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   240篇
  免费   1篇
  国内免费   6篇
教育   193篇
科学研究   37篇
各国文化   1篇
体育   6篇
综合类   7篇
文化理论   2篇
信息传播   1篇
  2023年   3篇
  2022年   2篇
  2021年   3篇
  2020年   5篇
  2019年   6篇
  2018年   8篇
  2017年   1篇
  2016年   2篇
  2015年   10篇
  2014年   12篇
  2013年   15篇
  2012年   16篇
  2011年   19篇
  2010年   24篇
  2009年   17篇
  2008年   10篇
  2007年   22篇
  2006年   21篇
  2005年   10篇
  2004年   3篇
  2003年   7篇
  2002年   1篇
  2001年   4篇
  2000年   4篇
  1999年   4篇
  1998年   1篇
  1997年   3篇
  1996年   2篇
  1995年   5篇
  1994年   1篇
  1993年   3篇
  1992年   2篇
  1989年   1篇
排序方式: 共有247条查询结果,搜索用时 9 毫秒
231.
通过对常用的测量共模抑制比的方法的分析 ,提出了一种高精度的简便的测量运放的共模抑制比的方法.  相似文献   
232.
本文运用循环数列的特征根;矩阵的对角化及二阶常系数线性差分方程等相关理论,给出了三种计算Fibonacci(裴波那契)数列通项公式的方法。  相似文献   
233.
对具有一定性质的全纯函数进行研究,得到了一族全纯函数的正规性质.  相似文献   
234.
运用斜长石-角闪石温压计对华北地块北缘内蒙古隆起及燕山褶断带内不同时期花岗质侵入岩的结晶压力及侵位深度进行了估算.结果表明,晚古生代-早中生代期间,在内蒙古隆起及燕山褶断带之间,存在有强烈的差异性隆升及剥露过程,但这种差异性隆升及剥露在早侏罗世以来的表现则不明显.晚古生代-早中生代差异性隆升及剥露可能是导致内蒙古隆起上大量基底岩石出露、中-新元古代及古生代沉积盖层缺失及燕山褶断带中-新元古代及古生代沉积盖层大量保留的主要原因.内蒙古隆起强烈的隆升及剥露过程发生在晚石炭世-早侏罗世期间,其东部的剥露幅度比中东部明显偏小.晚古生代-早中生代期间内蒙古隆起的强烈剥露及其与燕山褶断带之间的差异性隆升可能与古亚洲洋板块向华北地块的俯冲、消减、碰撞及华北北缘区域性断裂(如平泉-古北口-赤城-尚义断裂、赤峰-围场-多伦断裂)的活动有关.燕山褶断带的强烈隆升与剥露发生则在晚侏罗世-早白垩世之后.晚侏罗世-早白垩世以来,华北地块北缘南北两侧均有一次明显的剥露过程,这一剥露可能与本区及中国东部地壳强烈伸展有关.  相似文献   
235.
The contextual interference (CI) model hypothesizes random practice (high CI) leads to inferior acquisition, but superior retention and transfer capabilities compared to blocked practice (low CI). These phenomena are well established in laboratory settings. However, the transfer to applied settings, particularly in sports practice is still under discussion. The aim of this systematic review and meta-analysis is to evaluate the possible generalisability of the CI phenomenon in sports-based contexts with regard to performance outcomes. Up to April 16th, 2022, five electronic databases (PubMed, Web of Science, Scopus, Taylor & Francis, and SciELO) were used to search for relevant studies investigating differences between blocked and random schedules at post-acquisition, retention, and/or transfer tests. Using the PICOS criteria, a total of 933 records were screened. Outcomes evaluating the acquisition, retention, and/or transfer performances in sports skills in healthy participants were included. The quality of the selected studies was scored using the PEDro scale. Thirty-seven studies were selected, of which twenty-seven were of good quality and the remaining ten were rated as fair quality. Out of 205 overall pooled outcomes, only 43 performance outcomes (21%) agreed with the CI phenomenon after the acquisition (18 out of 103), retention (19 out of 84), and/or transfer (6 out of 36) phases. No statistically significant overall difference between blocked and random practice was detected at post-acquisition (effect size (ES) = 0.1, p = 0.154), retention (ES = −0.159, p = 0.141) or transfer testing (ES = −0.243, p = 0.071). The subgroup analysis showed inferior acquisition and superior retention following random practice only in individuals aged 20–24 years (ES = 0.282, p = 0.030 during the acquisition, and ES = −0.405, p = 0.011 during retention), with no difference at transfer testing for this specific age group. No similar significant effects have been concurrently identified during both acquisition and retention phases in any of the remaining subgroups (e.g., examined based on experience level, sports, skills, and testing protocol categories). The present results suggest CI effects can only be confirmed under very limited conditions, which seriously challenges the extension of CI effects to the sport context in general. Problematic conclusions for children's learning are discussed, as well as future research strategies to better understand counterintuitive learning approaches.  相似文献   
236.
民事诉讼中的级别管辖,是指按照一定的标准,划分上下级法院之间受理第一审民事案件的分工与权限的制度。我国民事诉讼级别管辖制度存在诸多问题,本文分析了其原因,并就如何进一步完善我国民事诉讼级别管辖制度提供了一些建议。  相似文献   
237.
向占宏 《宜春学院学报》2005,27(4):20-21,25
利用Leray—Schauder不动点定理,研究了一类多滞量微分方程非负周期解的存在性,得到了一些新的结果并改进了相应的结论.  相似文献   
238.
Broadband phase shifters are mostly proposed and fabricated based on the scheme proposed by Shiffman, which uses a coupled line with far ends connected together and a uniform transmission line to give a differential phase shift. Based on the unique dispersion property of the composite right/left-handed (CRLH) metamaterial structure, a new configuration is presented in this paper for fabricating the broadband differential phase shifter, which employs a novel CRLH metamaterial structure as one of the differential phase-shift arms, instead of the conventional coupled line. The new circuit can achieve a phase shift of 90° in an operational bandwidth as broad as one octave and its phase deviations are quite small. An original design of the novel broadband phase shifter is presented, in which the artificial CRLH structure was implemented by microstrip quasi-lumped elements. Both the simulated and measured results of the 90° broadband differential phase shifter are presented.  相似文献   
239.
刘好增  张晓华 《中国科技信息》2006,(19):270-270,272
在微分中值定理“中值点”存在的基础上,进一步研究微分中值定理“中值点”的个数问题.  相似文献   
240.
This paper examines the utility of the Differential Impact Theory for child protection practitioners who work in humanitarian settings, with a focus on war-affected children. A primary advantage of DIT is that it focuses efforts to strengthen children's resilience on improving children's social ecologies at different levels. This ecological focus is more likely to address the sources of children's suffering and resilience and also helps to avoid the problems associated with an individualized focus. It also shows how DIT provides a differentiated view of war-affected children and stimulates multiple interventions at different ecological levels, avoiding the common error of taking a one size fits all approach to intervention. In keeping with DIT, it suggests that child protection practice would benefit from addressing macro-level risks such as poverty and discrimination that are drivers of various harms to children and from more systematic linkages between macro- and micro-levels. It concludes that DIT serves as a critical lens for viewing current work on child protection in humanitarian settings and also for illuminating ways to develop more comprehensive supports for children's resilience.  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