基于ANSYS天然气水合物反应釜的有限元分析和优化设计

采用有限元分析软件ANSYS,对天然气水合物反应釜进行了应力计算和分析。在保证其它要求的情况下,以重量最小为优化目标,对其重要尺寸进行了优化设计和计算,得到了最合理的尺寸,达到减小容器总质量、降低成本的目的。这对水合物法储运天然气具有重要意义。     

两种游泳训练方式对大鼠心肌功能的影响

SD大鼠54只，随机分为对照组，高强度无氧间歇训练组，耐力性持续训练组，训练方式为强制游泳，研究长期训练后心肌功能和代谢变化之间的关系，以及长期高强度无氧训练与耐力性有氧训练对心肌的作用及其差异，结果表明，不同的训练方式对心脏的影响不同，耐力训练可促使心肌收缩能力增强，有氧能力提高；长期高强度无氧训练虽然能使心肌无氧能力有所提高，但却由于心脏负荷过重导致心肌收缩能力降低，尤以舒张功能下降出现得较早较明显。     

厌氧折流板反应器的工艺特性及其应用

综合讨论了厌氧折流板反应器(ABR)工艺特征,阐述了国内外关于ABR启动及实际应用的研究现状。认为ABR具有耐冲击负荷、对有毒物质适应性强、固液分离效果好等显著特点。因此,ABR作为一种新型高效生物处理技术,在我国废水处理中,特别是对高浓度有毒工业废水处理具有良好的研究开发价值。     

Investigating the potential of using acoustic frequency on the degradation of linear alkylbenzen sulfonates from aqueous solution

The effectiveness of using acoustical (sonochemical) reactor for degradation of linear alkylbenzen sulfonate (LAS) from aqueous solution was investigated. LASs are anionic surfactants,found in relatively high amounts in domestic and industrial wastewaters. In this study,experiments on LAS solution were performed using methylene blue active substances (MBAS) method. The effectiveness of acoustical processor reactor for LAS degradation is evaluated with emphasis on the effect of treatment time and initial LAS concentration. Experiments were performed at initial concentrations of 0.2,0.5,0.8 and 1.0 mg/L,acoustic fre-quency of 130 kHz,applied power of 500 W and temperature of 18 °C～20 °C. At the conditions involved,LAS degradation was found to increase with increasing sonochemical time. In addition,as the concentration increased,the LAS degradation rate de-creased in the acoustical processor reactor.     

The child and exercise: An overview

In this paper the complex topic of ‘the child and exercise’ is approached from a multidisciplinary angle. Research concerned with effects of exercise on growth and development is reviewed. In spite of traditional beliefs, there is not enough evidence to support the view that regular and intense physical training promotes an increase in body size, nor is there any physiological evidence that severe training has any harmful effect on the body.

Exercise capacity and aerobic power increase gradually throughout childhood. Investigations have shown that children aged 10 years or younger do not react with an increased VO₂ max as one would expect from endurance activities. The trainability of endurance seems to depend on the biological maturity level of growing children. After puberty the effects of endurance training are similar to those reported for adults. Just how much physical activity is necessary or optimal during the growing years is not known because individual variation is great. Even fewer results are available on the trainability of anaerobic capacity. The trainability of other factors such as strength, speed, flexibility and coordination is amply discussed. Finally some thoughts are given to young female athletes, both early and late maturers, with respect to their sport performance and expectancies.     

A comparison of two methods for the calculation of accumulated oxygen deficit

Abstract

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a VO_2peak test and a 115% VO_2peak test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medbø et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P<0.02) than that calculated from the second series: 52.3±11.7 and 43.9±6.4 ml·kg^?1, respectively (mean±s). Other significant differences between the two protocols were observed for VO_2peak, total work and maximal heart rate; all were higher during the modified protocol (P<0.01 and P<0.02, respectively). Oxygen kinetics were also significantly faster during the modified 2 min maximal test. We conclude that the difference in accumulated oxygen deficit between protocols was probably due to a reduced oxygen uptake, possibly caused by a slower oxygen on-response during the 115% VO_2peak test in the first series, and VO₂—power output regression differences caused by an elevated VO ₂ during the early stages of the second series.     

