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   15013篇
  免费   650篇
  国内免费   3篇
  2020年   203篇
  2019年   209篇
  2018年   375篇
  2017年   340篇
  2016年   342篇
  2015年   239篇
  2014年   269篇
  2013年   1132篇
  2012年   473篇
  2011年   482篇
  2010年   305篇
  2009年   284篇
  2008年   397篇
  2007年   385篇
  2006年   355篇
  2005年   303篇
  2004年   284篇
  2003年   249篇
  2002年   258篇
  2001年   527篇
  2000年   477篇
  1999年   344篇
  1998年   141篇
  1996年   133篇
  1993年   134篇
  1992年   267篇
  1991年   277篇
  1990年   258篇
  1989年   259篇
  1988年   265篇
  1987年   239篇
  1986年   220篇
  1985年   231篇
  1984年   217篇
  1983年   161篇
  1982年   164篇
  1979年   206篇
  1978年   152篇
  1977年   145篇
  1976年   139篇
  1975年   203篇
  1974年   221篇
  1973年   240篇
  1972年   204篇
  1971年   190篇
  1970年   158篇
  1969年   171篇
  1968年   223篇
  1967年   192篇
  1966年   182篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Multiunit activity (MUA) was recorded chronically in the hippocampus (CA3) and the medial geniculate body (mMG) during habituation to a tone followed by conditioning (tone paired with footshock) or pseudoconditioning (tone/footshock unpaired) in rats previously trained in a lever-pressing for food task (VI 60). In the conditioned group pairing tones with footshocks rapidly induced an increase in the initial CS-evoked response in the mMG, followed by the emergence of a hippocampal response and a marked conditioned suppression of lever-pressing to the tone. In contrast, in the pseudoconditioned group, the stimulus induced only transient cellular changes in the hippocampus and in the mMG, while no behavioral suppression to the tone could be seen. Moreover, presentations of the CS 45 days later induced multiunit and behavioral responses in both structures, only in the conditioned group. These results are used for discussion of the role of learning-induced changes in the sensory structure (mMG) as compared with changes in an associative structure (hippocampus), during acquisition and retention of a conditioned response.  相似文献   
63.
Previously we (Bruno & Cutting, 1988) explored the perception of spatial relations among objects laid out in a computer-generated environment. In his commentary on our article, Massaro (1988) raised several issues. The most important is from his reanalysis, which indicated that--because of a subadditive trend in the results--additive and multiplicative strategies fit our data in Experiment 1 about equally well. In reply, we performed a different analysis. Results corroborate subadditivity--and hence multiplicative information combination--in Experiment 1 but provide no evidence for it in Experiments 2 and 3. On the whole, then, the results still support additivity more strongly than any other combination rule and thus support our notion of minimodularity.  相似文献   
64.
After thermal cauterization of the area postrema in rats the absence of conditioned taste aversion to sucrose paired with lithium chloride (0.15 M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 degrees/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.  相似文献   
65.
66.
Black and White college students were studied to determine reactions to moral dilemmas when the race of the central character in the dilemma was changed.  相似文献   
67.
This article explores how the sales budget is set in a business organization. Findings from a longitudinal participant observation study revealed that the sales budget is considered of great importance to the organization as sales estimates serve as premises for planning of production and supply and new product developments. It was observed that the sales budget was based on a narrow, inner-directed perspective, almost looking away from important environmental driving forces such as competitors and customers. The findings also showed that individuals involved in the sales budgeting process behaved opportunistically, influencing the budgetary process and outcomes. Theoretical and normative implications are highlighted.  相似文献   
68.
The sensitivity of naturalistic prose material to retroactive interference (RI) was investigated in three experiments, with due consideration given to the conditions known to produce RI in non-prose material. In experiment 1, unrelated, related, and nearly identical (parapharase) prose passage conditions yielded a pattern of results very similar to those obtained with non-prose material, with only the related condition associated with significant amounts of RI. Based upon these results and a few simple assumptions, a classificatory scheme was developed within which predictions were made regarding RI in related prose material. Several such predictions were tested and confirmed in Experiments 2 and 3. It was concluded that the many previous failures to detect RI in the retention of prose may be attributed to factors other than any inherent insensitivity of the material itself, and that RI may be just as predictable in prose as it is non-prose material.  相似文献   
69.
Previous research on the effect of lecture handouts on student learning indicates that students who are given skeletal handouts usually perform better in course examinations than students who take all their own notes. The present study investigates whether the amount of detail in the handout is a critical factor in this. A randomized groups experiment was conducted in the context of a course on dental surgery. Four lecture handout conditions (headings and full text; headings and key points; headings only; no supplementary materials) were compared on tests 2 days and 2 weeks after the lecture. The significant differences between conditions were: ‘headings only’ better than ‘headings and key points’ on the first test; ‘headings only’ better than ‘no supplementary materials’ on the second test; and ‘headings and full text’ better than ‘no supplementary materials’ on the second test. These results indicate that the amount of detail is a critical factor in handout effectiveness.  相似文献   
70.
Study of child abusers reveals that many victimizers were once victims and that the behaviors underlying the perspectives of victims and victimizers are related. Three groups of abusing parents using directed self-help were studied at Parents Anonymous by participant observation methodology for two and-a-half years. Four of the 52 participating parents read and commented on a draft of the research. Their violence appeared to be an attempt to gain a sense of control or to deal with the frustration of not feeling in control. Suggestions are made for developing social services that enhance individuals' sense of control.Paper presented at the Groves Conference on Marriage and the Family, London, England, July, 1986.  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