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   1600篇
  免费   24篇
  国内免费   16篇
教育   1134篇
科学研究   168篇
各国文化   19篇
体育   185篇
综合类   28篇
文化理论   12篇
信息传播   94篇
  2022年   18篇
  2021年   23篇
  2020年   34篇
  2019年   47篇
  2018年   69篇
  2017年   60篇
  2016年   62篇
  2015年   32篇
  2014年   45篇
  2013年   183篇
  2012年   60篇
  2011年   46篇
  2010年   40篇
  2009年   42篇
  2008年   42篇
  2007年   55篇
  2006年   55篇
  2005年   50篇
  2004年   48篇
  2003年   93篇
  2002年   122篇
  2001年   114篇
  2000年   68篇
  1999年   24篇
  1998年   14篇
  1997年   17篇
  1996年   12篇
  1995年   14篇
  1994年   11篇
  1993年   13篇
  1992年   7篇
  1991年   9篇
  1990年   10篇
  1989年   4篇
  1988年   4篇
  1987年   8篇
  1986年   4篇
  1985年   10篇
  1984年   7篇
  1983年   4篇
  1982年   6篇
  1981年   3篇
  1980年   4篇
  1978年   7篇
  1974年   3篇
  1973年   4篇
  1887年   3篇
  1866年   2篇
  1865年   4篇
  1838年   2篇
排序方式: 共有1640条查询结果,搜索用时 484 毫秒
51.
For this study, information on Who Bullies Who was collected from 54 school classes with 918 children (M age = 11) and 13,606 dyadic relations. Bullying and victimization were viewed separately from the point of view of the bully and the victim. The two perspectives were highly complementary. The probability of a bully-victim relationship was higher if the bully was more dominant than the victim, and if the victim was more vulnerable than the bully and more rejected by the class. In a bully-victim dyad, boys were more often the bullies. There was no finding of sex effect for victimization. Liking reduced and disliking increased the probability of a bully-victim relationship.  相似文献   
52.
International Review of Education - This article examines the profile of prisoners who do not take part in formal education while being incarcerated (e.g. language or ICT courses) and the barriers...  相似文献   
53.
Research in Science Education - The first phase of this multiphase study involves modeling of college students’ thinking of friction at the microscopic level. Diagnostic interviews were...  相似文献   
54.
Pedometer-determined physical activity (PA) levels in Belgian adults were provided and compared to PA scores reported in the International Physical Activity Questionnaire (IPAQ). The representative sample (N=1239) of the Belgian population took on average 9655 (4526) steps/day. According to pedometer indices 58.4% were insufficiently active. Steps/day differed significantly between gender (F = 5.0, p = .026), age groups (F = 3.3, p = .01), employment status (F = 6.2, p = .013), and days of monitoring (F = 7.4, p = .007). Steps/day were negatively correlated to the time spent sitting and positively to PA at work, in transport, and in leisure time (p < .001). Steps data can discriminate between PA levels reported in the IPAQ. Belgian population pedometer-determined PA levels are higher than those reported in samples of the United States; however, there is a wide distribution of ambulatory behavior  相似文献   
55.
The aim of this study was to compare optimization and correction procedures for the determination of peak power output during friction-loaded cycle ergometry. Ten male and 10 female sports students each performed five 10-s sprints from a stationary start on a Monark 864 basket-loaded ergometer. Resistive loads of 5.0, 6.5, 8.0, 9.5, and 11.0% body weight were administered in a counterbalanced order, with a recovery period of 10 min between sprints. Peak power was greater and occurred earlier, with less work having been done before the attainment of peak power, when the data were corrected to account for the inertial and frictional characteristics of the ergometer. Corrected peak power was independent of resistive load (P > 0.05), whereas uncorrected peak power varied as a quadratic function of load (P < 0.001). For males and females, optimized peak power (971 +/- 122 and 668 +/- 37 W) was lower (P < 0.01) than either the highest (1074 +/- 111 and 754 +/- 56 W respectively) or the mean (1007 +/- 125 and 701 +/- 45 W respectively) of the five values for corrected peak power. Optimized and mean corrected peak power were highly correlated both in males (r = 0.97, P < 0.001) and females (r = 0.96, P < 0.001). The difference between optimized and mean corrected peak power was 37 +/- 30 W in males and 33 +/- 14 W in females, of which approximately 15 W was due to the correction for frictional losses. We conclude that corrected peak power is independent of resistive load in males and females.  相似文献   
56.