Physiological Profiles of High School Female Cross Country Runners

Abstract

Percent body fat, ratings of perceived exertion and maximal oxygen consumption during a continuous running treadmill test were obtained on 127 high school female cross country runners. These young runners (x 15.6 yrs) were running approximately 25 miles per week at the time of testing. They had an average [Vdot]O₂ max of 50.8 ml · min^-1 and an HR max of 198.0 bpm. The mean percent body fat, as determined from hydrostatic weighing, was 15.4%. The onset of metabolic acidosis was estimated to occur at 78% of [Vdot]O₂ max. A stepwise multiple regression with the 3000 meter run as the dependent variable indicated that max treadmill run time, weight relative [Vdot]O₂ max and [Vdot] max entered the equation in that order, yielding an R of 0.67. Both HR and RPE increased with work intensity, but not at equal rates. These high school female runners had higher [Vdot]O₂ max's than previously reported for this age group; however, they were considerably below these values reported for national caliber distance runners.     

A Methodological Consideration for the Determination of Critical Power and Anaerobic Work Capacity

Abstract

Laboratory research in motor learning has consistently demonstrated higher retention and!or transfer when practice occurs under conditions of high contextual variety (e.g., Lee &; Magill, 1983; Newell &; Shapiro, 1976; Shea of Morgan, 1979;). In the present study, an attempt was made to determine whether a contextual variety effect could be demonstrated in a standard physical education instructional setting. During practice trials on the long and short badminton serves, male and female subjects performed under either blocked (i.e., all trials of one serve followed by all trials of the other) or varied (i.e., alternating trials of long and short serves) conditions. Retention and transfer tests (i.e., using the service area opposite that employed during the practice phase) were administered at the end of the badminton unit. Although little difference was observed in the performance of the two groups during practice, alternating-trial subjects demonstrated significantly higher retention of the short serve and significantly higher transfer of both serves than blocked-trial subjects. The performance of male and female subjects was not differentially influenced by practice structure conditions. It was concluded that a practice schedule that requires performers to change their plan of action from trial to trial may facilitate the retention and transfer of motor skills in applied instructional settings.     

上海市10～18岁女青少年运动员生长发育与15 s无氧功特点及相关性分析

目的：探讨女青少年运动员生长发育与15S无氧功特点及其相关关系．对象和方法：以650名上海市10-18岁女运动员为对象,分别测试身高、体重、体脂率、肌肉量、瘦体重和立定跳远．并采集15S无氧功率自行车的最大功率、平均功率、最大转速、最大转速出现时间等指标,分析其特点及相关性、结果：上海市女青少年运动员身高及体重在10-13岁、最大和平均功率在㈤～15岁增长最快,15岁后趋于稳定,瘦体重、体重和肌肉与功率的相关性依次降低、结论：对女青少年运动员速度力量的训练要在15岁之前,评价女青少年运动员磷酸原代谢能力时最好使用瘦体重相对功率。     

优秀男子花剑运动员无氧代谢能力的特点

目的:通过准确测定与评价个体优秀花剑运动员的无氧代谢能力,为其合理制定体能训练计划提供帮助。方法:以叶冲等4名优秀花剑运动员为研究对象,采用MONAK839E功率自行车,分别进行15s和30s最大用力持续运动的测试。测定最大功率(Pmax)、平均功率(AP)、功率下降速率(PD)、最大圈数(Cmax)、达到最大功率的时间(Pmax-time)、达到最大圈数的时间(Cmax-time)、心率(HR)、血乳酸(BLa)等指标。结论:男子花剑运动员需要较强的磷酸原代谢能力和迅速调动无氧糖酵解代谢供能的能力;而应用MONAK839E功率自行车,根据需要设计不同测试方式测定优秀花剑运动员的无氧代谢能力,可清楚诊断和分析花剑运动员的磷酸原代谢能力和糖酵解代谢能力,为运动员机能状态诊断和制定不同阶段的训练计划提供参考。