高纯度超细镍粉的除杂研究

工业湿法制备超细镍粉过程中，提高镍粉的纯度一直是困扰生产厂家的难题，为此，在研究黑镍除杂和用螯合剂水溶液超声波搅拌洗涤除杂的基础上，讨论温度，pH值，黑镍量，螯合剂，超声波的搅拌洗涤次数等因素对除杂效果的影响。通过实验找出湿法制备高纯度超细镍粉除杂的最佳工艺条件。     

四川平武绿柱石宝石成矿地质特征

四川平武产出世界上十分稀少和珍贵的无色透明扁平板状绿柱石宝石。在野外详细调研和系统分析、测试基础上，全国总结和介绍矿床成矿地质环境，绿柱石宝石产出特征，绿柱石宝石矿物学、化学成分、结晶习性及晶体化学、谱学特征、包裹体特征，花岗岩与Be及W,Sn矿化关系和成矿的物理、化学条件。从而，确认该矿床为岩浆期后气成-热液型绿柱石宝石矿床。     

SIMULTANEOUS ANALYSIS OF Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ)AND Cd(Ⅱ)BY SPECTROPHOTOMETRY AND THE KALMAN FILTER

This paper describes the simultaneous determination of cobalt,nickel,copper,zinc and cadmium byspectrophotometry and the Kalman filter method.Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ)and Cd(Ⅱ)react with 5-bromo-2-(2-pyridylazo)-5-diethylaminophenol(5-Br-PADAP)in the presence of cationic surfactant cetylpyridinium bromide(CPB)to form five different coloured ternary complexes.The absorption curves ofthese complexes overlap severely in the scanning range 500-620 nm.The Kalman filter algorithm issuccessfully applied to resolve the overlapped absorption curves and therefore makes the simultaneousdetermination of these metallic ions possible without tedious pretreatment.The proposed method isapplied to analyse the titled elements in synthetic samples and in environmental samples such as hair,fingernail and river water samples with satisfactory results.     

A NON-PARAMETRIC CLASS MODELLING TECHNIQUE

A non-parametric method for supervised pattern recognition is presented. The method is of the classmodelling type, meaning that a classification rule is developed for each class, using the dissimilaritiesbetween the objects of the class. The dissimilarities between the objects within a class are related to thedistances between all pairs of training objects. As distance metric, a measure is proposed that takes thecorrelation between the interval-scale variables into account, and that moreover can be used for mixedtypes of variables. The classification rule is based on the construction of a boundary in the measurementspace. For the determination of the class boundary, several strategies are proposed and compared. The performance of the technique is evaluated on the basis of several data sets. Comparison with theclass modelling technique UNEQ shows its usefulness for practical applications.