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961.
Ewout Timmerman Joel De Water Kim Kachel Machar Reid Damian Farrow Geert Savelsbergh 《Journal of sports sciences》2015,33(10):1093-1100
The influence of scaling court-size and net height on children’s tennis performance was examined. Sixteen boys (9.7 ± 0.5 years) had to perform a 30-min match in four different conditions, where court-size and/or net height were scaled by using a scaling ratio based on the differences in temporal demands between the children and the adult game. These 30-min matches were analysed using Tennis Analyst (FairPlay Ltd., Jindalee, QLD, Australia) software to determine typical tennis match performance characteristics. Children hit more winners, more forced errors, played more volleys, struck more shots from a comfortable height and played in a more forward court position when the net was scaled. Scaling both the court and net lead to a faster children’s game, more closely approximating what is typical of the adult game. The differences between the typical tennis performance variables recorded suggested that scaling the net led to a more aggressive way of playing. Further, children enjoyed playing on the standard court–scaled net condition more than standard adult conditions. It is suggested that optimising the scaling of net height may be as critical as other task constraints, such as racquet length or court-size, as it leads to a more engaging learning environment for experienced children. 相似文献
962.
论陕西省社会资本形态对经济增长的影响 总被引:5,自引:0,他引:5
本文基于社会资本理论,分析了陕西社会资本形态及其对经济发展的影响,指出陕西商业文化的不足所导致的生产要素的低效使用是陕西经济增长缓慢的主要原因。 相似文献
963.
本文着重对领导授权行为和研发人员的授权感知进行研究,检验了不同授权行为的有效性。研究结果显示,信息共享对研发人员的授权感知具有显著影响,影响效果也最大。 相似文献
964.
从管理学和新兴古典经济学的角度,探讨了企业的组织结构随社会分工、进而社会产品交易效率变动的机理,这对于中国企业的管理者如何经营、管理企业有理论和现实指导意义。 相似文献
965.
Richard T. De George 《Ethics and Information Technology》2003,5(4):183-190
This paper considers the moralresponsibility of computer scientists withrespect to weapons development in post-911America. It does so by looking at the doctrineof jus in bello as exemplified in fourscenarios. It argues that the traditionaldoctrine should be augmented by a number ofprinciples, including the Principle of aMorally Obligatory Smart Arms Race, thePrinciple of Assistance to One's Enemies, thePrinciple of Public Debate on Weapons of MassDisruption, and the Principle of the MoralUnjustifiability of Private Wars. 相似文献
966.
967.
968.
Jayanta De Ananda Mukhopadhyay Pradip Kumar Saha 《Indian journal of clinical biochemistry : IJCB》2006,21(2):165-168
Four groups of subjects: normal healthy normotensive nonpregnant women (Group A), normal normotensive pregnant women (Group
B), women with preeclamptic toxaemia (Group C) and eclamptic women (Group D): with fifty subjects in each group, were investigated
for serum lipid profile in the third trimester of pregnancy. There was significant increase in serum triglyceride and VLDL
cholesterol leve as well as decrease in LDL cholesterol in normal pregnancy, while total cholesterol and HDL cholesterol levels
did not show any statistically significant alteration. The preeclampsia (Group C) was associated with a significant rise in
triglyceride and VLDL cholesterol and fall in HDL cholesterol concentration, while eclamptic women showed significant fall
in HDL cholesterol and rise in LDL cholesterol as compared to normal pregnant women. However, interestingly, elevation of
the ratios of total cholesterol: HDL cholesterol and triglyceride: HDL cholesterol as well as diminuition of the ratio of
HDL cholesterol: VLDL cholesterol showed statistical significance in pregnancy induced hypertension in both Groups C and D,
while eclamptic women showed significant elevation of LDL cholesterol: HDL cholesterol ratio in addition. 相似文献
969.
970.
金属氧化物纳米点薄膜的模板法合成 总被引:6,自引:0,他引:6
报道了一种简便的金属氧化物纳米点薄膜的合成方法.首先制备了具有有序纳米凹坑阵列的多孔阳极氧化铝模板,然后在模板表面真空蒸镀金属薄膜,对所制备的金属薄膜进行氧化处理,得到了具有有序纳米点阵列的金属氧化物纳米点薄膜.纳米点的直径约为 1 0 0nm,高度约为 45nm,以六边形有序排列,密度约为 2× 1 0 1 3个/m2 . 相似文献