以对-(4-烯丙氧基苯甲酰氧基)苯甲酸对-甲氧基苯酚酯为单体的液晶聚硅氧烷的合成与表征

A liquid crystalline polysiloxane has been prepared by a hydrosilation reaction of poly (methylhydrosiloxane) with (p-((4-allyloxy)benzoxy)benzoxy)-4-methoxyphenyl. The chemical structure of the monomer and polymer was confirmed by IR and 1H-NMR analysis, and as many as 13% α-addition isomeric side chains were found from the NMR spectrum of the polymer. In addition ,the phase behavior of the monomer and polymer were studied by optical polarized microscopy and DSC measurements.     

含SR桥的双核钼(I)配合物Mo2(CO)8-n(SR)2Ln的新合成途径和Mo2(C(O)6(SPh)2(MeCN)2的结构研究

经由零价双核钼含SR桥的配合物的氧化反应合成了一系列含各种SR桥的双核钼(I)配合物Mo2-(CO)8-n(μ-SR)2Ln(R=Br^t, Ph, Bz(C6H5CH2), CH2CO2Et;L=MeCN, PPh3; n=0,2]. 并应用红外光谱、元素分析等进行表征, 讨论了新的合成途径. 含MeCN配位体配位到Mo(I)上的配合物, Mo2(CO)6(SPh)2(MeCN)2经X射线结构测定, 系属单斜晶系, 空间群P21/c,a=9.241(2), b=9.330(3), C=15.458(4)A:β=105.77(2)°V=1283(1)A^3; Z=2; R=0.033. Mo-Mo距离为2.978A, 表明其Mo-Mo距离为2.978A, 表明其Mo-Mo键的形成, Mo-S键长为2.469A. 比较同系物Mo2(CO)8(μ-SCH2CO2-Et)2, Mo2(CO)6(μ-SCH2CO2Et)2(MeCN)2和Mo2(CO)8(μ-SBu^t)2的结构, 并讨论其结构与化学.     

石墨纤维氧化表面处理对环氧树脂界面粘合影响的研究

<正> 由于石墨纤维表面能较低,因此石墨纤维/树脂复合材料的界面粘合情况极为重要,为了阐明界面的粘合机理,需要对石墨纤维的表面特性如表面活化能、浸润性、表面积、表面化学基团等方面进行研究,为了提高复合材料的层间剪切强度,常常用各种方法对石墨纤维的表面进行处理,以期改变纤维表面的物理和化学结构来增加纤维和环氧树脂     

三种瓜环与4,4''''-联吡啶及N,N''''-二甲基4,4''''-联吡啶盐酸盐相互作用的研究

以七元瓜环(Q[7])和新型椭圆型改性瓜环--对称四甲基取代六元瓜环(TMeQ[6])为主体,4,4'-联吡啶的盐酸盐(44)以及N,N'-二甲基4,4'-联吡啶的盐酸盐(dm44)为客体的主客体相互作用进行了考察.实验结果表明,Q[7]与客体44及dm44作用体系中,客体为了更有效地被主体Q[7]包结,在Q[7]内腔中呈倾斜状分布的几率最高.用核磁共振、循环伏安以及紫外吸收光谱对实验结果进行了印证和补充,验证了TMeQ[6]与客体44及dm44可发生较强的相互作用,形成一维的自组装超分子结构.核磁共振以及循环伏安方法的实验结果表明,没有观察到Q[6]与客体44及dm44的明显作用,而紫外吸收光谱方法证实,Q[6]与客体44确实存在一定的相互作用,比较主客体的结构特征,该作用体系也可能存在自组装的一维超分子结构等多种作用形式.     

聚对硝基苯偶氮间苯二酚修饰电极伏安法测定多巴胺

采用循环伏安法研究了多巴胺(DA)在聚对硝基苯偶氮间苯二酚(p-nitrobenzenazo resorcinol,简称NBAR)膜修饰电极上的电化学行为,用差示脉冲伏安法对多巴胺的含量进行测定.结果表明,聚NBAR膜修饰电极对DA有明显的电催化作用.在pH4.0的磷酸盐缓冲液中,氧化峰电流与DA浓度在5.0×10-6~8.0×10-4mol/L范围内呈良好的线性关系,检测限为6.0×10-7mol/L.修饰电极可有效消除针剂中其它组分对DA测定的干扰,已用于实际样品DA含量的测定,结果令人满意.     

STUDIES ON PAN MACROMOLECULAR SEMICONDUCTING FIBER 1. PREPARATION OF PAN CONDUCTING FIBER TREATED BY STANNIC CHLORIDE AND ITS SEMICONDUCTING BEHAVIOUR

The PAN fiber treated by Lewis acid (e.g. stannic chloride) could be transformed into a macromolecular conducting fiber by further thermal treatment. Depending on thermal treatment condition the resistance of the fiber varied from 10~3 to 10~(12) Ωand kept stable after hydrolysis. The fiber has enough strength to be processed by various means. This is a new kind of macromolecular semiconducting fiber having some characteristics similar to those of organic semiconductors.     

MgFe2O4纳米粉体的水热合成及其表征(英)

MgFe₂O₄ nanoparticles were hydrothermally synthesized at 150 ℃ using iron nitrate [Fe(NO₃)₃·9H₂O], magnesium nitrate [Mg(NO₃)₂·6H₂O] and sodium hydroxide (NaOH) as starting materials by carefully controlling the reaction conditions. The influences of several factors such as presence or absence of Na⁺, molar ratio of Fe³⁺ / Mg²⁺, concentration of mental ions, temperature and reaction time on resultant products were investigated in the hydrothermal process. The sample was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and its magnetic properties were measured using vibrating sample magnetometer (VSM).     

白血病骨髓移植患者口腔黏膜病与微量元素锌的关系

为研究白血病骨髓移植患者全血微量元素锌与口腔黏膜病的关系，用原子吸收光谱法检测了正常对照组与白血病骨髓移患者预处理前及移植后骨髓空虚期全血微量元素锌的含量，并观察了白血病骨髓移植患者空黏膜病变情况。结果表明，正常对照组全血锌浓度与白血病骨髓移植患者预处理前全血锌浓度比较，差异无显著性（P＞0．05），而预处理前全血锌浓度与骨髓空虚期全血锌浓度有显著性差异（P＜0．01），白血病缓解后（预处理前）血锌接受正常水平，无口腔溃疡发生，而白血病骨髓移植患者处理后骨髓空虚期全血锌含量显著降低，并出现不同程度的口腔黏膜病变，说明预处理影响微量元素锌的代谢，微量元素锌的减少与白血病骨髓移植患者移植患者口腔黏膜病的发生有关。     

Structure and Photoluminescence of Polycrystalline MgxZn1-xO Films

Different photoluminescence （PL） spectra are observed for rf magnetron sputtered polycrystalline Mg0.25Zn0.75O and Mg0.37Zn0.63O films on silicon substrates when excited by different wavelengths. When the excitation wavelength is 280nm, a UV emission peak at 370nm and a blue peak at 462nm are generated for the Mg0.25Zn0.75O film, and those two peaks for the Mg0.37Zn0.63O film shift to 366nm and 466nm, respectively. The wavelengths of the PL peaks are related to the excitation wavelength. The stronger peak is obtained in the blue band due to a large number of oxygen vacancies caused by excess Zn and Mg atoms, while the weaker peak is obtained in the ultraviolet band.