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碳化硅纳米晶须的微波合成 总被引:4,自引:0,他引:4
SiC nanometer whisker, whose diameter was about 50nm and purity was 98.54%, was synthesized by microwave heating in an atmosphere of argon. Char pyrolyzed phenolformaldehyde resin and SiO2 nanometer powder were used as starting materials. The properties of the whisker were determined by XRD and TEM. The mechanism for synthesizing SiC nanometer whisker was discussed. 相似文献
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在硝酸酸度约为1.3 mol·L-1硼酸试样溶液中加入硝酸银溶液,使溶液中存在的微量氯离子与之反应生成氯化银胶悬体,加入适量的1,2,3-丙三醇作为胶悬体的稳定剂.选择在400 nm波长处测定此胶悬体的吸光度,其吸光度与氯离子浓度在0.017~0.20 mg·L-1范围呈线性关系,求测方法的检出限(3S/b)为0.016 mg·L-1.对此反应的各影响因素(如检测波长、试液酸度、硝酸银溶液及丙三醇的加入量、反应的适宜温度时间,以及进行吸光度测定的时间等)作了较系统的试验并予以优化.对方法的回收率及精密度也作了试验,所得回收率在96.0%~102.6%之间,测得的相对标准偏差(n=5)均小于2%. 相似文献
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自然界中硼铁矿属于多元素(Fe、B、Mg)共生矿,使用价值很高,是我国未来硼资源的主要来源.根据我国硼铁矿品位低的特点,东北大学提出了硼铁矿高炉铁硼分离生产含硼生铁及富硼渣、富硼渣硫酸浸出一步法生产硼酸的火法工艺路线[1],矿石中的镁以硫酸镁的形式存在于母液中.母液经浓缩、过滤,主要成分为硫酸镁和硼酸水溶液,母液中硫酸镁和硼酸分离是目前急需解决的问题.当温度高于80℃时,硫酸镁在水中的溶解度随温度的升高而降低,硼酸的溶解度随温度的升高而增加[2].根据硫酸镁和硼酸的溶解度特点,在常温下将两者分离是不可能的,通过高温结晶… 相似文献
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The solution of MgSO4-H3BO3-H2O system containing 20%(mass fraction)MgSO4 and 2.5% H 3BO 3 was prepared and the experimental study of its crystallization at 180℃ were carried out in a high pressured vessel. Only a solid phase MgSO4•H2O was separated out from the system. The experimetal data were fitted. With the aid of simplex optimum method and Runge-Kutta digital solution of a set of differential equations, Single-nuclear interface reaction model (MB2) was selected to describe the process of crystallization of kieserite. the dynamic equation is as follows:
-dc/dt=0.064(2.24-c) 4/3 (c-0.290)2 相似文献
-dc/dt=0.064(2.24-c) 4/3 (c-0.290)2 相似文献
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