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   24925篇
  免费   339篇
  国内免费   72篇
教育   17910篇
科学研究   2110篇
各国文化   258篇
体育   2052篇
综合类   50篇
文化理论   172篇
信息传播   2784篇
  2021年   245篇
  2020年   339篇
  2019年   507篇
  2018年   710篇
  2017年   752篇
  2016年   677篇
  2015年   459篇
  2014年   636篇
  2013年   4857篇
  2012年   618篇
  2011年   631篇
  2010年   555篇
  2009年   529篇
  2008年   562篇
  2007年   562篇
  2006年   552篇
  2005年   498篇
  2004年   380篇
  2003年   392篇
  2002年   346篇
  2001年   495篇
  2000年   418篇
  1999年   388篇
  1998年   218篇
  1997年   218篇
  1996年   272篇
  1995年   209篇
  1994年   236篇
  1993年   215篇
  1992年   338篇
  1991年   340篇
  1990年   351篇
  1989年   335篇
  1988年   270篇
  1987年   287篇
  1986年   303篇
  1985年   297篇
  1984年   271篇
  1983年   290篇
  1982年   237篇
  1981年   228篇
  1980年   216篇
  1979年   340篇
  1978年   266篇
  1977年   212篇
  1976年   219篇
  1975年   182篇
  1974年   183篇
  1973年   159篇
  1971年   180篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
221.
OBJECTIVE: The United States General Accounting Office (United States General Accounting Office [USGAO], 1989) report on out-of-home care affirmed that the foster care system is in crisis. To shed light on some factors that influence retention, the study reported here asked "What factors influence the satisfaction of foster parents?" and "What factors influence the intent of licensed foster parents to continue to foster?" METHOD: A sample of 539 foster parents in eight urban counties in a large Midwestern state completed questionnaires aimed at addressing these questions. RESULTS: Some of the factors exerting the strongest influence on satisfaction were: feeling competent to handle the children who were placed; wanting to take in children who needed loving parents; no regrets about investment in foster children; foster mother's age; and agency social worker providing information and showing approval for a job well done. An example of factors exerting influence on intent to continue to foster include overall satisfaction, readiness to phone the social worker, number of foster boys in the home, being treated like one needed help oneself, and agency affiliation (private). CONCLUSIONS: Efforts to increase the supply of foster homes through recruitment is not enough. The support, training, and professional regard given to parents after they have begun the fostering task is of greater need. Based on analysis of the findings, implications for practice, programming, and policy are offered.  相似文献   
222.
This paper reveals the complex diversity that underpins ostensibly similar transnational education programmes (TNE), through a comparison of UK TNE in Malaysia and Hong Kong. It draws on data from two different yet cognate studies on the role of UK universities in delivering higher education in Asia. Some fine-grained and informative differences between the ways in which ‘value’ in TNE is constructed in different host contexts is revealed. The paper brings to light the ‘voices’ of TNE students and graduates, which are very seldom heard. The arguments adapt and extend the concepts of education as a positional good, and as cultural capital. For various instrumental, intrinsic and personal reasons the authors discuss in detail, UK TNE is more highly valued in Malaysia than in Hong Kong. The paper makes a wider contribution to knowledge on the changing landscape of international higher education and the impact on social and personal (dis)advantage.  相似文献   
223.
G Nagendrappa 《Resonance》2005,10(8):80-90
Free radical synthetic methodology has grown by leaps and bounds in just about two decades. The limit to which the scope of free radical synthesis can go is restricted only by the imagination of the synthetic chemist. It greatly simplifies a synthetic sequence, makes use of readily available, relatively inexpensive reactants and reagen-ts; the transformations are selective, involve fewer steps, the yields are good, the reaction conditions are mild, etc. Therefore, such free radical reactions truly qualify to be called “Green Chemistry”.  相似文献   
224.
225.
226.
