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   2676篇
  免费   36篇
  国内免费   26篇
教育   1840篇
科学研究   181篇
体育   431篇
综合类   190篇
文化理论   1篇
信息传播   95篇
  2024年   2篇
  2023年   12篇
  2022年   16篇
  2021年   34篇
  2020年   52篇
  2019年   60篇
  2018年   47篇
  2017年   65篇
  2016年   47篇
  2015年   68篇
  2014年   111篇
  2013年   280篇
  2012年   162篇
  2011年   179篇
  2010年   123篇
  2009年   117篇
  2008年   150篇
  2007年   217篇
  2006年   179篇
  2005年   174篇
  2004年   149篇
  2003年   125篇
  2002年   107篇
  2001年   89篇
  2000年   43篇
  1999年   34篇
  1998年   27篇
  1997年   18篇
  1996年   17篇
  1995年   10篇
  1994年   4篇
  1993年   10篇
  1992年   6篇
  1991年   3篇
  1988年   1篇
排序方式: 共有2738条查询结果,搜索用时 15 毫秒
91.
基于结构异地协同控制试验网络平台的开发与研究   总被引:1,自引:0,他引:1  
结合我国国情建立远程结构试验网络系统,解决结构工程动力学科大型结构多节点试验资源不足的问题,分析了结构远程试验系统的组成以及网络远程协同控制的结构试验,初步实现把分布在各地的多个实验室连接在一起,利用各自不同的设备,完成复杂的试验和测试,同时让其他用户来实时观察所进行的试验,或参与试验过程,研究分析试验结果。  相似文献   
92.
美国小班教学综述   总被引:2,自引:0,他引:2  
郭春燕 《外国教育研究》2005,32(7):50-53,68
小班教学是美国教育改革中一项重要的课题,一些研究人员对这一课题进行了卓有成效的研究,许多州开展了小班教学实验或者推行与此相关的计划。美国小班教学的理论研究与实践表明:实施小班教学能够使教师给予每一个学生更多的关注时间,从而提高他们的学习成绩。  相似文献   
93.
在英译汉心理认知过程中,译者通常会受到一些因素的干扰而导致认知失误,但这却是推测,没有得到试验的检验。笔者尝试用两个具体的英译汉例子,提出三个有关心理认知干扰因素的假设,并设计四组英译汉测试题及与之相对应的问卷调查,用于三个实验组和一个对照组测试。通过对实验数据的收集、检验和分析,找出导致翻译认知失误的真正原因,即较偏僻词组和较长句式结构干扰了译者的翻译心理认知过程。  相似文献   
94.
大学英语口语测试是对英语口语能力的鉴定,测试能直接地反映考生的英语交际能力,从口语测试的意义、形式、原则及评分标准等方面分析了大学英语口语测试与口语教学的关系,强调科学的口语测试对大学英语口语教学的推动作用,口语测试与口语教学密切相关并对口语教学有促进作用。  相似文献   
95.
为弥补相关研究对中国工业碳排放估算过于粗略的不足,利用IPCC推荐的碳排放核算方法,基于30个省级行政区和36个两位数细分行业的工业能源消费数据,对1998—2010年中国工业能源碳排放总量、地区工业能源碳排放及工业细分行业能源碳排放进行估算,结果表明:工业能源碳排放占据中国能源碳排放的70%左右,主要集中分布在东部沿海地区(尤其是环渤海地区)和能源开采与加工、金属冶炼、设备制造及化工制品等重化工行业。因此,工业节能减排应考虑行业差异、地区差异及区域比较优势,依据行业与地区差别制定和实施适宜的工业低碳转型战略,推动工业结构优化升级与发展方式转变。  相似文献   
96.
