金的亲硫性分析

根据金在自然界中多种存在形式,通过元素结合规律的微观性质分析和微观性质的宏观统计原理——晶格能分析,剖析了金的亲硫性。据金在自然界演化史中的地球化学行为,总结了金的亲硫特点及其地质意义。

冶金与地球化学过程中Fe-Co-Ni-Cu亲氧性和亲硫性规律

Fe、Co、Ni、Cu在冶金上的提取分离与地球化学成矿在原理上具有高度的相似性,例如岩浆熔离成矿与火法冶金、热液成矿与湿法冶金、风化成矿与湿法冶金、生物地球化学成矿与生物冶金。元素在地球化学迁移和冶金提取过程中体现出的化学性质相似,在地球化学过程中,Fe、Co、Ni、Cu经常伴生成矿,如铁镍矿、镍钴矿、铜钴矿等硫化或氧化类矿物;在冶金过程中,这四个元素则体现出很强的亲氧亲硫化学规律性。利用过渡金属元素Fe、Co、Ni、Cu在成矿中显现出的元素亲和性差异作为相似元素相互分离的理论指导,可以从新的角度理解提取冶金。本文通过分析四种元素的地球化学行为与冶金行为,发现其对氧的亲和性顺序为Fe>Co>Ni>Cu,对硫的亲和性顺序为Fe<Co<Ni<Cu。此结论可为元素选择性硫化、氧化提供理论依据,同时也为金属元素相互分离提供更多可能的研究方法。

辽西新太古代片麻岩金矿中金与伴生元素的多重分形模型剖析

新太古代片麻岩在辽西地区分布面积广阔,其中发育的金矿矿产资源丰富。为了研究辽西地区新太古代片麻岩金矿中共伴生元素对于Au元素成矿的重要性,本文以辽西地区新太古代片麻岩中典型金矿床及矿化点矿体的组合分析数据为样本,运用多重分形理论进行Ag、Cu、Pb、Zn、S元素质量分数与金元素质量分数的相关性分析,进而建立了基于多重分形理论的金与共伴生元素多重分形模型。根据多重分形的拟合分析结果显示,Au、Cu、Pb、Zn和S元素的拟合曲线分布状态均呈明显的下凸型,其均匀程度介于正态分布和指数分布之间,广义分维值均大于1.3,说明它们之间存在明显的相关性。而银元素的拟合曲线分布状态明显不同于其它元素,说明银元素的富集不受或受到其它元素的影响很小。结合元素亲和性特征,以硫元素为核心,分析了Au、Ag、Cu、Pb、Zn的亲硫性,并将新太古代片麻岩金矿中金的演化过程划分成四个阶段,分别为①黄铁矿富集阶段,②自然金伴生阶段,③交代充填阶段,④变质氧化阶段。根据多重分形模型的拟合分析结果,并结合前人的理论研究成果表明:新太古代片麻岩金矿中共伴生元素组合对于金元素成矿极为重要,它为后期找矿的方向及隐伏矿床的发现提供了重要的指示。

定性分析分组的理论基础

本文从金属阳离子的X_+和Z^2/r值两个参数以及离子极化理论分析和论述金属阳离子的系统定性分析分组的理论基础。

Efficient in-situ end-functionalization of polydienes by isothiocyanate via neodymium mediated coordinative chain transfer polymerization system

End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.

Cleavage of catalytic ally grown carbon nanofibers into hydrophilic segments by oxidation in a mixture of concentrated HNO3-H2SO4 in an autoclave

The catalytically grown carbon nanofibers were treated by a mixture of concentrated nitric aid and sulfuric aid in an autoclave at temperature 333, 363 and 423 K. It was found that the samples treated at 363 K and 423 K were still well dispersed in water 15 hours later, indicating that carbon nanofibers can be made hydrophilicy. It was also found that the dispersion was destroyed when the pH value was lowered by adding acid. The results are significant when the carbon nanofibers are used as enhancing component in polymer composite material because several hundreds of nm are perfect size and the hydrophilicity controls the dispersion of CNFs in the polymer media. It is concluded that the amount of the oxygen-containing groups on the surface and the hydrophilicity of the carbon nanofibers can be controlled by the treatment temperature, and that the carbon nanofibers can be cleaved into uniform segments.