The Structuring of Invisibility Among the Hidden Homeless: The Politics of Space, Stigma, and Identity Construction     

Lynn M. Harter  Charlene Berquist  B. Scott Titsworth  David Novak  Tod Brokaw 《Journal of Applied Communication Research》2005,33(4):305-327

This ethnographic portrayal relies on participant observations at two supplemental support programs for youth without homes, narratives collected through in-depth interviews with educators and case managers, and focus group interviews with youth participants to explore the discursive (re)production of invisibility among youth without homes. Structuration theory is used to frame macro and micro forces coalescing to enable and constrain processes of invisibility among the hidden homeless. Analysis reveals how invisibility shapes (and is shaped by) processes of stigmatization, “street smarts” as enacted by youth, and “Mayberry” and “not in my backyard” community discourses, and how the disappearance of youth without homes simultaneously serves and undermines various stakeholders.  相似文献   

The effect of two different interval-training programmes on physiological and performance indices     

Mahmood Sindiani  Alon Eliakim  Daria Segev 《European Journal of Sport Science》2017,17(7):830-837

The aim of the present study was to compare the effect of an increasing-distance, interval-training programme and a decreasing-distance, interval-training programme, matched for total distance, on aerobic and anaerobic physiological indices. Forty physical education students were randomly assigned to either the increasing- or decreasing-distance, interval-training group (ITG and DTG), and completed two similar relevant sets of tests before and after six weeks of training. One training programme consisted of increasing-distance interval-training (100–200–300–400–500?m) and the other decreasing-distance interval training (500–400–300–200–100?m). While both training programmes led to a significant improvement in VO₂ max (ES?=?0.83–1.25), the improvement in the DTG was significantly greater than in the ITG (14.5?±?3.6 vs. 7.8?±?3.2%, p?<?.05). In addition, while both training programmes led to a significant improvement in all anaerobic indices (ES?=?0.83–1.63), the improvements in peak power (15.7?±?7.8 vs. 8.9?±?4.7), mean power (10.6?±?5.4 vs. 6.8?±?4.4), and fatigue index (18.2?±?10.9 vs. 7.0?±?14.2) were significantly greater in the DTG compared to the ITG (p?<?.05). The main finding of the present study was that beyond the significant positive effects of both training programmes on aerobic and anaerobic fitness, the DTG showed significant superiority over the ITG in improving aerobic and anaerobic performance capabilities. Coaches and athletes should therefore be aware that, in spite of identical total work, an interval-training programme might induce different physiological impacts if the order of intervals is not identical.  相似文献   

船舶永磁同步推进电动机的基于滑模变结构的SVM-DTC方法     

范辉  周志丽  汤天浩 《上海海事大学学报》2017,38(2):72-76

为解决船舶电力推进系统在螺旋桨负载受到风浪干扰时的稳定性问题,采用永磁同步电动机(Permanent Magnet Synchronous Motor,PMSM)作为推进电动机,在空间矢量调制(Space Vector Modulation,SVM)方法和直接转矩控制(Direct Torque Control,DTC)方法的基础上,提出一种基于滑模变结构的SVM-DTC方法.通过Simulink搭建模型进行船舶工况仿真,对推进电动机的转速和电磁转矩进行分析.仿真结果表明采用滑模控制的船舶电力推进系统具有很好的静态、动态特性和鲁棒性.  相似文献   

High-intensity interval training programme for obese youth (HIP4YOUTH): A pilot feasibility study     

SoJung Lee  Jenna Spector  Stephanie Reilly 《Journal of sports sciences》2017,35(18):1794-1798