Assessing comfort of running footwear reliably is challenging. The purpose of this study was to compare the intra-rater reliability between different assessment types, to calculate intra-individual reliability scores and to evaluate the effect of rater selection based on individual reliability scores on group level reliability. Three assessment types: ranking, Visual Analogue Scale (VAS), and Likert Scale (LS) were provided twice in six separate sessions among 30 participants, who assessed comfort of five shoes after treadmill running. Spearman's rho provided an evaluation of inter-session relative reliability and typical error as a measure of absolute reliability for each assessment type. Ranking (r?=?0.70, 95% confidence interval [CI] 0.61–0.78) yielded the highest relative reliability for overall comfort, followed by VAS (r?=?0.67, 95% CI 0.56–0.75) and LS (r?=?0.63, 95% CI 0.52–0.72), with large-scale overlaps of CIs between assessment types. The same order of assessment types was found for the percentage of reliable raters (r?≥?0.7) with 60% in ranking scale, 47% in VAS and 37% in LS. Forming subgroups corresponding to the intra-individual reliability substantially increased group level reliabilities. Based on measures of relative reliability, an extreme reduction in resolution as provided by the ranking from pairwise comparisons seems to be a valuable tool in footwear comfort assessments if assessment time is of minor importance. No preference can be provided for the two investigated rating scales. Besides the assessment type, a selection of the best raters in additional reliability checks seems to be a prerequisite for further comfort-related studies.  相似文献   
97.
Body position is known to alter power production and affect cycling performance. The aim of this study was to compare mechanical power output in two riding positions, and to calculate the effects on critical power (CP) and W′ estimates. Seven trained cyclists completed three peak power output efforts and three fixed-duration trial (3-, 5- and 12-min) riding with their hands on the brake lever hoods (BLH), or in a time trial position (TTP). A repeated-measures analysis of variance showed that mean power output during the 5-min trial was significantly different between BLH and TTP positions, resulting in a significantly lower estimate of CP, but not W′, for the TTP trial. In addition, TTP decreased the performance during each trial and increased the percentage difference between BLH and TTP with greater trial duration. There were no differences in pedal cadence or heart rate during the 3-min trial; however, TTP results for the 12-min trial showed a significant fall in pedal cadence and a significant rise in heart rate. The findings suggest that cycling position affects power output and influences consequent CP values. Therefore, cyclists and coaches should consider the cycling position used when calculating CP.  相似文献   
98.
There have been many conflicting observations between the linear or curvilinear decline in maximal heart rate (HRmax) with age. The aim of this study was to determine if linear or curvilinear equations would better describe the decline in HRmax with age in individuals of differing cardiorespiratory fitness (CRF) levels. Treadmill cardiopulmonary exercise test (CPX) results from participants (1510 men and 1134 women; 18–76 years) free of overt cardiovascular disease were retrospectively examined using cross-sectional and longitudinal study designs. Participants completing ≥2 CPX with ≥1 year between test dates were included in the longitudinal analysis (325 men and 150 women). Linear and quadratic regressions were applied to age and HRmax for the whole cohort and respective CRF groups (high, moderate, and low, relative to age and gender normative values). To test for differences among linear, quadratic, and polynomial equations, the change in R2 (cross-sectional analysis) and Bayesian information criterion (BIC) (longitudinal analysis) from the linear to the more complex models were calculated. The quadratic or polynomial regression in the cross-sectional analysis, marginally improved the variance in HRmax explained by age compared to the linear regression for the whole cohort (0.2%), moderate fit group (0.3%), and low fit group (0.8%). With no improvements in the high fit group. BIC did not improve for any CRF category in the longitudinal analysis. In conclusion, the minimal differences among linear, quadratic, and polynomial equations in the respective CRF groups, emphasizes the use of linear prediction equations to estimate HRmax.  相似文献   
99.
从教法和教学结构方面对标枪技术教学改革进行了探讨, 目的是使学生在较短的时间内更快、更好地掌握这项技术, 从而提高教学质量。  相似文献   
100.
随着散打运动的发展和激烈竞争,比赛的胜负在某种上取决于心理因素。散打运动员赛前大多数存在过分激动、过分紧张、过分盲目自信等不良心理状态,在某种程度上,不良的心理状态对比赛胜负有直接影响。如何在比赛前做好心理准备,使运动员达到最佳竞技状态,是值得进一步研究的问题。为此,文章通过调查问卷、文献资料、专家访谈和统计分析等研究方法,针对沈阳体育学院散打运动员赛前产生的不良心理状态(紧张、激动、盲目自信)对比赛胜负的影响进行分析,进而提出了赛前不良的心理状态的调节方法,以期为教练员和运动员在今后的运动训练提供理论参考。  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