芳香族羟肟的合成及其萃取铜的结构-性能研究

合成了一系列不同结构高纯度的芳香族羟肟, 测得了它们的反式羟肟含量和解离常数, 用HMO法计算了配位原子的电荷密度, 并用多元线性回归法研究了这类化合物的结构参数与其萃取铜反应平衡常数的关系。     

季铵盐结构与高氯酸根离子选择电极性能关系的研究

本文报道了由七种长链季铵盐制得的高氯酸根离子选择电极,测定了这些电极的Nernst响应范围和检测下限,并研究了各种阴离子的干扰。通过大量实验测得,随着季铵盐分子中取代烷基碳链的增长,电极电势响应范围增宽、检测下限降低、抗外部阴离子干扰能力增强。若取代烷基碳链过长,则季铵盐纯化困难,在膜相中溶解度降低,不适于电极的研制。根据用上述七种选择电极在相同水相条件下测得的数据表明,阴离子的干扰次序为:PA~->ClO_4~->BF_4~->SCN~->I~->ClO_3~->N_3~->N_3~->CN~-～Br~->H_2PO_4~->F~->Cl~-。这些数据对阴离子选择电极研制与相转移催化反应研究均有现实意义。     

A NEW PROPERTY OF BERNSTEIN-KANTOROVIC OPERATORS

In the present paper,we prove that the Bernstein-Kantorovic operators have the ability of preserving translation property in both C and L^p norms.     

CaCl~2-KCl熔体结构的X射线衍射分析

用高温液态X射线衍射方法, 测定了摩尔比为1:2的CaCl~2-KCl熔体的径向分布函数。结果表明, 熔体中Ca^2^+-Cl^-、K^+-Cl^-和Cl^--CL^-离子对间的最近邻距离分别为0.278,0.306和0.380nm。由于Ca^2^+与Cl^-间的强Coulomb作用, 在熔融的摩尔比为1:2的CaCl~2-KCl体系中, Cl^--Cl^-间的最近邻距离明显小于纯KCl熔体中Cl^--Cl^-间的最近邻距离。     

稠杂环化合物研究 i: 3-(4'-吡啶基)-6-芳基-均-三唑并[3,4-b]-1,3,4-噻二唑的合成及其抗菌性能

本文研究3-(4'-吡啶基)-4-氨基-5-巯基-1,2,4-三唑(1)与取代苯甲酸(2s-s)在氯化氧磷催化下的反应, 制得19种新的3-(4'-吡啶基)-6-芳基-均-三唑并[3,4-b]-1,3,4-噻二唑(3a-s), 确证了结构。初步观察了它们在约0.01%的浓度时, 对枯草杆菌, 大肠杆菌, 变形杆菌和金黄色葡萄球菌繁殖的抑制作用。     

促δ-波睡眠肽的结构与功能的研究

用固相法合成了促δ-波睡眠肽Trp-Ala-Gly-Gly-Asp-Ala-Ser-Glu(DSIP)及其十四种类似物和三个短肽,研究了结构与功能的关系,类似物的设计,主要考虑在分子中引入D-氨基酸以抑制酶的作用和增强稳定性,以及引入疏水侧链氨基酸如Phe和Trp等。位置的修饰主要在1,3,4,5,8和9位,即:D-Trp[1],Tyr[1],Tyr[1]Phe[5],D-Trp[1]Phe[8],Trp[3,4],D-Trp[3,4],D-Trp[1,3,4]Phe[8],D-Glu[9],D-pF-Phe[3,4]Phe[8]D-Glu[9],Phe[5],Glu[5]Asp[9],Tyr[5]Asp[9],Ala[7]和Asp[9]-DSIP以及Trp-Ala-Gly-Gly-Asp,Trp-Ala-Gly-Gly-Glu和Trp-Gly-Glu.合成肽的纯度经氨基酸组成分析、元素分析、薄层层析以及纸电泳鉴定。生物试验表明D-Trp[1],Tyr[1],Tyr[1]Phe[5],Ala[7]-DSIP无促眠活性;而Phe[5]-DSIP的促眠活性与DSIP相接近,其他类似物的生物试验结果将另文发表。     

