叶蛇纹石同步辐射X射线粉末衍射脱水动力学研究

采用同步辐射X射线粉末衍射方法在等温条件下研究粒径为~5 μm的叶蛇纹石脱水动力学,在680、700、710和720℃下观测叶蛇纹石脱水前后特征峰随时间变化的特征。结果发现,随加热时间的增加,叶蛇纹石的特征峰缓慢消失,伴有镁橄榄石特征峰出现,但无顽火辉石相出现。通过Avrami方程,获得叶蛇纹石脱水反应级数（n）为1.1~1.3,表明叶蛇纹石脱水过程受晶界成核控制。利用Arrhenius方程,获得叶蛇纹石脱水仅出现镁橄榄石相所需活化能为105.97 kJ/mol,指前因子为333.62 s^-1。     

Modeling and optimization of catalytic dehydration of ethanol to ethylene using central composite design

The central composite design in the modeling and optimization of catalytic dehydration of ethanol to ethylene was performed to improve the ethylene yield. A total of 20 experiments at random were conducted to investigate the effect of reaction temperature, Si/Al ratios of H-ZSM-5 catalyst and liquid hourly space velocity (LHSV) on the ethylene yield. The results show that the relationship between ethylene yield and the three significant independent variables can be approximated by a nonlinear polynomial model, with R-squared of 99.9% and adjusted R-squared of 99.8%. The maximal response for ethylene yield is 93.4% under the optimal condition of 328 °C, Si/Al ratio 85, and LHSV 3.8 h⁻¹.     

脱水诱导基因RD特性及功能

脱水诱导基因（Responsive to Dehydration,RD）是一类能够调节植物脱水的基因,对植物脱水胁迫具有一定耐受性,有些成员还对低温、高盐等非生物胁迫具有不同程度的响应。RD成员分属于不同家族,在结构和功能方面存在差异。归纳不同RD的结构组成、蛋白保守基序、调控机理以及应对生物以及非生物胁迫时的功能, 以及RD基因启动子区域中不同的顺式作用元件在基因应对非生物胁迫时发挥的作用,可为今后对RD基因的研究提供相关参考。     

Organic synthesis using clay catalysts

Conclusion The clay minerals can catalyze a variety of organic reactions occurring on their surface and interstitial space. Synthetic organic chemists have been attracted to their tremendous potential as catalysts only relatively recently. Modification of their properties by incorporating different metal cations, molecules or complexes, can lead to catalysts that are useful in effecting even more varieties of reactions and higher selectivity in product structure and yield. There is a theory that the molecules of life actually developed in sedimentary clays. As the organic chemist is becoming more aware of the clay’s efficacy, its uses in organic synthesis are bound to increase, especially because it helps in developing eco-friendly chemical processes. The dark clay has a bright future in the area of organic synthesis.     

软质聚氨酯泡沫塑料脱模剂的研制

对一种用于软质聚氨酯泡沫塑料成型加工的脱模剂进行了配方研究，脱模性能优良，可以重复多次利用，成本低廉，而且配料较为充足。     

桑拿浴后渐增负荷运动对有氧能力的影响

观察10名身体健康的体育系男子大学生在桑拿高温脱水恢复期，运动时的最大吸氧量(VO2max)、血乳酸浓度(HLa)、通气阈值(VT)的变化，并与常温条件相同运动负荷时相比较，探讨桑拿高温脱水恢复期时的运动对有氧能力的影响。其结果发现在桑拿浴后，恢复期常温条件运动时，VO2max、VT及运动时间都比常温条件增加，同时HR和HLa浓度有所下降，表明桑拿后恢复期可能具有“应激保护”作用。     

The impact of making-weight on cognitive performance in apprentice jockeys

Jockeys regularly engage in rapid weight-loss practices in preparation for competition. These practices are thought to impair cognitive function, although the evidence in support of this theory remains inconclusive. The purpose of this study was to examine the effects of making-weight on cognitive function in apprentice jockeys in a simulated and competitive environment. Apprentice jockeys (n = 12) reduced their body mass by 4% in 48 h in a simulated environment using weight-loss methods typically adopted in preparation for racing. Simple and choice reaction time, attention, learning and memory were assessed before and after the weight loss. A further 10 apprentice jockeys performed the cognitive function assessment in a competitive racing environment at both a self-reported “normal” and “light” body mass. Hydration status and body mass were assessed in all trials. In the simulated environment, body mass was reduced by 4.2 ± 0.3%, yet no change in cognitive function was observed. Cognitive function also remained unchanged in the competitive environment after a body mass loss of 5.7 ± 1.9%. Typical reductions in body mass in preparation for racing have no effect on cognitive function in apprentice jockeys in a simulated and competitive environment. Further research is required to investigate the physiological mechanisms preventing the adverse effects of making-weight on cognitive function in jockeys.     

热应激与运动

在热环境下运动时,热应激和运动应激联合作用导致体温、脑和肌肉局部温度升高并且出现脱水,全面影响运动员的生理功能、心理过程及运动能力.通过运动与热环境的联合刺激,运动员可获得对运动热应激的有效适应.科学补液是缓解运动中热应激和热脱水问题的有效措施.     

脱水山药片的加工工艺初探

脱水山药片是近年来出现的有一定药用价值的方便食品,能较好保持新鲜山药特有的营养成分,其色泽自然风味好、工艺简便、市场前景看好。     

Measures of cardiac autonomic control in women with differing volumes of physical activity

Abstract

The most recent (1996) drinking guidelines of the American College of Sports Medicine (ACSM) propose that athletes should drink “as much as tolerable” during exercise. Since some individuals can tolerate rates of free water ingestion that exceed their rates of free water loss during exercise, this advice has caused some to overdrink leading to water retention, weight gain and, in a few, death from exercise-associated hyponatraemic encephalopathy. The new drinking guidelines of the International Olympic Committee (IOC), recently re-published in this Journal, continue to argue that athletes must drink enough to replace all their weight lost during exercise and to ingest sodium chloride since sodium is “the electrolyte most critical to performance and health”. In this rebuttal to that Consensus Document, I argue that these new guidelines, like their predecessors, lack an adequate, scientifically proven evidence base. Nor have they been properly evaluated in appropriately controlled, randomized, prospective clinical trials. In particular, these new guidelines provide erroneous recommendations on five topics.

If novel universal guidelines for fluid ingestion during exercise are to be promulgated by important international bodies including the IOC, they should first be properly evaluated in appropriately controlled, randomized, prospective clinical trials conducted under environmental and other conditions that match those found in “out-of-doors” exercise. This, and the potential influence of commercial interests on scientific independence and objectivity, are the two most important lessons to be learned from the premature adoption of those 1996 ACSM drinking guidelines that are not evidence-based. These concerns need to be addressed before the novel IOC guidelines are accepted uncritically. Otherwise the predictable consequences of the premature adoption of the 1996 ACSM guidelines will be repeated.