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   4498篇
  免费   57篇
  国内免费   10篇
教育   3362篇
科学研究   236篇
各国文化   43篇
体育   404篇
综合类   3篇
文化理论   62篇
信息传播   455篇
  2022年   22篇
  2021年   43篇
  2020年   59篇
  2019年   112篇
  2018年   141篇
  2017年   151篇
  2016年   146篇
  2015年   99篇
  2014年   118篇
  2013年   936篇
  2012年   131篇
  2011年   128篇
  2010年   149篇
  2009年   135篇
  2008年   146篇
  2007年   144篇
  2006年   108篇
  2005年   95篇
  2004年   99篇
  2003年   81篇
  2002年   96篇
  2001年   66篇
  2000年   107篇
  1999年   74篇
  1998年   74篇
  1997年   63篇
  1996年   65篇
  1995年   52篇
  1994年   63篇
  1993年   59篇
  1992年   44篇
  1991年   68篇
  1990年   51篇
  1989年   44篇
  1988年   36篇
  1987年   45篇
  1986年   44篇
  1985年   42篇
  1984年   47篇
  1983年   37篇
  1982年   31篇
  1981年   33篇
  1980年   29篇
  1979年   22篇
  1978年   29篇
  1977年   36篇
  1976年   27篇
  1975年   20篇
  1974年   22篇
  1971年   12篇
排序方式: 共有4565条查询结果,搜索用时 437 毫秒
41.
In 2013, The Better Image (TBI) was contacted to examine A Play of Selves, a unique work created by artist Cindy Sherman during her graduate studies in 1975. The work is composed of 244 paper doll-like photographs of Sherman that are presented within 72 frames. During initial condition checks, it was noted that a number of individual elements had begun to show signs of chemical staining. Over the course of 2013/2014, a collaborative response was developed with the help of the artist, the artist's printer, the representing gallery, TBI staff and the owner. The main goal was to address the physical and chemical issues present and preserve this work for future exhibition and study. Determining an effective decision- making model based on a hierarchy of values was crucial before undertaking any conservation treatment, as there were several invested parties, each with a different perspective. The focus of this paper is the interplay of our responsibilities as conservators with the concerns of the artist, her gallery, her printer, and the owner to balance aesthetic vs. physical integrity of the artwork, reversibility of treatments, importance of record keeping while developing a balanced response within a world of rapidly disappearing traditional photographic papers.  相似文献   
42.
43.
The purpose of this study was to analyse the effect of bike type – the 26-inch-wheel bike (26“ bike) and the 29-inch-wheel bike (29“ bike) – on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recovery between trials (three trials on a 26“ bike and three trials on a 29“ bike, alternate order, randomised start-bike). The course consisted of two separate sections expected to favour either the 29“ bike (section A) or the 26“ bike (section B). For each trial performance, power output, cadence and heart rate were recorded and athletes’ experiences were documented. Mean overall performance (time: 304 ± 27 s vs. 311 ± 29 s; P < 0.01) and performance in sections A (P < 0.001) and B (P < 0.05) were better when using the 29“ bike. No significant differences were observed for power output, cadence or heart rate. Athletes rated the 29“ bike as better for performance in general, passing obstacles and traction. The 29“ bike supports superior performance for elite mountain bikers, even on sections supposed to favour the 26“ bike.  相似文献   
44.
Abstract

Physical exercise, beyond the mere physical aspect, is very much a social construct. But it is as well a means of constructing the social and as such it can be used in different ways. The contribution, taking a broad comparative perspective, will reflect on two major possibilities: the one may be called social inclusion as subordination and the other can be looked at as a matter of social inclusion by strengthening individuals. This also allows an understanding of new dangers of exclusion in the era of liquid modernity.  相似文献   
45.
Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling.  相似文献   
46.
This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F2-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response.  相似文献   
47.
Purpose: The purpose of this study was to investigate whether loads carried in a backpack, with a load mass ranging from 0 to 20?kg, causes respiratory muscle fatigue. Methods: Eight males performed four randomised load carriage (LC) trials comprising 60?min walking at 6.5?km?h?1 wearing a backpack of either 0 (LC0), 10 (LC10), 15 (LC15) or 20?kg (LC20). Inspiratory (PImax) and expiratory (PEmax) mouth pressures were assessed prior to and immediately following each trial. Pulmonary gas exchange, heart rate (HR), blood lactate and glucose concentration and perceptual responses were recorded during the first and final 60?s of each trial. Results: Group mean PImax and PEmax were unchanged following 60-min load carriage in all conditions (p?>?.05). There was an increase over time in pulmonary gas exchange, HR and perceptions of effort relative to baseline measures during each trial (p?p?>?.05). Conclusions: These findings indicate that sub-maximal walking with no load or carrying 10, 15 or 20?kg in a backpack for up to 60?min does not cause respiratory muscle fatigue despite causing an increase in physiological, metabolic and perceptual parameters.  相似文献   
48.
Peter Colenso 《Compare》2005,35(4):411-428
There is increasing interest in understanding and describing the links between education and ‘social cohesion’. However, the theoretical and empirical base for understanding these links is limited. There is also a shortage of practical tools for education policy‐makers and planners, to help them assess the impact of policies and investments, and to plan for future reform. This paper describes the initial development of an analytical and planning framework for addressing education and social cohesion within the context of a sector‐wide approach to education reform in Sri Lanka. A brief literature review suggests three inter‐connected domains in which links between education and social cohesion might be usefully analysed, together with three working hypotheses: (i) political economy/governance: education affects social cohesion through transparency and participation in education policy formulation, planning and management; (ii) equity/equality of opportunity: education affects social cohesion through the distribution of education resources, opportunities and outcomes; (iii) teaching/learning: education affects social cohesion through the development of certain competencies in students. Drawing on this analytical framework, research conducted in Sri Lanka is used to identify a set of interventions to promote social cohesion, with corresponding baseline, process and outcome indicators as benchmarks for measuring the progress and impact of intended policy measures. This process is described within the context of a ‘sector‐wide approach’ to education reform, intended to bring together the activities of the government and external partners within a single comprehensive medium‐term planning and budgetary framework.  相似文献   
49.

The present article gives an outline of the state of art in computer assisted intervention by learning-concomitant differential feedback. Based on the spectrum of possible meanings and interpretations given to the concepts ‘interaction’ and ‘interactive’ this concept is elaborated and illustrated by prototypical theoretical approaches. Based on our own empirical findings arguments are given showing that sophisticated audiovisual interactive new technologies can properly be used even on the small machines available in schools if the content materials and the flow of control given to the learner are carefully designed and based on principles of cognitive science.

  相似文献   
50.
In this part of the series on butterflies, we look at the types of variations found within species as well as their causes.  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