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   5340篇
  免费   58篇
  国内免费   3篇
  2020年   20篇
  2019年   34篇
  2018年   145篇
  2017年   127篇
  2016年   211篇
  2015年   125篇
  2014年   65篇
  2013年   145篇
  2012年   312篇
  2011年   297篇
  2010年   55篇
  2009年   55篇
  2008年   74篇
  2007年   76篇
  2006年   67篇
  2005年   1347篇
  2004年   683篇
  2003年   471篇
  2002年   155篇
  2001年   41篇
  2000年   22篇
  1999年   32篇
  1998年   17篇
  1997年   11篇
  1995年   12篇
  1994年   13篇
  1993年   10篇
  1992年   32篇
  1991年   44篇
  1990年   66篇
  1989年   47篇
  1988年   30篇
  1987年   50篇
  1986年   41篇
  1985年   33篇
  1984年   30篇
  1983年   23篇
  1979年   33篇
  1978年   15篇
  1976年   11篇
  1975年   29篇
  1974年   37篇
  1973年   31篇
  1972年   29篇
  1971年   26篇
  1970年   18篇
  1969年   20篇
  1968年   22篇
  1967年   19篇
  1966年   19篇
排序方式: 共有5401条查询结果,搜索用时 15 毫秒
61.
The number of active sweat glands (PSI), heart rate, systolic (SBP) and diastolic blood pressure (DBP) were assessed every 2 minutes in 109 male blood donors. Three measurements were taken at the beginning (adaptation phase), three later but before blood donation (baseline), one during the venous puncture (phase 3), three thereafter but still during donation (phase 4), and four after removal of the cannula (phase 5). Analysis of variance yielded significant differences between phases; PSI and SBP behaved similarly, decreasing from adaptation to baseline, rising during puncture, and decreasing again thereafter. Mean within-subject correlations between variables were significantly above 0. Between-subjects correlations were significantly negative for PSI and DBP. This is best explained by the influence of age on both variables. Correlations of PSI values as determined by three raters had a mean of 0.90. The study shows that the PSI is a very sensitive indicator of stress that is easily accessible also in field studies.  相似文献   
62.
An investigation was made into the extent and time course of anticipatory coarticulation in the speech of two normal and two anterior aphasic, German-speaking subjects. Both labial and velar coarticulation gestures were investigated. Subjects produced sentences containing target words contrasting in postconsonantal vowel rounding (e.g., [geli:ge]/[gely:gel]) and in nasality (e.g., [ti:de]/[ti:ne]). Speech kinematics were monitored by means of electromagnetic articulography. The data revealed that for correct productions, aphasic speakers' coarticulatory patterns were more highly variable than those of control subjects. These differences, however, were found chiefly for spatial displacement characteristics, while the temporal aspects of articulator movement necessary for anticipatory coarticulation appeared largely intact. Articulator mistiming did not appear to explain a small corpus of stop/nasal substitution errors produced by one of the aphasic speakers.  相似文献   
63.
Americans vote party lines; nothing predicts election outcomes as well. People may vote party lines because party candidates have views that accurately reflect the positions of their members, because party identification acts as a convenient cue that eliminates the need for greater information search or cognitive processing, or because party classification biases interpretation of other information people have about the candidates. To investigate these competing hypotheses for party effects on voter decision making, participants were presented with a choice between 2 candidates whose policy positions were more inconsistent than consistent with their party identification (Study l), or completely inconsistent with their party identification (Study 2). People voted as a function of party label in Study I, but issue stand emerged as a stronger predictor in Study 2 (although Democrats were more likely to cross party lines than Republicans). These results suggest that party identification influences how other information about the candidate is perceived and processed. Theoretical and practical implications are discussed.  相似文献   
64.
Book reviews     
Thirty‐Five Oriental Philosophers. Diane Collinson & Robert Wilkinson, 1994, London and New York, Routledge, vi + 205 pp., £35

Essays on Indian Philosophy Traditional and Modern. J. N. Mohanty (edited by Purushottama Bilimoria), 1993, Delhi, Oxford University Press, xxxvii + 347 pp., Rs. 500

Gates of Light (Sha'are Orah). Rabbi Joseph Gikatilla, 1994, London, Harper Collins, 400 + xxxiv pp., $30  相似文献   

65.
This paper addresses a problem in reporting scientific research. The problem is how to distinguish between justifiable and unjustifiable data selection. Robert Millikan is notorious for an infamous remark that he used all his data when in fact he had used a selection. On this basis he has been accused of fraud. There is a tension here — historians and his defenders see his selection as understandable and legitimate, while current statements about the Responsible Conduct of Research imply his selection was illegitimate. This paper discusses two main issues that arise in assessing his conduct, whether he was intentionally misleading and whether he actually did mislead the scientific community about some facts of nature. It is argued that he was not intentionally misleading, and that it is unlikely that he misled the scientific community.  相似文献   
66.
67.

To what extent do differences in biologicalsexand psychological gender identity influence affectivereactions to different genres of film? In order toaddress this question, this investigation examined the impact of sex and gender roleself-perceptions on viewers' responses to neutral,melodramatic, and violent film segments. Working with apredominantly Caucasian population (93% Caucasian) at asoutheastern university, the results emphasize theimportance of sex and gender role self-perceptions onviewers' affective responses to media entertainment. Theimplications of these findings are discussed.

  相似文献   
68.
We explore a model that examines how personal and environmental variables explain violent behavior by adolescents. Repeated interviews with youths from 1984–1992 from 10 cities across the United States provided the data. These interviews first occurred with 2,787 youths when they were adolescents (1984–85 and 1986–87) and the interviews were repeated on a subsample of 602 youths when they were young adults (1989–90 and 1991–92). Longitudinal multivariate analyses showed that almost a third of the variance in adolescent violent behaviors was predicted by a combination of personal variables (gender, substance misuse) and environmental variables (history of child abuse, stressful events, traumatic events, and city rates of unemployment). Further, almost a third of the variance in change in violent behaviors from year to year was predicted by prior violent behavior and a combination of personal variables (gender, suicidality, and substance misuse) and environmental variables (stressful events).  相似文献   
69.
Inhibition of protein synthesis by anisomycin for a short duration impairs memory of a one-trial inhibitory avoidance task in rats. Memory of escape conditioning involving eight trials is disrupted only if the duration of protein synthesis is prolonged by repeated injections. In marked contrast, olfactory memory of rats trained on two odor discriminations is not affected by anisomycin even if the duration of inhibition is prolonged and the number of trials is reduced to a minimum. In previous work, leupeptin, a thiol proteinase inhibitor, was shown to impair olfactory discrimination learning, but left inhibitory and avoidance conditioning intact. Together, these results provide a pharmacological double dissociation of memory, and suggest that the same chemistries, or mixtures of chemistries, may not be involved in all types of memory.  相似文献   
70.
Lesions localized to specific areas of the amygdala and overlying cortex in rats produced differential effects in several behavioral tasks. Three different types of lesions were tested: central, basolateral, and cortex lateral to the amygdala. Lesions restricted to the central nucleus produced increased activity on all parameters studied in an open-field test, but the other two groups were not changed. In one-way active avoidance all three groups with lesions showed deficits. The most pronounced change was observed in the central group. All groups showed the same degree of retention loss, but in forced extinction of one-way active avoidance after retraining, the cortical and basolateral groups were most defective. A fear-reduction hypothesis is proposed for the central lesion. The basolateral and cortical areas may be more specifically involved in passive avoidance behavior.  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