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排序方式: 共有419条查询结果,搜索用时 15 毫秒
91.
ME Goldberg BW Lex NK Mello JH Mendelson TA Bower 《Canadian Metallurgical Quarterly》1996,66(2):228-238
Research on achievement goal orientation in sport has relied primarily on traditional statistical methodology to examine group mean differences. Unfortunately, examination of the measurement model is generally ignored prior to means testing. This study reports an application of structural equation modeling (SEM) in testing measurement invariance and latent mean structure of the Task and Ego Orientation in Sport Questionnaire (TEOSQ; Duda & Nicholls, 1989) using male and female college students. A confirmatory factor analysis for testing invariance revealed invariant measurement properties and factor structures across gender, indicating that task and ego orientation are similarly conceptualized by male and female students. Subsequent testing of latent mean structures, however, showed significant gender differences with respect to ego orientation, but no difference in task orientation. The SEM procedures used in the present study demonstrate additional construct validity and internal consistency reliability for the TEOSQ and, by confirming its factor structure, provide a sound psychometric basis for its continued use in substantive studies focusing on the comparison of achievement goal orientation across gender. 相似文献
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Mateus Wagner Dantas de Assis Gustavo Walace Pacheco Leite Luis Carlos Cunha Júnior Renato de Mello Prado Edson Perito Amorim João Paixão dos Santos Neto Lívia Cirino de Carvalho Gustavo Henrique de Almeida Teixeira 《International Journal of Food Science & Technology》2020,55(7):2893-2900
Due to the importance of banana consumption in developing countries and producing zinc-rich foods, the objective of this study was to evaluate the feasibility of banana bunch sprays and bunch stalk feeding with Zn aiming to biofortify this fruit. Zn sprays were carried out with a dose of 80 g ha−1 using ZnCl2 and ZnCl2 combined with a chelating agent in two banana cultivars (‘Maravilha’ and ‘FHIA 18’). Bunch stalk feeding with Zn was carried out by fixing plastic bags on the stem end containing solutions of ZnSO4 (0, 0.5, 1.0 and 2.0 g L−1) in two banana cultivars (‘Williams’ and ‘Prata Anã’). Both strategies resulted in a maximum fruit Zn content of 0.14 mg 100 g−1. Although it was possible to increase the Zn content in banana fruit from ‘FHIA 18’ and ‘Prata Anã’ cultivars, both strategies did not result in biofortified banana fruit with a Zn level which would fulfil the Zn dietary reference intake (DRI) of 2 mg dia−1 for children. Banana bunch sprays with Zn did not affect the fruit quality, but bunch stalk feeding with Zn resulted in fruits with lower ratio, pH and ascorbic acid content. 相似文献
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Isolated power systems which fit the structure of a single equivalent generator supplying an equivalent composite load can experience a voltage oscillatory instability entirely traceable to the effects of induction motor loads interacting with automatic voltage regulators. This scenario is one where an AVR properly tuned for open circuit conditions is not necessarily well tuned for the on load condition. The phenomenon is explained and a simple solution through AVR compensation is suggested 相似文献
98.
J. D. B. De Mello S. Hamar-Thibault M. Durand-Charre 《Journal of Materials Science》1985,20(10):3453-3461
Delta ferrite undergoes some rather complex solid-state transformations during solidification and cooling. These have been investigated in a series of alloyed high carbon steels. Solidification paths have been determined using the quenching during differential thermal analysis method (ODTA). The different phases produced were identified by scanning and transmission electron microscopy and were analysed by electron probe microanalysis. Four different types of transformation were identified: solid state precipitation, cellular precipitation, delta eutectoid transformation and plate formation followed by two further precipitation reactions. The latter transformation results in the development of very hard and complex structures in which four phases are intimately associated. An explanation has been proposed for the mechanism of their formation. 相似文献
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The behavioral effects of the nonpeptidic delta opioid agonist SNC80 and a series of related piperazinyl benzamides derived from the parent compound BW373U86 were evaluated in rhesus monkeys. SNC80 (0.1-10 mg/kg) decreased response rates maintained by food-reinforcement in a dose- and time-dependent manner, with maximal effects occurring within 10 min of intramuscular injection. The potency of SNC80 and five other piperazinyl benzamides in this assay of schedule-controlled responding correlated with their affinity at cloned human delta opioid receptors but not with their affinity for cloned human mu receptors. Moreover, the effects of SNC80 were selectively antagonized by the delta-selective antagonist naltrindole (1.0 mg/kg), but not by the mu selective antagonist quadazocine (0.1 mg/kg) or the kappa-selective antagonist norbinaltorphimine (3.2 mg/kg). These findings indicate that SNC80 functions as a systemically active, delta-selective agonist with a rapid onset of action in rhesus monkeys. The antinociceptive effects of SNC80 were examined in a warm-water tail-withdrawal assay of thermal nociception. SNC80 (0.1-10 mg/kg) produced weak but replicable antinociceptive effects that were antagonized by naltrindole (1.0 mg/kg). SNC80 antinociception was also dose-dependently antagonized by BW373U86 (0.56-1.0 mg/kg), which was inactive in this procedure. These findings suggest that SNC80 may have higher efficacy than BW373U86 at delta opioid receptors. Moreover, SNC80 at doses up to 32 mg/kg did not produce convulsions, which suggests that SNC80 may also be safer than BW373U86. The effects of SNC80 were also examined in monkeys trained to discriminate cocaine (0.4 mg/kg i.m.) or self-administer cocaine (0.032 mg/kg/injection,i.v.). In drug discrimination studies, SNC80 (0.1-10 mg/kg) produced a dose-dependent and naltrindole-reversible increase in cocaine-appropriate responding, and complete substitution for cocaine was observed in five of seven monkeys tested. However, SNC80 (1.0-100 micrograms/kg/injection) did not maintain responding in monkeys trained to self-administer cocaine. Thus, despite its ability to produce cocaine-like discriminative stimulus effects, SNC80 may have relatively low abuse potential. 相似文献