全文获取类型
收费全文 | 887篇 |
免费 | 19篇 |
专业分类
教育 | 627篇 |
科学研究 | 44篇 |
各国文化 | 8篇 |
体育 | 150篇 |
文化理论 | 10篇 |
信息传播 | 67篇 |
出版年
2023年 | 11篇 |
2022年 | 20篇 |
2021年 | 22篇 |
2020年 | 32篇 |
2019年 | 52篇 |
2018年 | 83篇 |
2017年 | 62篇 |
2016年 | 46篇 |
2015年 | 40篇 |
2014年 | 40篇 |
2013年 | 209篇 |
2012年 | 33篇 |
2011年 | 29篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 17篇 |
2007年 | 16篇 |
2006年 | 18篇 |
2005年 | 17篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1880年 | 1篇 |
排序方式: 共有906条查询结果,搜索用时 15 毫秒
181.
José Joaquín Muros Cristóbal Sánchez-Muñoz Jesús Hoyos Mikel Zabala 《European Journal of Sport Science》2019,19(1):86-94
AbstractThe aim of this study was to quantify the food intake of an International Cyclist Union (UCI) World Tour professional cyclist team and to analyse changes in body composition during the Tour of Spain. Nine male professional road cyclists (31.3?±?3.0 years) volunteered to participate in the study. Nutritional data were collected each day throughout the 3-week Tour by two trained investigators who weighed the food ingested by the cyclists. Mean nutritional intake of the cyclists was as follows: carbohydrate, 12.5?±?1.8?g/kg/day of body weight (BW) (65.0?±?5.9%); fat, 1.5?±?0.5 g/kg/day BW (17.9?±?5.6%); and protein, 3.3?±?0.3?g/kg/day BW (17.1?±?1.6%). Intake of all micronutrients, except for folate, vitamin D and potassium (which were 78.7%, 46% and 84% of Recommended Dietary Allowances (RDA), respectively), exceeded the RDA. Height, weight, skinfolds, circumferences and diameters were taken following the guidelines outlined by the International Society for the Advancement of Kinanthropometry. Body density, body fat percentage, muscle mass, total muscle mass and fat mass of the arms and thighs were calculated. Percentage body fat, fat mass and upper arm fat mass significantly decreased (p < .05) after the Tour independent of the equation method used in the calculations. Total muscle mass remained unchanged. Generally, this sample of cyclists consumed more protein and less fat than the recommended amount and had low weight, BMI and fat mass. It is suggested that sports nutritionists design personalised diets in order to maintain a correct proportion of nutrients as well as controlling possible anthropometrical changes that could affect performance. 相似文献
182.
Luciano Rossi Rafael J.P. Damaceno Igor L. Freire Etelvino J.H. Bechara Jesús P. Mena-Chalco 《Journal of Informetrics》2018,12(4):1042-1058
Academic genealogy aims to structure and analyze the mentoring relationships between advisor and advisee. The representation of this structure results in academic genealogy graphs. For the analysis and characterization of these graphs, we present a set of metrics and their corresponding mirror metrics that capture the characteristics of its topological structure and represent them as quantitative attributes. The metrics of fecundity, fertility, descendants, cousins, generations, and relationships consider the descendants of the academics represented in the graph. The mirror metric of these topological metrics considers the ascendancy of academics. Individually, the metrics have strong semantic intuition and define characteristics regarding the performance in the mentoring of an academic. Together, the metrics are useful for the identification, characterization, and classification of communities and their members. The genealogical data available through the platforms of the Mathematics Genealogy Project and the Academic Family Tree were used as case studies. Two hundred thirteen thousand and 675,000 academic records were obtained for each project. We analyze the capacity of characterization of the metrics using the structuring of a similarity graph and through the distribution of the nodes in principal components. We observed that the set of metrics is capable of capturing the configuration pattern existing in genealogy graphs independently of its scale. 相似文献
183.
