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   45421篇
  免费   1633篇
  国内免费   20篇
  2019年   483篇
  2018年   635篇
  2017年   706篇
  2016年   772篇
  2015年   588篇
  2014年   660篇
  2013年   3451篇
  2012年   1187篇
  2011年   1228篇
  2010年   762篇
  2009年   763篇
  2008年   1059篇
  2007年   1054篇
  2006年   914篇
  2005年   881篇
  2004年   826篇
  2003年   818篇
  2002年   857篇
  2001年   1341篇
  2000年   1272篇
  1999年   947篇
  1998年   442篇
  1996年   412篇
  1992年   860篇
  1991年   847篇
  1990年   845篇
  1989年   815篇
  1988年   790篇
  1987年   752篇
  1986年   797篇
  1985年   840篇
  1984年   684篇
  1983年   619篇
  1982年   463篇
  1981年   507篇
  1980年   414篇
  1979年   759篇
  1978年   550篇
  1977年   484篇
  1976年   452篇
  1975年   660篇
  1974年   789篇
  1973年   816篇
  1972年   666篇
  1971年   643篇
  1970年   619篇
  1969年   619篇
  1968年   789篇
  1967年   726篇
  1966年   692篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
The study investigated possible sex differences in the types of problems that are correlated with Beck Depression Inventory (BDI) scores, using a sample of college students. Problems related to assertiveness and feeling ill at ease were positively correlated with BDI scores for males, but not for females. In contrast, conflicts with parents, feelings of being boxed in and of boredom, lack of money, and chronic physical complaints were positively related to BDI scores for females, but not for males.  相似文献   
912.
Problems involved in scaling the output regularities observed in free recall are outlined, and assumptions underlying attempted solutions for both categorized and “unrelated” lists are discussed. Several studies that make claims for the superiority of particular measures have indeed demonstrated that it matters which index is selected, but they are shown to provide no justification for preferring one to another. Evidence from simulation studies, however, suggests that a number of measures have “built-in” correlations with theoretically relevant variables such as recall. Some of these biases have proved elusive because their appearance is confined to nonrandom output sequences. The relation between theoretical assumptions and simulation studies is discussed.  相似文献   
913.
914.
Engelhardt HT 《Zygon》1984,19(3):281-295
Abstract. This article argues that there are neither moral considerations that in principle forbid the development or use of recom-binant DNA technology, nor grounds to hold that its application is likely to cause more harm than good. A defensible moral position would enjoin a prudent assessment of consequences, rather than an absolute prohibition. The technology may remain controversial because it presupposes the difference between being a person, an entity who can evaluate and manipulate its own biological structure, and human-ness as a biological structure likely to be the subject of engineering over the long-range future.  相似文献   
915.
One purpose of this investigation was to examine the importance of assessing treatment integrity in a study evaluating a treatment for specific anxiety disorders. Three subjects, two social phobics and one simple phobic, received self-instruction training (Phase I) followed by exposure and self-instruction training (Phase II) in a multiple baseline across subjects design. All subjects were assessed during a pretreatment baseline and throughout treatment using measures of treatment integrity and measures of change in phobic severity. Improvement took place at different times for different subjects. Measures of treatment integrity, which consisted of monitoring of self-statements as well as practice outside the session, indicated that treatment was not always received as intended and that improvement was correlated with practice. The usefulness of measures of treatment integrity in both clinical and research settings is highlighted.  相似文献   
916.
This study examined the reliability and reactivity of participant observation. Twelve couples engaged in two discussions in a laboratory, one on a conflict topic and one on a consensus topic. For the eight couples in the experimental sequences, a baseline discussion was followed by participant observation in which the husband recorded his wife's use of I while continuing to converse. The four couples in the control sequences conversed without participant observation. Compared to observations made by a trained observer, the husbands were unreliable observers, underestimating their wives' use of I. Participant observation was reactive (P<.01), with more wives decreasing their use of I in the experimental sequences than in the control sequences (p<.094). The topic of discussion did not differentially influence reliability or reactivity.This research was conducted as the first author's independent doctoral research project. We extend gratitude to the Research Council of the University of North Carolina at Greensboro for Grant 0-2-110-218-XXXXX-7548; the Statistical Consulting Center of the University of North Carolina at Greensboro; two anonymous reviewers; and our research assistants, Suzanne Brannon, Ben Hardie, Kathy Lindamood, Amy Mitchem, Regina Pierce, and Elga Wulfert. Portions of this paper were presented at the meeting of the Association for Advancement of Behavior Therapy, Washington, D.C., December 1983.  相似文献   
917.
918.
919.
The functional significance of learned population differences in male song in the white-crowned sparrow was explored in natural populations using playback tests. Laboratory results have shown that learning of the population-specific song seems to take place in early life and is strongly dependent upon the nature of the auditory experience at that time. However, the varied results of recent studies make it difficult to reach a confident conclusion about the ecological functions of song learning. The present research took advantage of naturally occurring variation in the differences between songs of adjacent populations to determine a function relating degree of difference in song to intensity of territorial singing elicited. Applying a typological evaluation of syllable structure to the four segments of the song allowed a crude quantitative ranking of the differences between local songs and playback stimuli. These results, together with those of other studies, suggest a unimodal aggressive response function of males to songs of other males. A maximum response to songs slightly different from the local song environment suggests that male exclusion based upon acquired song components may contribute to the maintenance of discrete and stable song dialects.  相似文献   
920.
Kinetic subjective contours   总被引:2,自引:0,他引:2  
  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