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   123886篇
  免费   1906篇
  国内免费   238篇
教育   86445篇
科学研究   13456篇
各国文化   2048篇
体育   9357篇
综合类   174篇
文化理论   1137篇
信息传播   13413篇
  2021年   953篇
  2020年   1698篇
  2019年   2635篇
  2018年   3129篇
  2017年   3426篇
  2016年   3482篇
  2015年   2404篇
  2014年   3283篇
  2013年   27960篇
  2012年   2405篇
  2011年   2729篇
  2010年   2374篇
  2009年   2675篇
  2008年   2437篇
  2007年   2127篇
  2006年   2415篇
  2005年   2374篇
  2004年   3033篇
  2003年   2388篇
  2002年   2188篇
  2001年   1985篇
  2000年   1626篇
  1999年   1548篇
  1998年   1493篇
  1997年   1551篇
  1996年   1742篇
  1995年   1521篇
  1994年   1511篇
  1993年   1505篇
  1992年   1472篇
  1991年   1409篇
  1990年   1389篇
  1989年   1285篇
  1988年   1165篇
  1987年   1071篇
  1986年   1117篇
  1985年   1384篇
  1984年   1263篇
  1983年   1262篇
  1982年   1262篇
  1981年   1182篇
  1980年   1177篇
  1979年   1205篇
  1978年   1202篇
  1977年   1115篇
  1976年   1001篇
  1975年   802篇
  1974年   785篇
  1973年   760篇
  1971年   606篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Data from surveys of parents of students in Russian schools of various types in the years 2006 to 2011 show a high level of desire to invest in their children's education. There has been a high degree of stability in aspirations and investment in spite of the economic problems caused by global recession.  相似文献   
992.
993.
994.
Using a participatory learning approach, we report on the delivery and evaluation of a climate change and risk assessment tool to help manage water risks within the agricultural sector. Post-graduate water-professional students from a range of countries, from both developed and emerging economies were involved in using this tool. Our approach included participative learning tools – group discussion, software, and risk matrices. The materials developed met the needs of the students, allowing these students to incorporate their learning and adapt the package of materials for use in their home countries. Analysis of evaluations show that the tools and materials are particularly useful and emphasizes the need for sound learning materials and tools, funding to deliver training, and policy support to accelerate education and adoption of authentic climate change adaptation practices. The expected benefits for water professionals about climate change will be translated into improved socioeconomic and environmental outcomes if adopted.  相似文献   
995.
996.
Counselors (N = 911) reported the research skills needed for practice and subsequent research training needs. Findings indicate that counselors have a high need for research skills at work, but training needs differ significantly by counselor type. Recommendations include increasing emphasis on single‐case design, survey design, and widely available data analysis tools.  相似文献   
997.
998.
999.
Objective: To analyze the possible dose-response association between components of sports participation (intensity, volume and previous engagement) and 4-year mortality rates among Brazilian adults.

Methods: 679 males and females (mean age among men = 66.7 ± 9.3 years old and mean age among women = 64.8 ± 8.9 years old) composed the study sample. Sports participation was assessed using Baecke’s questionnaire, which considers intensity, duration and previous engagement. Medical records were used to identify the cause of the death. Cox regression analysis was performed to determine the independent associations of exercise components and mortality.

Results: Participants that reported exercising at moderate-vigorous intensity (Moderate/vigorous: 4.1% versus None/light: 10.3% [p-value = 0.012]; HR = 0.42 [0.1 to 0.94)] and for more than four months (≥4 months: 5.3% versus <4 months: 10.2% [p-value = 0.038]; HR = 0.47 [0.24 to 0.94]) had lower mortality risk. The percentage of survival according to all-cause mortality was significantly higher for participants engaged in sports at moderate-vigorous intensity (p-value = 0.014), as well as for those engaged in sports for periods superior than four months (p-value = 0.036).

Conclusion: We found higher percentage of survival among adults engaged in sports at moderate-vigorous intensity and with at least four months of previous engagement.  相似文献   

1000.
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