玉米蛋白PAGE法鉴定玉米品种及纯度

本文比较了国内外应用的玉米品种及纯度鉴定的方法。玉米蛋白质聚丙烯酰胺凝胶电泳法(PAGE)具有准确、快速、经济、易于普及等优点,是目前国内外最先进的玉米品种及纯度鉴定技术。     

真空热压烧结对高纯W-Si合金靶材性能影响

以高纯W-Si合金粉(>99.995%)为原料,采用真空热压烧结工艺制备高纯W-Si合金靶材。研究烧结温度、热压压力、保温时间等工艺条件对靶材密度、微观组织性能的影响。结果表明,烧结温度在1350~1380℃,热压压力25~30 MPa,保温时间1.5~2 h,可制备出相对密度99%以上、平均晶粒尺寸100μm以内的高性能W-Si合金靶材。     

1,5-环辛二烯氯化铱的HPLC法测定

建立了用高效液相色谱分析1,5-环辛二烯氯化铱纯度的方法。以C18色谱柱为固定相,以乙腈/水53/47 (V/V)溶液为流动相,检测波长为285 nm,可以获得满足1,5-环辛二烯氯化铱纯度测定要求的色谱图。在1,5-环辛二烯氯化铱浓度为0.224~0.336 mg/mL时,线性相关系数(r)为0.9993,样品加标回收率为99.13%~101.37%, 相对标准偏差为1.01%。     

高纯氧化铥的分离制备研究

用ＣＬ－Ｐ５０７－ＨＣｌ体系柱色层法分离原料氧化铥中铒、镱等稀土和非稀土杂质。讨论了树脂粒度、温度、淋洗剂浓度１负载量、进样比等条件对铥、镱 分离的影响,观没蛭铥、镱之间存在萃取抑制现象。选择合适分离条件以９９．９％氧化铥 为原料制备出９９．９９５％的高纯氧化铥产品,其主要稀土杂质铒,镱 均小于５μｇ／ｇ,非稀土杂质铁小于２μｇ／ｇ,钙小于５μｇ／ｇ。     

Formulation and technology research of new silver solder with flux covering

In their eutectic compositions, Au–Si alloys have a melting point of 369°C, and a colour similar to that of high-grade gold. Results of the manufacture of gold alloys with 2.5%, 2.8% and 3.0% silicon, by means of melting in a plasma furnace with an inert argon atmosphere, are presented in this study. Chemical composition characterisation was carried out by energy dispersion spectroscopy and wave dispersion spectrometry, and metallographic and microstructural analysis by optical microscopy, SEM and DRX, Vickers hardness and mircohardness testing, melting point evaluation by DSC and determination of the SCIELab colorimetric coordinates. The results of the hardness and micro-hardness testing gave values around 110HV, presenting an important increase in the mechanical properties with respect to the traditional high purity gold alloys. The melting temperature for the alloys was around 374°C as well as being a heat very close to the values of pure gold.     

Mechanochemical synthesis of cerium orthophosphate

A facile, simple and rapid preparation method of cerium orthophosphate was presented. The synthesis of low-crystalline CePO₄ occurred upon mixing of cerium (III) nitrate and sodium phosphate, and was an exchange-type reaction. The phase composition of the obtained powder was checked by the XRD and FTIR methods, indicating the presence of cerium phosphate. Further investigations on thermal behavior of the synthesized cerium salt had shown that the obtained orthophosphate crystallized at first in rhabdophane-type structure. It converted to monazite (monoclinic symmetry) during heating at the temperatures of above 600 ºC. Oxidation of Ce³⁺ to Ce⁴⁺ was avoided during the syntheses, as confirmed by the XPS experiments.     

从海鱼加工下脚料中提取核酸的试验(Ⅱ)——从鱼白中提取核酸及产物纯度分析和组分鉴定

对地产海鱼加工下脚料之一——鱼白中核酸的提取方法、产品纯度测定和组分鉴定方法进行了一些探索。结果显示,DNA粗产物得率为4.62％,DNA质量分数为4.77％。RNA粗产物得率为1.98％,RNA质量分数为4.06％,提取方法基本可行。     

Contamination due to process gases

A survey is given of the BOC Group technical research programs, whose purpose is to relate purity in gas processing to ULSI device parameters. Results from the following research programs are presented: how inert gas purity affects the Ti silicide for IGFET metallization; the effects of argon versus nitrogen used in silicon gate oxidation process steps; and preliminary work on a new gas analytical tool, Atmospheric Pressure Ionization Mass Spectrometry (APIMS), which allows measurement of sub ppb impurity levels in processing gases.     

高纯稀土冶炼厂的设计及生产实践

介绍了我国某高纯稀土冶炼厂的设计及生产实践。内容包括冶炼厂的生产规模和产品方案的确定；冶炼厂的厂址、原料、生产工艺技术及设备的选择；三废状况及其治理方法；主要技术经济指标；产品的销售方向及冶炼厂建成后的实践效果。     

直流氩等离子体硅粉纯化工艺的研究

针对立式反应室、直流氩等离子体情况,建立硅粉的运动学模型,绘出粉粒沉降时间与粉粒粒度和进气速率的关系曲线,并通过该模型选择进气速率为4～10L/s,粉粒的粒度范围为70～100μm.为了提高粉粒沉降过程中纯化效果,建立并分析鞘层模型中与鞘层厚度、鞘层区离子浓度以及鞘层离子平均动能有关的工艺参数的变化关系并提出一套优化选择放电参数的方法.通过该方法优化工艺参数为反应室总压力为4～6Pa,阴极电压为2000V或是更高,鞘层厚度为1.2～2cm.提纯实验结果表明,硅粉的纯度可由99.6%提高到99.95%.