运动与补Na     

常燕  郑师超  邓晓岚 《武汉体育学院学报》2002,36(1):60-61

对运动员大量出汗导致体内总Na的亏空所引起的各种类型的热疾病分别进行了论述，强调了运动前和运动中补Na的重要性，并推荐了几种补Na的方法。  相似文献   

中国古代汞化物的制备方法     

马梅玉 《新疆教育学院学报》2004,20(2):119-121

中国古代汞化物的制备方法很多，本重点讨论与现代汞化物制备方法相似的硫化汞；氧化汞；氯化汞；氯化亚汞的制备方法及化学反应方程式。  相似文献   

氯化银沉淀提取金属银方法探讨   总被引：5，自引：0，他引：5  

郭红  张群 《玉溪师范学院学报》2002,18(3):75-76

利用碳酸盐与氯化银在高温下作用生成碳酸银 ,碳酸银分解得到金属银 ,从而提取回收含银废液中的金属银 .  相似文献   

Environmentally-induced stone decay: the cumulative effects of crystallization–hydration cycles on a Lincolnshire oopelsparite limestone     

Belinda J. Colston  David S. Watt  Helen L. Munro   《Journal of Cultural Heritage》2001,2(4)

An investigation has been undertaken at St Andrew’s church, Walpole St Andrew, Norfolk, to establish the underlying causes of the observed stone decay to the upper parts of the six stone piers. The stone decay was first recorded in the early 1930s. The salt-contaminated masonry within the church has been shown to undergo severe salt decay during the summer, with little damage occurring over the winter months. The south aisle piers have been shown to decay 2.5 times faster than the north aisle piers. Although crystallization–hydration cycles have been identified, the rate of decay is at its greatest when the cycling is relatively infrequent. This was not the expected trend. Furthermore, it has been shown that during extended periods where the ambient relative humidity is less than 75%, the rate of decay reaches a maximum. It is the length of this ‘drying’ period that apparently has the greatest influence on the rate of decay and could explain the significant difference in the rate of decay between the south and north aisle piers. The results have serious implications for passive conservation, where it is often recommended to lower the ambient relative humidity to well below the equilibrium relative humidity of the salt contaminant, to avoid crystallization–hydration cycles. Since, at the time of building, the church was situated on the coast, it is possible that the sodium chloride contamination occurred during the building process (1440–1520), particularly since the area was prone to sea-flooding at this time. Alternatively, the salt could have been applied as a treatment during the general restoration of 1897. Whatever the source of the salt, it seems likely that the ambient environment was changed by the insertion of a sealed floor in 1897, which could account for the onset of the salt decay.  相似文献   

平直界面一维晶体生长问题的相似解     

刘竞 《石家庄职业技术学院学报》2005,17(6):1-3

对于平直界面下由过冷边界开始的熔体的一维凝固过程，考虑液态中远场温度高于凝固温度，而底板温度低于凝固温度，利用相似性解法分别求解固液态温度，分析其结果，说明由低温区长入高温区的界面总是稳定的，从而更加完善了一维晶体生长理论．  相似文献   

常用低指数晶面标准极射图绘制及应用     

朱杰武  郭从盛 《陕西理工学院学报(社会科学版)》2003,21(6):51-54,72

在详细阐述晶面(晶向)标准极射赤面投影原理及其完整投影图绘制过程的基础上，绘制了立方晶系常用的低指数晶面(晶向)标准极射赤面投影示图；应用“滑移三角块”扼要阐释了滑移系确定与优先滑移、复滑移、双滑移及晶体在滑移过程中的转动行为。  相似文献   

N-甲基苯氨基-4,6-二甲氧基-1,3,5三嗪的合成与表征     

李宪平  肖深初  熊知行  梅光泉 《宜春学院学报》2006,28(6):19-21

目的:为了进一步研究与发展均三嗪衍生物的制备方法.方法:在丙酮介质中,三聚氯氰先后与N-甲基苯胺、甲醇反应,合成了N-甲基苯氨基-4,6-二甲氧基-1,3,5三嗪.结果:标题化合物经红外光谱和质谱对它进行了表征,筛选出了最佳的工艺条件.结论:制备方法简单,反应条件温和,效果良好.  相似文献   

结晶紫催化动力学光度法测定微量草酸     

彭金云 《南宁师范高等专科学校学报》2007,24(4):144-145

在稀磷酸介质中,微量草酸对KBrO3氧化结晶紫的褪色反应有显著的活化作用,据此建立了测定微量草酸的新方法。方法的线性范围是O.5-5.0μg/mL,检出限为O.2μg/mL.方法简便,快速,灵敏度高,用于茶叶中草酸含量的测定,结果满意。  相似文献   

一维二元光子晶体滤波特性研究     

汤炳书  刘丽丽  丁红星  周艳玮  杨昭  徐健良 《连云港师范高等专科学校学报》2006,(1):104-108

把一维时域有限差分方法用于一维二元光子晶体的滤波特性研究,数值模拟多种因素对一维二元光子晶体的滤波特性的影响,结果表明组成一维二元光子晶体的折射率、厚度、层数、入射角、光源的偏振态等都对滤波特性有影响,掺杂层位置、厚度、电磁参数都能调节其偏振滤波特性。  相似文献   

无机洗涤助剂的进展     

贾静娴 《唐山师范学院学报》2002,24(5):30-31

介绍了国内外洗涤助剂的发展状况，传统洗涤助剂磷酸盐被限制，沸石类助剂有局限，层状硅酸钠以优良的洗涤性能，环保无污染的特点，成为洗涤工业的新宠。  相似文献