酯化硅胶的物理结构和表面性质的研究

本文利用正庚醇或正辛醇与硅胶表面羟基反应制备了酯化硅胶。测定了酯化硅胶的物理结构、水蒸气吸附等温线、润湿热、差热分析和红外光谱。结果表明: (1)所有酯化硅胶的真密度(dT)、比表面(S)和比孔体积(V)均减少, 而有观密度(dA)增加, 但平均孔半径(r)变化不大; (2)酯化硅胶是憎水的, 其对水蒸气吸附, 以及对水和环己烷的润湿热均显著减少; (3)酯化硅胶的表面酯基在空气中于235-350℃破坏; (4)酯化反应是可逆的, 硅胶表面酯基在水中大约可水解41-47%。     

Kenaf/polypropylene biocomposites: effects of electron beam irradiation and alkali treatment on kenaf natural fibers

Thermal and dynamic mechanical properties of kenaf natural fiber reinforced polypropylene (PP) biocomposites were examined to compare the effects of natural fiber treatment by electron beam irradiation (EBI) and alkalization. The alpha cellulose contents, the functional groups on the surfaces and the thermal stability of the untreated and treated kenaf fibers were studied. Kenaf fiber/polypropylene(PP) biocomposites were fabricated by means of a compression molding technique using chopped kenaf fibers treated with electron beam (EB) dosages of 100, 200, 500 kGy or with NaOH concentrations of 2, 5, 10 wt%, respectively. The thermal stability, the dynamic mechanical and the interfacial properties of untreated and treated kenaf/PP biocomposites were also investigated through a thermogravimetric analysis, a dynamic mechanical analysis and a fractographic observation, respectively. The results show that the characteristics of kenaf fibers and biocomposites depended on the different treatment level with the EB dosages or on the NaOH concentrations used. In this study, the modification of kenaf fiber surfaces at 200 kGy EBI and treatment with 5 wt% NaOH was most effective for improving the performance of kenaf/PP biocomposites. This study suggests that EBI can be used for modification of natural fiber as an environmentally friendly process and contribute to an improvement in the performances of kenaf/PP biocomposites.     

The Effects of Surface and Pore Characteristics of Natural Fiber on Interfacial Adhesion of Henequen Fiber/PP Biocomposites

The pore characteristics and morphological changes of henequen fiber after electron beam (EB) irradiation were studied, and their effects on interfacial adhesion between henequen fiber and polypropylene (PP) matrix of biocomposites were investigated. The surface morphologies of the fibers exposed to various EB irradiation doses were observed with an atomic force microscope (AFM). The porosity and pore distribution of fibers were characterized by mercury porosimetry and nonfreezing bound water (NFW) was measured by differential scanning calorimeter (DSC). Henequen fiber-reinforced polypropylene biocomposites were manufactured by the compression molding method and interlaminar shear strength (ILSS) was analyzed to examine the interfacial adhesion between henequen fiber and the PP matrix of the biocomposites. The AFM images indicated that pectin, waxy materials and impurities were removed from the surfaces of the henequen fibers during EB irradiation, resulting in changes of the surface morphology and characteristics of the fibers. When pectin, waxy compounds and impurities were removed, small pores of 1–0.01 μm were produced, and total surface area and porosity were increased. The increase in total surface area and porosity induced better adhesion between fiber and polymer which was confirmed by ILSS tests. However, the excessive creation of small pore size gives a negative effect on the tensile strength of henequen fiber. The best interfacial adhesion between henequen fiber and PP was obtained for the biocomposite reinforced with the henequen fiber treated with 10 kGy, which has the highest surface area and optimum pore diameter for interlocking between henequen fiber and polypropylene.     

1-取代芳基-4-乙氧羰基-5-酰胺基-1, 2, 3-三唑的合成及 抗菌性能的研究

报道了1-取代芳基-4-乙氧羰基-5-氨基-1,2,3-三唑同各种酰氯的反应,制得23种新型衍生物1-芳基-4-乙氧羰基-5-酰胺基-1,2,3-三唑。讨论了产物的收率与所用酰化试剂的关系,新化合物的结构经IR,^1HNMR,MS及元素分析确证,并评价了这些化合物的抗菌性能。