稀土化合物催化内酯开环聚合（Ⅲ）──氯化钕－环氧化合物体系催化ε

稀土化合物催化内酯开环聚合（Ⅲ）──氯化钕－环氧化合物体系催化ε－己内酯本体聚合申有青，沈之荃，沈建良，张富尧，张一烽（浙江大学高分子科学与工程学系，杭州，３１００２７）关键词氯化钕，环氧化合物，ε－己内酯，本体聚合聚己内酯（ＰＣＬ）和聚丙交酯（ＰＬ...     

Synthesis and Crystal Structure of 3,3‘—（Hexane—1,6—diyl）bis（1—acetyl—5,5—dimethylhydantoin）,a New Inducer of Differentiation

The title compound C20H30N4O6, Mr = 422.48)was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P ī with cell parameters: a = 8.330(2), b = 8.468(2), c = 16.017(3) A, α = 97.30(3), β = 92.33(3), γ = 103.94(3)o, V = 1084.7(4) A3, Dc = 1.294 g/cm3, Z = 2, F(000) = 452 and μ = 0.096 mm-1. The structure was refined to R = 0.0483 for 3732 observed reflections with I>2(I) and wR = 0.1335 for 4828 unique reflections. The hydantoin rings are planar and the two ring planes of one molecule are paralleled to each other.     

微乳液体系中过硫酸钾氧化碘离子的动力学研究

分别在不同盐浓度的自由水和不同液滴尺寸的微乳液中测量了过硫酸钾氧化碘 离子的化学反应速率常数，获得微乳液不核中水的活度，探讨了水的活度及体系中 离子强度与反应速率的关系，发现当表面活性剂与水的摩尔比R≤20时，水的活度 随微反应器尺寸减小而快速下降。     

Poly（meta-phenylene） Derivative with Rigid Twisted Biphenyl Units in Backbone： Synthesis, Structural Characterization, Photophysical Properties and Electroluminescence

A soluble poly(meta-phenylene)derivative with rigid twisted biphenyl unit was synthesized by the Yamamoto coupling reaction.The polymer is soluble in common organic solvents,and the number-average molecular weight is about 6500.The UV-Vis and quantum chemical calculation indicate that the different conformation segments named "conformers" exist in the polymer backbones;it was also further confirmed by the single crystal X-ray diffraction study of the dimeric model compound.The π-π transition of biphenyl segments of twisted and planar conformations made the polymer exhibit a strong absorption around 256 nm and a weak absorption at about 300 nm.Furthermore,the polymer exhibits a strong UV photoluminescence at 372 nm when the excitation wavelengths are longer than 300 nm.The ultraviolet-emitting electroluminescence(EL)device with the single layer structure shows EL λmax of the derivative at 370 nm.     

CARBON-13 NMR STUDY OF MOLECULAR MOTION OF 1, 2-POLYBUTADIENES IN SOLUTION Ⅰ. STRUCTURE DEPENDENCE OF MOLECULAR MOTIOM

Proton decoupled, partially relaxed, Fourier-transform 50.3 MHz carbon-13 NMR in naturalabundance was used to determine spin-lattice times (T_1) and nuclear Overhauser enhancement fac-tors (NOE) of individual carbon of a serics of 1,2-polybutadienes with different structures in solutionin CDCl_2 The structure dependence of molecular metion and the internal motion of vinyl group in1,2-polybutadiene have been studied by nT_1 and NOE values. The nT_1 values of the carbons in cis-1,4-units are the highest and those of the carbons in 1.2-units are the lowest in three types of units in1,2-polybutadiene. The nT_1 values of carbons in the same unit become greater when the adjacent1,2-units are replaced by 1,4-units, and nT_1 values of the carbons in all units decrease sharply withthe increase of content of 1,2-units in the polymers. The fact that nT_1 values of --CH=are larger than those of=CH_2 in vinyl group impliesthat there are complex internal motions of vinyl group. It is shown by calculation that the dominantfactor causing the difference in nT_1 of--CH=and=CH_2 in vinyl group is a swing of vinyl group ina plane peopndicular to the chain backbone.     

