杜氏盐藻多糖的高效体积排阻色谱的保留特性及其分析方法的研究

通过对从杜氏盐藻中提取出的不同多糖级分在高效体积排阻色谱柱(Waters Ultrahydragel Linear,7.8 mm i.d.×300 mm,2根串联)上的保留特性的考察及其分离分析条件的优化,建立了高效体积排阻色谱分析盐藻多糖平均相对分子质量及其分布的方法。结果表明:流动相中盐的种类及其浓度、pH值对3种酸性多糖级分(特别是硫酸化多糖级分PD4a)的保留行为有显著影响;在柱温为45 ℃,流速为0.9 mL/min条件下,使用0.1 mol/L的NaAc水溶液作流动相基本上能消除非特异性吸附作用及分子间缔合等因素的干扰,使各多糖级分基本以非缔合状态按立体排除机制保留和分离。在优化的色谱条件下,测得的盐藻多糖5个级分的重均相对分子质量(Mw)分别为1548000,33000,67000,424000,10000;测得的硫酸化多糖级分PD4a的Mw和峰面积的相对标准偏差分别为1.7%和 0.88%(n=5)。     

液/液界面生长法制备一维纳米硒

采用均相反应界面生长法制备了一维结构的纳米硒。在制备过程中,初始硒纳米粒子首先在均相反应液中生成,然后加入与该反应液不互溶的溶剂,使其形成液液界面,硒纳米粒子聚集在界面上生长为一维结构。用扫描电镜、透射电镜、X射线粉末衍射等测试技术对样品进行了表征,并讨论了界面生长的机理及其影响因素。     

一种结构新颖的肟醚类化合物的合成及其生物活性研究

以苯并五元环为基本结构对肟醚类strobilurin杀菌剂侧链进行修饰, 共设计合成了13个结构新颖的肟醚类化合物. 室内生物活性测试结果表明所合成的化合物对小麦白粉病(Eryiphe graminis)和黄瓜霜霉病(Pseudoperonospora cubensis)均具有优异的抑菌活性, 而所合成的部分茚取代肟醚类化合物还具有广谱的杀虫活性. 同时, 用钯催化“一锅法”反应以较高的收率合成了关键中间体2-乙酰基茚衍生物.     

稀土-沸石-TiO2三元体系光催化材料的性能研究

以钛酸丁酯、稀土硝酸盐、斜发沸石为主要原料,用溶胶-凝胶法制备了稀土-沸石-TiO2三元体系的光催化剂.使用IR,TG-DSC,XRD,SEM等手段对样品进行了表征; 以甲基橙为目标物,太阳光为光源,用光解率对光催化剂性能进行了评价.实验表明,随着沸石负载TiO2量的增加,光催化剂的3 h光解率也逐渐提高; 反应体系的温度越高,光解率越大; 当溶液pH约等于5时,光解率达到最大.     

Design, synthesis and antifungal activity of novel triazole derivatives

Twenty-three 1 -(1H-1,2,4-triazole-1 -y1)-2-(2,4-difluorophenyl)-3-(iV-cycloproyl-N-substituted-amino)-2-propanols were designed and synthesized on the basis of the active site of lanosterol 14α-demethylase. In vitro antifungal activities showed that some of the title compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.     

Synthesis, crystal structure and configuration of acetylated aryl Pyrogallol[4]arenes

A series of aryl and ferrocenyl pyrogallol[4]arenes have been synthesized by the HCl-catalyzed condensation reactions of pyrogallol with aromatic aldehydes and ferrocenecarbaldehyde. The fully acetyl and ethoxycarbonylmethoxy derivatives were also prepared and fully characterized. The crystal structures show that acylated phenyl pyrogallol[4]arene exists in rctt (cis-trans-trans) configuration, while the corresponding ferrocenyl pyrogallol[4]arene in rccc (all cis) configuration.     

Enhancement of corrosion resistance of electrocodeposited Ni–SiC composites by magnetic field

The corrosion behavior and surface morphology of Ni–SiC composite coatings produced by electrodeposition with the aid of magnetic field were studied. The results of the electrochemical analysis including polarization resistance and potentiodynamic polarization curves showed that a magnetic field of 0.1 T could significantly improve the corrosion resistance of the composite. The electrochemical impedance spectra revealed that a passive layer was formed on the surface of the Ni–SiC coating with the magnetic field. The microstructures of electrodeposited Ni–SiC composite coatings were also examined. More SiC particles were found to be incorporated into the coating with the presence of magnetic field, which was considered to be one of the reasons for the enhancement of corrosion resistance as SiC particles were reported to be corrosion inhibitors. Contribution to special issue “Magnetic field effects in Electrochemistry”     

Effect of Transition Metals (Cu, Co and Fe) on the Autothermal Reforming of Methane over Ni/Ce0.2Zr0.1Al0.7Oδ Catalyst

The transition metals (Cu, Co, and Fe) were applied to modify Ni/Ce0.2Zr0.1Al0.7Oδ catalyst.The effects of transition metals on the catalytic properties of Ni/Ce0.2Zr0.1Al0.7Oδ autothermal reforming of methane were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS.Tests in autothermal reforming of methane to hydrogen showed that the addition of transition metals (Cu and Co) significantly increased the activity of catalyst under the conditions of lower reaction temperature,and Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ was found to have the highest conversion of CH4 among all catalysts in the operation temperatures ranging from 923 K to 1023 K. TPR, XRD and XPS measurements indicated that the cubic phases of CexZr1-xO2 solid solution were formed in the preparation process of catalysts.Strong interaction was found to exist between NiO and CexZr1-xO2 solid solution. The addition of Cu improved the dispersion of NiO, inhibited the formation of NiAl2O4, and thus significantly promoted the activity of the catalyst Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ.     

Studies on lignan constituents from Schisandra chinensis (Turcz.) Baill. fruits using high-performance liquid chromatography/electrospray ionization multiple-stage tandem mass spectrometry

A reversed-phase high-performance liquid chromatography-diode array detector-electrospray ionization multiple-stage tandem mass spectrometry (RP-HPLC-DAD-ESI-MS(n)) method has been developed for the detection and analysis of lignan constituents in the methanol extract from the fruits of Schisandra chinensis (Turcz.) Baill. RP-HPLC-DAD-ESI-MS(n) and electrospray ionization Fourier transform ion cyclotron resonance multiple-stage tandem mass spectrometry (ESI-FT-ICR-MS(n)) have been applied to investigate the characteristic product ions of four lignan reference compounds. Then, the logical fragmentation pathways of the lignans have been proposed. By comparing the retention time (t(R)) of HPLC, the ESI-MS(n) data and the structures of analyzed compounds with the data of reference compounds and in the literature, 11 peaks in HPLC have been unambiguously identified and another 5 peaks have been tentatively identified or deduced. Also, in the present paper, the extracted ion chromatograms (EIC) have been used to analyze the lignan isomers. The experimental results demonstrate that RP-HPLC-DAD-ESI-MS(n) is a specific and useful method for the identification of the lignan constituents and their isomers.     

Mesoporous TiO2/SiO2 composite nanofibers with selective photocatalytic properties

Mesoporous TiO2/SiO2 composite nanofibers with a diameter of 100-200 nm and silica shell thickness of 5-50 nm have been fabricated by a sol-gel combined two-capillary co-electrospinning method; the composite nanofibers exhibited selective photocatalytic activity based on the decomposition of Methylene Blue, Active Yellow and Disperse Red.