Mechanisms and Kinetics of Reactions of the O（^1D,^3P） ＋ CF3Cl System

In the stratosphere,CF3Cl(CFC13)can either photodecompose or react directly with atomic oxygen to generate ozone-depleting agents such as Cl and ClO in the gas phase[1—3].Since the1970s,attention has been focused on the effects of these compounds on the …     

离子色谱法测定皂粒中葡萄糖酸钠含量

建立了离子色谱检测皂粒中葡萄糖酸钠含量的分析方法。样品经METROSEP CARB 1糖分析色谱柱(150 mm×4.0 mm,5μm)分离,以150 mmol·L~(-1) NaOH+20 mmol·L~(-1)NaAc水溶液为流动相进行等度洗脱,流速1.0 mL·min~(-1),采用瑞士万通850型离子色谱仪,选择脉冲安培检测器进行测定,外标法定量。结果显示:葡萄糖酸钠在0.5～200 mg·L~(-1)质量浓度范围内呈良好的线性,相关系数(r~2)为0.999 6,检出限为0.25 mg·L~(-1),定量下限为0.63 mg·L~(-1)。葡萄糖酸钠在1～20 mg/g加标范围内的回收率为80.7%～104%。该方法无需衍生化处理,操作简单方便,灵敏度高,可用于皂粒产线葡萄糖酸钠含量的监控与测定。     

氨水溶液制备ZnO纳米晶阵列的研究

以氨水和硝酸锌为前躯体，采用低温水溶液法在涂敷ZnO晶种层的玻璃衬底上外延生长了ZnO纳米棒晶阵列。应用SEM、TEM、SAED和XRD表征了ZnO纳米晶的形貌和结构。讨论了该组成体系水溶液法纳米棒外延生长的机理及其对棒晶形貌的影响。通过对水溶液pH值的原位二次调整，制备出了ZnO纳米管和表面绒毛状的棒晶阵列，基于生长机理探讨了它们的形成原因，为实现不同形貌ZnO纳米晶阵列的优化控制提供了可能的技术途径。结果表明，不同形貌的ZnO均属沿c轴择优取向的六方纤锌矿结构。     

钇(Ⅲ)-莫西沙星配合物的荧光性质及分析应用

钇(Y3+)与莫西沙星(MoxifloxacinMXFX)形成的配合物能显著地增敏莫西沙星的荧光强度,据此,建立了测定莫西沙星的新方法。该方法的检出限为8.5×10-10mol/L;莫西沙星的浓度在1.0×10-8～1.0×10-6mol/L范围内与配合物体系的荧光强度呈良好的线性关系。对1.0×10-6mol/L莫西沙星平行测定12次,RSD为1.1%。该法可用于测定尿样中的莫西沙星。对荧光增强机理作了简要的探讨。     

染料敏化太阳能电池中大孔TiO2薄膜电极的制备及应用

采用溶胶-凝胶水热法制备了TiO₂纳晶薄膜电极，晶型为锐钛矿型。为了提高电极的光电性能，利用聚苯乙烯小球做造孔剂，制备了含有大孔隙的TiO₂纳晶薄膜电极，孔径约为200 nm，该电极具有较好的光漫反射性能，更重要的是球形大孔的存在，提高了凝胶电解质在TiO₂薄膜电极中的渗透和I₃^-离子的扩散性能，与不含大孔的TiO₂电极相比，电池的短路光电流提高约2 mA·cm^-2，光电转换效率提高0.6%。     

Electrochemical Characteristics of Mg0.9Ti0.1-xZrxNi （x=0.02, 0.04, 0.06） Alloys

Mg-based hydrogen storage alloys Mg0.9Ti0.1-xZrxNi (x=0.02, 0.04, 0.06) were successfully prepared by means of mechanical alloying (MA). The effects of Zr addition on the discharge capacity and the cycle performance of the Mg-based electrodes were also studied. It was found that the discharge capacities were improved with addition of a small amount of Zr and the cycle performances of the alloy were stabilized with the addition of Ti. The effects of surface modification or coating on the properties of Mg0.9Ti0.06Zr0.04Ni were also studied. The results indicated that coating with graphite improved both the discharge capacity and cycle life of the amorphous Mg0.9Ti0.06Zr0.04Ni electrode.     

IMMOBILIZATION OF POTENTIALLY BIOACTIVE MOIETIES ONTO POLYETHER WITH POLY(ETHYLENE GLYCOL)-SULFONATE SPACER

A new reactive graft copolymer, poly(tetramthylene glycol) - graft-w-propyl sodiumsulfonate-poly(ethylene glycol) (PTMG-g-PEG-CH_2CH_2CH_2SO_3~-Na~+), was synthesizedby the cationic polymerization of a-w-bifunctional PEG macromonomer (O?CH_2—PEG——CH_2 CH_2 CH_2 SO_3 Na) and THF. The obtained copolymer exhibits the expected structureas indicated by the result of characterization. Two amino acids (L-arginine, L-tyrosine)were covalently attached to the copolymer after converting the sulfonate group to sulfonylchloride. So the new reactive graft copolymer (PTMG-g-PEG-CH_2CH_2CH_2SO_3~-Na~+) isexpected to be very useful in attachment of potentially bioactive moieties to polymer viaa hydrophilic PEG spacer.     

Unprecedented isospecific 3,4-polymerization of isoprene by cationic rare earth metal alkyl species resulting from a binuclear precursor

The isospecific 3,4-polymerization of isoprene has been achieved for the first time by use of a combination of a binuclear rare earth metal dialkyl complex, such as [Me2Si(C5Me4)(mu-PCy)YCH2SiMe3]2 (Cy = cyclohexyl), and an equimolar amount of [Ph3C][B(C6F5)4] as a catalyst system. A DFT calculation suggested that a binuclear monocationic monoalkyl species, such as [Me2Si(C5Me4)(mu-PCy)Y(mu-CH2SiMe3)Y(mu-PCy)(C5Me4)SiMe2]+, in which the alkyl group bridges the two metal centers, could be the true catalyst species.     

Preparation and Properties of Urease Immobilized onto Glutaraldehyde Cross-linked Chitosan Beads

Urease was immobilized onto the glutaraldehyde cross-linked chitosan beads that were prepared under microwave irradiation. The activity and the yield of activity of immobilized urease was 10.83 U/g B and 47.7%, respectively. The conditions of urease immobilization were optimized. The properties of the immobilized urease were investigated and compared with that of the free enzyme.     

2-(2′-羟基苯基)间氮杂硫茚激发态质子转移反应的理论研究

人们早就认识到质子转移互变异构反应的存在。近年来,发现的激发态分子内质子转移反应更引入注目,因为它有重大的应用前景,如