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   9097篇
  免费   333篇
  国内免费   4篇
  2021年   84篇
  2020年   102篇
  2019年   162篇
  2018年   240篇
  2017年   218篇
  2016年   226篇
  2015年   175篇
  2014年   174篇
  2013年   812篇
  2012年   364篇
  2011年   350篇
  2010年   188篇
  2009年   185篇
  2008年   276篇
  2007年   282篇
  2006年   224篇
  2005年   261篇
  2004年   243篇
  2003年   218篇
  2002年   203篇
  2001年   265篇
  2000年   259篇
  1999年   179篇
  1998年   84篇
  1997年   71篇
  1996年   84篇
  1993年   77篇
  1992年   141篇
  1991年   148篇
  1990年   147篇
  1989年   117篇
  1988年   114篇
  1987年   117篇
  1986年   132篇
  1985年   126篇
  1984年   117篇
  1983年   100篇
  1979年   106篇
  1978年   82篇
  1977年   76篇
  1975年   71篇
  1974年   101篇
  1973年   108篇
  1972年   75篇
  1971年   80篇
  1970年   82篇
  1969年   80篇
  1968年   113篇
  1967年   88篇
  1966年   100篇
排序方式: 共有9434条查询结果,搜索用时 281 毫秒
201.
Strong representability of fork algebras, a set theoretic foundation   总被引:1,自引:0,他引:1  
  相似文献   
202.
Current status of the Rorschach Inkblot Method   总被引:1,自引:0,他引:1  
The current scientific, clinical, and professional status of the Rorschach Inkblot Method (RIM) is reviewed with respect to its psychometric properties, the applied purposes it can be expected to serve, the extent of its use, and the nature of prevailing attitudes toward it. Available evidence indicates that the RIM is a psychometrically sound measuring instrument that provides valid assessments of personality characteristics and can facilitate differential diagnosis and treatment planning and evaluation. The RIM continues as in the past to be widely used by both clinicians and researchers. However, the esteem in which it is held by practitioners, who are generally agreed that clinical psychologists should be competent in Rorschach assessment, is not universally shared by academicians, many of whom presently question the future place of Rorschach training in graduate education.  相似文献   
203.
204.
Molecular sequence data, made available in the last 15 years or so, have led to the classification of living cells into three phylogenetic domains: Bacteria, Archaea, and Eucarya. All the organisms that have been tested belonging to either domain were capable of mounting a stress response with essentially the same characteristics, regardless of the stressor. The protagonists in the cell's stress response are the stress genes and their protein products. Some of the latter are molecular chaperones. Under physiological conditions, these chaperones aid other cellular proteins to fold properly and achieve a native -functional- configuration, and to translocate from the place of synthesis to the cell's locale in which they will operate. In a stressed cell, the stress proteins that are chaperones protect other molecules from denaturation and help those partially damaged to regain a functional configuration. Thus, cell death is avoided and recovery is enhanced. The study of stress genes and proteins has progressed considerably in organisms belonging to the domains Bacteria and Eucarya. Less is known about the archaeal stress genes. Here, research with an organism from the Archaea is discussed, focusing on the stress genes of the hsp70 (dnaK) locus. Future perspectives for basic and applied research within the health sciences and biotechnology industries are presented.  相似文献   
205.
Adaptiveness constitutes coping consistently with Stressors so to reduce distress or, at worst, not aggravate it. Accordingly, it should moderate the adverse impact of hassles. Undergraduate volunteers (N = 200) responded to measures of hassles, adaptiveness, and the criteria of subjective distress, psychiatric symptomatology and minor physical ailments. In all three regression analyses, hassles made a substantial positive contribution and adaptiveness a small negative contribution to adverse outcome. The interaction between hassles and adaptiveness was non-significant in all three cases. Alternative interpretations were identified to guide further research.  相似文献   
206.
