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   24901篇
  免费   185篇
  国内免费   11篇
教育   18017篇
科学研究   2867篇
各国文化   113篇
体育   1323篇
综合类   17篇
文化理论   538篇
信息传播   2222篇
  2022年   95篇
  2021年   134篇
  2020年   206篇
  2019年   279篇
  2018年   2546篇
  2017年   2478篇
  2016年   1953篇
  2015年   379篇
  2014年   475篇
  2013年   2219篇
  2012年   554篇
  2011年   1049篇
  2010年   1141篇
  2009年   686篇
  2008年   923篇
  2007年   1445篇
  2006年   334篇
  2005年   614篇
  2004年   704篇
  2003年   581篇
  2002年   360篇
  2001年   315篇
  2000年   351篇
  1999年   253篇
  1998年   139篇
  1997年   195篇
  1996年   174篇
  1995年   118篇
  1994年   130篇
  1993年   115篇
  1992年   196篇
  1991年   188篇
  1990年   213篇
  1989年   210篇
  1988年   180篇
  1987年   192篇
  1986年   172篇
  1985年   207篇
  1984年   150篇
  1983年   131篇
  1982年   124篇
  1981年   109篇
  1980年   112篇
  1979年   174篇
  1978年   130篇
  1977年   113篇
  1976年   90篇
  1975年   92篇
  1974年   94篇
  1973年   91篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
This study evaluated the effects of South Korea’s Brain Korea 21 (BK 21) project, a special research funding program designed to build world-class research university. The effects were measured by examining the frequency of article publications in SCI journals during the 1995–2005 period. The results of the analysis indicated that the growth of research publications from Korean research universities was increased significantly following the implementation of the BK 21 project in 1999. In addition, during the period under study, four research universities (Yonsei, Korea, Sungkyunkwan, and Hanyang) were newly emerged. However, the growth rate of research publications was not different from that of the US and Japan, and even less than that of China. Thus, although the BK 21 project contributed to the growth of research publications of Korean universities, the project did not lessen the gap between Korea universities and world-class research universities in the US or Japan in number of publications.  相似文献   
972.
This paper describes our efforts to systematically generate knowledge from ethnographic and other qualitative scholarship as a way of bridging intellectual gaps found in quantitative research. We ground this scholarly endeavor in the study of gangs, which has a lengthy history in the field of criminology, yet lacks a coherent, coordinated, and comparative understanding of gang dynamics, behavior, and impacts. We discuss the importance of acknowledging the multiple and mixed methodologies used in gang scholarship and detail the inductive, deductive, and iterative process that helped us (1) develop a comprehensive coding instrument for coding a range of qualitative works, (2) establish the instrument’s inter-rater reliability, and (3) remain cognizant and reflexive about the strengths of both quantitative and qualitative research. Finally, we share the critical yet informative challenges we faced throughout the project and conclude with reflections on why the project was unsuccessful in the way we originally envisioned.  相似文献   
973.
This paper presents a systematic review of university students’ emotions in connection with virtual learning based on 91 articles published between 2002 and 2017 in four international journals that focus on virtual learning and educational technology or on learning in higher education. These journals were considered potential channels for research on emotions in virtual learning and higher education. The objective was to analyse the articles for concepts and theoretical background related to virtual learning and emotions, contextual focus, methodological choice, and/or results. The review showed that the most common emotion-related concept was “satisfaction.” The most common context for the articles was a complete non-physical learning environment (e.g. Second Life). Approximately 60% of the articles used quantitative methods. The most common design for studying emotions was an explanatory design. Students’ emotions were mainly studied through concepts related to emotion (e.g. “satisfaction”). Yet only a few of the studies focused on the fluctuation of emotions in the course of events, relying instead on post hoc data that treat students’ emotions as traits rather than states.  相似文献   
974.
