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   7869篇
  免费   348篇
  国内免费   2篇
  2021年   92篇
  2020年   150篇
  2019年   133篇
  2018年   204篇
  2017年   180篇
  2016年   231篇
  2015年   174篇
  2014年   209篇
  2013年   769篇
  2012年   360篇
  2011年   376篇
  2010年   243篇
  2009年   231篇
  2008年   333篇
  2007年   335篇
  2006年   268篇
  2005年   293篇
  2004年   294篇
  2003年   266篇
  2002年   267篇
  2001年   127篇
  2000年   96篇
  1999年   131篇
  1998年   114篇
  1997年   116篇
  1996年   95篇
  1995年   90篇
  1994年   83篇
  1993年   85篇
  1992年   93篇
  1991年   89篇
  1990年   70篇
  1989年   54篇
  1988年   54篇
  1987年   64篇
  1986年   67篇
  1985年   81篇
  1984年   76篇
  1983年   79篇
  1982年   73篇
  1981年   85篇
  1980年   78篇
  1979年   72篇
  1978年   82篇
  1977年   82篇
  1976年   72篇
  1975年   64篇
  1974年   75篇
  1973年   53篇
  1966年   46篇
排序方式: 共有8219条查询结果,搜索用时 31 毫秒
131.
An overview is presented of a pilot psychoendocrine study of PTSD inpatients in comparison with several subgroups of schizophrenic and affective disorder patients. Using a hormonal profile including Cortisol, norepinephrine, epinephrine, testosterone, and thyroxine, it was found that the mean values for the PTSD group were at or near the extreme end of the range for every hormone measured, i.e., relatively low for Cortisol and high for the remaining hormones. The possible clinical meaning of these findings is considered in the light of prior psychoendocrine research on chronic stress. The hormonal alterations in PTSD appear to be persistent and suggest the possibility of being linked largely to traits or character structure, perhaps particularly to cognitive variables related to defense and coping mechanisms, as reviewed in detail for each hormonal system. There appears to be a potential for a fruitful union between the traumatic stress and psychoendocrine fields and some future strategies for developing and strengthening such a union are suggested.  相似文献   
132.
133.
134.
The purpose of this study was to examine the predictive validity of a teacher nomination procedure for identifying at- risk children. Two hundred and twenty-five children were nominated by their teachers as well- adjusted (n= 75), socially withdrawn (n=76), or socially aggressive (n=74) during the fourth grade. Five years later, 198 of these children (88%) were located and their adjustment evaluated. Significant differences among the nominated children were found on a variety of measures, including academic grades, sociometric status, and social behavior. In addition, differences in school dropout and delinquent offenses were noted. Results are discussed in terms of the validity of teacher nomination procedures and their utility in identifying at- risk youth.  相似文献   
135.
136.
137.
When procedural artifacts are controlled, it has been difficult to demonstrate directed forgetting in pigeons. However, previous research with pigeons has not allowed for the reallocation of working memory (from forget items to remember items) on forget-cued trials as is possible in human directed forgetting experiments. In the present experiment, directed forgetting was found while controlling for procedural artifacts and allowing the pigeons to reallocate memory resources on forget trials. The results indicate that under these conditions, pigeons have active control over memory processing.  相似文献   
138.
A multidisciplinary group of genetic and other professionals discuss a complex case of familial conflict over access to genetic information. One twin wishes to know the results of her deceased mother's tests for BRCA1 mutations; a second twin objects to researchers making this information available. As the case discussion unfolds, the apparent facts of this case are called into question and the lines of ethical certainty become less clear.  相似文献   
139.
Tail shock induces reflex sensitization inAplysiaand, in parallel, induces a number of modulatory effects in central neurons, such as increased excitability in tail sensory neurons (SNs) and facilitation of synaptic transmission from SNs to motor neurons. Both of these modulatory effects are mimicked by exogenous application of serotonin (5HT) or electrical stimulation of the tail nerve P9. In the present study we examined the activation thresholds for increased excitability and synaptic facilitation induced by either 5HT or P9 stimulation. We found that the concentration of 5HT sufficient to produce a significant increase in excitability produced no significant synaptic facilitation and, conversely, that the intensity of nerve stimulation sufficient to produce significant synaptic facilitation produced no excitability changes. This reversal of relative thresholds for these modulatory effects may reflect the differential access of exogenous 5HT and endogenous 5HT (released by tail nerve stimulation) to the SN cell body and synaptic terminals, respectively.  相似文献   
140.
In the typical induction of the orientation-contingent color aftereffect (CCAE), the stimuli are composed of elements that differ in both color and luminance. Three experiments are reported that show that chromatic contrast between stimulus elements is insufficient for the induction of the orientation-CCAE and that luminance contrast is necessary. These experiments expand on previous research concerned with the role of luminance contrast in the induction of orientation-CCAEs by eliminating alternative explanations.  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