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   62142篇
  免费   2495篇
  国内免费   36篇
  2020年   760篇
  2019年   946篇
  2018年   1327篇
  2017年   1308篇
  2016年   1425篇
  2015年   940篇
  2014年   1187篇
  2013年   5649篇
  2012年   2104篇
  2011年   2245篇
  2010年   1396篇
  2009年   1418篇
  2008年   2115篇
  2007年   2054篇
  2006年   1824篇
  2005年   1634篇
  2004年   1651篇
  2003年   1487篇
  2002年   1511篇
  2001年   1908篇
  2000年   1822篇
  1999年   1419篇
  1998年   821篇
  1997年   704篇
  1996年   603篇
  1995年   639篇
  1994年   620篇
  1993年   626篇
  1992年   1111篇
  1991年   1042篇
  1990年   1026篇
  1989年   937篇
  1988年   911篇
  1987年   892篇
  1986年   877篇
  1985年   935篇
  1984年   770篇
  1983年   658篇
  1982年   563篇
  1981年   534篇
  1980年   523篇
  1979年   748篇
  1978年   581篇
  1976年   528篇
  1975年   646篇
  1974年   690篇
  1973年   644篇
  1972年   568篇
  1968年   554篇
  1967年   551篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
891.
In a study of recognition memory for pictures, we observed an asymmetry in classifying test items as "same" versus "different" in left-right orientation: Identical copies of previously viewed items were classified more accurately than left-right reversals of those items. Response bias could not explain this asymmetry, and, moreover, correct "same" and "different" classifications were independently manipulable: Whereas repetition of input pictures (one vs. two presentations) affected primarily correct "same" classifications, retention interval (3 hr vs. 1 week) affected primarily correct "different" classifications. In addition, repetition but not retention interval affected judgments that previously seen pictures (both identical and reversed) were "old". These and additional findings supported a dual-process hypothesis that links "same" classifications to high familiarity, and "different" classifications to conscious sampling of images of previously viewed pictures.  相似文献   
892.
This study examined the effects of two social cues on women's and men's self-confidence: the sex and performance of another in an achievement setting. Before trying to solve 60 anagrams, women expected to perform more poorly than men. In addition, both sexes expected to perform more poorly when paired with a male confederate than when paired with a female confederate. The effect of the partner's sex showed up in anagram performance: people with a female partner solved more anagrams than people with a male partner. The effect of subject's sex on performance was unexpected: women solved more anagrams than men. After the task, sex differences in self-confidence disappeared; neither sex of subject nor sex of partner influenced self-confidence. The partner's performance, however, had a strong effect on everyone: people were less self-confident if they had worked with a high-scoring partner. The pattern of results suggests that sex-of-subject differences in self-confidence, while important, are less powerful than the effects wielded by the sex of others in achievement settings.  相似文献   
893.
The term pioneer is used for girls aspiring to male-dominated careers. This longitudinal study assesses the career choices of 68 middle-class girls during childhood (8–13 years, Phase I) and again during adolescence (13–18 years, Phase II), and investigates the relation between pioneering career choice and personal and family characteristics. Subjects were originally selected for exposure vs nonexposure to exogenous hormones during pregnancy. In childhood, pioneers were somewhat older, were more often persistent tomboys, had higher IQs, and had parents with higher educational attainment. In adolescence, paternal education was the only variable that showed the same relation to career choice. Adolescent girls who had wanted to get married at the time of the childhood assessment were now less likely to choose pioneering careers. Adolescent pioneers also had higher educational aspirations than nonpioneers and less likely anticipated being married within ten years than nonpioneers. A number of statistically borderline relationships were also observed: pioneers had somewhat fewer older brothers than nonpioneers, less often came from homes in which traditional femininity was stressed, and more frequently had mothers who had worked outside the home throughout their daughters' school years than mothers of nonpioneers. Prenatal exposure to exogenous sex hormones was not related to career choice during either childhood or adolescence.  相似文献   
894.
目的、意向和意识   总被引:1,自引:0,他引:1  
本文提出了一个意向性目标搜寻的计算机模型,它有两个部分,静态部分包括一个目标表征和到达这个目标的程序。动态部分是一个感觉输入、中间信息加工,行为输出的重复的反馈循环。人类意向必然伴有意识,但机器人则可能无意识而有意向。 利用目标搜寻系统机器人模型,我们对目标搜寻系统的目的连续统下了定义;这个连续统从简单的直接反应系统一直到意向性系统。对这个目的连续统有两种传统的解释:一是柏拉图、亚里士多德和普罗提诺的终极原因理论,二是希腊原子论者和现代进化生物学家的还原主义学说。本文评价了这些学说。 本文考察了几种类型的意识机能,提出了以自动机为依据的意识理论,比较了人类和计算机。从计算机结构的角度来看,人类意识是一类特殊的计算机控制系统。  相似文献   
895.
Perceived control (PC) is defined as thebelief that one can determine one’s own internal states and behavior, influence one’s environment, and/or bring about desired outcomes. Two important dimensions of PC are delineated: (1) whether the object of control is located in the past or the future and (2) whether the object of control is over outcome, behavior, or process. A variety of constructs and measures of PC (e.g., efficacy, attribution, and locus of control) are discussed in relation to these dimensions and selected studies are reviewed. The issues, controversies, and limits of the research on perceived control and health are addressed in terms of the antecedents and consequences of perceived control. Investigations should clearly conceptualize the object of perceived control, use measures that match the conceptualization, and when attempting to manipulate control, directly measure perceived control. The relation between PC and health outcomes is complex, and different aspects of PC may interact to affect health outcomes.  相似文献   
896.
897.
898.
Effects of smoking on spontaneous bilateral skin conductance were studied as a consequence of interactions with set and setting. Bilateral skin conductance was recorded in six men and six women who smoked and an equal number of nonsmokers on two different days. On the first day, spontaneous electrodermal activity was recorded before and after a 10-minute rest period during which half the smokers smoked a cigarette. On the second day, one week later, spontaneous activity was again recorded before and after a 10-minute rest period during which the remaining smokers smoked a cigarette. Nonsmokers did not smoke at any time. Following smoking there was a significant negative correlation between a preference for visual over nonvisual imagery and spontaneous skin conductance responsivity in the left as compared to the right hand. Correlations were significantly different in smokers and nonsmokers. Smokers showed significantly greater preferences for either visual or nonvisual imagery than nonsmokers. Nonresponding nonsmokers were higher on the psychoticism (P) scale of the Eysenck Personality Questionnaire (EPQ) than responding nonsmokers. Smokers scored higher on P than nonsmokers. Interactions between personality, cognitive style, and the experimental situation, set, and setting were discussed in relation to the arousing effects of nicotine.  相似文献   
899.
900.
Among a sample of American college students, body image and the degree of desired weight change were associated with academic self-rankings, with social and psychological well-being, and with the development of eating difficulties. The effects of body image and desired weight change on eating disorders were generally found to be greater for women than for men, and their effects on student self-rankings of academic ability, social, and psychological traits were more pervasive for women than for men. The less attractive a woman perceived herself to be and the more weight she wanted to lose, the greater was her overall sense of academic, social, and psychological impairment. Women who had poor body images and who desired to lose weight were more likely to report eating difficulties.  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