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   78431篇
  免费   3140篇
  国内免费   35篇
  2020年   816篇
  2019年   1056篇
  2018年   1484篇
  2017年   1524篇
  2016年   1577篇
  2015年   1078篇
  2014年   1346篇
  2013年   6489篇
  2012年   2412篇
  2011年   2631篇
  2010年   1529篇
  2009年   1565篇
  2008年   2353篇
  2007年   2315篇
  2006年   2091篇
  2005年   1885篇
  2004年   1855篇
  2003年   1676篇
  2002年   1737篇
  2001年   2493篇
  2000年   2313篇
  1999年   1802篇
  1998年   978篇
  1997年   809篇
  1996年   767篇
  1995年   757篇
  1994年   730篇
  1992年   1446篇
  1991年   1384篇
  1990年   1360篇
  1989年   1259篇
  1988年   1231篇
  1987年   1169篇
  1986年   1205篇
  1985年   1303篇
  1984年   1033篇
  1983年   936篇
  1979年   1078篇
  1978年   803篇
  1976年   746篇
  1975年   942篇
  1974年   1022篇
  1973年   1037篇
  1972年   873篇
  1971年   791篇
  1970年   741篇
  1969年   774篇
  1968年   960篇
  1967年   886篇
  1966年   828篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.

Alcohol, tobacco and other drug use continue to pose serious public health concerns among youth. Bullying victimization has been identified as a risk factor and religiosity a protective factor for adolescent substance use. No previous research has examined the potential moderating role of religiosity. We explore the association between bullying victimization and substance use in adolescents with low and high levels of religiosity. A cross-sectional survey was conducted with a representative sample of high school students in greater Beirut. Binary and multinomial logistic models were used, adjusting for demographics, and stratified by level of religiosity. Of the 986 students responding to the survey, 65% were females; 48% had experienced some form of bullying; and 52% self-rated as low in religiosity. Between 10 and 30% were current users of alcohol or tobacco. Students of lower religiosity levels who had been bullied were more likely to use substances than those who self-rated as high religiosity. Religiosity may be a potential moderator of the association between being bullied and substance use, but the exact mechanisms and underlying reasons need further investigation.

  相似文献   
102.
Previous work from our laboratory showed that intermittently re-exposing rats to reinforcement for lever pressing in a training (A) context, while eliminating lever pressing in a second (B) context, increased ABA renewal of lever pressing relative to rats that experienced only Context B during response elimination. In the current study, we replicated these procedures while assessing renewal in the presence of a novel context (i.e., ABC renewal). Unlike the findings described above, renewal was reduced in the group that experienced re-exposure to Context A during lever-press elimination relative to rats that experienced only Context B. These findings suggest that alternating between contexts associated with reinforcement and extinction during treatment reduces the probability that organisms will respond in novel contexts. These outcomes may be the result of discrimination and/or generalization processes. Moreover, this training procedure may offer a potential mitigation strategy for ABC renewal.  相似文献   
103.
Book reviews     
TOATES, F. Animal Behaviour: A Systems Approach. Chichester: John Wiley and Sons. 1980. Pp. 299. Hardback £17. Paper back £6.40 ISBN 0 471 27724.

DICKINSON, A. Contemporary Animal Learning Theory. Cambridge: University Press. 1980. Pp. 177. Hardback £12.50. Paperback £3.95. ISBN 0 521 23469 7.  相似文献   
104.
105.
Although a great deal of research has been conducted on the relationship between social support and physical health, the contribution of personality characteristics to this relationship has rarely been assessed. Structural equation modeling was employed to derive and test a model of the direct and indirect relationships between personality characteristics, social network size, the perceived availability of support, socially supportive behaviors, and perceived physical health with a sample of Pennsylvania adults. Significant paths indicate that individuals who perceive themselves as affiliative and as help seekers and help givers report larger social networks, receive more socially supportive behaviors, and perceive that more support is available to them. The perception that support is available shared a direct relationship with perceived physical health. The utility of including multiple measures of social support and personality characteristics related to receiving support in investigations of the relationship between social support and physical health is discussed.  相似文献   
106.
Mental health scholarship of military populations is largely guided by researchers in psychiatry and psychology. Recent advocacy efforts have created increased opportunities for professional counselors to serve military clients, but the research within the profession has yet to be explored. A content analysis of 23 professional counseling journals from June 1998 to June 2018 was conducted to determine military population research trends. Findings indicated that counselors are researching topics similar to those of other mental health fields, such as posttraumatic stress, but are contributing to those topics conceptually rather than empirically. Topical areas in which counselors do produce more empirical studies include career counseling, and these studies relied on college student veteran populations. Suggestions for incorporating the philosophical principles of counseling into future research are provided to inform the trajectory of military scholarship in the profession.  相似文献   
107.
Suicides among older adults in the United States and Canada in the last decade have accounted for an increasing share of all suicides. In both countries the use of firearms among older adults has steadily increased. Despite these trends, little is known about the extent to which crisis centers are prepared to prevent elder suicide. A survey of AAS-listed crisis prevention centers examined the training, knowledge, and current practices relevant to elder suicide among personnel in 321 crisis prevention centers in both countries. Results revealed insufficient training, a lack of familiarity with recent suicide trends, and limited outreach to older adults.  相似文献   
108.
The country‐of‐origin effect is a topic central to the field of international marketing. Country of origin has been found to exert a particularly potent effect on consumer evaluation in situations where there is a strong link between a country and a particular product category. The present study provides further insight into how this particular effect can be understood. Drawing on a novel conceptualization of how country image and product categories interact, this study tested the relative evaluative relevance of product category with respect to estimates of brand equity across a variety of product categories. The findings suggest that facets of a country's image that are more closely related to the evaluation situation exert a greater influence on the evaluation of brands. This result encourages scholars as well as practitioners to re‐evaluate which situations might cause the country of origin effect to hold managerial relevance and paves the way for new paths toward a more comprehensive understanding of the effect. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
109.
110.
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