In a rule induction problem positive hypothesis tests select evidence that the tester expects to be an example of the correct rule if the hypothesis is correct, whereas negative hypothesis tests select evidence that the tester expects to be a nonexample if the hypothesis is correct. Previous research indicates the general effectiveness of a positive test strategy for individuals, but there has been very little research with cooperative groups. We extend the analysis of Klayman and Ha (Psychological Review, 1987) of ambiguous verification or conclusive falsification of five possible types of hypotheses by positive and negative tests by emphasizing the importance of further examples following hypothesis tests. In two experiments four-person cooperative groups solved rule induction problems by proposing a hypothesis and selecting evidence to test the hypothesis on each of four arrays on each trial. In different conditions the groups were instructed to use different combinations of positive and negative tests on the four arrays. Positive tests were more likely to lead to further examples than negative tests, and the proportion of correct hypotheses corresponded to the proportion of positive tests, in both experiments. We suggest that positive tests are more effective than negative hypothesis tests in generating further evidence, and thus in inducing the correct rule, in experimental rule induction tasks with a criterion of certainty imposed by the researcher.  相似文献   
207.
This study uses feminist theory to examine the variables of relationship length and relationship satisfaction as predicators of both self-esteem and emotional functioning for women. Using a national sample of data gathered from 1,257 female survey respondents this study found significant relationships between emotional functioning, self-esteem, and self-reported relationship satisfaction which was supported by regression testing and path analysis. In addition, a significant negative relationship was noted between a woman's self-esteem and her with-holding of verbalized displeasure or disagreement with her partner. Implications for women in therapy were discussed.  相似文献   
208.
Abstract— The apparent brightness of a surface is profoundly influenced by the brightness of an adjacent surface., but these contrast effects are reduced when the surface are perceived as separate three-dimensional entities. Previous work has suggested that high-level perceptual and cognitive processes involved in scence segmentation may be responsible for modifying a surface's appearance. We demonstrate large reductions in contrast effects when the sues available for segmentations are restricted to those that isolate separate groups of early cortical neurons in the visual system. Our data contradict standard contract-signaling models of brightness perception and imply that mechanisms of figure-ground segmentation are already available at low levels of visual processing.  相似文献   
209.
TIME COURSE OF ACTIVATING BRAIN AREAS IN GENERATING VERBAL ASSOCIATIONS   总被引:2,自引:0,他引:2  
Abstract— Generating a use far a visual word in comparison with reading the word aloud activates frontal attention areas first (170 MS), a left lateral frontal area next (250 ms), and then a left temporoparietal (Wernicke's) area (650 ms). A brief period of practice reduces these activations. If subjects are asked to respond to a word from the same practiced list by giving a novel use, the original activations reappear and are joined by activity similar in location and time to Wernicke's activation but in the right hemisphere. These findings demonstrate the time course of activations of neuroanatomical areas in word processing and indicate a role for the right hemisphere when semantic processing is more difficult, such as in generating a less frequent association in the presence of a highly practiced one.  相似文献   
210.
The primary objective of the present investigation was to examine adaptive functioning in the families of patients with a wide range of psychiatric disorders. Seven dimensions of family functioning, as measured by the Family Assessment Device (FAD), were compared across families of patients with a schizophrenia spectrum disorder (n = 61 ), bipolar disorder (n = 60 ), major depression (n = 111 ), anxiety disorder (n = 15 ), eating disorder (n = 26 ), substance abuse disorder (n = 48 ), and adjustment disorder (n = 46 ). Families in each psychiatric group were also compared to a control group of nonclinical families (N = 353 ). Results indicated that regardless of specific diagnosis, having a family member in an acute phase of a psychiatric illness was a risk factor for poor family functioning compared to the functioning of control families. However, with few exceptions, the type of the patient's psychiatric illness did not predict significant differences in family functioning. Thus, having a family member with a psychiatric illness is a general stressor for families, and family interventions should be considered for most patients who require a psychiatric hospitalization for either the onset of, or an acute exacerbation of, any psychiatric disorder.  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