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   39122篇
  免费   739篇
  国内免费   736篇
教育   22762篇
科学研究   8147篇
各国文化   253篇
体育   2711篇
综合类   1312篇
文化理论   224篇
信息传播   5188篇
  2022年   304篇
  2021年   1041篇
  2020年   796篇
  2019年   535篇
  2018年   592篇
  2017年   648篇
  2016年   552篇
  2015年   1129篇
  2014年   1617篇
  2013年   3886篇
  2012年   2239篇
  2011年   2521篇
  2010年   2269篇
  2009年   2095篇
  2008年   2061篇
  2007年   2395篇
  2006年   2285篇
  2005年   1846篇
  2004年   984篇
  2003年   1001篇
  2002年   940篇
  2001年   878篇
  2000年   643篇
  1999年   627篇
  1998年   413篇
  1997年   366篇
  1996年   320篇
  1995年   220篇
  1994年   218篇
  1993年   183篇
  1992年   215篇
  1991年   174篇
  1990年   183篇
  1989年   197篇
  1988年   141篇
  1987年   116篇
  1986年   160篇
  1985年   157篇
  1984年   138篇
  1983年   129篇
  1982年   107篇
  1981年   91篇
  1980年   95篇
  1979年   135篇
  1978年   106篇
  1977年   100篇
  1976年   94篇
  1974年   104篇
  1973年   80篇
  1971年   91篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
ABSTRACT

Distal-to-proximal redistribution of joint work occurs following exhaustive running in recreational but not competitive runners but the influence of a submaximal run on joint work is unknown. The purpose of this study was to assess if a long submaximal run produces a distal-to-proximal redistribution of positive joint work in well-trained runners. Thirteen rearfoot striking male runners (weekly distance: 72.6 ± 21.2 km) completed five running trials while three-dimensional kinematic and ground reaction force data were collected before and after a long submaximal treadmill run (19 ± 6 km). Joint kinetics were calculated from these data and percent contributions of joint work relative to total lower limb joint work were computed. Moderate reductions in absolute negative ankle work (p = 0.045, Cohen’s d = 0.31), peak plantarflexor torque (p = 0.004, d = 0.34) and, peak negative ankle power (p = 0.005, d = 0.32) were observed following the long run. Positive ankle, knee and hip joint work were unchanged (p < 0.05) following the long run. These findings suggest no proximal shift in positive joint work in well-trained runners after a prolonged run. Runner population, running pace, distance, and relative intensity should be considered when examining changes in joint work following prolonged running.  相似文献   
2.
文化功能也就是"出之于人,归之于人",江口土家族"金钱杆"起于秦末时期的西楚霸王,形于族人生产生活实践中。经过研究发现,"金钱杆"是具有彰显土家族文化的独特符号、"常"与"非常"之间转换的独特节点、教化孩童的重要载体以及增强体质的独特途径的少数民族传统体育活动。本研究主要探求"金钱杆"发展逻辑,旨在为"金钱杆"的传承和发展提供有益的指导。  相似文献   
3.
[目的/意义] 大数据政策是大数据应用和发展的推动力量,其价值取向分析可以为我国政府大数据政策的制定、执行和评估提供借鉴,为大数据政策未来的发展方向提供依据。[方法/过程] 收集国务院及其各部门门户网站发布的政务大数据政策文本共计58份,运用主题分析方法对政策文本中表达政务大数据价值取向的主题进行编码分析,编码过程以NVivo12软件为辅助工具。[结果/结论] 通过主题分析,构建大数据政策价值取向总体框架,框架总结政治、经济、社会、生态与科技5个维度的价值取向,并探讨各维度及其具体价值取向间的交互关系。  相似文献   
4.
[目的/意义] 作为政府与青年群体沟通的重要平台,政务Bilibili账号的信息传播效果直接决定其沟通效率和效果。对政务Bilibili账号信息传播效果影响因素的研究有利于沟通效果的提升。[方法/过程] 本研究基于共青团中央Bilibili账号的471个样本,采用内容分析和回归分析等系统考察内容主题、视频类别、封面图类型、屏幕形式、字幕、组织形式、剪辑率和视频时长等因素对政务Bilibili账号信息传播效果的影响。[结果/结论] 结果表明,科技类、音乐类和时尚类主题的视频能够提升整体传播效果,科技类视频的贡献度最高;情景剧、实拍视频和监控视频都正向显著影响整体传播效果,实拍视频的贡献度最高。视频剪辑率、竖屏视频、字幕添加、合作创作等均能显著提高整体传播效果,竖屏在整体传播效果模型中的贡献度最大。视频时长和封面图的作用不显著。政务Bilibili账号运营应充分释放青年的爱国势能、创新视频形式、优化视频制作流程、创新组织形式。  相似文献   
5.
