Nanostructure Pt Electrode Obtained via Self-assembly of Nanoparticles on Conductive Oxide-coated Glass Substrate

Self-assembly of platinum nanoparticles were applied to fabrication of counter electrode for dye-sensitized solar cells on conductive oxide-coated glass substrate. The present Pt electrode exhibits high exchange current density of 220 mA/cm^2, which is comparable to those prepared by electrodeposition, magnetron sputtering or thermal decomposition of platinum chloride. After analysis by transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), it was found that the catalyst was structurally characterized as nanosized platinum metal clusters and was continuously arranged on electrode surface. The present nanostructure electrode had high electrocatalytic activity for the reduction of iodine in organic solution.     

Au/CeO2/Y和Au-MFe2O4催化剂用于有氧条件下CH4还原NOx的研究

以CeO2／Y分子筛和MFe2O4(M=Ni,Co，Zn)为载体，制备Au／CeO2／Y和Au-MFe2O4负载型金催化剂．用CH4做还原剂，考察了它们在有氧条件下催化还原NOχ的活性．结果表明：在Au-Y中引人助剂Ce，使得Au／CeO2／Y的催化活性高于Au／Y；Au-CoFe2O4的催化活性高于Au-Fe2O3，反应温度为300℃时，NOχ在Au-CoFe2O4上的转化率达到39．70%．     

辣根过氧化物酶自组装多层膜结构形貌与活性的研究

用分子沉积自组装作制备了阳离子化和阴离子化的辣根过氧化物酶自组装膜；并用原子力显微镜（AFM）研究了不同离子化辣根过氧化物酶单层及多层自组装膜的形貌结构与自组装膜的活性变化关系。结果表明：阴离子化的辣根过氧化物酶自组装膜的表面形貌比较粗糙，均方根粗糙度（RMS）及酶分子粒径较大，且组装膜的活性比较大。     

Phenylsulfonic Acid Functionalized Mesoporous Silica Catalyzed Transetherification of Alcohols with Dimethoxymethane

Phenylsulfonic acid functionalized mesoporous silica was synthesized by condensation of tetraethylorthosilicate with phenyltrimethoxysilane, and then sulfonation using 30% fuming sulfuric acid. The material was characterized using FT‐IR, DSC, XPS, TEM and N2 adsorption/desorption measurements. DSC revealed that sulfonic acid group of the catalyst was decomposed at 354.8°C, indicating that the catalyst exhibited high thermal stability. XPS showed that there existed three kinds of different silicon species on surface of the catalyst. The catalytic performance of the catalyst was evaluated using transetherification of alcohols with dimethoxymethane. It was found that among primary alcohols, the selectivities of the two long‐chain alcohols for n‐dedocanol and n‐tetradecyl alcohol were higher than 97.0% at the conversions of 43.6% and 65.3%, respectively, while the selectivities of the short‐chain alcohols except for n‐hexanol were less than 90.0% at the conversions of over 80.0%. Due to steric barrier, the secondary alcohols such as iso‐butanol and cyclohexanol afforded conversions of 79.4% and 60.5%, and the selectivities of the two alcohols were more than 90.0%. The sequence in conversion of the substituted phenols is as follows: p‐nitrophenol>p‐fluorophenol≥p‐bromophenol>p‐cresol>m‐cresol.     

N-茄呢基胺类糖酯化合物的合成及生理活性

在氢氧化钠和四丁基溴化铵存在下,将化合物2-N-茄呢基胺基苯甲酸(3)和N-茄呢基己二酰胺酸(6)分别与O-乙酰基溴代葡萄糖、O-乙酰基溴代半乳糖、O-乙酰基溴代乳糖和O-乙酰基溴代麦芽糖反应制得对应的糖酯4a～4d和7a～7d,由元素分析,IR,1H NMR和MS确证了8个新化合物的结构,并对其中6个化合物(4a,4d和7a～7d)在三种癌细胞模型上进行了一些初步体外生理活性的测试.     

吉西他滨类似物的设计、合成及体外抗肿瘤活性

吉西他滨是临床一线治疗恶性肿瘤的药物,但其4-位氨基(N4)易与脱氧胞苷脱氨酶(CDA)作用而失活,导致代谢稳定性差,严重影响了临床治疗效果。以吉西他滨为起始原料,经3步反应合成了N4保护的脂溶性吉西他滨衍生物(3a和3b),其结构经1H NMR,13C NMR和HR-MS(ESI)表征。体外活性测试结果显示:化合物3a对多种肿瘤细胞的抗增殖作用均强于临床药物吉西他滨(P<0.05)。酶稳定性实验结果表明:3a几乎不受CDA影响,代谢稳定性显著高于原药吉西他滨。     

分子诱导效应指数与链烷烃的沸点

利用基团的诱导效应指数，首次提出了分子的诱导效应指数的概念，并定义了 链烷烃的有效碳链长度NC＝（MIs,N/MIb,N)·N，式中MIs,N,MIb,N分别为直链和支 链异构体的分子诱导效应指数。研究结果表明，链烷烃的沸点Tb(℃）与NC关系是 ：1n(806.5-Tb)=6.9824-0.11431NC^2/3     

薄层扫描法测定冬眠过程中刺猬活性组织酶的周期变化

薄层扫描法测定冬眠过程中刺猬活性组织酶的周期变化冯金城（天津师范大学天津３０００７４）孙金生（天津水产研究所天津３００２２１）１前言为了跟踪观察刺猬在冬眠过程中体内乳酸脱氢酶的周期性变化，利用薄层扫描仪测定了其相关的组织同工酶的差异。实践证明，此法简...     

《高分子化学》课程中“活性自由基聚合”的教学实践

《高分子化学》课程是五大化学基础课程(无机化学、有机化学、分析化学、物理化学、高分子化学)之一,是化学类、高分子材料与工程、材料化学专业的必修课程。"活性"/可控自由基聚合是一种相对较新且重要的聚合物合成技术和方法,针对目前《高分子化学》课程中活性自由基聚合的教学比较薄弱的现状,从教学的角度探讨了活性聚合和可控/"活性"自由基聚合的本质和特点,介绍了本人在这方面的教学实践活动,遵循成果导向教育理念,通过以学为中心的教学方式,打造金课,提高教学质量。     

氢部分选择性催化还原NO反应研究

在低钯含量活性非均布Pd/Al2O3催化剂上，实现了富氧条件下，氢部分选择性催化还原NO过程，低温、富氧条件下NO的转化率高达80％－100％。NO直接分解实验表明，600℃，NO分解转化率在无氧时为17．3％，有0．5％氧存在时接近于0。氢非选择性还原NO条件下，100℃以下，NO转化率为100％。根据实验结果及文献，推测了氢部分选择性还原NO过程中可能存在的反应，不同的反应温度下，NO脱除反应有所不同。在115℃以下，NO还原产物为NH3；115℃－155℃，NO还原产物为NH3、N2O和N2；155℃以上，NO还原产物中无NH3存在。NO还原反应与氢氧反应是平行的竞争反应。