全文获取类型
收费全文 | 70篇 |
免费 | 1篇 |
专业分类
教育 | 32篇 |
科学研究 | 7篇 |
体育 | 15篇 |
文化理论 | 1篇 |
信息传播 | 16篇 |
出版年
2022年 | 1篇 |
2019年 | 4篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 18篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 1篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1964年 | 1篇 |
1872年 | 1篇 |
1871年 | 1篇 |
排序方式: 共有71条查询结果,搜索用时 15 毫秒
61.
62.
A comparison of the physiological response to simulated altitude exposure and r-HuEpo administration
Michael J. Ashenden Allan G. Hahn David T. Martin Peter Logan Robin Parisotto Christopher J. Gore 《Journal of sports sciences》2013,31(11):831-837
Concerns have been raised about the morality of using simulated altitude facilities in an attempt to improve athletic performance. One assumption that has been influential in this debate is the belief that altitude houses simply mimic the physiological effects of illegal recombinant human erythropoietin (r-HuEpo) doping. To test the validity of this assumption, the haematological and physiological responses of 23 well-trained athletes exposed to a simulated altitude of 2650-3000 m for 11-23 nights were contrasted with those of healthy volunteers receiving a low dose (150 IU·kg-1 per week) of r-HuEpo for 25 days. Serial blood samples were analysed for serum erythropoietin and percent reticulocytes; maximal oxygen uptake ([Vdot]O2max) was assessed before and after r-HuEpo administration or simulated altitude exposure. The group mean increase in serum erythropoietin (422% for r-HuEpo vs 59% for simulated altitude), percent reticulocytes (89% vs 30%) and [Vdot]O2max (6.6% vs -2.0%) indicated that simulated altitude did not induce the changes obtained with r-HuEpo administration. Based on the disparity of these responses, we conclude that simulated altitude facilities should not be considered unethical based solely on the tenet that they provide an alternative means of obtaining the benefits sought by illegal r-HuEpo doping. 相似文献
63.
Joshua R. Allen Timothy J. Mccue Jason J. Borger Michael E. Hahn 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):38-53
Fly-fishing is a popular form of recreation. Recent evidence has associated overhand fly-casting movements with upper extremity pain. However, little research exists on the motions and coordination common to fly-casting. The aim of this study was to establish upper extremity kinematic trends of fly-casting while casting greater line lengths. It was hypothesized that kinematic casting parameters would increase and time between peak angular velocities would decrease with greater line length. Eighteen males participated in the study. Three-dimensional motion capture was conducted to calculate shoulder, elbow, and wrist kinematics during casting conditions of 6.1, 12.2, 18.3, and 24.4 m of line. Multiple analyses of variance were used to assess the condition effect of line length on the kinematic variables (P = 0.05). Overall, total range of movement increased with increasing length of line cast. Peak angular velocity exhibited a proximal-to-distal trend: peak shoulder internal rotation followed by elbow extension, then wrist ulnar deviation. Time between peak shoulder and elbow angular velocities increased significantly as line length increased. Our findings indicate that specific changes in total range of movement accommodate the demands of casting greater lengths of line. Also, joint velocity coordination patterns of fly-casting appear to follow a proximal-to-distal pattern. These findings represent an initial foundation for connections between kinematics and upper extremity pain reported by fly-fisherman. 相似文献
64.
65.
66.
67.
The aims of this study were to compare the physiological and anthropometric characteristics of successful mountain bikers and professional road cyclists and to re-examine the power-to-weight characteristics of internationally competitive mountain bikers. Internationally competitive cyclists (seven mountain bikers and seven road cyclists) completed the following tests: anthropometric measurements, an incremental cycle ergometer test and a 30 min laboratory time-trial. The mountain bikers were lighter (65.3+/-6.5 vs 74.7+/-3.8 kg, P= 0.01; mean +/- s) and leaner than the road cyclists (sum of seven skinfolds: 33.9+/-5.7 vs 44.5+/-10.8 mm, P = 0.04). The mountain bikers produced higher power outputs relative to body mass at maximal exercise (6.3+/-0.5 vs 5.8+/-0.3 W x kg(-1), P= 0.03), at the lactate threshold (5.2+/-0.6 vs 4.7+/-0.3 W x kg(-1), P= 0.048) and during the 30 min time-trial (5.5+/-0.5 vs 4.9+/-0.3 W x kg(-1), P = 0.02). Similarly, peak oxygen uptake relative tobody mass was higher in the mountain bikers (78.3+/-4.4 vs 73.0+/-3.4 ml x kg(-1) x min(-1), P = 0.03). The results indicate that high power-to-weight characteristics are important for success in mountain biking. The mountain bikers possessed similar anthropometric and physiological characteristics to previously studied road cycling uphill specialists. 相似文献
68.
The majority of the objects found in the textiles collection at the German Historical Museum in Berlin have been treated with different biocides at various points in the past. Prior to this study, the presence of organochlorinated pesticides in rooms and storage cabinets had already been proven in an analysis of air samples that employed gas chromatography and mass spectroscopy. To estimate the risks these toxins pose to both collections and museum staff, we conducted a field study with the help of a portable X-ray fluorescence spectrometer. In this study, we present an attempt at a reliable quantitative analysis. In addition to chlorine, other potentially hazardous elements such as lead, arsenic, and mercury were found in the majority of the objects. In some cases, however, it has to be taken into account that the detected elements might have originated from manufacturing processes rather than biocide treatments. Such knowledge is a crucial prerequisite to proper risk prediction. 相似文献
69.
This paper describes a new and facile approach for the formation of pore-spanning bilayer lipid membranes (BLMs) within a poly(dimethylsiloxane) (PDMS) microfluidic device. Commercially, readily available polycarbonate (PC) membranes are employed for the support of BLMs. PC sheets with 5 μm, 2 μm, and 0.4 μm pore diameters, respectively, are thermally bonded into a multilayer-stack, reducing the pore density of 0.4 μm-pore PC by a factor of 200. The BLMs on this support are considerably stable (a mean lifetime: 17 h). This multilayer-stack PC (MSPC) membrane is integrated into the PDMS chip by an epoxy bonding method developed to secure durable bonding under the use of organic solvents. The microchip has a special channel for guiding a micropipette in the proximity of the MSPC support. With this on-site injection technique, tens to hundreds of nanoliters of solutions can be directly dispensed to the support. Incorporating gramicidin ion channels into BLMs on the MSPC support has confirmed the formation of single BLMs, which is based on the observation from current signals of 20 pS conductance that is typical to single channel opening. Based on the bilayer capacitance (1.4 pF), about 15% of through pores across the MSPC membrane are estimated to be covered with BLMs. 相似文献
70.
This article investigates strategies for internationalisation at technical universities in the Nordic countries. The study explores the institutional rationales for internationalisation, the stories told in the strategy documents, the importance of leaders, faculty, administration and students for implementation of the strategy, and barriers and key components of successful internationalisation. We studied the strategic work with internationalisation across 27 technical universities in Denmark, Finland, Iceland, Norway and Sweden. This work reflects both global trends of competition and the traditional Nordic model of cooperation. Overall, the universities incorporated internationalisation in their strategies in order to increase quality in research and education, and to establish strategic partnerships and networks. There is a shift in rationales from a more traditional approach of internationalisation to a new integrated form. 相似文献