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   22722篇
  免费   286篇
  国内免费   27篇
教育   15642篇
科学研究   2538篇
各国文化   454篇
体育   1870篇
综合类   11篇
文化理论   164篇
信息传播   2356篇
  2021年   238篇
  2020年   352篇
  2019年   490篇
  2018年   628篇
  2017年   632篇
  2016年   595篇
  2015年   406篇
  2014年   509篇
  2013年   3997篇
  2012年   508篇
  2011年   530篇
  2010年   453篇
  2009年   406篇
  2008年   500篇
  2007年   447篇
  2006年   411篇
  2005年   380篇
  2004年   415篇
  2003年   332篇
  2002年   294篇
  2001年   578篇
  2000年   433篇
  1999年   387篇
  1998年   202篇
  1997年   234篇
  1996年   209篇
  1995年   191篇
  1994年   208篇
  1993年   193篇
  1992年   310篇
  1991年   324篇
  1990年   321篇
  1989年   340篇
  1988年   276篇
  1987年   265篇
  1986年   265篇
  1985年   347篇
  1984年   278篇
  1983年   253篇
  1982年   225篇
  1981年   196篇
  1980年   200篇
  1979年   289篇
  1978年   206篇
  1977年   194篇
  1976年   166篇
  1975年   182篇
  1974年   177篇
  1973年   181篇
  1971年   164篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
Urinary excretion of 3 methoxy-4-hydroxy phenyl glycol (MHPG) and 3-methoxy-4-hydroxy mandelic acid (VMA) were estimated in 18 Post-Japanese Encephalitis depressive patients and 20 unipolar depressive patients to determine their biochemical differences. Both the metabolites were low in the former group in comparison to the later group, indicating that the metabolic events in respect to catecholamine turn over are different in two disorders.  相似文献   
972.
In order to identify factors associated with on-field moral functioning among student athletes within the unique context of football, we examined masculine gender role conflict, moral atmosphere, and athletic identity. Using structural equation modeling to assess survey data from 204 high school football players, results demonstrated that moral atmosphere (i.e., the influence of coaches and teammates) was significantly associated with participants' process of on-field moral functioning across the levels of judgment, intention, and behavior. Neither masculine gender role conflict nor athletic identity significantly predicted moral functioning, but the results indicated that participants' identification with the athlete role significantly predicted conflict with socialized gender roles. Results suggest that in the aggressive and violent sport of football, coaches can have a direct influence on players' moral functioning process. Coaches can also have an indirect effect by influencing all the players so that a culture of ethical play can be cultivated among teammates and spread from the top down.  相似文献   
973.
974.
This paper has 2 goals: to review the history of the developmental study of infants and children at biological risk and to appraise the current state of the art. The scope of the review is from 1920 to the present and emphasizes the role of developmentalists. 4 research phases are identified, each reflecting aspects of the social, political, health, and psychological zeitgeist. First, from 1920 to World War II, research was primarily "catalog" and had diverse themes; however, several issues were raised that continue to have relevance. Second, during the postwar years, research often focused on the cognitive and emotional residuals of handicaps, particularly cerebral palsy and poliomyelitis. Third, the 1960s marked the funding of major seminal longitudinal investigations of perinatal risk factors, and studies of very young infants "at risk." And fourth, in the last and current period, technological advances of the 1970s first applied to research with normally developing children were then extended to at-risk groups and revolutionized the methods of studying risk. Finally, we suggest that, although a considerable amount of information has been obtained about developmental phenomena subsequent to biological risk, our research literature is fragmented and difficult to synthesize. We conclude by offering strategies to foster research and the integration of knowledge.  相似文献   
975.
There is little research investigating the maintenance of perceptual-cognitive expertise in general and even less comparing coaches of different ages. The aim of this study was to test for perceptual-cognitive differences between age groups, licence levels, and their interaction. This study investigated differences in skilled performance between young and middle-aged coaches of three different skill levels. Participants performed an accuracy-oriented pattern recall (mean distance in pixel) and a time-oriented flicker test (mean detection time in ms). There were some significant differences between age groups and between skill groups for both tests, but no interactions. For the pattern recall test, the effect sizes were larger for skill level differences, while for the flicker test effects were larger for ageing. These results suggest coaches are able to maintain accuracy skills better than reaction timed tasks. This is in line with findings on speeded performance in general populations, which show declines with age. Moreover, results also support findings on perceptual expertise in skills where accuracy was important.  相似文献   
976.
977.
This study provides a foundation for discussion of major issues facing community colleges in America. The purpose of the study was to ascertain how many community college presidents rank order issues facing their institutions, now and five years hence. Additionally, the study sought to more comprehensively examine recent literature about issues facing community colleges for purposes of comparison with the findings of the study, and for explication of issues identified. The data for analysis were collected from a population survey of all public and private community college presidents listed in the Education Directory of Colleges and Universities, 1981‐1982. Issues used in the survey were identified a priori, from a review of the literature, and were validated using a panel of community college presidents. The major findings were that both public and private community college presidents agree that the top issues facing their institutions five years hence are: financial support for institution, achieving institutional mission, and maintaining enrollments. Other major current issues include faculty and staff relations, planning and administering the budget, governing board relations, administrative team relations, state relations, public and community relations, and program development and evaluation. Additionally, questions were raised in the study regarding “presidential priority rankings of issues,” based upon directions suggested in the literature review about what issues seem most pressing in the decade of the 1980s.  相似文献   
978.
979.
Readers' advisory databases are used by public librarians to assist patrons in finding books based on the facts of the plot, the factors used to describe the appeal of the book, or read titles similar to another book they have read. Librarians depend on these databases to give a complete view of the titles available given these limiters, and may assume that identical searches in each database would give similar results. This study compares search results from four databases to see the extent of crossover within those results, using fact-based searches, appeal factor searches, and read-alike searches.  相似文献   
980.
The dynamics of nuclear reactions are surveyed on an elemental basis with emphasis upon the c.g. system of coordinate axes. Corrections are given for angular distributions, angular straggling, and thin target straggling.  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