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   4481篇
  免费   498篇
  国内免费   3篇
  2023年   29篇
  2022年   36篇
  2021年   71篇
  2020年   83篇
  2019年   100篇
  2018年   204篇
  2017年   218篇
  2016年   255篇
  2015年   162篇
  2014年   141篇
  2013年   551篇
  2012年   251篇
  2011年   273篇
  2010年   179篇
  2009年   211篇
  2008年   202篇
  2007年   215篇
  2006年   180篇
  2005年   151篇
  2004年   138篇
  2003年   145篇
  2002年   139篇
  2001年   71篇
  2000年   68篇
  1999年   62篇
  1998年   46篇
  1997年   35篇
  1996年   48篇
  1995年   50篇
  1994年   34篇
  1993年   30篇
  1992年   41篇
  1991年   34篇
  1990年   33篇
  1989年   23篇
  1988年   35篇
  1987年   32篇
  1986年   28篇
  1985年   29篇
  1984年   32篇
  1983年   16篇
  1982年   26篇
  1981年   26篇
  1980年   22篇
  1979年   18篇
  1978年   21篇
  1977年   16篇
  1975年   17篇
  1974年   20篇
  1972年   20篇
排序方式: 共有4982条查询结果,搜索用时 31 毫秒
51.
This study investigated sex stereotypes as natural language categories. Ten years ago, sex stereotypes were found to have a core-peripheral structure similar to that of the nonevaluative categories studies by Rosch (1973). Changes and stability in these conceptions were studied by having 56 female and 56 male undergraduate students rate 217 adjectives on Likert scales according to how well each adjective represented their own view of typical Men or Women. Mean ratings were analyzed to reveal a structure of core, peripheral, and nonmembers for Men and for Women. As was the case ten years ago, core traits reflected dimensions of “niceness-nurturance” for Women and “potency-strength” for Men. Female students also viewed Women as “competent,” while male students also viewed Women as “socially effective.” Adjectives that constituted the core for one category were generally placed in the periphery for the other category. As compared to ten years ago, the peripheries of the categories were expanded and showed a greater degree of overlap. College students' conceptions of Men and Women are best characterized as overlapping rather than as bipolar opposites. The formation of sex stereotype categories was discussed in terms of cognitive and social learning processes.  相似文献   
52.
This study was designed to examine the correlates of developmental psychological stress for 36 middle-aged professional men. Based on sex role convergence and role adjustment theories, two sets of predictor variables were hierarchically entered into a multiple regression equation with a third set of variables entered to control for individual stressors. Controlling for individual stressors, midlife stress outcome was found to be influenced only by role adjustment (R2=.3593). The sex role convergence cluster did not account for a significant increase in variance. Controlling for individual stressors, the best univariate predictors of stress outcome associated with the midlife transition were (a) the quality of the parent-adolescent relationship and (b) marital satisfaction.  相似文献   
53.
The purpose of this study was to investigate the structure of emotional responses to pictorial stimuli within the affective space defined by orthogonal dimensions of positive affect (PA) and negative affect (NA). College student participants (N = 151) viewed 60 color photographic slides from the International Affective Picture System (Lang, Bradley, & Cuthbert, 1995) and rated their emotional responses to each slide using the Positive and Negative Affect Schedule (Watson, Clark, & Tellegen, 1988). Consistent with prediction, affective reactions to pleasant slides were characterized as high in PA, and low in NA. Unpleasant slides produced elevations on the NA scale, but contrary to expectation, also produced elevated ratings of PA, with the magnitude of PA scale scores increasing systematically with NA scale scores. The results suggest an interesting divergence between the structure of pictorially elicited affective reactions and that of ad hoc mood states. Directions for future research are discussed in relation to the unique properties of the slide viewing paradigm.  相似文献   
54.
Deutsch's theory of cooperative and competitive conflict may be usefully extended to Dutch people. Results of LISREL analyses on data collected from interviews of Dutch employees in 2 companies indicate that competitive goals interfered with the open, constructive discussion of opposing views. However, cooperative goals were not found to contribute to constructive controversy. Dutch who discussed their opposing views openly made progress on the task, worked efficiently, and strengthened their work relationship and their confidence in future collaboration. These results do not argue that Dutch and North Americans handle conflict similarly, for how these groups operationalize the theory may differ significantly. Goal interdependence may have the potential to be a framework for promoting conflict management between Dutch and North Americans.  相似文献   
55.
Formal systems are standardly envisaged in terms of a grammar specifying well-formed formulae together with a set of axioms and rules. Derivations are ordered lists of formulae each of which is either an axiom or is generated from earlier items on the list by means of the rules of the system; the theorems of a formal system are simply those formulae for which there are derivations. Here we outline a set of alternative and explicitly visual ways of envisaging and analyzing at least simple formal systems using fractal patterns of infinite depth. Progressively deeper dimensions of such a fractal can be used to map increasingly complex wffs or increasingly complex value spaces, with tautologies, contradictions, and various forms of contingency coded in terms of color. This and related approaches, it turns out, offer not only visually immediate and geometrically intriguing representations of formal systems as a whole but also promising formal links (1) between standard systems and classical patterns in fractal geometry, (2) between quite different kinds of value spaces in classical and infinite-valued logics, and (3) between cellular automata and logic. It is hoped that pattern analysis of this kind may open possibilities for a geometrical approach to further questions within logic and metalogic.\looseness=-1  相似文献   
56.
There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.  相似文献   
57.
The present study describes the diagnostic profile of over 800 adolescents admitted to residential therapeutic community programs for treatment of drug abuse and related problems. The relationship between race/ethnicity and psychiatric disturbance is examined, and the association among these factors to outcome is investigated. Over 90% of the sample had a DSM-III-R nonsubstance diagnosis. There were significant differences among the race/ethnic groups on attention deficit-hyperactivity and the disruptive behavior and affective disorders. In general, African-American adolescents yielded the lowest rates of disturbance across all categories of disorders. There was no relationship among race/ethnicity, psychiatric disturbance, and 1-year posttreatment outcomes.  相似文献   
58.
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   
59.
Abstract -Object tokens are episodic visual representations that mediate the ability to track visual events as they move about and change over time. Multiple tokens also allow the viewer to individuate multiple instances of a single type of object. In the present study, we established a functional link for object tokens in two seemingly disparate visual phenomena: apparent motion and repetition blindness [RB]. In RB, repeated items are more difficult to perceive than unre-peated items. Using displays in which two sets of alphanumeric characters streamed in opposite directions across a computer screen in apparent motion, we found increased RB for targets appearing within a single apparent motion stream, relative to targets in different apparent motion streams. The results are inconsistent with refractory period or memory retrieval accounts of RB and support the role of object tokens in both apparent motion and RB.  相似文献   
60.
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