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   156篇
  免费   3篇
教育   92篇
科学研究   4篇
各国文化   2篇
体育   38篇
文化理论   7篇
信息传播   16篇
  2022年   6篇
  2021年   5篇
  2020年   10篇
  2019年   19篇
  2018年   12篇
  2017年   20篇
  2016年   17篇
  2015年   2篇
  2014年   5篇
  2013年   20篇
  2011年   6篇
  2010年   1篇
  2009年   5篇
  2008年   5篇
  2007年   1篇
  2006年   2篇
  2005年   3篇
  2004年   5篇
  2003年   3篇
  2002年   1篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1992年   1篇
  1989年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
排序方式: 共有159条查询结果,搜索用时 796 毫秒
1.
2.
This study aimed to explore the strength of the force–velocity (FV) relationship of lower limb muscles and the reliability of its parameters (maximum force [F0], slope [a], maximum velocity [V0], and maximum power [P0]). Twenty-three men were tested in two different jump types (squat and countermovement jump: SJ and CMJ), performed under two different loading conditions (free weight and Smith machine: Free and Smith) with 0, 17, 30, 45, 60, and 75?kg loads. The maximum and averaged values of F and V were obtained for the FV relationship modelling. All FV relationships were strong and linear independently whether observed from the averaged across the participants (r?≥?0.98) or individual data (r?=?0.94–0.98), while their parameters were generally highly reliable (F0 [CV: 4.85%, ICC: 0.87], V0 [CV: 6.10%, ICC: 0.82], a [CV: 10.5%, ICC: 0.81], and P0 [CV: 3.5%, ICC: 0.93]). Both the strength of the FV relationships and the reliability of their parameters were significantly higher for (1) the CMJ over the SJ, (2) the Free over the Smith loading type, and (3) the maximum over the averaged F and V variables. In conclusion, although the FV relationships obtained from all the jumps tested were linear and generally highly reliable, the less appropriate choice for testing the FV relationship could be through the averaged F and V data obtained from the SJ performed either in a Free weight or in a Smith machine. Insubstantial differences exist among the other combinations tested.  相似文献   
3.
Environmental policy increasingly resorts to market-based instruments in order to meet sustainability objectives. The ‘carbon market’ instituted by the European Emissions Trading directive from 2003 is a canonical example, which has been described, and critiqued, as a delegation of policy objectives to market exchanges. In this paper, we examine the complex ways in which the operationalization of policy objectives and the organization of markets are intertwined, focusing on two other examples of European environmental regulation. The first one is the Integrated Pollution Prevention and Control directive from 1996, which defined the ‘best available techniques’ to curb emissions in air, water and soil. The second one is the Renewable Energy Directive from 2009, which introduced criteria for the definition of the sustainability of biofuels. Through the analysis of the design and implementation of these two directives, we identify a central concern for the coexistence of various objects, and various initiatives undertaken by European institutions, member states and private actors. We use the notion of coexistence to describe a European political and economic ordering that is inherently hybrid, and cannot be reduced to a mere delegation of policy objectives to the market, or a legal constraint imposed on all European actors. It grounds its political legitimacy and economic rationality on the distribution of roles and responsibilities across public and private actors, and on the ability to ‘keep things different’ according to local variabilities.  相似文献   
4.

Eight gifted and eight general‐education students engaged in discussions regarding their observations of, experiences in, and recommendations for education. Six categories emerged through qualitative analysis of their conversations. These categories include: problem solving, task commitment, self‐perceptions, education, communication, and discrimination. Content within each category provides a glimpse into the students’ perceptions of their schooling experiences. The roles of ethnic identity development, identification with majority culture, adolescence, and gifted‐ness are examined and recommendations for future research are provided.  相似文献   
5.
The combined effects of pH and temperature on red pigment production and fungal morphology were evaluated in a submerged culture of Penicillium purpurogenum GH2, using Czapek-Dox media with d-xylose as a carbon source. An experimental design with a factorial fix was used: three pH values (5, 7, and 9) and two temperature levels (24 and 34 °C) were evaluated. The highest production of red pigment (2.46 g/L) was reached with a pH value of 5 and a temperature of 24 °C. Biomass and red pigment production were not directly associated. This study demonstrates that P. purpurogenum GH2 produces a pigment of potential interest to the food industry. It also shows the feasibility of producing and obtaining natural water-soluble pigments for potential use in food industries. A strong combined effect (p<0.05) of pH and temperature was associated with maximal red pigment production (2.46 g/L).  相似文献   
6.
7.
8.
The purpose of this study was to investigate the relationship between the cable force and linear hammer speed in the hammer throw and to identify how the magnitude and direction of the cable force affects the fluctuations in linear hammer speed. Five male (height: 1.88 +/- 0.06 m; body mass: 106.23 +/- 4.83 kg) and five female (height: 1.69 +/- 0.05 m; body mass: 101.60 +/- 20.92 kg) throwers participated and were required to perform 10 throws each. The hammer's linear velocity and the cable force and its tangential component were calculated via hammer head positional data. As expected, a strong correlation was observed between decreases in the linear hammer speed and decreases in the cable force (normalised for hammer weight). A strong correlation was also found to exist between the angle by which the cable force lags the radius of rotation at its maximum (when tangential force is at its most negative) and the size of the decreases in hammer speed. These findings indicate that the most effective way to minimise the effect of the negative tangential force is to reduce the size of the lag angle.  相似文献   
9.
Societal response to climate change has been inadequate. A perception that the issue is both physically and temporally remote may reduce concern; concern may also be affected by the political polarization surrounding the issue in the USA. A feeling of connection to nature or to animals may increase personal relevance, and a supportive social context may counteract political tensions. Zoos may provide opportunities for both sense of connection and social support. We surveyed over 7000 zoo and aquarium visitors to examine the ways in which a feeling of personal connection among zoo visitors may encourage concern about climate change. Results show that feeling connected to animals at the zoo is significantly associated with cognitive and emotional responses to climate change, as well as with other social groupings and social responses. Overall, the zoo seems to present a supportive social context for considering the topic.  相似文献   
10.
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