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   13963篇
  免费   180篇
  国内免费   23篇
教育   9797篇
科学研究   1540篇
各国文化   128篇
体育   1164篇
综合类   8篇
文化理论   103篇
信息传播   1426篇
  2021年   140篇
  2020年   199篇
  2019年   276篇
  2018年   376篇
  2017年   360篇
  2016年   370篇
  2015年   251篇
  2014年   331篇
  2013年   2449篇
  2012年   298篇
  2011年   324篇
  2010年   283篇
  2009年   225篇
  2008年   273篇
  2007年   245篇
  2006年   240篇
  2005年   216篇
  2004年   235篇
  2003年   211篇
  2002年   180篇
  2001年   447篇
  2000年   303篇
  1999年   260篇
  1998年   129篇
  1997年   162篇
  1996年   134篇
  1995年   136篇
  1994年   150篇
  1993年   118篇
  1992年   194篇
  1991年   195篇
  1990年   205篇
  1989年   205篇
  1988年   174篇
  1987年   160篇
  1986年   170篇
  1985年   211篇
  1984年   163篇
  1983年   153篇
  1982年   137篇
  1981年   125篇
  1980年   119篇
  1979年   173篇
  1978年   139篇
  1977年   119篇
  1976年   97篇
  1975年   117篇
  1974年   105篇
  1973年   114篇
  1971年   104篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Numerous lines of evidence implicate a role of myeloperoxidase (MPO) in the pathogenesis of cardiovascular disease (CVD). It is a well accepted fact that patients with chronic kidney disease (CKD) are at an increased risk for CVD. MPO is a pro-oxidant enzyme which could be involved in the increased susceptibility of these patients to CVD. Hence, the levels of plasma MPO was determined in healthy controls as well as in patients with CKD [stratified with the level of their kidney failure as CKD stages II–V (end stage renal disease)]. Plasma MPO was assayed by a spectrophotometric method. Serum urea and creatinine were estimated on a clinical chemistry analyzer using standard laboratory procedures. The mean plasma MPO levels were significantly lower with advancing stages of renal failure (P < 0.001). There was a positive correlation between MPO and GFR (r = +0.89, P < 0.001) and a negative correlation with urea (r = −0.85, P < 0.001) and creatinine (r = −0.82, P < 0.001). While an inverse association was observed between plasma MPO and urea in CKD patients, such an association was not observed in control subjects (P = 0.43). In conclusion, the decline in plasma MPO levels may be due to the inhibitory effect of uraemic toxins on the enzyme.  相似文献   
992.
Researchers have shown the benefits of mentoring in both personal and professional growth. It would seem that group mentoring would only enhance those benefits. This work represents a literature review of peer-reviewed articles and dissertations that contribute to the theory and research of group mentoring. This work reviews the articles that contributed to the development of group mentoring theory as well as relevant research. Four primary types of group mentoring emerge—peer group, one-to-many, many-to-one, and many-to-many. Despite over 20 years of research, significant gaps remain in the research methods, demographic focus, and fields of study. The review concludes with recommendations for future research.  相似文献   
993.
This study was conducted to find out the level of oxidative stress and effect of supplementation of vitamin C, D and Calcium on levels of SOD, serum and urinary fluoride in children residing in endemic fluorosis area. For this the fluoride belt of Jaipur district was selected. The parameters selected were Super oxide dismutase, serum fluoride and urinary fluoride. The study was conducted on one hundred children, selected from four areas (25 from each area) consuming water containing 1.2, 2.4, 5.6 and 13.6 mg/l of fluoride. Drinking water fluoride, serum and urinary fluoride were measured by Ion selective electrode method. Serum SOD by Xanthine oxidase method using kit of Ransod (kit cat. No. SD125). The post treatment values showed a significant reduction in serum fluoride and SOD. Urinary fluoride levels increased significantly in post treatment stage. The results revealed a normal SOD levels in all groups but an increasing trend was observed with increasing fluoride concentration. Treatment with Calcium, Vitamin D and Vitamin C showed a significant reduction in serum fluoride and SOD and increase in urinary fluoride. A high positive correlation between pretreatment and post treatment group was observed in serum fluoride, SOD and urinary fluoride (P < 0.05). The study indicated an increasing oxidative stress in cases of fluorosis with increasing drinking water fluoride concentration. Treatment with Calcium, Vitamin D and Vitamin C resulted a significant reduction in serum fluoride and SOD and increase in urinary fluoride.  相似文献   
994.
