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   177篇
  免费   2篇
教育   104篇
科学研究   23篇
各国文化   2篇
体育   38篇
文化理论   4篇
信息传播   8篇
  2022年   4篇
  2021年   5篇
  2020年   3篇
  2019年   9篇
  2018年   9篇
  2017年   14篇
  2016年   14篇
  2015年   4篇
  2014年   11篇
  2013年   35篇
  2012年   9篇
  2011年   10篇
  2010年   11篇
  2009年   10篇
  2008年   2篇
  2007年   2篇
  2006年   4篇
  2004年   3篇
  2003年   3篇
  2002年   5篇
  2000年   1篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
排序方式: 共有179条查询结果,搜索用时 15 毫秒
11.
The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon), an oral booster immunomodulator, or placebo to 16 professional cyclists (n = 8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.  相似文献   
12.
13.
ABSTRACT

The aim of this article is to show the result of research into the situation of the integration of visually impaired children in Seville (Spain). This work refers to both classroom and peripatetic teachers’ perspectives. We have worked with four peripatetic teachers and nine classroom teachers from Seville. We have used qualitative methodological procedures for data collection and analysis. The results indicate that classroom organization is the most important problem in integration, and within this problem the relationship between classroom and peripatetic teachers becomes a fundamental issue.  相似文献   
14.
This study examined the effect of (a) high- and low-level questions and (b) reading the text before the questions asked on performance, delayed text recall, and deep text comprehension, as well as on specific text-inspection patterns. Participants were 37 undergraduate students who answered either high- or low-level questions using the software Read&Answer to read and answer questions on the computer screen. Additionally, half of the sample read first a text and then answered the questions (reading-first condition), whereas the other half answered the questions without having read the text in advance (no-reading-first condition). All participants had the text available to search for the answer. Results indicated that high-level questions facilitated deep comprehension but not immediate performance or delayed recall of text, independently of the reading condition, and that high- and low-level questions differentially affected text-inspection patterns.  相似文献   
15.
16.
This paper presents a solution to the problem of global exact output tracking for uncertain MIMO (multiple-input–multiple-output) linear plants with non-uniform arbitrary relative degree using output feedback sliding mode control. The key idea to overcome the relative degree obstacle is to generalize our previous hybrid estimation scheme to a multivariable version by combining, through switching, a standard linear lead filter with a non-linear one based on robust exact differentiators, achieving uniform global exponential practical stability and exact tracking.  相似文献   
17.
Knowledge Management Research & Practice - Nowadays knowledge has become a key asset for firms in order to build a sustainable competitive advantage. The environment changes quickly and...  相似文献   
18.
A general input-to-state stability (ISS)-type small-gain result is presented. It specializes to a small-gain theorem for ISS operators, and it also recovers the classical statement for ISS systems in state-space form. In addition, we highlight applications to incrementally stable systems, detectable systems, and to interconnections of stable systems.  相似文献   
19.
Digital libraries of scientific articles contain collections of digital objects that are usually described by bibliographic metadata records. These records can be acquired from different sources and be represented using several metadata standards. These metadata standards may be heterogeneous in both, content and structure. All of this implies that many records may be duplicated in the repository, thus affecting the quality of services, such as searching and browsing. In this article we present an approach that identifies duplicated bibliographic metadata records in an efficient and effective way. We propose similarity functions especially designed for the digital library domain and experimentally evaluate them. Our results show that the proposed functions improve the quality of metadata deduplication up to 188% compared to four different baselines. We also show that our approach achieves statistical equivalent results when compared to a state-of-the-art method for replica identification based on genetic programming, without the burden and cost of any training process.  相似文献   
20.
The aims of this study were (a) to assess the ability of the rating of perceived exertion (RPE) to predict performance (i.e. number of vertical jumps performed to a fixed jump height) of an intermittent vertical jump exercise, and (b) to determine the ability of RPE to describe the physiological demand of such exercise. Eight healthy men performed intermittent vertical jumps with rest periods of 4, 5, and 6 s until fatigue. Heart rate and RPE were recorded every five jumps throughout the sessions. The number of vertical jumps performed was also recorded. Random coefficient growth curve analysis identified relationships between the number of vertical jumps and both RPE and heart rate for which there were similar slopes. In addition, there were no differences between individual slopes and the mean slope for either RPE or heart rate. Moreover, RPE and number of jumps were highly correlated throughout all sessions (r = 0.97-0.99; P < 0.001), as were RPE and heart rate (r = 0.93-0.97; P < 0.001). The findings suggest that RPE can both predict the performance of intermittent vertical jump exercise and describe the physiological demands of such exercise.  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