新显色剂2-(2-咪唑偶氮)-4-磺酸酚与镍的分光光度研究及其应用

本文合成了显色剂,研究了它的性质与Ni(Ⅱ)的显色反应,确定了反应条件、络合物组成和稳定常数,应用拟定的方法测定了铸铁、合金钢中的微量镍。     

头孢唑啉钠的荷移分光光度法测定

研究了头孢唑啉钠与７，７，８，８－四氰基对二次甲基苯醌（ＴＣＮＱ）的荷移（ＣＴ）反应，确立了荷移反应的最佳条件。结果表明：在丙酮－甲醇介质中，两者于３０℃水浴中恒温３０ｍｉｎ即可形成１∶２的络合物，在其最大吸收波长７４３ｎｍ处表观摩尔吸光系数ε＝１７６×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，在０～２４ｍｇ／Ｌ范围内符合比尔定律线性关系。方法的相对标准偏差小于３％（ｎ＝１０）。对形成ＣＴ络合物的机理进行了探讨。并应用拟定的方法对样品注射用头孢唑啉钠进行了含量测定，结果与标准方法一致，回收率符合要求     

A New Isomalabaricane Triterpenoid from Sponge Jaspis sp.

From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23-dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.     

偶氮胂Ⅲ与牛血清白蛋白作用的分光光度研究

本文研究了溶液基本条件如酸度和离子强度等对偶氮胂Ⅲ－牛血清白蛋白分子复合物形成的影响。在pH2．0条件下，标准工作曲线的线性范围为0～60mg／L；桑德尔灵敏度为0．15μg／cm2。采用平衡透析法、双波长法及摩尔比法测定了pH2．0时牛血清白蛋白对偶氮胂Ⅲ的最大结合数。结果表明有两类结合，第一类结合的最大结合数为30～40；结合常数约106mol－1L.     

氯化钠介质中小牛胸腺脱氧核糖核酸对铈（Ⅲ）的荧光猝灭机理

在ＰＨ〈６．２的ＮａＣｌ介质中，Ｃｅ（Ⅲ）受２５４．０ｎｍ紫外光激发所产生的３５０．０ｎｍ荧光因Ｃｅ（Ⅲ）的各种阳离子型体与小胸腺ＤＮＡ上的磷酸根发生静电作用而被猝灭。     

高钙镁铅锌矿中锌的交流示波极谱滴定

本文阐述了用交流示波极谱滴定法测定高钙镁铅锌矿中的锌。在NH_4Cl—NH_3H_2O(pH=10)支持电解质中采用微银汞膜电极进行实验。分别用NH_4F和铜试剂掩蔽钙、镁、铜、铅、镉及其它竽金属元素。铁和铝不干扰测定。用EDTA滴定锌获得令人满意的结果,对两种矿样分析,准标偏差为0.05%和0.07%。该法快速准确,适用于测定高钙镁的铅锌矿中锌。     

Synthesis of thiourea derivatives as CCR4 antagonists

A series of thiourea derivatives have been synthesized. Their structures were confirmed by MS and 1H NMR. Several compounds showed potent activities as antagonists of CCR4 receptor.     

A new triterpene saponin from the leaves of Ilex kudincha

A new compound,kudinoside LZ_2(1),was isolated from the leaves of Ilex kudincha.Its structure was elucidated by the combination of one- and two-dimensional NMR analysis,HR-ESI-MS,CD spectrum measurement and chemical evidences.     

Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses

The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-alloying strategy and the substitutions of similar elements. Bulk metallic glasses with diameters of 3 mm take shape at compositions formulated under the clus- ter-plus-glue-atom model [M9B]B~[(Ni1-xFex)7.71(Si0.66Ta0.34)1.29B]B0.94=(Ni1-xFex)70.5B17.7Si7.8Ta4, x=0.35–0.45, where the bracketed part is the cluster and the unbracketed part is the glue atoms. These alloys exhibit good magnetic properties. The maximum Is is found in the (Ni0.55Fe0.45)70.5B17.7Si7.8Ta4 alloy which reaches 0.51 T, with its Hc as low as 8.5 A/m. Interestingly, these alloys display dual glass transitions at (Ni0.65Fe0.35)70.5B17.7Si7.8Ta4, (Ni0.60Fe0.4)70.5B17.7Si7.8Ta4 and (Ni0.55Fe0.45)70.5B17.7- Si7.8Ta4 as unveiled by Temperature-Modulated Differential Scanning Calorimetry.     

Spectroscopic studies on the spontaneous assembly of phenosafranin on glycosaminoglycans templates

Spectroscopic studies showed that binding of phenosafranin (PSF) molecules to glycosaminoglycans (GAGs) resulted in the following observations: (i) appearance of a 52.6 nm hypsochromic shift of the visible absorption band; (ii) static quenching of fluorescence from PSF; (iii) induction of strong circular dichroism (CD) signal of PSF. Stoichiometry of the PSF-GAGs complex was determined by spectrophotometric titration, spectrofluorimetric titration and MacIntosh extraction method. These studies demonstrated the formation of the extended helical PSF array aligned on the helical backbone of GAGs templates by electrostatic force, and the dimeric binding mode of PSF to each anionic site was proposed. The comparative studies between PSF-heparin (Hep) and PSF-chondroitin 4-sulfate (CS) complexes revealed that: (i) stoichiometry of PSF-Hep complex was 1.8 times of PSF-CS complex; (ii) Hep was more effective than CS (1.8 times) in decreasing the absorbance of PSF; and (iii) Stern-Volmer constants of the Hep-PSF system were greater than that of the CS-PSF system. These differences were attributed to the different charge density on the Hep and CS molecules, which in turn suggested that the electrostatic force was dominant in the interaction between PSF and GAGs.