Recently, there has been growing interest in high-intensity interval training (HIT) as a strategy to improve health. In this pilot study, we examined the feasibility of a 4-week low-volume HIT and its effects on cardiorespiratory fitness (CRF), blood pressure (BP) and enjoyment in overweight and obese youth. Twelve adolescents (body mass index (BMI): 34.8 ± 3.9 kg · m^?2, 14.9 ± 1.5 years) participated in 12 sessions of HIT (10 × 60 s cycling bouts eliciting ~90% maximal heart rate, interspersed with 90 s recovery, 30 min/session, 3 sessions/week) over ~4 weeks. All the participants completed the study and exercise attendance averaged 92%. Despite no changes in body weight and total fat, HIT resulted in significant (P < 0.01) increases in CRF (pre: 20.1 versus post: 22.2 ml · kg^?1 · min^?1) and exercise time (pre: 425 versus post: 509 s) during peak oxygen uptake test, and a reduction in resting systolic BP (pre: 115.8 versus post: 107.6 mmHg). The majority of study participants (83%) enjoyed HIT and more than half of the participants (58%) reported that HIT is a more enjoyable form of exercise compared to other types of exercises. Low-volume HIT is a useful strategy to promote exercise participation and improve cardiovascular health in overweight and obese youth.  相似文献   

间歇性低氧训练对大鼠血清T、C和LH的影响     

王林  张云丽 《辽宁体育科技》2009,31(3):39-41

采用实验法观察间歇性低氧训练对大鼠血清睾酮（T）、皮质醇（C）、T／C比值和黄体生成素（LH）的影响,结果表明：间歇性低氧训练比游泳训练更能促使血清T、T／C比值和血清LH水平的提高,而使C下降更为明显,从而保持高睾酮低皮质醇水平;间歇性低氧训练比游泳训练对大鼠血清激素有更大的影响,暗示其更有利于提高大鼠的运动能力。  相似文献   

非紧L—凸度量空间中极大极小不等式的解集性质及其应用     

文开庭  余廷忠  夏仁强 《毕节学院学报》2011,29(4):27-36

研究了非紧完备L—凸度量空间中极大极小不等式的解集的性质,作为应用,进一步研究了非紧L—凸度量空间中极大元集、鞍点集、Ky Fan截口和相交点集的性质,获得了非紧L—凸度量空间中的Fan—Browder型不动点定理。  相似文献   

李白《蜀道难》时空解读   总被引：1，自引：0，他引：1  

张红运  铁丽芳 《天中学刊》2001,16(4):42-44

李白《蜀道难》一诗自面世以来，不仅给诗人带来了极高的声誉，而且引起了历代诗评者的极大关注。要真正解读该诗意境和结构方面的佳境妙笔，必须准确把握时间、空间意象在其中所起的作用。唯其如此，方能透析。  相似文献   

基于因素计点法和IAHP的企业管理类岗位价值评价   总被引：2，自引：0，他引：2  

陈丽芬  江卫东 《软科学》2011,25(4):100-105

系统地阐述了如何提取有效的薪酬要素,构建了企业管理类岗位价值评价递阶层次结构模型;提出了基于因素计点法和区间层次分析法(IAHP)的管理类岗位价值评价方法;用区间数代替传统层次分析法判断矩阵中的点值,合理地解决了薪酬要素两两比较结果的不确定性和模糊性问题,提高了岗位评价结果的可信度;运用实例,展示了基于因素计点法和IAHP的岗位价值评价的具体操作过程。  相似文献   

武术训练强度和密度的生化分析     

韩旭升 《体育科技文献通报》2007,15(9):122-123

文章从武术训练强度和密度方面进行生化分析,认为间歇训练是提高武术运动员专项能力的有效手段和方法,它可造成运动员训练时体内血乳酸的逐步积累,而且有助于提高运动员体内CP的含量,进一步提高无氧代谢能力。在武术运动训练和教学时,应以生化指标为科学依据,根据武术运动供能的特点进行训练,从而提高运动成绩和教学质量。  相似文献   

血乳酸在自行车训练监控中的应用   总被引：2，自引：0，他引：2  

连建华 《山东体育科技》2004,26(3):41-42

依据项目的供能特点，结合实验数据的分析，提出了血乳酸在山地自行车爬坡间歇训练、自行车50公里团体项目的有氧训练、场地自行车的速度耐力训练中的应用方法。  相似文献