The main purpose of this study was to explore the factors mediating the translation of second grade teachers’ nature of science (NOS) views into classroom practice after completing a graduate level NOS course. Four second grade in-service elementary teachers comprised the sample of this study. Data were collected from several sources during the course of this study. The primary data sources were (a) assessment of the elementary teachers’ NOS views before and after the graduate level NOS course using the Views of Nature of Science Questionnaire Version B (VNOS-B) (Lederman et al., 2002) coupled with interviews, and (b) a classroom observation and videotaped recording of the elementary teachers’ best NOS lessons coupled with interview. We identified three distinct but related factors that mediated the translation of NOS views into classroom practice: the teachers’ perspectives about the developmental appropriateness of the NOS aspect, the teachers’ selection of target NOS aspects, and the relative importance placed by teachers on each NOS aspect.  相似文献   
975.
Using a random sample of 389 grade 11 science students, the factor structure of the Longeot test (a measure of logical thinking) is investigated and some psychometric properties of the test items are determined. Varimax rotation on six principal component factors resulted in a simple structure. An attempt is made to interpret the obtained orthogonal factors. Implications of the findings on the “unity hypothesis” of the Piagetian construct of logical thinking and, consequently, on grade 11 science education are discussed.  相似文献   
976.
Intellectual property protection mechanisms in research partnerships   总被引:1,自引:0,他引:1  
A set of US-based companies is investigated regarding the effectiveness of intellectual property protection mechanisms (IPPMs) in the formation of research partnerships. Patents are the most frequently used IPPM to protect both background and foreground knowledge in partnerships. Other IPPMs are used to protect know-how, especially in the early, forming stages of a partnership. Existing IP titles are quite useful when negotiating new partnerships. IPR negotiations are reported to be more complex in horizontal partnerships and when universities are involved.  相似文献   
977.
Subtypes of developmental dyslexia: The influence of definitional variables   总被引:1,自引:0,他引:1  
The purpose of this study was to investigate the hypothesis that the manner in which a reading disability is defined will influence the conclusions that are made about the characteristics of the disability. To test this hypothesis, learning disabled and normally achieving children, aged 6 to 14, were administered tasks measuring grammatical, shortterm memory, phonological, reading, and visual-spatial skills. The poor readers were divided into groups of poor readers with
1.  inadequate phonics skills,
2.  inadequate word recognition skills,
3.  adequate word recognition skills but low reading comprehension scores, and
4.  adequate word recognition scores but a slow reading speed.
These children were compared with children who had normal reading scores. Children with deficits in phonics and/or word recognition scored significantly below normal on all the cognitive tests, except some of the visual-spatial tasks. Reading comprehension difficulties were characterized by average phonics, word recognition, and language skills but below average scores on some memory tasks. Slow readers had cognitive profiles similar to the normal children. The presence of a deficit in phonics and/or word recognition constituted the basis of the most serious impairment of language and memory functioning. Reading disabled children, defined in this manner, appear to be reasonably homogeneous in regard to the presence of language and memory problem. There does not appear to be evidence for a distinctive non-language impaired subtype within this type of reading disability. Children with low comprehension scores and/or slow readers did not have language problems. The definition of a reading disability appears to determine the subtypes and characteristics of reading disability that will emerge.  相似文献   
978.
The objective of this study was to describe the anthropometric profiles of elite older triathletes participating in the 2009 Ironman Brazil and to compare their somatotype, anthropometric and body composition characteristics with those of elite young triathletes and older non-athletes. The sample consisted of 64 males, divided into three groups: (1) older triathletes (n = 17), (2) young triathletes (n = 24), and (3) older non-athletes (n = 23). Somatotype was analysed according to the Carter and Heath ( 1990 ) method. Body mass index, sum of four skinfolds, percentage body fat, body fat mass, and fat-free mass were also estimated. Older non-athletes had higher endomorphy, sum of four skinfolds, fat percentage, and body fat mass than the athletes. Older athletes who participated in the Ironman and elite young triathletes had higher fat-free mass than older non-athletes. Older triathletes and older non-athletes were considered mainly endomorphic mesomorphs and young triathletes mainly ectomorphic mesomorphs. The findings that characterize the anthropometric profile of athletes in this sports modality could be used as a reference.  相似文献   
979.
980.
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