P204-P507-H2SO4体系萃取稀土元素的研究

对P204与P507混合萃取剂在硫酸介质中萃取分离Nd和Sm的行为进行了研究。重点考察了在硫酸介质中,P204添加一定量P507对稀土萃取能力、反萃性能以及Nd-Sm分离效果的影响。测定了不同比例的混合有机相在不同平衡酸度下的Nd,Sm分配比以及协同系数,并得到了相应条件下的Sm/Nd分离系数。试验结果表明,P204与P507混合体系在硫酸介质中萃取分离Nd,Sm时存在不同程度的正协同效应。     

Regiodivergent and Enantioselective Hydroxylation of C−H bonds by Synergistic Use of Protein Engineering and Exogenous Dual-Functional Small Molecules

It is a great challenge to optionally access diverse hydroxylation products from a given substrate bearing multiple reaction sites of sp³ and sp² C−H bonds. Herein, we report the highly selective divergent hydroxylation of alkylbenzenes by an engineered P450 peroxygenase driven by a dual-functional small molecule (DFSM). Using combinations of various P450BM3 variants with DFSMs enabled access to more than half of all possible hydroxylated products from each substrate with excellent regioselectivity (up to >99 %), enantioselectivity (up to >99 % ee), and high total turnover numbers (up to 80963). Crystal structure analysis, molecular dynamic simulations, and theoretical calculations revealed that synergistic effects between exogenous DFSMs and the protein environment controlled regio- and enantioselectivity. This work has implications for exogenous-molecule-modulated enzymatic regiodivergent and enantioselective hydroxylation with potential applications in synthetic chemistry.     

HDEHP和HEH/EHP混合萃取剂在硫酸介质中协同萃取RE(Ⅲ)的机制研究

对HDEHP(H2B2)和HEH/EHP(H2L2)混合萃取剂在硫酸介质中萃取稀土元素(La,Nd,Sm,Gd)的机制进行了研究。研究表明,在水相平衡pH=2.0时,混合萃取剂萃取这几种元素的协萃系数分别为:1.96(La),3.52(Nd),5.96(Sm),5.71(Gd),并且协萃系数随水相平衡pH的升高而增加。利用斜率法分别确定了单一萃取剂HDEHP和HEH/EHP以及混合萃取剂HDEHP HEH/EHP在硫酸体系中萃取稀土元素的配合物结构式分别为RE(SO4)xH2x(HB2)3,RE(SO4)xH2x(HL2)3以及RE(HB2)2(HL2)。计算了反应的平衡常数及形成常数并确定了反应机制为阳离子交换反应。     

稀土萃取分离废水制备高纯碳酸氢镁溶液过程中铁杂质的行为与影响

以稀土冶炼分离过程中产生的氯化镁废水和白云石为原料制备氢氧化镁,然后采用碳化法制备高纯碳酸氢镁溶液,研究了铁杂质离子的行为与影响。结果表明:碳酸氢镁溶液中的杂质铁是由于二价固态铁发生碳化反应而引入并以重碳酸亚铁(Fe(HCO3)2)形式存在,即碳化反应过程是除铁的核心工序,Mg(HCO3)2溶液经过除铁后沉淀稀土离子可以明显降低沉淀产物中铁杂质含量。本文为氯化镁废水-白云石碳化法制备碳酸氢镁溶液过程中铁杂质离子的去除提供切实可行的理论指导。     

含氟硫酸体系HEH/EHP萃取铈(Ⅳ)的动力学研究

采用层流恒界面池法研究了2-乙基己基膦酸单2-乙基己基酯(HEH/EHP)萃取含氟复杂硫酸体系中铈(Ⅳ)的动力学。考察了搅拌速度、水相金属离子浓度、萃取剂浓度、酸度和温度对萃取速率的影响。试验结果表明:萃取反应为一级反应,萃取反应的正向表观活化能为50.8 kJ·mol-1,属于化学反应控制。试验得到萃取动力学方程为R=k[Ce(HF)(HSO4-)3+]1.05[H2A2]2.07[H+]-2.43,并探讨了反应机制。     

稀土与天青石共伴生矿焙烧及浸出过程研究

稀土与天青石共伴生多金属矿主要由稀土氟碳酸盐和天青石组成,研究了含稀土和锶的混合矿的焙烧及浸出过程,考察了焙烧温度、焙烧时间、浸出初始酸浓度、浸出温度、浸出时间等对浸出率的影响,获得优化的工艺参数为:焙烧温度500℃,焙烧时间2 h,浸出初始酸浓度1.0 mol.L-1,浸出温度35℃,浸出时间1 h,稀土浸出率达95%以上,锶浸出率小于5%,几乎不进入溶液相而保留在固相浸出渣中得以分离和富集。     

李群的解析对合自同构对的分类

本文给出复单李代数的对合自同构对的分类,并利用它研究单连通,单李群的解析对合自同构对的分类.     

Multiple-Color Platinum Complex with Super-Large Stokes Shift for Super-Resolution Imaging of Autolysosome Escape

It is of great significance to track the platinum drugs in real time with super-resolution to elucidate their mechanism of action, such as their behavior and distribution in live cells. Such information is required for further drug development. However, it is always challenging to design platinum complexes suitable for such research. Herein, we design a luminescent building block ( L ) for metal complexes and a dinuclear platinum complex ( Pt₂L ) for super-resolution imaging. Because of its super-large Stokes shift and excellent photophysical properties, Pt₂L is capable of serving as an ideal candidate for super-resolution imaging with extremely low luminescence background and high photobleaching resistance. Moreover, upon light stimulation, a matter flux of Pt₂L escaping from autolysosomes to nucleus was observed, which represents a new transportation path. Utilizing the photoactivated escape properties, we can regulate the nuclear accessibility of Pt₂L form autolysosomes with photo-selectivity, which provides a new way to improve the targeting of platinum drugs.