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   23499篇
  免费   201篇
  国内免费   10篇
  2023年   50篇
  2022年   41篇
  2021年   43篇
  2020年   99篇
  2019年   102篇
  2018年   3569篇
  2017年   2912篇
  2016年   2362篇
  2015年   265篇
  2014年   176篇
  2013年   442篇
  2012年   714篇
  2011年   2544篇
  2010年   2605篇
  2009年   1567篇
  2008年   1818篇
  2007年   2297篇
  2006年   144篇
  2005年   318篇
  2004年   258篇
  2003年   208篇
  2002年   159篇
  2001年   98篇
  2000年   92篇
  1999年   56篇
  1998年   52篇
  1997年   44篇
  1996年   32篇
  1995年   35篇
  1994年   40篇
  1993年   26篇
  1992年   33篇
  1991年   29篇
  1990年   30篇
  1989年   26篇
  1988年   31篇
  1987年   23篇
  1986年   28篇
  1985年   30篇
  1984年   19篇
  1983年   18篇
  1982年   18篇
  1980年   15篇
  1979年   21篇
  1978年   31篇
  1977年   19篇
  1975年   14篇
  1974年   19篇
  1973年   17篇
  1972年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
Those contending for the 'normalcy' of homosexuality claim there are 800,000 to 7 million homosexual parents raising between 1 and 9 million children. The 1996 National Household Survey on Drug Abuse, a nationally representative sample of 12,321 ages 18 through 59 yr., reported about 416,000 parents-most of whom were married-living with children under the age of 17 yr. who reported same-sex "vaginal, oral, or anal sex" in the past 12 months. Two random-sample surveys suggested that there are fewer than half a million homosexual parents, and a total sample of 14,000 mothers in Avon suggests even fewer. Thus, it is likely that fewer than 500,000 homosexual parents live with fewer than 750,000 children under 18 yr.  相似文献   
202.
The perception of 2nd-order, texture-contrast-defined motion was studied for apparent-motion stimuli composed of a pair of spatially displaced, simultaneously visible checkerboards. It was found that background-relative, counter-changing contrast provided the informational basis for the perception of 2nd-order apparent motion; motion began where contrast changed toward the contrast value of the background checkerboard and ended where contrast changed away from the background value. The perceived apparent motion was not attributable to either postrectification motion-energy analysis or salience-mapping/feature-tracking mechanisms. Parallel results for 1st-order, luminance-defined motion (H. S. Hock, L. A. Gilroy, & G. Harnett, 2002) suggest that counter-changing activation provides a common basis for the perception of both luminance- and texture-contrast-defined apparent motion.  相似文献   
203.
204.
The authors describe the effects of practice conditions in motor learning (e.g., contextual interference, knowledge of results) within the constraints of 2 experimental variables: skill level and task difficulty. They use a research framework to conceptualize the interaction of those variables on the basis of concepts from information theory and information processing. The fundamental idea is that motor tasks represent different challenges for performers of different abilities. The authors propose that learning is related to the information arising from performance, which should be optimized along functions relating the difficulty of the task to the skill level of the performer. Specific testable hypotheses arising from the framework are also described.  相似文献   
205.
Standard psycholexical studies of personality structure have produced a similar 6-factor solution in 7 languages (Dutch, French, German, Hungarian, Italian, Korean, Polish). The authors report the content of these personality dimensions and interpret them as follows: (a) a variant of Extraversion, defined by sociability and liveliness (though not by bravery and toughness); (b) a variant of Agreeableness, defined by gentleness, patience, and agreeableness (but also including anger and ill temper at its negative pole); (c) Conscientiousness (emphasizing organization and discipline rather than moral conscience); (d) Emotionality (containing anxiety, vulnerability, sentimentality, lack of bravery, and lack of toughness, but not anger or ill temper); (e) Honesty-Humility; (f) Intellect/Imagination/Unconventionality. A potential reorganization of the Big Five factor structure is discussed.  相似文献   
206.
Convergent evidence highlights the differential contributions of various regions of the prefrontal cortex in the service of cognitive control, but little is understood about how the brain determines and communicates the need to recruit cognitive control, and how such signals instigate the implementation of appropriate performance adjustments. Here we review recent progress from cognitive neuroscience in examining some of the main constituent processes of cognitive control as involved in dynamic decision making: goal-directed action selection, response activation and inhibition, performance monitoring, and reward-based learning. Medial frontal cortex is found to be involved in performance monitoring: evaluating outcome vis-a-vis expectancy, and detecting performance errors or conflicting response tendencies. Lateral and orbitofrontal divisions of prefrontal cortex are involved in subsequently implementing appropriate adjustments.  相似文献   
207.
Faculty members at Canadian business schools were surveyed regarding their ethical perceptions of behaviours related to undergraduate instruction. Fifty-five behavioural statements were listed and respondents were asked to rate the extent to which they felt each behaviour was ethical or unethical. The only item that respondents endorsed as unequivocally unethical (90% indicated it was definitely unethical) was Becoming sexually involved with an undergraduate in one of your classes. We also compared the results of our sample to those of an American sample. Overall, an interesting pattern of differences emerged between the responses obtained in Canada and the U.S. In general, the direction of the significant differences was such that Canadian professors viewed the behaviours in question as less ethical than did their American counterparts.  相似文献   
208.
Previous research on schizophrenia suggests that context-processing disturbances are one of the core cognitive deficits present in schizophia. However, it is not clear whether such deficits are specific to schizophrenia as compared with other psychotic disorders. To address this question, the authors administered a version of the AX Continuous Performance Test designed to assess context processing in a sample of healthy controls, patients with schizophrenia, and patients with other psychotic disorders. Participants were tested at index (when medication naive and experiencing their first contact with psychiatric services) and 4 weeks later, following medication treatment. At index, patients with schizophrenia and the psychotic comparison group demonstrated similar impairments in context processing. However, context-processing deficits improved in the psychotic comparison group at 4 weeks but did not improve in patients with schizophrenia.  相似文献   
209.
The purpose of this study is to examine the mechanisms by which personality traits influence performance and satisfaction. Specifically, the authors examined how 3 personality characteristics derived from self-determination theory (autonomy, control, and amotivated orientations) influence performance and enjoyment through achievement goal patterns, goal level, and mental focus. Data were collected from 284 students at 5 points in time. In particular, mental focus emerged as an important aspect of the self-regulation process. The results suggest that global personality traits can help researchers to understand and predict the motivational strategies that people use while working toward goals in achievement settings.  相似文献   
210.
Social identity approaches assume that social identification affects both self-conception and intergroup orientation. The authors contend that such social identification effects are accentuated when people hold a fixed view of human character and attribute immutable dispositions to social groups. To these individuals, social identities are immutable, concrete entities capable of guiding self-conception and intergroup orientation. Social identification effects are attenuated when people hold a malleable view of human character and thus do not view social identities as fixed, concrete entities. The authors tested and found support for this contention in three studies that were conducted in the context of the Hong Kong 1997 political transition, and discussed the findings in terms of their implications for self-conceptions and the meaning of social identification.  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