995.
The aim of this study was to evaluate newly developed performance feedback tools from the student perspective. The tools were innovative in both their mode of delivery and the range of stakeholders they involved in the feedback process. By using the tools in health and social care settings, students were able to engage in interprofessional assessment of common competences and obtain performance feedback from a range of stakeholders not commonly involved in work-based learning; these included peers and service users. This paper discusses the ways in which the performance feedback tools were developed by a collaborative programme and compares their delivery, across a wide range of professions and work-based settings, in paper-based, web-based and mobile formats. The tools were evaluated through a series of profession-specific focus groups involving 85 students and 7 professions. The data were analysed thematically and reduced to three key categories: mode of delivery, assessment tool dynamics and work-based issues. These will be discussed in detail. The students agreed that the structured way of capturing and documenting feedback from several sources would support their practice placement learning. The reflective nature of the tools and the capacity for guiding reflection was also welcomed. The concepts of gaining service user, peer and/or interprofessional feedback on performance were new to some professions and evoked questions of reliability and validity, alongside appreciation of the value they added to the assessment process.  相似文献   
996.
Oh and LaRose (2016) contended that problem severity and channel publicness shape support seekers’ goals, time spent composing messages, and the sophistication of those messages. The current study seeks to replicate and extend Oh and LaRose’s study to produce a more accurate understanding of the factors that influence the sophistication of support-seeking messages online. Support seekers’ goals varied according to the severity of a stressor and the publicness of a channel, and the amount of time people spent composing a message influenced its sophistication. We extend the original study by examining associations that were not initially tested. Time spent composing messages mediated the influence of problem severity on the quality of people’s messages, and this effect was moderated by channel publicness.  相似文献   
997.
为促进高校学生身心健康成长,随机抽取122名学生,对其进行日常活动及膳食情况的调查,结果显示,能量的消耗与摄入处于不平衡状态.对此提出了相应的对策与建议.  相似文献   
998.
999.
The purpose of this paper is twofold: to describe robust rationales for integrating inquiry-based learning into undergraduate science education, and to propose that digital libraries are potentially powerful technological tools that can support inquiry-based learning goals in undergraduate science courses. Overviews of constructivism and situated cognition are provided with regard to how these two theoretical perspectives have influenced current science education reform movements, especially those that involve inquiry-based learning. The role that digital libraries can play in inquiry-based learning environments is discussed. Finally, the importance of alignment among critical pedagogical dimensions of an inquiry-based pedagogical framework is stressed in the paper, and an example of how this can be done is presented using earth science education as a context.  相似文献   
1000.
对高校健美操教学动作编排和音乐选用技巧的研究   总被引:7,自引:0,他引:7  
运用文献资料法、实践法等方法,对高校健美操教学动作编排和音乐选用进行了初步研究,认为健美操编排设计要有整体性和创新性;动作的选择应充分考虑健美操的自身特点,在编排中要合理运用具有健美操特点的对称组合动作;编排设计应有外型姿态美,要能充分体现出项目的特色和个性特征.健美操动作的主要部分选用快节奏的音乐更容易提高练习者的兴趣和更易于引起观众的共鸣.在开始部分或结束部分选用较慢节奏的音乐能够更充分的表现出快节奏音乐的速度和力度;选用单纯的音乐比带有外文歌曲的音乐可能产生的效果更好.  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