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991.
大学生压力问题是当前高校关注的重点问题。本研究运用《大学生压力测评问卷》,对692名北京高校在读大学生进行调查,结果发现:1)大学生的整体压力感介于“有点压力”和“中度压力”之间:其中,人际压力最小,前途压力最大;2)非运动群体大学生在整体压力感、人际、学业、经济、前途和个人日常压力上得分也均显著高于运动群体大学生;3)女大学生压力偏高,但总的来说,男女大学生压力差异不显著;4)大四学生的压力相对较大,大一、大二的压力相对较小。  相似文献   
992.
高校学生党支部是党在高校的基层组织,当代大学生的培养是关系国家命运的伟大工程,做好高校学生党支部建设对提高学生思想政治理论水平,促进良好学风、班风,具有重要作用.文中通过分析目前高校学生党支部建设现状,探寻高校学生党支部建设和作用发挥的途径.  相似文献   
993.
为有效控制裂缝的产生,文章从力学角度出发,分析了提高各龄期混凝土的弹性模量和降低温差混凝土的强度。混凝土温度收缩应力在大体积混凝土施工中,由于水泥水化热引起混凝土浇注内部温度和温度应力剧烈变化,由此而产生的温度应力是导致混凝土产生裂缝的原因。  相似文献   
994.
Abstract

The purpose of this study was to compare moment-to-moment appraisals and coping strategies of 4 non-elite and 2 elite male trap shooters during competitions and in particular during periods of competition perceived as critical to performance. Appraisals and coping patterns of trap shooters were captured via verbal reports of thinking provided between sets of shots during major competitions. Verbal reports were coded according to an appraisal and coping typology. Coded data as well as shooting performance data were subjected to a sequential analysis of probabilities of pairs of events. Fewer reports of negative appraisals (NEGAs) and more frequent reports of problem-focused coping (PFC) were observed among both elite athletes compared to non-elite athletes. After making a NEGA, non-elite shooters often progressed to the next target without attempting to cope, whereas elite shooters used both PFC and emotion-focused coping (EFC) before proceeding to the next target. After missing a target, the non-elite athletes used more EFC than expected. These results indicate that elite athletes are more likely to cope with NEGAs than non-elite athletes using a wider variety of coping strategies. Athletes might benefit from increased awareness of the potentially detrimental impact of NEGAs on performance and by integrating coping strategies within preparatory routines.  相似文献   
995.
996.
Abstract

The present study was designed to examine physiological responses during motocross riding. Nine Finnish A-level motocross riders performed a 15-min ride at a motocross track and a test of maximal oxygen uptake ([Vdot]O2max) in the laboratory. Cardiopulmonary strain was measured continuously during the ride as well as in the [Vdot]O2max test. During the ride, mean [Vdot]O2 was 32 ml · kg?1 · min?1 (s = 4), which was 71% (s = 12) of maximum, while ventilation (V E) was 73% (s = 15) of its maximum. The relative [Vdot]O2 and V E values during the riding correlated with successful riding performance (r = 0.80, P < 0.01 and r = 0.79, P < 0.01, respectively). Mean heart rate was maintained at 95% (s = 7) of its maximum. Mean blood lactate concentration was 5.0 mmol · l?1 (s = 2.0) after the ride. A reduction of 16% (P < 0.001) in maximal isometric handgrip force was observed. In conclusion, motocross causes riders great physical stress. Both aerobic and anaerobic metabolism is required for the isometric and dynamic muscle actions experienced during a ride.  相似文献   
997.
Abstract

