聚[碳酸(亚丁酯-co-ε-己内酯)酯]的制备及其载药微球性能的研究

采用阴离子配位聚合方法, 合成了二氧化碳、1,2-环氧丁烷与ε-己内酯的三元共聚物: 聚[碳酸(亚丁酯-co-ε-己内酯)酯](PBCL). 并采用复相乳液(W/O/W)溶剂挥发法制备了包裹抗菌药物甲磺酸帕珠沙星的可降解微球. 对聚合物进行了FTIR, ¹H NMR, ¹³C NMR, DSC, TGA和WAXD等表征, 以及降解性能和载药微球特性的研究. 结果表明, PBCL热稳定性及降解性能优于聚碳酸亚丁酯(PBC). 所得PBCL微球球形规整、表面光滑. 大部分微球粒径在0.5～1 μm的范围内, 载药量和包封率分别达到38.21%和87.9%. 微球的体外释药性能研究在pH 7.4的磷酸缓冲溶液中进行, 释放21 d后, PBCL微球的累积释药量为84.74%, PBC微球的释药量仅为17.29%. 药物的体外释放行为符合Higuchi方程. PBCL载药微球具有长效缓释作用.     

离子液体相转移催化环己醇氧化制备环己酮

以不同种类的离子液体作为相转移催化剂,用双氧水作为氧化剂,Na2WO4·2H2O为催化剂,在适当的反应条件下,能有效进行相转移催化环己醇氧化制备环己酮.实验结果表明,采用酸性离子液体[C16mim]HSO4和[C14mim]HSO4相转移催化合成环己酮,可提高环己酮的产率,具有反应条件温和、操作简便、需用时间短、相转移催化剂可以循环使用等优点.在反应温度为90℃,反应时间为50min条件下,环己醇的转化率高达100%,选择性99%以上.     

微波等离子体炬发射光谱法去溶系统性能的研究

用微波等离子体矩（MPT）作激发光源，等离子体的工作气体为氩气，研究了气动雾化进样去溶系统的工作参数对分析性能的影响，探讨了水冷凝与浓硫酸吸收二者协同去溶的相关性，结果表明，OH （Q1带，带头谱线为308.520nm）的发射强度即可判别样品去溶效果。     

Effects of Calcination Temperature on the Acidity and Catalytic Performances of HZSM-5 Zeolite Catalysts for the Catalytic Cracking of n-Butane

The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature.The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.     

三芳基膦配体的合成研究

从间溴苯酚出发, 利用新的合成方法经五步反应合成了一系列具有不同烷氧基的芳基膦配体. 改进后的方法可方便地通用于在苯环上具有各种不同基团基的膦配体衍生物的合成, 且有原料易得、操作简单、产率较高的优点.     

一阶导数差示脉冲极谱法用于甲硝唑的定量研究

本实验运用一阶导数差示脉冲极谱法对甲硝唑及其制剂进行了定量研究。在０．００１ｍｏｌ／Ｌ氯化钾－０．００１ｍｏｌ／Ｌ盐酸－水（１＋０．２＋４８）的底液中，甲硝唑于－０．８００Ｖ（ｖｓ Ａｇ／ＡｇＣｌ）处出现一良好的一阶导数差示脉冲极谱峰，在５０～３００μｇ／ｍＬ范围内，药物浓度与其导数峰幅值呈线关系，检测限为８．０×１０＾－８ｍｏｌ／Ｌ。本法操作简便，快速，灵敏，结果准确。     

Further Daphniphyllum Alkaloids from the Leaves of Daphniphyllum macropodum Miq.

Five new polycyclic Daphniphyllum alkaloids, macropodumines F ( 1 ) and G ( 2 ), 17‐oxoyuzurimine ( 3 ), and macropodumines H ( 4 ) and I ( 5 ), were isolated from the leaves of D. macropodum Miq ., collected in Sichuan Province, China. The structures and relative configurations of the new compounds – as well as of four known, related alkaloids – were elucidated on the basis of in‐depth spectroscopic and mass‐spectrometric analyses, by chemical derivatization, and by comparison of spectroscopic data with those of known compounds.     

Calix [ 4 ] arene Polyaza Derivatives： Novel Effective Neutral Receptors for Cations and α-Amino Acids

IntroductionCalixarenes are one of the most important supra-molecular building blocks, which can be modified byintroducing different functional and/or structural groupsto create a specific interaction between the host and thetarget molecules, such as meta…     

碳纳米管/ZnO纳米复合体的制备和表征

通过将不同直径的ZnO纳米颗粒与碳纳米管连接制备了碳纳米管/ZnO纳米复合体. 将团聚的ZnO纳米颗粒分散并用表面活性剂CTAB使纳米颗粒带正电. 化学氧化碳纳米管使其带负电. ZnO/CTAB微团通过碳管表面羧基与CTAB的静电作用与碳纳米管连接形成纳米复合体. 研究了复合体形成的不同实验条件, 表征了碳纳米管/ZnO纳米复合体的结构并研究了纳米复合体的光学特性. 研究表明, 与碳纳米管连接的ZnO纳米颗粒是互不连接的并保持量子点的特性. 光致发光研究表明ZnO纳米颗粒的激发在纳米复合体中有淬灭.     

Binding sites of nitrogenase: kinetic and theoretical studies of cyanide binding to extracted FeMo-cofactor derivatives

The first kinetic study of a substrate (CN(-)) binding to the isolated active site (extracted FeMo-cofactor) of nitrogenase is described. The kinetics of the reactions between CN(-) and various derivatives of extracted FeMo-cofactor [FeMoco-L; where L is bound to Mo, and is NMF, Bu(t)NC, or imidazole (ImH)] have been followed using a stopped-flow, sequential-mix method in which the course of the reaction is followed indirectly, by monitoring the change in the rate of the reaction of the cofactor with PhS(-). The kinetic results, together with DFT calculations, indicate that the initial site of CN(-) binding to FeMoco-L is controlled by a combination of the electron-richness of the cluster core and lability of the Mo-L bond. Ultimately, the reactions between FeMoco-L and CN(-) involve displacement of L and binding of CN(-) to Mo. These reactions occur with a variety of rates and rate laws dependent on the nature of L. For FeMoco-NMF, the reaction with CN(-) is complete within the dead-time of the apparatus (ca. 4 ms), while with FeMoco-CNBu(t) the reaction is much slower and exhibits first order dependences on the concentrations of both FeMoco-CNBu(t) and CN(-) (k = 2.5 +/- 0.5 x 10(4) dm(3) mol(-1) s(-1)). The reaction of FeMoco-ImH with CN(-) occurs at a rate which exhibits a first order dependence on FeMoco-ImH but is independent of the concentration of CN(-) (k = 50 +/- 10 s(-1)). The results are interpreted in terms of CN(-) binding directly to the Mo site for FeMoco-NMF and FeMoco-ImH, but with FeMoco-CNBu(t) initial binding at an Fe site is followed by movement of CN(-) to Mo. Complementary DFT calculations are consistent with this interpretation, indicating that, in FeMoco-L, the Mo-L bond is stronger for L = ImH than for L = CNBu(t) and the binding of CN(-) to Mo is stronger than to any Fe atom in the cofactor.