victimization by peers.  相似文献   
149.
Recent research on hunger and eating has shown that (a) among individuals with adlibitum access to food, hunger and eating are not regulated by deviations in the body's energy resources from set-points, and (b) it is healthier for people to consume their daily caloric intake as several small snacks than as 3 large meals. People's beliefs about hunger and eating were assessed in 2 questionnaire studies. In Study 1, a large sample of undergraduates was surveyed; in Study 2, dietetics students, nursing students, medical students, dietitians, nurses, and doctors were surveyed. Both studies revealed that people's personal theories of hunger and eating were inconsistent with research findings in ways that could promote overconsumption. These results suggest that educational programs designed to modify the beliefs about hunger and eating of people suffering from problems of overconsumption and of health professionals who treat problems of overconsumption may increase the effectiveness of current treatment regimens.  相似文献   
150.
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