计算机最优化技术在分析化学中的应用

在分析化学中,研究分析方法、选择分离条件、确定分析仪器最佳操作条件等等,总希望所选择的方案是一切可能的方案中最佳的方案,这就是最优化问题。目前是利用现代计算机技术,按照一定的数学模型(或数据项),得     

钇提高YT14硬质合金耐磨性的机制

研究了不同Ｙ添加量对ＹＴ１４硬质合金显微组织、结构和耐磨性的影响。结果表明，在ＹＴ１４硬质合金中添加微量Ｙ，可显著提高合金的耐磨性。Ｙ的主要作用是均匀细化碳化物相和Ｃｏ相；提高Ｃｏ粘结相中Ｗ、Ｔｉ元素的固溶量及αＣｏ相所占的体积分数，从而提高Ｃｏ粘结相的强韧性；Ｙ在合金中形成Ｙ２ＷＯ６，表明Ｙ还可还原和清除碳化钨表面氧化膜，增强Ｃｏ粘结相与硬质相之间的结合强度     

Dislocation Analysis for Large-sized Sapphire Single Crystal Grown by SAPMAC Method

In this paper,large-sized sapphire (230×210 mm,27.5 kg) was grown by SAPMAC method (sapphire growth technique with micro-pulling and shoulder-expanding at the cooled center). Dislocation peculiarity in large sapphire boule (0001) basal plane was investigated by chemical etching,scanning electron microscopy and X-ray topography method. The triangular dislocation etch pit measured is 7.6×101～8.0×102 cm-2,in which relative high-density dislocations were generated at both initial and final stages of crystal growth. The analysis of single-crystal X-ray topography shows that there are no apparent sub-grain boundaries; the dislocation lines are isolated and straight. Finally,the origins of low-density dislocation in sapphire crystal are discussed by numerical analysis method.     

痤疮患者血清中微量元素含量的变化

测定了52例痤疮患者血清Ca,Mg,Zn,Cu,Fe五种元素的含量。结果表明，痤疮患者血清Zn水平显著低于正常人（P＜0．001），血清Ca,Mg,Cu,Fe水平则与正常人无差别（P＞0．05）。部分病人口服补充锌剂后痤疮症状有所好转。提示痤疮患者应重视体内微量元素含量的变化，并做适当的补充。     

SOLUBILITIES OF POLYCYCLIC AROMATIC HYDROCARBONS AND DI-REGION THEORY

By using the relationship equation of Partition coefficients with water solubilities for polycyclic aromatic hydrocarbons (PAHs), we have estimated the solubilities of PAHs. In addition the high-performance liquid chromatograph (HPLC) method has been used for the indirect determination of solubilities of PAHs. t3ased on the di-region theory, We have studied the relationship of the solubilities of PAHs with carcinogenicity and introduced the solubility parameter into the di-region theory equation. The calculated carcinogenicity of PAHs from the obtained equation shows little difference from that calculated from Dai Qianhuan's equation.     

Detection of Tumor Necrosis Factor Gene by Piezoelectric Nucleic Acid Sensor

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｇｅｎｅｄｉａｇｎｏｓｉｓｔｅｃｈｎｏｌｏｇｙ ,ａｌｓｏｃａｌｌｅｄｎｕｃｌｅｉｃａｃｉｄｐｒｏｂｅｔｅｃｈｎｏｌｏｇｙ ,ｈａｓｂｅｃｏｍｅａｎａｔｔｒａｃｔｉｖｅｍｅｔｈｏｄｉｎｔｈｅｆｉｅｌｄｓｏｆｂｉｏｃｈｅｍｉｓｔｒｙａｎｄｃｌｉｎｉｃａｌｍｅｄｉｃｉｎｅ .Ｉｔｉｓｐｒｏｖｅｄｔｏｂｅｃｏｎｖｅｎｉｅｎｔａｎｄｓａｆｅｕｓｉｎｇｎｏｎ ｒａｄｉｏａｃｔｉｖｅｒｅａｇｅｎｔｓｗｉｔｈｅｌｅｃｔｒｏｃｈｅｍｉｃａｌａｎｄｏｐｔｉｃａｌｄｅｔｅｃｔｏｒ.Ｅｓｐｅ ｃ…     

Chemical Constituents of Ailanthus triphysa

Two new compounds,8(14),15-isopimaradiene-2α，３α，19-triol(1),and 6α，７β－dihydroxy-17(20)-cis-5α－pregna-16-one(2),together with four known copounds,a oxygenated rare phyllocladane,phyllocladan-16α，19-diol(3),kaempferol-3-0-β－Ｄ-galactopyranosied,kaempferol-3-0-α－Ｌ－rhamnopyranoside and scopoletin, were isolated from the leaves of Ailanthus tripysa.Structures of 1-3 were elucidated on the basis of spectroscopic data as compared with related compounds.     

高分散直接甲醇燃料电池Pt／C阴极电催化剂的制备过程机理与表征

 通过调变的多元醇法制备了40％Pt／C直接甲醇燃料电池阴极电催化剂，应用透射电镜（TEM）及X射线衍射（XRD）方法表征催化剂．结果表明，由该制备方法可得到高分散，金属粒子粒径分布窄的高载量贵金属催化剂．TEM统计结果表明，调变多元醇法制备的40％Pt／C催化剂的金属粒子平均粒径约为2．9nm．直接甲醇燃料电池单池性能测试表明，该方法制得的40％Pt／C的电催化氧还原能力比同型商品催化剂更好．另外，利用UV－Vis光谱研究了催化剂的制备过程．结果表明，在调变的多元醇法中，Pt4＋的还原是一步完成的．     

O—（1—甲硫基乙叉胺基）硫代磷酰胺（酯）的合成及生物活性…

首次报道了甲硫基乙醛肟与硫代磷酰氯的缩合反应，合成了１６种新型Ｏ－（１－甲硫基乙叉胺基）硫代磷酰胺酯及硫代磷酸酯类化合物，化合物６ｂ具有很好的杀虫活性。     

制备纳米氧化锌的新方法

以草酸和醋酸锌为原料，用室温固相化学反应首先制备前驱物二水合草酸锌，后者在微波场辐射分解得到产物纳米氧化锌。用XRD，TEM和IR等技术对产物的组成，大小及形貌进行了表征。结果表明：产物纳米氧化锌为粒度分布均匀的球形六角晶系结构，平均粒径约为8nm。