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   341篇
  免费   3篇
  国内免费   1篇
教育   254篇
科学研究   17篇
体育   37篇
信息传播   37篇
  2023年   2篇
  2022年   2篇
  2021年   10篇
  2020年   4篇
  2019年   9篇
  2018年   16篇
  2017年   11篇
  2016年   11篇
  2015年   7篇
  2014年   6篇
  2013年   85篇
  2012年   11篇
  2011年   12篇
  2010年   6篇
  2009年   5篇
  2008年   9篇
  2007年   10篇
  2006年   10篇
  2005年   8篇
  2004年   3篇
  2003年   10篇
  2002年   7篇
  2001年   6篇
  2000年   10篇
  1999年   9篇
  1998年   4篇
  1997年   3篇
  1996年   9篇
  1995年   4篇
  1994年   3篇
  1992年   5篇
  1991年   4篇
  1989年   3篇
  1988年   3篇
  1985年   1篇
  1984年   1篇
  1983年   4篇
  1980年   2篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
  1969年   2篇
  1934年   1篇
  1862年   1篇
  1830年   1篇
排序方式: 共有345条查询结果,搜索用时 15 毫秒
1.
基于域加权词频法的XML文档级检索实现与评价   总被引:1,自引:0,他引:1  
利用BM25F模型,通过实验,在INEX 04数据集的基础上,实现了对多个域(元素)词频进行加权的XML文档级检索。XML文档结构的确蕴含了一定的语义信息。利用这些语义信息,可以提高检索性能。表2。图1。参考文献16。  相似文献   
2.
3.
Brain injury research in sport employs a variety of physical models equipped with accelerometers. These acceleration signals are commonly processed using filters. The purpose of this research was to determine the effect of applying filters with different cutoff frequencies to the acceleration signals used as input for finite element modeling of the brain. Signals were generated from reconstructions of concussion events from American football and ice hockey in the laboratory using a Hybrid III headform. The resulting acceleration signals were used as input for the University College Dublin Brain Trauma Model after being processed with filters. The results indicated that using a filter with a cutoff of 300 Hz or higher had little effect on the resulting strain measures. In some cases there was some effect of the filters on the peak linear (8–30g) and rotational measures (1000–4000 rad/s2), but little effect on the finite element strain result (approximately 2–6 %). The short duration and high magnitude accelerations, such as the puck impact, were most affected by the cutoff frequency of different filters.  相似文献   
4.
5.
This study investigated the extent to which position in the Australian Football League (AFL) national draft is associated with individual game performance metrics. Physical/technical skill performance metrics were collated from all participants in the 2014 national under 18 (U18) championships (18 games) drafted into the AFL (n = 65; 17.8 ± 0.5 y); 232 observations. Players were subdivided into draft position (ranked 1–65) and then draft round (1–4). Here, earlier draft selection (i.e., closer to 1) reflects a more desirable player. Microtechnology and a commercial provider facilitated the quantification of individual game performance metrics (= 16). Linear mixed models were fitted to data, modelling the extent to which draft position was associated with these metrics. Draft position in the first/second round was negatively associated with “contested possessions” and “contested marks”, respectively. Physical performance metrics were positively associated with draft position in these rounds. Correlations weakened for the third/fourth rounds. Contested possessions/marks were associated with an earlier draft selection. Physical performance metrics were associated with a later draft selection. Recruiters change the type of U18 player they draft as the selection pool reduces. juniors with contested skill appear prioritised.  相似文献   
6.
The relationships between team performance indicators and match outcome have been examined in many team sports, however are limited in Australian Rules football. Using data from the 2013 and 2014 Australian Football League (AFL) regular seasons, this study assessed the ability of commonly reported discrete team performance indicators presented in their relative form (standardised against their opposition for a given match) to explain match outcome (Win/Loss). Logistic regression and decision tree (chi-squared automatic interaction detection (CHAID)) analyses both revealed relative differences between opposing teams for “kicks” and “goal conversion” as the most influential in explaining match outcome, with two models achieving 88.3% and 89.8% classification accuracies, respectively. Models incorporating a smaller performance indicator set displayed a slightly reduced ability to explain match outcome (81.0% and 81.5% for logistic regression and CHAID, respectively). However, both were fit to 2014 data with reduced error in comparison to the full models. Despite performance similarities across the two analysis approaches, the CHAID model revealed multiple winning performance indicator profiles, thereby increasing its comparative feasibility for use in the field. Coaches and analysts may find these results useful in informing strategy and game plan development in Australian Rules football, with the development of team-specific models recommended in future.  相似文献   
7.
Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost.  相似文献   
8.
Scottish schools have provided performance data for five international surveys of attainment in mathematics since 1990. Performance measured against national targets and progression over time and between age‐stages have been monitored nationally, on a regular basis, for 20 years, within the Assessment of Achievement Programme (AAP) (Scotland). The 1994 AAP mathematics survey findings facilitated interpretation of the age 9 and 13 TIMSS results for Scotland. Both studies were influential in formulation of national policies to improve learning and teaching of mathematics, at ages 5–14. Research available to support policies recommended in 1997 is examined. Concerns about validity and reliability of findings from international studies are discussed in the context of a collaboration undertaken between Scotland and France in 1994. It is concluded that simplistic comparisons ignore important cultural and curricular differences. Outcomes of more recent national and international surveys are reported and performance findings from 1988–2000 that relate to gender are reviewed.  相似文献   
9.
10.
Since the first development of counselling services in Australian universities in 1953, the tertiary system, and counselling services within them, have undergone a forty-year period of growth and change, and now all universities have counselling services which typically focus on short-term counselling interventions and are characterised by high levels of professionalism. Two case studies provide a picture of the situation in Australian universities. One case is that of an older and larger institution recently formed as a multi-campus university by amalgamations and with its main campus in the inner city of Australia's second-largest city. The contrasting case is of a newer, suburban university in one of the smaller capital cities. The challenges facing university counselling services in the future include the continuing pressure for greater accountability, the increasing demands of a multi-cultural clientele, the temptation to take on a wider range of tasks than can be sustained, and its obverse, the risk of over-specialisation.  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