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   64127篇
  免费   2638篇
  国内免费   41篇
  2020年   723篇
  2019年   906篇
  2018年   1231篇
  2017年   1275篇
  2016年   1363篇
  2015年   925篇
  2014年   1145篇
  2013年   5039篇
  2012年   2096篇
  2011年   2104篇
  2010年   1318篇
  2009年   1328篇
  2008年   1855篇
  2007年   1871篇
  2006年   1674篇
  2005年   1468篇
  2004年   1404篇
  2003年   1316篇
  2002年   1331篇
  2001年   1986篇
  2000年   1967篇
  1999年   1478篇
  1998年   657篇
  1997年   637篇
  1995年   625篇
  1992年   1260篇
  1991年   1127篇
  1990年   1154篇
  1989年   1061篇
  1988年   1076篇
  1987年   1003篇
  1986年   1014篇
  1985年   994篇
  1984年   877篇
  1983年   819篇
  1982年   626篇
  1979年   976篇
  1978年   695篇
  1977年   612篇
  1976年   603篇
  1975年   776篇
  1974年   879篇
  1973年   922篇
  1972年   734篇
  1971年   690篇
  1970年   622篇
  1969年   691篇
  1968年   834篇
  1967年   754篇
  1966年   671篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
881.
In the context of an annual fundraising drive for the American Society, two field experiments were conducted to test the relative effectiveness of suggesting either small or large contributions. In experiment 1, as part of a door-to-door campaign 300 people were randomly assigned to: (a) a standard request for contributions (control); (b) the standard request plus the words, “even a penny will help”; or (c) the standard request plus the words, “a generous contribution would really help.” As hypothesized, asking for a generous contribution significantly decreased the percentage of people who donated and failed to increase the average size of contribution by those who gave. Inconsistent with previous findings, the even-a-penny condition did not increase donating. In the second experiment conceptually similar requests were made in a mail-out campaign: 6,000 requests were made—2,000 suggested relatively small amounts (options beginning at $5); 2,000 suggested large amounts (options beginning at $5); and 2,000 were unspecified with regard to recommended amount (control). As expected, compared to the control condition, asking for small amounts increased the proportion of donors to nondonors without decreasing the average size of contributions, while asking for large amounts decreased the proportion of donors to nondonors without increasing the size of contributions. It is suggested that the findings have important implications for charitable fundraising.  相似文献   
882.
The development of generalized job initiative was examined with three severely retarded men working in an industrial assembly area of a sheltered workshop. Interventions included discrimination training, role-play training, and self-monitoring. For each participant, training was applied sequentially to three sets of job initiative behaviors. Intensive training was required to establish the first set of job initiative behaviors; however, the second and third sets of job initiative behaviors were learned with only discrimination training. The discussion summarizes the findings and suggests research needed to develop more powerful learning-to-learn paradigms.  相似文献   
883.
We evaluated the effects of aversive taste treatment of thumb sucking on untreated trichotillomania (habitual hair pulling) in two children who chronically pulled their hair and sucked their thumbs. A combination of withdrawal and nonconcurrent multiple baseline designs showed that, concomitant with the successful treatment of thumb sucking, hair pulling was also eliminated. The results suggest an efficient method for changing behaviors that are difficult to treat directly.  相似文献   
884.
The acquired immune deficiency syndrome (AIDS) has rapidly become the most serious medical consequence of injecting illicit drugs. Its potential impact on intravenous (IV) drug use is enormous. Human immunodeficiency virus (HIV, also known as HTLV-III and LAV), the virus that causes AIDS, appears, usually, to lead to lifelong infection. At present there is no effective treatment, and the treatments under development may require lifelong antiviral therapy. Since most of the antibody produced in response to HIV infection does not neutralize the virus, and since there is substantial genetic variation in the virus, it will be difficult to develop a vaccine. Even after vaccines are developed, testing their safety and efficacy will be formidable problems. Until either effective treatment or vaccines are developed, control of the epidemic among IV drug users must be attempted through behavior change/prevention efforts. In this paper we will review the epidemiology of AIDS among IV drug users and characteristics of the IV drug-use subculture relevant to prevention efforts. We will then identify different target groups for these prevention efforts, present available evidence about behavior change in these groups, and then briefly discuss how to prevent transmission of HIV to heterosexual partners who are not themselves IV drug users and to the children of IV drug users.  相似文献   
885.
The present study examined the hypothesis that individuals are more influenced by a drug name than by the side effects associated with that drug when making recommendations regarding regulation. Subjects recommended the amount of regulation that should exist for eight drugs ranging from aspirin to LSD. One third of the subjects were asked to make recommendations based only on the drug name. Another third made recommendations based only on the facts associated with the drugs (i.e., side effects, symptoms). A final third made recommendations based on both facts and the drug name. Results indicated that, when given only the facts, subjects' recommendations deviated greatly from the actual regulation of the drugs but that the facts were ignored if subjects knew the name of the drug. These results suggest that critical information may be ignored when decisions are made about drug regulation. The implications for self-regulated drug use are discussed.  相似文献   
886.
To facilitate the classroom and workshop integration of three autistic clients, we examined the feasibility of teaching them to respond appropriately without the continual presence of specially trained treatment providers. Within a multiple baseline design, a 4-step treatment process was implemented to promote durable responsive performance. Results indicated that the therapist could be removed from the treatment environment and that appropriate behavior could be successfully maintained in community settings with only infrequent and delayed contingencies.  相似文献   
887.
Correspondences between verbal responding (saying) and nonverbal responding (doing) may be organized in terms of the classes of verbal/nonverbal relations into which particular instances of verbal/nonverbal response sequences can enter. Contingency spaces, which display relations among events in terms of the probability of one event given or not given another, have been useful in analyses of nonverbal behavior. We derive a taxonomy of verbal/nonverbal behavior relations from a contingency space that takes into account two conditional probabilities: the probability of a nonverbal response given a verbal response and that probability given the absence of the verbal response. For example, positive correspondence may be said to exist as a response class when the probability of doing is high given saying but is otherwise low. Criteria for other generalized classes, including negative correspondence, follow from this analysis.  相似文献   
888.
889.
As part of a prospective, longitudinal study of suitability for and outcome of psychoanalysis, 22 patients were evaluated for changes in the level and quality of their object relations. These patients had been accepted for supervised analysis with candidates in training by senior analysts who had diagnosed them as neurotic. The majority of these patients reported difficulties in relationships as at least one of their reasons for originally seeking psychoanalytic treatment. Prior to beginning analysis, each patient was given a battery of psychological tests. One year after the termination of analysis, the test battery was readministered and a followup interview was conducted separately with each patient and analyst. Ratings of change based on patient and analyst interviews and comparisons of psychological tests before and after treatment all showed statistically significant improvement in the level and quality of object relations for this patient group. The results of this study support what is often observed in clinical practice, that psychoanalysis has a positive effect on the level and quality of a patient's object relations.  相似文献   
890.
L G Streetman 《Adolescence》1987,22(86):459-464
The self-esteem of 93 unmarried females between the ages of fourteen and nineteen was measured upon entry into several state-sponsored training programs. Some significant differences were discovered concerning the impact of early motherhood on these individuals. The symbolic importance of motherhood, as a passage into adult status, and the intervening effects of normative group anchorage may mediate between individuals' cognitive ability and their level of self-esteem.  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