ABSTRACT

The purpose of this study was to examine the relationships between grandparents’ use of relational maintenance behaviors (RMB) and their young adult grandchildren’s willingness to serve as future caregivers for their grandparents. Undergraduate students (N = 209) completed a questionnaire in which they reported on a specific grandparent’s use of RMB and how willing they were to serve as future caregivers for that specific grandparent. Results of a multiple regression analysis provided partial support for the hypothesized positive relationships between grandparents’ use of RMB and grandchildren’s willingness to serve as future caregivers for their grandparents.  相似文献   
6.
The on-going Coronavirus disease(COVID-19)outbreak in China has become the world's leading health headline and is causing major panic and public concerns.On January 30,2020,the World Health Organization(WHO)declared that the new coronavirus outbreak is a public health emergency of international concern.1 The virus has already had a direct impact on more than 10 million people in the city of Wuhan and has reached other parts of China as well,posing a health threat of unknown magnitude globally.As of February 8,2020,WHO reported 34,886 confirmed cases of COVID-19 globally,with 34,589 of them occurring in China(including 6101 severe cases and 723 deaths).A total of 288 other confirmed cases(with 1 death)have been reported in 24 countries,including Japan,Australia,Germany,and United States.2 However,these daily estimates are expected to rise even higher as reports from health authorities in China3 are gathered and near real-time updates of the Johns Hopkins virus dashboard are made 4 The outbreak has caused governments in various countries to take swift and protective measures.In China,these included putting cities on lockdown,5 implementing travel wamings/bans and cancellations,6 extending national holidays,and closing schools and postponing classes7.  相似文献   
7.
目的:基于决策树模型探讨引起幼儿超重的关键因素。方法:招募南昌市23所幼儿园5870名3~6岁幼儿,测量身高、体重;问卷调查幼儿身体活动、静坐行为、出生信息,父母的育儿方式、身体形态、锻炼行为和家庭情况,并将其划分为36个变量;采用IBM SPSS modeler软件创建CHAID决策树模型,筛选幼儿超重的关键性因素。结果:CHAID模型准确率达85.23%。CHAID模型结果显示,8个变量与幼儿超重有较强关联性,各变量按重要性排序依次为室外身体活动时间、父亲BMI、母亲BMI、父亲收入、室内身体活动时间、父亲受教育程度、喂养方式、看电视时间。结论:身体活动尤其是室外身体活动与幼儿超重的关系最为密切,父母肥胖程度、父亲收入与受教育情况、喂养方式、静坐行为也是导致幼儿超重的关键性因素。  相似文献   
8.
文章通过分析慕课和财务管理课程特征以及财务管理课程在传统教学中存在的主要问题,认为基于慕课的财务管理课程教学改革需要相应的策略:转变教学理念,要以学生为中心;加强团队建设,落实分工职责;慕课与传统教学相结合;改革督学和评价方式;加强和改进实践教学环节。  相似文献   
9.
为观察气膜厚度对反气泡稳定性的影响,通过加热反气泡内外溶液来加热气膜内气体从而改变气膜厚度。实验发现:在一定温度范围内,加热反气泡气膜可以延长其稳定时间,但是当加热反气泡气膜使其厚度超过其稳定存在的阈值时,反气泡的稳定性会急剧下降甚至无法产生反气泡;在一定温度范围内温度对溶液表面张力影响很小,这使得文中实验数据合理化。本文为反气泡稳定性的理论研究提供实验支持,并考虑到气膜厚度为微米级,可为微米级气膜传热提供实验素材。  相似文献   
10.
The value that willed body donors provide to medical education is priceless. Their precious gift helps to teach anatomy, spatial relationships between morphological structures, anatomical variation, and professionalism to medical students in a way that plastic models, podcasts, and lectures cannot. They are also an important resource for medical research and a wide variety of postgraduate training opportunities. While many body donation programs throughout the world are nonprofit organizations, there are body donation companies in the United States that sell donors for-profit. These “body brokers” have accumulated large profits from this business. It is incongruous that others would profit from such a priceless, freely donated gift. To prevent this incongruity, it is proposed that the international anatomical community develop a normative culture (a bioethos) for body donation programs. This would involve the conscious and systematic development of ethical principles for the day-to-day policies and practices of institutions that collect and use human bodies. With the development of this bioethos, a cultural shift in how donors are treated would occur and, over time, this would become the normal practice. These principles would become fundamental and foundational for the procurement and use of priceless human tissues.  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