Research suggests growth mindset, or the belief that knowledge is acquired through effort, may enhance women’s sense of belonging in male-dominated disciplines, like computing. However, other research indicates women who spend a great deal of time and energy in technical fields experience a low sense of belonging. The current study assessed the benefits of a growth mindset on women’s (and men’s) sense of intellectual belonging in computing, accounting for the amount of time and effort dedicated to academics. We define “intellectual belonging” as the sense that one is believed to be a competent member of the community. Whereas a stronger growth mindset was associated with stronger intellectual belonging for men, a growth mindset only boosted women’s intellectual belonging when they did not work hard on academics. Our findings suggest, paradoxically, women may not benefit from a growth mindset in computing when they exert a lot of effort.  相似文献   
227.
This study examined the direct association between parental educational expectations and adolescents’ academic self‐efficacy, as well as the moderating influence of parental academic socialization messages. Participants were 148 Latino parent–adolescent dyads with the majority of Mexican origin (80.4%). Most of the parent participants were mothers (85.8%). Adolescents were 13 (46%) or 14 (54%) years of age, and 53% identified as female. Adolescents reported their academic self‐efficacy and perceptions of their parents’ educational expectations; parents reported on their academic socialization messages of shame/pressure and effort regarding academics. The results suggest that, after accounting for parents’ level of education and immigrant status, parental educational expectations were positively associated with adolescent academic self‐efficacy. This association was stronger among adolescents whose parents reported transmitting fewer messages of shame/pressure and academic effort. These results point to the importance of nuances in the content and type of academic socialization messages within Latino families.  相似文献   
228.
229.
Rats were trained in a three-alternative spatial delayed matching-to-sample task in a starburst maze. Samples consisted of rewarded forced choices of one arm, and retention was indicated by rats’ returning to that arm after a 90-sec delay. If a rat made an error on its first choice, it was returned to the start compartment and allowed a second choice. Unlike in previous experiments with this task, all three arms were available during the animals’ second choices. The rats tended to perseverate in their second choices by returning to the arm that they had erroneously visited on their first choice. In Experiment 1, the accuracy of second choices following first-choice errors was below chance during the first block of sessions, when a 90-sec delay intervened between the first choice and the second choice, and at chance during the second block of sessions, when a short (5–6 see) delay intervened between first and second choices. In Experiment 2, long-delay and short-delay sessions were randomly presented to naive subjects. Similar results were obtained. In both experiments, the tendency to repeat the erroneous first choice was greater when long delays separated the two choices than when short delays were used. The results suggest that rats make their first-choice errors because they erroneously encode or remember the location of the sample and that they base their second choices on the same erroneous-memory. The increase in perseveration at long delays implies some kind of rehearsal-like mechanism that slows forgetting of the memory controlling the first choice.  相似文献   
230.
OBJECTIVE: The purpose of this study is to examine processing of facial emotions in a sample of maltreated children showing high rates of post-traumatic stress disorder (PTSD). Maltreatment during childhood has been associated independently with both atypical processing of emotion and the development of PTSD. However, research has provided little evidence indicating how high rates of PTSD might relate to maltreated children's processing of emotions. METHOD: Participants' reaction time and labeling of emotions were measured using a morphed facial emotion identification task. Participants included a diverse sample of maltreated children with and without PTSD and controls ranging in age from 8 to 15 years. Maltreated children had been removed from their homes and placed in state custody following experiences of maltreatment. Diagnoses of PTSD and other disorders were determined through combination of parent, child, and teacher reports. RESULTS: Maltreated children displayed faster reaction times than controls when labeling emotional facial expressions, and this result was most pronounced for fearful faces. Relative to children who were not maltreated, maltreated children both with and without PTSD showed enhanced response times when identifying fearful faces. There was no group difference in labeling of emotions when identifying different facial emotions. CONCLUSIONS: Maltreated children show heightened ability to identify fearful faces, evidenced by faster reaction times relative to controls. This association between maltreatment and atypical processing of emotion is independent of PTSD diagnosis.  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