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   85969篇
  免费   3482篇
  国内免费   37篇
  89488篇
  2020年   1020篇
  2019年   1217篇
  2018年   1692篇
  2017年   1785篇
  2016年   1831篇
  2015年   1307篇
  2014年   1583篇
  2013年   7237篇
  2012年   2906篇
  2011年   2905篇
  2010年   1801篇
  2009年   1808篇
  2008年   2556篇
  2007年   2560篇
  2006年   2296篇
  2005年   1981篇
  2004年   1968篇
  2003年   1863篇
  2002年   1829篇
  2001年   2756篇
  2000年   2589篇
  1999年   1983篇
  1998年   939篇
  1997年   845篇
  1996年   891篇
  1995年   836篇
  1994年   809篇
  1993年   818篇
  1992年   1654篇
  1991年   1503篇
  1990年   1545篇
  1989年   1422篇
  1988年   1436篇
  1987年   1327篇
  1986年   1324篇
  1985年   1329篇
  1984年   1139篇
  1983年   1031篇
  1979年   1226篇
  1978年   884篇
  1975年   983篇
  1974年   1095篇
  1973年   1150篇
  1972年   941篇
  1971年   890篇
  1970年   780篇
  1969年   807篇
  1968年   1015篇
  1967年   911篇
  1966年   800篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
A group of 211 first-to fourth-grade children who had experienced one or more recent stressful life events were compared to a demographically matched sample of 211 children who had not experienced such events on measures of school adjustment problems and competencies. Stressful life events were found to be associated with the presence of more serious school adjustment problems and fewer competencies. Those associations were strongest for children who had experienced multiple recent stressful events. The importance of preventive interventions for this at-risk group was emphasized and future research steps in the area were considered.  相似文献   
992.
Preweanling (21 days old) and adult (60-80 days old) rats were exposed to ethanol odor either paired with the early stages of apomorphine-induced toxicosis, paired with the recovery from toxicosis, or unpaired with the induction of distress. Twenty four hours later, ethanol preferences were measured in a spatial olfactory test (ethanol vs lemon odor) or a drinking test (5.6% v/v ethanol vs 0.25% w/v citric acid solutions). During the olfactory test both young and adult rats expressed substantial ethanol odor aversions when previously exposed to this odor paired with toxicosis. However, changes in ethanol intake became apparent only in preweanling subjects. Preweanlings which received the ethanol odor paired with illness drank significantly less of the ethanol solution relative to controls, while subjects experiencing the odor paired with recovery from distress significantly increased their consumption of the ethanol solution. These prior aversive and appetitive olfactory experiences had no effect upon ethanol intake in adult rats. These results implicate both an ontogenetic and a sensorial factor in the regulation of ethanol intake.  相似文献   
993.
The suppression of corticosterone synthesis with metyrapone (25 mg/kg) reduced the hyperactivity and altered the exploratory activity of hippocampally lesioned animals (HPC) in the open field to the level of cortical and sham controls (Experiment 1). In a second experiment, corticosterone (600 micrograms/kg) pretreatment 2 h, but not 1 h, before metyrapone partially restored the hyperactivity of HPC animals that had been decreased by the corticosteroid-suppressant drug. Alterations in exploratory behavior induced by metyrapone were also prevented by corticosterone pretreatment. The results suggest that the suppression of corticosterone in hippocampally lesioned animals produces a normalization of behavior that can be prevented by pretreatment with corticosterone.  相似文献   
994.
In his theorizing about self-actualization, Maslow speculated that physical ability and physical self-confidence were two aspects of cooperative dominance which were associated positively with actualization. These aspects of dominance bear close resemblance to the Perceived Physical Ability (PPA) and the Physical Self-Presentation Confidence (PSPC) dimensions of the Physical Self-Efficacy (PSE) Inventory. Accordingly, the PPA and PSPC scores of undergraduate men and women were correlated with their scores on the Personal Orientation Inventory (POI), a popular measure of actualization, to test Maslow's hypotheses. The results showed that, contrary to Maslow's claims, PPA is not a positive correlate of self-actualization. However, strong support was found for Maslow's contention that high-PSPC individuals are more likely to be actualizing than low-PSPC people. Also, Maslow's hypothesis that actualizers are high in global sensation seeking (SS) was tested. The data indicated that only male actualizers were high in various aspects of SS, but female actualizers were not. Multiple regression analyses revealed further that both SS and PSPC are primary contributors to POI for men, but only PSPC contributes significantly to POI for women. Discussion focused on the reasons why research findings showing that increases in physical fitness lead to increases in self-esteem cannot be used to support the view that physical fitness and actualization are linked positively.  相似文献   
995.
