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   50717篇
  免费   1956篇
  国内免费   28篇
  52701篇
  2019年   638篇
  2018年   887篇
  2017年   953篇
  2016年   951篇
  2015年   714篇
  2014年   795篇
  2013年   3992篇
  2012年   1404篇
  2011年   1538篇
  2010年   974篇
  2009年   955篇
  2008年   1321篇
  2007年   1307篇
  2006年   1183篇
  2005年   1041篇
  2004年   960篇
  2003年   1001篇
  2002年   973篇
  2001年   1798篇
  2000年   1744篇
  1999年   1272篇
  1998年   560篇
  1997年   475篇
  1996年   488篇
  1992年   1077篇
  1991年   1044篇
  1990年   996篇
  1989年   939篇
  1988年   928篇
  1987年   892篇
  1986年   870篇
  1985年   939篇
  1984年   742篇
  1983年   614篇
  1982年   472篇
  1981年   478篇
  1979年   769篇
  1978年   563篇
  1977年   508篇
  1976年   486篇
  1975年   651篇
  1974年   737篇
  1973年   793篇
  1972年   637篇
  1971年   577篇
  1970年   553篇
  1969年   548篇
  1968年   691篇
  1967年   616篇
  1966年   636篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
931.
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   
932.
933.
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   
934.
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   
935.
936.
937.
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   
938.
Three experiments investigating the effects of arousal on the T-maze choice behavior of inbred mouse strains are reported. In Experiment 1, CBA and NZB mice were administered unrewarded free choice alternation tests on 10 consecutive days under either No Shock, Shock Start (shocked in the start box), or Shock Choice (shocked at the choice point) treatment conditions. Both strain and treatment effects were observed: In the No-Shock condition, the nonreactive CBA strain alternated, but the reactive NZB strain did not. In the Shock Start condition the CBA strain showed only a suppressed alternation, while the NZB strain administered the same treatment perseverated. Both strains perseverated in the Shock Choice condition. In Experiment 2, NZB mice administered identical shocks in the start box and goal arms on both trials of five consecutive tests conducted once a day perseverated to the same goal arm in which they had been shocked on the first trial. In Experiment 3, NZB mice punished for perseverating (with shock continuation) and simultaneously reinforced for alternating (with shock termination) showed a “punishment paradox”; they perseverated despite the reinforcement contingencies. These results, which are congruent with the optimal arousal theory and several characteristics the theory shares with the emergent neophobia construct, support the contention that arousal mediates a symmetrical relationship between approach and avoidance along a novelty-familiarity continuum.  相似文献   
939.
940.
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