Self-biases are well described in adults but remain poorly understood in children. Here, we investigated in 6–10 year-old children (N = 132) the self-prioritization effect (SPE), a self-bias which reflects, in adults, the perceptual advantage for stimuli arbitrarily associated with the self as compared to those associated with other persons. We designed a child-friendly adaptation of a paradigm originally introduced in adults by Sui, He, and Humphreys (2012) in order to test whether the SPE also occurs in children and if so, to determine its evolution with age. A robust SPE was obtained from the age of 6, and this effect was similar-sized in our four age groups. These findings are discussed with reference to the development of the self during childhood. 相似文献
184.
中国体育管理体制改革研究述评 总被引:20,自引:0,他引:20
肖林鹏 《西安体育学院学报》2005,22(1):23-26
回顾与总结中国体育管理体制改革研究的基本状况。结果表明,中国体育管理体制改革是内因、外因交互作用的结果。中国体育管理体制改革的最终目标是建立符合中国实际情况的、良性运行的体育管理体制及运行模式。目前中国体育管理体制改革呈现鲜明的过渡型特征。中国体育管理体制改革取得了一定实效,但也存在着某些问题与不足。 相似文献
185.
186.
187.
188.
News use and political discussion are often studied as important factors in understanding the effects of political efficacy on participation. However, measurements of external efficacy often blur distinctions between personal ability and government responsiveness. This study establishes a measure for perceptions of competence in the institutions of democratic government—government efficacy (GE). Drawing on panel survey data from the United States, confirmatory factor analysis introduces GE as a unique construct. Political efficacy dimensions are tested for their impact on news consumption, discussion, and political participation. Results add to the extant literature revolving the role of political efficacy on news use, discussion, and participation. 相似文献
189.
Ricardo?CamposEmail authorView authors OrcID profile Ga?l?Dias Alípio?Mário?Jorge Célia?Nunes 《Information Retrieval》2017,20(4):363-398
Despite a clear improvement of search and retrieval temporal applications, current search engines are still mostly unaware of the temporal dimension. Indeed, in most cases, systems are limited to offering the user the chance to restrict the search to a particular time period or to simply rely on an explicitly specified time span. If the user is not explicit in his/her search intents (e.g., “philip seymour hoffman”) search engines may likely fail to present an overall historic perspective of the topic. In most such cases, they are limited to retrieving the most recent results. One possible solution to this shortcoming is to understand the different time periods of the query. In this context, most state-of-the-art methodologies consider any occurrence of temporal expressions in web documents and other web data as equally relevant to an implicit time sensitive query. To approach this problem in a more adequate manner, we propose in this paper the detection of relevant temporal expressions to the query. Unlike previous metadata and query log-based approaches, we show how to achieve this goal based on information extracted from document content. However, instead of simply focusing on the detection of the most obvious date we are also interested in retrieving the set of dates that are relevant to the query. Towards this goal, we define a general similarity measure that makes use of co-occurrences of words and years based on corpus statistics and a classification methodology that is able to identify the set of top relevant dates for a given implicit time sensitive query, while filtering out the non-relevant ones. Through extensive experimental evaluation, we mean to demonstrate that our approach offers promising results in the field of temporal information retrieval (T-IR), as demonstrated by the experiments conducted over several baselines on web corpora collections. 相似文献
190.
Vanda Correia Pedro Passos Duarte Araújo Keith Davids Ana Diniz J. A. Scott Kelso 《European Journal of Sport Science》2016,16(1):11-19
This study investigated interpersonal coordination tendencies in 1vs.1 dyads in rugby union, here expressed by participants' movement velocity towards or away from the sideline as they competed to score or prevent a try. We examined whether coupling tendencies of members of each dyad shaped key performance outcomes (try or successful tackle). Data on movement displacement trajectories of eight male rugby union players (aged 11–12 years) were analysed during performance in 47 trials. To assess coordination tendencies during exploratory behaviours in the dyads, analyses of performance time series data were undertaken using variable time graphs, running correlations and cross-correlations. Results revealed distinct coupling patterns characterised by shifts between synchronous coordination and asynchronous coordination tendencies and uncoordinated actions. Observed behaviours were interpreted as attempts of competing participants to create and perceive possibilities for action while seeking to achieve specific performance goals. Findings also revealed that a variety of patterned relations between participants resulted in different performance outcomes. 相似文献