防污染的自消应力高纯度气体低温换热器的设计

该设计解决了低温工程与低温技术等领域所使用的高纯度气体介质换热的要求,具有显著的经济效益和社会效益。其换热器是由四个管壳式热交换器串联组合而成,壳体呈窄矩形,换热管采用U形换热管,四个管壳式热交换器呈方阵置放在低温换热器筒体内。低温换热器采用的材料是0Cr18N i9/304,该种材料的透气性小、耐磨损、抗腐蚀能力强和性能稳定,防止了气体被污染。另外在低温下,考虑了材料的热胀冷缩所产生的应力,使应力能够自行消除,提高了它的密封性能,最终使低温换热器密封性能好,防止了气体被污染,保证了气体的高纯度。     

高纯度超导氧化物RuSr2GdCu2O8的合成与超导电性

RuSr2GdCu2O8据报道是转变温度为30－40K的超导体，其合成的主要问题是，在合成过程中有相当多的铁磁性的SrRuO3杂相伴随着主相一起生成，本文报道了合成RuSr2GdCu2O8（Ru-1212相）纯相的新方法，即在O2和水蒸气气氛中首先合成纯相的Sr2GdRuO6(Ru-211相）先驱物，然后Sr2GcRuO6与CuO高温烧结，生成RuSr2GdCu2O8。合成的RuSr2GdCu2O8电阻为半导体温度行为，该体系的超导转变与生成的杂相有关。     

Measurement and Analysis of Spall Characteristics of High-Pure Aluminium at One-Dimensional Strain Loading

With an impact velocity varying from 196.9m/s to 317.9m/s and ratios of flyer/sample thickness of 2：4 and 3：6, the free-surface velocity profiles of the shock compressed high purity aluminium （HPA 99.999%） samples are measured with a velocity interferometer system for any reflector. Based on the vibrating features of the velocity profiles, the damage behaviour of HPA is analysed. The results indicate that the vibrating amplitude increases with increasing shock stress, and the subsequent reverberations describing the spall become more obvious. When the shock stress in the material is below a critical or smaller than the threshold level, the free-surface velocity profile replicates virtually the form of the compression pulse inside the sample. When the impact stress exceeds a critical value （1.4 GPa）, the micro damage would appear, and the free-surface velocity profile changes significantly, showing a series of short-duration reverberations in the profile. When the impact stress exceeds the threshold of damage, a compressive disturbance called the ＂spall pulse＂ appears in the free-surface velocity profile, and the subsequent reverberation becomes regular again. The measured spall strength of HPA is much higher than those of commercially pure aluminium reported in many references. In addition, the strength of HPA is similar to that of single-crystal aluminium.     

以粉煤灰为原料采用两步法制备高纯度ZSM-5型沸石的研究

采用经碱熔融-离心提取处理后的粉煤灰为原料,经水热反应研究两步法合成高纯度ZSM-5型沸石的过程,探讨了碱灰比、焙烧温度对硅铝溶出量的影响,研究了碱度、晶化时间、晶化温度与硅铝比对合成ZSM-5型沸石的影响.结果表明:碱灰比为2.3∶1,焙烧温度为680 ℃时可获得最高的硅铝溶出量;当SiO2/Na2O =7(摩尔比),SiO2/Al2O3=45(摩尔比),晶化时间为68 h,晶化温度为180 ℃时可获得高纯度的ZSM-5型沸石.     

一种制备高纯度单分散金纳米棒的新方法

报道了一种温和的、低成本、有效制备高纯度单分散金纳米棒的新方法.采用种子生长法,在两种表面活性剂体系下液相合成金纳米棒,向粗产品中加入氯化钠溶液,通过提高反应液的离子强度,利用制备的金纳米棒与球形颗粒不同的静电作用将金纳米棒分离纯化.运用透射电子显微镜(TEM)和扫描电子显微镜(SEM)对金纳米棒的表面形貌进行表征.结果表明,在较短时间内可获得纯度达97％以上的金纳米棒,并初步探讨了提纯机理.     

2-氯-5-三氟甲基苯基硼酸合成

研究了重要的药物中间体2-氯-5-三氟甲基苯基硼酸的合成方法,并提出了适用于工业化生产的高产率、高纯度的合成途径.产物结构均经IR、1H NMR、13C NMR谱得以证实.     

Quantification of Trace Amounts of Impurities in High Purity Cobalt by High Resolution Inductively Coupled Plasma Mass Spectrometry

Cobalt metal has been used in the production of magnetic alloys, cobalt and nickel based superalloys and sputtering targets in the field of advanced electronic devices1. The determination of trace impurities in high purity cobalt is extremely important be…