In the present investigation, we integrated self-theories (specifically, theories of cognitive consistency and self-esteem) with attribution theory. Our intent was to clarify the effects of different levels of self-esteem and performance satisfaction on causal internalization of academic performance. Subjects were 162 university students who attributed causality for their individual performances on a midterm examination. Attributions to four internal and four external causal sources were analyzed with a 2 × 2 (Self-Concept × Performance Satisfaction) MANOVA and with follow-up univariate F ratios. Most of the findings support the predictions based on self-esteem theory; i.e., satisfaction with performance, rather than consistency of performance with self-esteem, served as the primary influence on internalization of causality, with students internalizing satisfying outcomes more than dissatisfying outcomes. Cognitive-consistency theory and B. Weiner's (1979, Journal of Educational Psychology, 71, 3–25) attribution proposal regarding maintenance of a stable self-concept also received support, as attributions to the internal and stable causal sources of ability and general effort were a function of an interaction of self-esteem and performance satisfaction. Hence, neither self-theory adequately anticipated the effects of self-esteem and performance satisfaction on causal internalization. Rather, a consolidation of theories is needed to explain the results.  相似文献   
996.
The present experiments examined the effects of self-focus, as produced by focusing on feelings, on memory. In an initial experiment subjects did complex mental arithmetic significantly faster after self-focus. Because complex mental addition involves internally generated stimuli, the remaining experiments compared the effects, on memory, of self-focus on internally generated stimuli to the effect of self-focus on stimuli supplied by the experimenter. In a second experiment, self-focus facilitated memory for digits recalled in reverse order but not for digits when recalled in the given order. In a third experiment, self-focus facilitated the memory for the classification of digits but not for the digits themselves. In a fourth and fifth experiment, self-focus aided memory for classification of objects into categories such as small, medium, or large but did not aid memory for the objects themselves. In general, improved performance due to feeling focus was attributed to the role that self-focus may play in increasing attention to internally generated stimuli.  相似文献   
997.
998.
The present study examined the direction of the relation between sex role self-concept and depression. A total of 23 males and 32 females were given the Personal Attributes Questionnaire and the Beck Depression Inventory at two times separated by a 3-month interval. Results of a cross-lagged panel correlational analysis found no evidence for sex role orientation as a cause of depression. Instead, the data suggested that emotional well being precedes self-perceived instrumentality, but the influence of third variables could not be overlooked. The implications of these data are discussed with particular reference to the need for more complex theoretical formulations of the relation between self-perceived instrumentality and adjustment.  相似文献   
999.
The reading performance of a Japanese Broca-type aphasic patient on a single-word reading test was investigated. The result indicated that the subject fits the symptom complex of deep dyslexia in more than one aspect. Unique characteristics of this subject included (1) the isolated subcortical site of the lesion, which apparently produced deep dyslexia, and (2) double dissociations between kanji and kana processing and between oral reading and reading comprehension. The performance of this subject was compared with that of another Japanese deep dyslexic subject in S. Sasanuma (1980, In M. Coltheart, K. Patterson, & J. C. Marshall (Eds.), Deep dyslexia, London: Routledge & Kegan Paul). A theoretical implication was attempted based on a dual coding process scheme by S. Sasanuma and O. Fujimura (1978, Cortex, 7, 1-18).  相似文献   
1000.
Subjects performed a visual target-detection task in eight experiments. We examined the effects of word relevancy (word in relevant or irrelevant location) and display load (1-4 words) on physical, semantic, and controlled processing of nontargets. Interwoven with the detection task was a test-word identification task that was used to measure priming potency of nontargets. Physical and semantic levels of processing were measured in terms of identity and semantic priming, respectively. Nontarget primes were repeated as test words in identity priming. Nontarget primes were semantic associates of test words in semantic priming. Controlled processing of nontargets was measured in terms of recognition memory on a subsequent test. All measures increased with word relevancy and decreased with display load. The priming effects remained intact even when word presentation was speeded up and controlled processing was sharply curtailed. The data indicate that all levels of processing are selective and capacity limited.  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