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101.
Takayoshi Yoshida Yoshiyuki Fukuoka Richard L. Hughson 《Measurement in physical education and exercise science》2013,17(1):1-9
We examined whether the system analysis for step and pseudorandom binary sequence (PRBS) exercises could be useful to characterize oxygen uptake (VO2) kinetics of female sedentary subjects and endurance athletes. Breath-by-breath VO2 was determined during step- and PRBS-cycle ergometer exercises. The time course of the VO2 kinetics was evaluated by the time constant of the second phase, which should reflect the adjustment of the oxidative metabolism at the skeletal muscle level. The VO2 kinetics were significantly faster in long-distance runners than in sedentary subjects for both exercises. A significant relationship was observed in the VO2 kinetics obtained from step and PRBS exercises. In each group, there was no significant difference in the VO2 kinetics for step and PRBS exercises. These results indicated that the system analysis with PRBS exercises revealed the faster VO2 kinetics in endurance athletes than in sedentary subjects. 相似文献
102.
John Blackwell Duane Knudson 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):187-191
This study investigated the effect of the larger diameter (Type 3) tennis ball on performance and muscle activation in the serve. Sixteen male advanced tennis players performed serves using regular size and Type 3 tennis balls. Ball speed, surface electromyography, and serve accuracy were measured. There were no significant differences in mean initial serve speeds between balls, but accuracy was significantly greater (19.3%) with the Type 3 ball than with the regular ball. A consistent temporal sequence of muscle activation and significant differences in mean activation of different muscles were observed. However, ball type had no effect on mean arm muscle activation. These data, combined with a previous study, suggest that play with the larger ball is not likely to increase the risk of overuse injury, but serving accuracy may increase compared to play with the regular ball. 相似文献
103.
根据铁对过氧化氢氧化酸性铬蓝 K有强烈的催化作用 ,并使之褪色明显的特性 ,研究了最佳实验条件和动力学参数 ,建立了测定痕量铁的新方法。 相似文献
104.
105.
Assessing the Higher National Diploma Chemical Engineering programme in Ghana: students’ perspective
Cyril D. Boateng Edem Cudjoe Bensah Julius C. Ahiekpor 《European Journal of Engineering Education》2012,37(2):205-215
Chemical engineers have played key roles in the growth of the chemical and allied industries in Ghana but indigenous industries that have traditionally been the domain of the informal sector need to be migrated to the formal sector through the entrepreneurship and innovation of chemical engineers. The Higher National Diploma Chemical Engineering programme is being migrated from a subject-based to a competency-based curriculum. This paper evaluates the programme from the point of view of students. Data were drawn from a survey conducted in the department and were analysed using SPSS. The survey involved administering questionnaires to students at all levels in the department. Analysis of the responses indicated that the majority of the students had decided to pursue chemical engineering due to the career opportunities available. Their knowledge of the programme learning outcomes was, however, poor. The study revealed that none of the students was interested in developing indigenous industries. 相似文献
106.
本文分析了目前毕业实习(论文)存在的问题,提出了毕业论文(设计)实施产学研互动教学模式的可行性,介绍了实施这种教学模式的几种方式、采取的措施和获得的成效,并对进一步实施产学研互动教学模式提出了几点设想。 相似文献
107.
用TG-DTG(热重-微分热重)联用技术研究了氨茶碱片剂在氮气气氛中的热分解行为。首先运用普适法Kissinger和Ozawa法计算了氨茶碱片剂的表观活化能E和指前因子lnA,然后运用一般积分法Coats-Redfern法和Satava-Sestak法推测了主分解阶段的最佳热分解机理,推测出热分解机理为相边界反应,求出了热分解反应的表观活化能和指前因子。几种方法求得的表观活化能和指前因子的平均值分别为113.933KJ/mol,lnA为22.101(1/min).用malek法对所得结果进行了验证,进一步证明所得动力学参数和机理函数的正确性。 相似文献
108.
Chemical and isotope characterization of lead finds at the Santa Barbara nuraghe (Bauladu, Sardinia)
Twenty lead finds, unearthed in Late Bronze–Early Iron Age levels at the Santa Barbara nuraghe situated at Bauladu in Sardinia (Italy), have been examined. Their chemical composition has been determined using the ICP-MS plasma-mass technique (Cu, Fe, As, Ag, Sn, Sb, Bi, Zn, Cs, Tl, Mo, Cd, In, Te, W, Th, U, Li, Se). Lead isotope ratios (208/206, 207/206, 206/204) have also been determined. The results are discussed in relation to the mineral source and some aspects of the metal extraction processes. The finds are composed of high purity lead obtained using a smelting at low temperature. Based on the isotope ratios it has been possible to establish that the metal originated from Sardinian ore deposits type. 相似文献
109.
Xiao-jing Zhao Zhuo Pen Ping Li Er-xiu Chen Jian Liu Yan-xia Gao Yun-xia Ren Li-jun Li 《Journal of Zhejiang University. Science. B》2013,14(6):505-510
Objective
We investigated the influence of β-receptor blocker metoprolol on return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR) in rats with induced myocardial infarction (MI).Methods
Male Sprague-Dawley rats were randomly divided into three groups: the sham-operated group, the MI group without metoprolol, which was fed the vehicle, and the MI+metoprolol group receiving intragastric metoprolol. Each group was further divided randomly into three subgroups, depending on the dosage of epinephrine administered during subsequent CPR applied after the induction of asphyxial cardiac arrest.Results
The ROSC rate was significantly decreased in the low dose subgroup of MI group, unchanged in the medium dose subgroup of MI group, and significantly decreased in the high dose subgroup of MI group, compared with the same dose subgroup of sham-operated group. MI+metoprolol group had a lower ROSC rate than MI group in the medium dose subgroup, and a higher ROSC rate than MI group in the high dose subgroup. There was no difference in blood K+ values of successful rats between MI group and MI+metoprolol group. The rats with successful CPR had lower blood K+ values than rats with unsuccessful CPR in each of the three treatment groups.Conclusions
Metoprolol administered to MI rats over a long period significantly improved ROSC rates under an appropriate dose of epinephrine during CPR. An increasing high blood K+ value would attenuate the rate of a successful CPR. 相似文献110.
Nilmara Braga Mozzer 《International Journal of Science Education》2013,35(3):429-458
Analogies are parts of human thought. From them, we can acquire new knowledge or change that which already exists in our cognitive structure. In this sense, understanding the analogical reasoning process becomes an essential condition to understand how we learn. Despite the importance of such an understanding, there is no general agreement in cognitive science literature about this issue. In this study, we investigated students' analogical reasoning as a creative process where an environment was set up to foster the students' generating and explaining their own analogies. Data were gathered from pre- and post-teaching interviews, in which the 13–14-year-old students were asked to make comparisons that could explain how atoms are bound. Such data supported the discussion about how students reasoned analogically. Our results made it evident that the task aims and the students' salient knowledge exerted a great influence on the drawing of analogies. 相似文献