Preparation and Crystal Structure of Sodium Hydrogen Epoxysuccinate

1 INTRODUCTION In recent years, sodium hydrogen epoxysuccinatehas gained special attention as a raw material of po-lyepoxysuccinic acid (PESA)[1～3]. We have synthes-ized sodium hydrogen epoxysuccinate by the reac-tion of H2O2 and maleic anhydride in water ca-talyzed by tungstate and obtained its single crystal[1].Its structure was determined by X-ray Nonius CAD4diffractometer. Up to now some crystal structures oforganic carboxyl sodium have been determined[4～6].In this paper we …     

Conformational statistics of polymer chain terminally attached to wall (I)——NRW model tail chain

The simplest form of a polymer chain adsorbed on a solid surface is that the polymer chain has only one end group attached to the surface, i.e. the polymer chain forms the "tail" conformation. In the present work, the problem was simplified as the random walk confined in the half-infinite space and studied systematically. The conformational distribution functions of the model tail chain in different dimensions were obtained. It has been found that the ratio of the conformational number of the model tail chains to that of the free chains varies as a power function N-12 when the chain length N→∞. It has also been proved that for the tail chain the component of the mean square end-to-end distance in the normal direction of the confined boundary is doubled and the other components are constant in comparison with the case of the free chain.     

SrCe0.95Er0.05O3-α固体电解质的导电性

SrCe_0.95Er_0.05O_3-α ceramic of a single orthorhombic phase of perovskite-type SrCeO₃ was prepared by high-temperature solid state reaction. Using the ceramic as solid electrolyte and porous platinum as electrodes, the measurements of conductivities and ionic transport numbers on SrCe_0.95Er_0.05O_3-α ceramic were performed by using electrochemical methods in the temperature range of 600～1 000 ℃ in wet hydrogen, dry air and wet air, respectively. The results indicate that the sample is a pure protonic conductor with a maximal conductivity of 0.01 S·cm^-1 in wet hydrogen, a mixed conductor of oxide-ion and hole in dry air, and a mixed conductor of proton, oxide-ion and hole in wet air.     

二(2-苯基-8-羟基喹啉)锌及其衍生物的电子光谱性质的含时密度泛函理论研究

采用从头算(ab initio)和密度泛函理论(DFT B3LYP)方法。对二(2-苯基-8-羟基喹啉)锌(Zn(qPh)₂)及其衍生物的基态结构进行优化，同时用ab initio HF单激发组态相互作用(CIS)法在6-31G基组上优化其最低激发单重态几何结构，用含时密度泛函理论(TD-DFT/B3LYP)及6-31G基组计算吸收和发射光谱。计算表明，该类物质电子在基态与激发态间的跃迁，主要是电子云分布由定域化向离域化的转变。吸收及发射光谱的计算值与实验值基本符合。该类化合物的电子亲和能较大，都是优良的电子传输材料，改变中心金属原子对配合物光谱性质影响不大。而羟基氧被硫原子取代后，化合物的吸收光谱产生明显红移。     

含改性硅微粉硅橡胶阻燃抑烟研究

为进一步提升硅橡胶(SR)的阻燃性能,利用硅烷偶联剂对硅微粉(SF)进行表面改性,以改性后的SF为阻燃剂,制备出SR样品。通过扫描电子显微镜(SEM)对改性前后SF表面形貌进行表征,通过极限氧指数(LOI)、水平垂直测试、锥形量热仪(CCT)、烟密度测试(SDT)等手段研究SR复合材料力学性能、阻燃性能、抑烟性能。研究表明:添加相同质量的SF和改性SF时,含改性SF的SR力学性能明显提升。其中,含21%(wt)改性SF/SR复合材料的力学、阻燃性能综合最佳。与纯SR相比,改性SF/SR复合材料的LOI增加了15%,热释放速率峰值降低86%,火灾增长指数降低了58%,最大烟密度降低43%。     

稀土—5—Br—PADAP螯合物的高效液相色谱分离与测定

以配合物形式分离金属离子已有报道.胡之德等研究了In、Pt、Pd等金属与5-Br-PADAP螯合物的色谱行为,在硅胶柱上成功地分离了这几种金属元素.林长山等应用反相高效液相色谱法,分离了Fe(Ⅲ)、Co(Ⅱ)和V(Ⅱ)3种金属的5-Br-PADAP螯合物,并做了定量的研究.本文应用高效液相色谱法研究了镧系-5-Br-PADAP螯合物色谱行为,探讨了相关因素对分离和测定的影响,讨论了螯合物的保留值与稀土元素原子半径的关系.     

The asymmetric addition of phenylacetylene to aldehydes

Enantioselective formation of C-C bonds is an area of intense research.Among them, the asymmetric addition of alkynyl reagents to aldehydes is very useful for the synthesis of chiral secondary propargyl alcohols, which are very important building blocks for many chiral organic compounds, and the acetylene and hydroxyl founctional group of propargyl alcohol can be easily transfered into many other structures.1Recently, many significant chiral ligands have been disclosed.2 Here, we report our r…     

光圈性能测试仪的研制

介绍一种在实验室条件下对电视系统环境光照度适应范围测试的光圈性能测试仪.包括系统的组成和工作原理、主要技术难点及解决办法,给出了已达到的技术指标.该装置光学耦合系统的分辨率高,图像照度调整范围大、精度好、仪器结构紧凑,重量轻,性能稳定可靠.     

气相色谱法测定脱羧氯雷他定中有机溶剂残留量

采用气相色谱技术建立脱酸氯雷他定中5种有机溶剂乙醇、乙腈、乙酸乙酯、四氢呋喃、甲苯残留量的测定方法；以N，N-二甲基甲酰胺为溶剂，苯为内标，在聚乙二醇-20M柱和OV-101毛细管柱串联柱上，程序升温可有效分离各组分，氢火焰检测器检测；各有机溶剂在5-200mg／L范围内线性良好(r=0．999)，在高、中、低3个浓度水平上的平均回收率分别为乙醇98．6％、乙腈98．9％、乙酸乙酯105％、四氢呋喃98．4％、甲苯100％；检出限分别为25、50、25、25、10μg／g。     

同载基因和药物的超微载体粒子的制备及体外评价

以聚乳酸_乙醇酸共聚物 (PLGA)和自行制备的O_羧甲基壳聚糖 (O_CMC)为原料 ,以 5_氟尿嘧啶 (5 Fu)为抗癌药物模型 ,以反义EGFR(表皮生长因子受体 )为基因药物模型 ,构建与评价了同载抗癌药物与基因的复合功能纳米药物载体系统。同载超微粒子的平均粒径为 2 5 8 7nm ,粒径分布指数为 0 14 2 ,粒子表面 ξ电位为 - 10 6 7eV。同载超微粒子在PBS中的释药行为研究表明 :超微粒子中 5_FU和基因均具有零级缓慢释放特性。体外肿瘤细胞存活率实验和免疫组化实验均证实同载超微粒子能高效抑制TJ90 5人脑胶质瘤细胞的增殖。最后用荧光共聚焦显微镜动态监测了超微粒子进入瘤细胞的转染过程 ,发现粒子可在不同时间内进入细胞浆和细胞核。