低于300℃时两种氧化铈材料对稀燃阶段NOx存储性能的影响

研究了低于300 ℃时两种氧化铈对稀燃阶段NO_x存储性能的影响,催化剂由2%（w）Pt/Al₂O₃（PA）与CeO₂-X（X=S,I）机械混合制备. X射线衍射（XRD）,BET表面积和扫描电子显微镜（SEM）用于表征材料的物理结构. X射线光电子能谱（XPS）和H₂程序升温还原（H₂-TPR）用于表面Ce³⁺和活性氧定量. 原位漫反射傅里叶变换红外光谱（in-situ DRIFTS）用于分析表面NO_x吸附物种. 相比于CeO₂-I,CeO₂-S 具有优良的物理化学性能,包括高比表面积、丰富的空隙结构、较高的抗老化能力及表面Ce³⁺浓度. 因而,Pt/Al₂O₃+CeO₂-S 表现出优异的NO_x存储能力. 此外,PA+CeO₂-X（X=S,I）上存在Pt 与CeO₂之间的相互作用,可提高表面氧物种的活性进而促进NO氧化及NO_x存储. PA+CeO₂-S上的这种相互作用要强于PA+CeO₂-I. 研究表明,表面Ce³⁺浓度和活性氧含量对NO_x存储起到重要作用. 然而经过水热处理后,Pt 与老化的氧化铈（ACS,ACI）之间的相互作用降低,并且两种氧化铈NO_x存储性能显著下降. 另外,与PA+ACS（ACI）相比,PA+PACS（PACI）样品NO_x存储能力得到改善,这归因于表面氧物种活性增加能促进硝酸盐的形成.     

Ni／Al2O3催化剂上CH4／CO2重整的脉冲反应研究

报道了用脉冲反应研究Ｎｉ／Ａｌ２Ｏ３催化剂上ＣＨ４／ＣＯ２重整反应的结果。脉冲反应显示，在还原的Ｎｉ／Ａｌ２Ｏ３催化剂上，ＣＨ４在６７３Ｋ就开始发生分解，并有Ｃ２Ｈ６、Ｃ２Ｈ４生成，１０２３Ｋ下，ＣＨ４几乎完全分解，单纯的ＣＯ２则很难在还原的催化剂上发生反应，在９７３Ｋ以上的高温下才会有少量Ｃ胜成ＣＯ．ＣＨＣＯ２的脉冲反应表明，当ＣＨ４在较低温度下开始分解时，ＣＯ２也会发生分解，并生成ＣＯ。脉冲反     

蒙脱土表面键合配位体固相萃取填料的制备及其对重金属离子的吸附性能

通过酸洗、硅烷偶联剂表面活化、键合苯甲酰异硫氰酸酯对蒙脱土进行改性,制得新型固相萃取(SPE)材料。 采用红外光谱、扫描电子显微镜、X射线光电子能谱表征了改性蒙脱土的结构和形貌。 考察了制备的SPE填料对水中As³⁺、Bi³⁺、Cu²⁺、Sb³⁺、Sn²⁺和Pb²⁺的吸附性能,确定了最佳固相萃取条件,对6种金属离子吸附容量分别为10.83、11.92、12.67、10.43、10.01及10.54 mg/g。 通过SPE与电感耦合等离子体质谱联用测定了样品中As³⁺、Bi³⁺、Cu²⁺、Sb³⁺、Sn²⁺和Pb²⁺ 6种重金属离子的含量,检出限分别为0.024、0.013、0.075、0.037、0.011和0.064 μg/L。     

γ辐照引发无皂乳液聚合法一步合成Ag-聚4-乙烯基吡啶杂化微凝胶

无机-聚合物纳米复合材料是将聚合物与一种或多种无机纳米粒子复合而成的一种材料,它同时具有无机纳米粒子和聚合物的优良特性,在许多重要技术领域具有广泛的应用前景.近20年来,无机-聚合物纳米复合材料的制备及应用备受关注[1~6].包括杂化微凝胶在内的纳米复合微球是无机-聚合     

新型单膦配位羧酸银配合物的合成、表征及其热稳定性的研究(英)

0 IntroductionIn recent years, silver carboxylates have attractedmany interests, mostly because they are promisingcandidates in the growth of metal thin films via metal-organic chemical vapor deposition (MOCVD) tech-niques. These sliver compounds show low light sensi-tivity and relatively high thermal stability. Several ex-amples of bisphosphine ligands coordinated silver car-boxlylates have been reported[1￣4].Monophosphine coordinated silver complexes areexpected to have better volatility,…