Asymmetric Intramolecular Hydroalkoxylation of Unactivated Alkenes Catalyzed by Chiral N‐Triflyl Phosphoramide and TiCl4†

By using a combination of a chiral N‐triflyl phosphoramide and TiCl₄ as the catalyst, a new process for asymmetric intramolecular hydroalkoxylation of unactivated alkenes was developed, producing various chiral tetrahydrofuran derivatives in 51%—99% yields with 30%—71% ee's.     

贵金属同时浮选分离富集行为的研究及ICP－AES的测定

本文通过对贵金属－碘化钾－孔雀绿显色体系的浮选行为研究，建立了一种同时浮选富集分离铂、钯、铑、铱、金的新方法。实验结果表明，在０．３６ｍｏｌ／ＬＨＣｌ０．１ｍｏｌ／ＬＫＩ和２．４×１０￣（－４）ｍｏｌ／ＬＭＧ的溶液中，加入环已烷振荡１ｍｉｎ，铂、钯、铑、铱、金可被定量浮选，继而用ＩＣＰ－ＡＥＳ测定。对含量为５～１５０μｇ的贵金属，浮选回收率分别为铂８８．６％～９５．７％，钯９２．３％～９９．５％，铑９３．７％～１０１％，铱９２％～９８．５％，金８６．４％～９４％。方法应用于铜镍矿、铂网废料等物料中上述贵金属元素的测定，结果满意。     

ZnO-TiO2的表面结构与表面性质

本文通过XRD相定量及低能离子散射谱研究了ZnO-TiO_2体系的结构. 实验表明, ZnO单层分散在TiO_2表面上, ZoO与TiO_2之间的结合较弱, 这种表面结合并不导致新的表面酸位。本文还讨论了ZnO-Al_2O_3、ZnO-SiO_2、ZnO-TiO_2三种含锌二元氧化物在结构、性能方面的明显差异及其根源。     

环磷酰胺的示波极谱法测定

研究了环磷酰的示波极谱法。环磷酰胺经亚硝化反应后，其产物在０．１ｍｏｌ／Ｌ ＨＣｌ介质中于－０．４９０Ｖ附近出现一清晰的阴极还原波。在１．０×１－＾－４ｍｏｌ／Ｌ范围内，浓度与波高有良好的线性关系，检测下限可达５×１０＾－８ｍｏｌ／Ｌ．用于针剂，注剂和尿液中环磷酰胺的测定均获满意的结果。     

Mechanism of TiO2-assisted photocatalytic degradation of dyes under visible irradiation: photoelectrocatalytic study by TiO2-film electrodes

Photoelectrocatalytic degradation of various dyes under visible light irradiation with a TiO(2) nanoparticles electrode has been investigated to reveal the mechanism for TiO(2)-assisted photocatalytic degradation of dyes. The degradation of both cationic and anionic dyes at different biases, including the change in the degradation rate of the dyes and the photocurrent change with the bias potential, the degraded intermediates, the voltage-induced adsorption of dyes, the accumulation of electrons in the TiO(2) electrode, the effect of various additives such as benzoquinone (BQ) and N,N-dimethyl aniline (DMA), and the formation of active oxygen species such as O(2)(*-) and H(2)O(2) were examined by UV-visible spectroscopy, HPLC, TOC, and spin-trap ESR spectrometry. It was found that the dyes could controllably interact with the TiO(2) surface by external bias changes and charging of dyes. The cationic dyes such as RhB and MG underwent efficient mineralization at negative bias, but the N-dealkylation process predominated at positive bias under visible light irradiation. The discolorations of the anionic dyes SRB and AR could not be accelerated significantly at either negative or positive bias. At a negative bias of -0.6 V vs SCE, O(2)(*-) and dye(*+) were formed simultaneously at the electrode/electrolyte interface during degradation of cationic RhB. In the case of anionic dyes, however, it is impossible for the O(2)(*-) and dye cationic radical to coexist at the electrode/electrolyte surface. Experimental results imply both the superoxide anionic radical and the dye cationic radical are essential to the mineralization of the dyes under visible light-induced photocatalytic conditions.     

利用电荷迁移反应测定头孢羟氨苄

提出一种基于电荷迁移反应简便可靠地测定头孢羟氨苄的分光光度法。在甲醇－乙醇介质中，头孢羟氨苄与氯冉酸于５０℃反应１５ｍｉｎ能够形成稳定的１：１络合物，其λｍａｘ＝５２８ｎｍ，线性范围为２０￣４００ｍｇ／Ｌ。用拟定的方法测定原粉和胶囊，结果与药典法一致。对浓度１００ｍｇ／Ｌ的药物１０次测定相对标准偏差为１．４％，样品的标准加入回收率为９９．０％￣１００．８％。     

Studies of poly-<Emphasis Type="Italic">L</Emphasis>-lysine-starch nanoparticle preparation and its application as gene carrier

Anion starch nanoparticle (StNP) with a diameter of 50 nm was prepared in water-in-oil microemulsion, with soluble starch as raw materials and POCl₃ as crosslinking agent. PLL-StNP was prepared by linking poly-L-lysine (PLL) on the surface of StNP. At the same time, the size of PLL-StNP and its stability in aqueous solution were checked by AFM. The analysis of plasmid DNA binding, DNase I enzymatic degradation, toxicity and transfection were done. We discovered that PLL-StNP may be used as non-virus nanoparticle gene carrier. And we developed the method of preparing PLL-StNP gene carrier and used it in cell transfection. As non-virus gene carrier, PLL-StNP has some advantages, such as large load of DNA, high transfection efficiency, low cell toxicity and biodegradability.     

汞—钯试剂络合物极谱吸附波的研究

在极谱催化波和吸附波方面,国内进行了大量的研究,但汞的络合物吸附波至今未见报道。钯试剂已用于光度法测定钯等。我们在研究该试剂与金属离子络合的极谱行为时发现,在硼砂介质中,试剂与Hg~(2+)可形成电活性络合物并可用于汞的测定。     

智能型水凝胶

智能型水凝胶是一类具有广泛应用前景的功能高分子材料，但由于传统水凝胶存在一些缺点因而限制了其应用，因此近年来围绕提高传统水凝胶的性能做了大量研究工作。本文从四个主要方面综述了近年来智能型水凝胶改性的研究进展。     

同步荧光光谱分析中几个问题的探讨

通过实验阐明了同步荧光光谱与普通荧光光谱之间的关系，在此基础上讨论了溶剂散射光对同步荧光分析的影响以及同步荧光分析的灵敏度。