Purpose:To investigate whether blood flow restriction(BFR) without concomitant exercise mitigated strength reduction and atrophy of thigh muscles in subjects under immobilization for lower limbs.Methods:The following databases were searched:PubMed,CINAHL,PEDro,Web of Science,Central,and Scopus.Results:The search identified 3 eligible studies,and the total sample in the identified studies consisted of 38 participants.Isokinetic and isometric torque of the knee flexors and extensors was examined in 2 studies.Cross-sectional area of thigh muscles was evaluated in 1 study,and thigh girth was measured in 2 studies.The BFR protocol was 5 sets of 5 min of occlusion and 3 min of free flow,twice daily for approximately 2 weeks.As a whole,the included studies indicate that BFR without exercise is able to minimize strength reduction and muscular atrophy after immobilization.It is crucial to emphasize,however,that the included studies showed a high risk of bias,especially regarding allocation concealment,blinding of outcome assessment,intention-to-treat analyses,and group similarity at baseline.Conclusion:Although potentially useful,the high risk of bias presented by original stodies limits the indication of BFR without concomitant exercise as an effective countermeasure against strength reduction and atrophy mediated by immobilization.  相似文献   
57.
中国区域经济与环境协调度预测分析   总被引:64,自引:0,他引:64  
经济发展与环境之间的关系已经成为全世界特别是发展中国家关心的问题,但有关的定量研究比较缺乏。该文首先解释了经济与环境协调度基本概念与模型内涵,并介绍了灰色系统在贫信息系统中进行预测的基本原理。通过灰色系统GM(1,1)模型对90年代我国省级区域的经济与环境协调度进行了计算,经过检验,模型模拟精度较高。因此运用此模型对2005年与2010年的区域协调度进行了预测。结果表明,我国大部分地区的经济与环境关系基本处于调和状态,即经济的增长是以牺牲环境为代价的。未来10a的协调度空间分布仍然呈现“U”型特征。处于转折点附近的省区协调度波动比较大,包括广大的中部地区。尽量减少波动并尽快实现协调度的转折是这些地区在经济发展过程中要注意的问题;西部大部分地区如果继续沿用90年代的发展策略,对经济发展政策和手段不作宏观的调控,在西部开发过程中出现的环境问题将会越来越严重。  相似文献   
58.
采用单因子实验方法研究了湛江港礁膜配子的成熟放散与温度、光照、比重和pH值的关系,并对黑暗时间对配子接合及合子附着的影响进行了初步研究。实验结果表明,在温度为20℃、光照强度为80.13μmol/(m^2·s)左右、pH值为7.9、比重为1.018的室内培养条件下,为礁膜配子体成熟和配子囊大量放散配子的最适宜生态条件。早期合子附着的适宜黑暗时间为5—6h。  相似文献   
59.
从网络安全的实际需要出发 ,阐述了用Linux开发个人防火墙的思想、方法和注意事项 ,并给出了具体的设计实例 .  相似文献   
60.
劳动力市场分割与大学毕业生失业   总被引:102,自引:5,他引:102  
具有大学以上学历者占我国全部劳动者的比例非常低 ,但最近几年大学毕业生找工作却有越来越难的趋势。这种看似矛盾的现象是转型过程中劳动力市场分割这一制度背景下 ,大学毕业生与用人单位相互搜寻的结果。过大的城乡收入差距和过高的工作转换成本 ,使大学毕业生“宁要城里一张床 ,不要农村一幢房”,但城里的用人单位却因过高的解聘成本和户口成本而不能吸收更多的大学毕业生。因此 ,大学毕业生就业难的缓解和解决 ,要依赖经济发展 ,也离不开体制改革  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