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   26702篇
  免费   214篇
  国内免费   14篇
教育   19232篇
科学研究   2968篇
各国文化   154篇
体育   1571篇
综合类   19篇
文化理论   558篇
信息传播   2428篇
  2022年   110篇
  2021年   157篇
  2020年   257篇
  2019年   362篇
  2018年   2629篇
  2017年   2566篇
  2016年   2042篇
  2015年   441篇
  2014年   549篇
  2013年   2689篇
  2012年   606篇
  2011年   1099篇
  2010年   1190篇
  2009年   734篇
  2008年   972篇
  2007年   1493篇
  2006年   383篇
  2005年   652篇
  2004年   741篇
  2003年   604篇
  2002年   392篇
  2001年   331篇
  2000年   373篇
  1999年   268篇
  1998年   156篇
  1997年   211篇
  1996年   185篇
  1995年   135篇
  1994年   140篇
  1993年   120篇
  1992年   213篇
  1991年   201篇
  1990年   223篇
  1989年   223篇
  1988年   191篇
  1987年   204篇
  1986年   178篇
  1985年   216篇
  1984年   164篇
  1983年   140篇
  1982年   137篇
  1981年   113篇
  1980年   119篇
  1979年   179篇
  1978年   140篇
  1977年   119篇
  1976年   94篇
  1975年   95篇
  1974年   95篇
  1973年   91篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
943.
944.
945.
946.
A recent meta-analysis performed by Wellman, Cross, and Watson clears the air surrounding young children's performance on tests of false belief by showing that it is highly likely that there is some type of conceptual development between 3 and 5 years of age that supports improved task performance. The data concerning the evolutionary origin of these abilities, however, is considerably less clear. Nonetheless, there is some reason to suspect that theory of mind is unique to our species, and that its original function was to provide a more abstract level of describing ancient behavioral patterns (such as deception, reconciliation, and gaze following)-behaviors that humans share in common with many other species. Thus, the initial selective advantage of theory of mind may have been because it increased the flexibility of already-existing behaviors, not because it generated scores of radically new ones.  相似文献   
947.
Culture not only justifies the existence of libraries but also determines the level of funding libraries receive for development. Cultural appreciation of the importance of libraries encourages their funding; lack of such appreciation discourages it. Medical library development is driven by culture in general and the culture of physicians in particular. Nineteenth-century North American medical library funding reflected the impact of physician culture in three phases: (1) Before the dawn of anesthesia (1840s) and antisepsis (1860s), when the wisdom of elders contained in books was venerated, libraries were well supported. (2) In the last third of the nineteenth century, as modern medicine grew and as physicians emphasized the practical and the present, rather than books, support for medical libraries declined. (3) By the 1890s, this attitude had changed because physicians had come to realize that, without both old and new medical literature readily available, they could not keep up with rapidly changing current clinical practice or research. Thus, "The Medical Library Movement" heralded the turn of the century.  相似文献   
948.
949.
A well-documented observation after eccentric exercise is a reduction in maximal voluntary force. However, little is known about the ability to maintain maximal isometric force or generate and maintain dynamic peak power. These aspects of muscle function were studied in seven participants (5 males, 2 females). Knee extensor isometric strength and rate of fatigue were assessed by a sustained 60 s maximal voluntary contraction at 80 degrees and 40 degrees knee flexion, corresponding to an optimal and a shortened muscle length, respectively. Dynamic peak power and rate of fatigue were assessed during a 30 s Wingate cycle test. Plasma creatine kinase was measured from a fingertip blood sample. These variables were measured before, 1 h after and 1, 2, 3 and 7 days after 100 repetitions of the eccentric phase of the barbell squat exercise (10 sets x 10 reps at 80% concentric one-repetition maximum). Eccentric exercise resulted in elevations in creatine kinase activity above baseline (274+/-109 U x l(-1); mean +/- s(x)) after 1 h (506+/-116 U x l(-1), P < 0.05) and 1 day (808+/-117 U x l(-1), P < 0.05). Isometric strength was reduced (P < 0.05) for 7 days (35% at 1 h, 5% at day 7) and the rate of fatigue was lower (P < 0.05) for 3 days at 80 degrees and for 1 day at 40 degrees. Wingate peak power was reduced to a lesser extent (P < 0.05) than isometric strength at 1 h (13%) and, although the time course of recovery was equal, the two variables differed in their pattern of recovery. Eccentrically exercised muscle was characterized by an inability to generate high force and power, but an improved ability to maintain force and power. Such functional outcomes are consistent with the proposition that type II fibres are selectively recruited or damaged during eccentric exercise.  相似文献   
950.
Despite extensive research devoted to determining the nature of the relationship between stress and performance, there has been little systematic examination of the mechanisms underlying this relationship. Recently, researchers have begun to empirically address the attentional mechanisms underlying theoretical accounts of how stress, anxiety and arousal influence performance. Given the critical role of visual attention to sport expertise, this paper focuses primarily on literature dealing with how visual cues are differentially identified and processed when performers are anxious. Emerging evidence indicates that gaze behaviour tendencies are reliably altered when performers are anxious, leading to inefficient and often ineffective search strategies. Alterations of these visual search indices are addressed in the context of both self-paced and externally paced sports events. Recommendations concerning the utility of perceptual training programmes and how these training programmes might be used as anxiety regulation interventions are discussed. The theoretical implications and directions for future research are also addressed.  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