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Research progress of transparent conducting ZnO:Al(ZAO)films 总被引：1，自引：0，他引：1
Owing to both of its high carrier concentration and large band gap,ZnO:Al(ZAO)films which is an n-type degenerate semiconductor,exhibits low resistance and high transmittance in the visible range.This work studies the crystal structure,optical and electrical properties and preparation methods of ZAO films,and discusses the existing problems and application prospective of ZAO films. 相似文献
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The aim of this study was to develop an exercise protocol to simulate tennis matchplay on a 'category 2' surface. Match analyses were used to form the basis for the design of the protocol. The protocol involved playing against a tennis ball serving machine. Part A of the protocol comprised 92 min 46 s of simulated tennis matchplay; Part B consisted of continuous hitting to the point of 'volitional fatigue' or when the required hitting frequency for two consecutive ball feeds could no longer be maintained. Ten elite tennis players (5 males, 5 females) volunteered to participate in the study, which was performed on an indoor tennis court (Matchplay?, En-Tout-Cas)?. Their age, body mass and estimated maximal oxygen uptake were as follows: males, 21.7±1.0 years, 73.6±2.6 kg and 58.0±1.7 ml?·?kg?1?·?min?1, respectively; females, 21.9±1.3 years, 62.3±2.0 kg and 42.2±0.7 ml?·?kg?·?min?1, respectively (mean±). Heart rate, change in body mass and time to volitional fatigue were monitored. The heart rate responses of the participants to the simulated matchplay (range: 140-157 beats?·?min?1, 73-81% peak heart rate) were consistent with the results of previous studies, for 'actual' matchplay. This protocol was successful in simulating similar physiological responses in Part A to 'actual' matchplay on a 'category 2' surface, in a controlled environment; it was also a sensitive evaluation tool of skilled performance in Part B. The current protocol may be used as a baseline protocol for studying the influence of, for example, training and dietary intervention on performance. 相似文献
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伟大的科学家Einstein曾说他感觉到自然界有统一性,他说“这是一种壮丽的感觉”,他首先提倡研究四种作用力的统一场论,提出过“黎曼空间几何统一场论”[1,2],未能成功。后来也有人提出“量子统一场论”[3],“规范统一场论”[4],“弱-电统一场论”[5,6,7],“三种力统一场论”[8] 相似文献
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Paul Josephson 《Metascience》2007,16(1):117-120