党参花粉多糖的研究

从蜜峰采集的党参花粉中,分离到5种多糖CPA～CPE,经凝胶过滤及电泳法验证了纯度并测定了分子量。对CPA进行了全水解、甲基化分析、NalO_4氧化和Smith降解分析,用旋光法测定了CPA中单糖残基的绝对构型,对CPA的IR、~1H NMR、~(13)C NMR及~1H NMR、~(13)C偶合NMR进行了分析,确定了异头碳的构型。对CPA进行了电子显微镜分析,首次在透射电子显微镜下观察并拍摄到了具有串珠状特殊二级结构的多糖照片,经分析得到了CPA二级结构的一些信息。     

Mesoscale organization of CuO nanoribbons: formation of "dandelions"

A two-tiered organizing scheme with multiple-length scales for construction of dandelion-like hollow CuO microspheres has been elucidated: (1) mesoscale formation of rhombic building units from smaller nanoribbons via oriented aggregation and (2) macroscopic organization of these units into the CuO microspheres. This self-assembly concept may also be applicable to other metal oxides by creating geometric constraints for constructional units.     

催化动力学光度法测定痕量钒（Ⅴ）的研究

本文研究了在酸性介质中痕量钒（Ⅴ）催化氯酸钾氧化变色酸及抗坏血酸体系的反应和动力学条件，建立了催化动力学光度法测定痕量钒（Ⅴ）的新方法。该方法的检出限为０．０８ｎｇ／ｍＬ Ｖ（Ⅴ），线性范围为０～０．３μｇ／２５ｍＬ Ｖ（Ⅴ）。将该方法用于水样及人发中痕量钒（Ⅴ）测定，结果令人满意。     

四（对三甲铵苯基）卟啉分光光度法测定稻米中的微量锌

四（对三甲铵苯基）卟啉，在乙二胺存在下与Ｚｎ（Ⅱ）形成络合物。据此提出了用分光光度法测定微量锌的方法，该络合物最大吸收波长为４２５ｎｍ表观摩尔吸光系数为３．４２×１０＾５，锌量在０～４．５μｇ／２５ｍＬ范围内符合比尔定律，本法可用于稻米中微量锌的测定。     

SiO2/α-FeOOH和SiO2/γ-Fe2O3微粒的界面研究

α－FeOOH微粒由于其表面高活性，在转变成γ－Fe2O3的热处理过程中容易烧结，一旦这种烧结现象发生，得到的γ－Fe2O3磁粉磁性能大大下降[1]．为了克服这一困难，目前采用在α-FeOOH微粒表面包敷有机物[2]和无机物[3]来隔离颗粒，阻止其聚集．其中SiO2表面包敷处理是最令人感兴趣的研究课题之一[4，5]．SiO2是一种难烙性的非磁性材料，它包敷在α-FeOOH微粒表面外，不仅可提高α－FeOOH转变成γ－Fe2O3的热处理温度，有利于得到外形完好、晶格完整的γ－Fe2O3磁粉，而且由包效层与内核之间的界面相互作用引起的表面各向异性常…     

Effects of the structure and morphology of zinc glutarate on the fixation of carbon dioxide into polymer

Zinc glutarates were synthesized from zinc oxides with varying purities via different stirring routes. The particle size and structure of these zinc glutarates were determined by wide‐angle X‐ray diffraction, transmission electron microscopy, and the laser particle size analyzer technique. The results demonstrated that the crystallinity and crystalline perfectness of zinc glutarate are the crucial factors that affect the catalytic activity for the copolymerization of carbon dioxide (CO₂) and propylene oxide (PO). Additionally, the catalyst with a small particle size dramatically increased the yield of the copolymerization between CO₂ and PO. High‐molecular‐weight and regular molecular structure poly(propylene carbonate)s (PPC)s were obtained from CO₂ and PO with the synthesized zinc glutarates. Very high catalytic activity of 160.4 g polymer/g catalyst was afforded. The NMR technique revealed that the PPC copolymer exhibits an exact alternating copolymer structure. The relationships between the crystallinity and the particle size of catalyst with the catalytic activity are correlated and discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3579–3591, 2002     

不同分子筛载体对CO加氢产物分布的影响

研究了几种小孔分子筛ＺＳＭ－５，ＨＹ，ＮａＹ及β担载ＺｒＯ２对Ｃ加氢反应的催化作用，并就产物的分布情况与担载ＺｒＯ２的硅铝中孔分子筛进行了对比研究。其中中孔分子筛分别用季铵盐和一级胺为模板剂，在水热条件和常温常压下合成；并用ＢＥＴ，ＸＲＤ，ＳＥＭ等手段表征了它们的孔道和骨架结构。另外，考察了碱金属Ｋ＾２＋，Ｎａ＾２＋对催化剂催化性能的影响。     

Photo-controllable bioorthogonal chemistry for spatiotemporal control of bio-targets in living systems

The establishment of bioorthogonal chemistry is one of the most significant advances in chemical biology using exogenous chemistry to perturb and study biological processes. Photo-modulation of biological systems has realized temporal and spatial control on biomacromolecules in living systems. The combination of photo-modulation and bioorthogonal chemistry is therefore emerging as a new direction to develop new chemical biological tools with spatiotemporal resolution. This minireview will focus on recent development of bioorthogonal chemistry subject to spatiotemporal control through photo-irradiation. Different strategies to realize photo-control on bioorthogonal bond-forming reactions and biological applications of photo-controllable bioorthogonal reactions will be summarized to give a perspective on how the innovations on photo-chemistry can contribute to the development of optochemical biology. Future trends to develop more optochemical tools based on novel photochemistry will also be discussed to envision the development of chemistry-oriented optochemical biology.

The establishment of photo-controllable bioorthogonal chemistry is one of the most significant advances in chemical biology to perturb and study biological processes.     

A Mild Isomerization Reaction for β,γ‐Unsaturated Ketone to α,β‐Unsaturated Ketone

A series of β,γ‐unsaturated ketones were isomerized to their corresponding α,β‐unsaturated ketones by the introduction of DABCO in iPrOH at room temperature. The endo‐cyclic double bond (β,γ‐position) on ketone was rearranged to exo‐cyclic double bond (α,β‐position) under the reaction conditions.     

Modifying electronic communication in dimolybdenum units by linkage isomers of bridged oxamidate dianions

Reactions of Mo(2)(O(2)CCH(3))(DAniF)(3), DAniF = N,N'-di-p-anisylformamidinate, with oxamidate dianions [ArNC(O)C(O)NAr](2-), Ar = C(6)H(5) and p-anisyl, give pairs of isomeric compounds where the [Mo(2)] units are bridged by the oxamidate anions. For the alpha isomers, the C-C unit of the dianion is nearly perpendicular to the Mo-Mo bonds, and these are essentially perpendicular to each other. For the beta isomers, the corresponding C-C unit and the Mo-Mo bonds are essentially parallel to each other. Each type of isomer is stable in solution. The electronic communication as measured by the DeltaE(1/2) for the oxidation of each of the Mo(2) units is significantly better for the beta isomers. This is supported also by the appearance of what is conventionally called an intervalence charge-transfer band in the near infrared region upon oxidation of the beta isomers but not the alpha isomers. Molecular mechanics and DFT calculations help explain the relative conformations in the alpha isomers and the relative energy differences between the alpha and beta isomers.