Thirty-six male rats were used; divided into 6 groups (n = 6): saline; creatine (Cr); eccentric exercise (EE) plus saline 24 h (saline + 24 h); eccentric exercise plus Cr 24 h (Cr + 24 h); eccentric exercise plus saline 48 h (saline + 48 h); and eccentric exercise plus Cr 48 h (Cr + 48h). Cr supplementation was administered as a solution of 300 mg · kg body weight?1 · day?1 in 1 mL water, for two weeks, before the eccentric exercise. The animals were submitted to one downhill run session at 1.0 km · h?1 until exhaustion. Twenty-four and forty-eight hours after the exercise, the animals were killed, and the quadriceps were removed. Creatine kinase levels, superoxide production, thiobarbituric acid reactive substances (TBARS) level, carbonyl content, total thiol content, superoxide dismutase, catalase, glutathione peroxidase, interleukin-1b (IL-1β), nuclear factor kappa B (NF-kb), and tumour necrosis factor (TNF) were analysed. Cr supplementation neither decreases Cr kinase, superoxide production, lipoperoxidation, carbonylation, total thiol, IL-1β, NF-kb, or TNF nor alters the enzyme activity of superoxide dismutase, catalase, and glutathione peroxides in relation to the saline group, respectively (P < 0.05). There are positive correlations between Cr kinase and TBARS and TNF-α 48 hours after eccentric exercise. The present study suggests that Cr supplementation does not decrease oxidative stress and inflammation after eccentric contraction.  相似文献   
998.
Abstract

This study examined Easterbrook's (1959) hypothesis that performance on a primary task would improve or at least be maintained with increased levels of arousal, while performance on a secondary task would decrease. To test this hypothesis, the performance of 20 collegiate rifle shooters (10 experienced, 10 inexperienced) on a primary target shooting task and a secondary auditory task were compared while shooting under low- and high-time stress conditions. Heart rate results, but not a self-report anxiety measure, provided evidence for the effectiveness of the stress manipulation. The results primarily supported Easterbrook's hypothesis. There were no differences in secondary task performance between experienced and inexperienced shooters. However, subjects who first underwent high time stress followed by low (H-L) shot better than those given the reverse order (L-H). These findings are discussed in relation to the attention demands of self-paced sports as well as the transfer effects of stress.  相似文献   
999.
Abstract

Researchers have postulated that hope may be an important factor associated with burnout. Consistent with hope theory contentions, low-hope individuals may be susceptible to burnout because they are prone to experience goal blockage, frustration, and negative affect, all of which likely increase the risk of burnout. We examined the relationship between hope and athlete burnout among 178 competitive athletes (63 females and 115 males) aged 15–20 years. Hope was significantly and negatively correlated with all three burnout subscales: emotional/physical exhaustion, a reduced sense of accomplishment, and sport devaluation. Moreover, results of a multivariate analysis of variance showed that low-hope athletes scored significantly higher than medium- and high-hope athletes on all three burnout dimensions. Finally, results revealed that agency thinking was a significant predictor of all burnout dimensions. Frustration over unmet goals and a perceived lack of agency, a characteristic of low-hope athletes, might pose a risk factor in athlete burnout, whereas being able to maintain hope appears to be associated with health and well-being.  相似文献   
1000.
Abstract

The primary purpose of this study was to assess perceived and experienced role conflict of high school female athletes in enacting the roles of female and female athlete. Data were collected on 133 high school varsity athletes by the use of a 33-item questionnaire designed to assess perceived and experienced role conflicts of the subjects, their socioeconomic backgrounds, and specific instances of encouragement or discouragement from significant others experienced during their athletic careers. Thirty-two percent of the subjects responded that they perceived little or no problem with role conflict, and 50% had experienced little or no role conflict. Seventeen percent of the subjects responded that they perceived role conflict to be a great or very great problem with 11% experiencing role conflict to the same degree. A chi square analysis of perceived and experienced role conflict computed for the entire group of subjects indicated that the athletes perceived greater role conflict than they had experienced (p<.01). A one way analysis of variance was performed comparing the means of the athletes in traditionally socially approved sports, those in non-traditionally socially approved sports, and those participating in both categories. Results indicated a tendency for those participating simultaneously in both socially approved and non-socially approved sports to have experienced more role conflict (p≤.07).

A distinction between internal and external role conflict was suggested as a method of understanding the different types of pressures with which the female athlete must deal.  相似文献   
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