丙烯在ZSM-5沸石上齐聚反应的研究 Ⅰ. 模板剂用量对丙烯齐聚反应的影响

考察了不同正丁胺（NBA）模板剂用量合成ZSM-5沸石的物化特性和催化性能。采用XRD、SEM、NH3-TPD和BET等手段对合成样品的物化特性进行了表征。结果表明，模板剂与SiO2摩尔比在0.67～0.22时合成的ZSM-5沸石结晶度高于90%；随着模板剂用量的减少，ZSM-5沸石的平均粒径减小，强酸量也存在相同的趋势。丙烯齐聚反应评价结果显示,模板剂用量对合成ZSM-5沸石的催化活性有显著影响，模板剂与SiO2摩尔比在0.67～0.45之间合成的沸石催化性能较好。     

A Magnesium-Selective Ionophore Containing Four Amide Carbonyl Ligands Derived from L-Tartaric Acid and Axial Furano Oxygen Binding Sites

Octahedrally converging hexadentate macrocyclic receptors 1 and 2, based on L-tartaric acid and furanmoieties, were synthesized andtheir complexation properties studied. In this paper,magnesium ion selectivitiesdetermined by ISE experiments, chiroptical changes observedby circular dichroism(CD) on complexation, and association constants measuredby NMR titration arediscussed.     

Effects of Calcination on the Physical and Photocatalytic Properties of TiO<Subscript>2</Subscript> Powders Prepared by Sol–Gel Template Method

TiO₂ powders were prepared by sol–gel template method and calcined under different conditions. XRD, BET and TEM were used to characterize the TiO₂ powders obtained. The photocatalytic activity of TiO₂ was investigated by the degradation of methyl orange. It was found that TiO₂ powder has the highest photocatalytic activity at a calcination temperature of 673 K. The effects of physical properties such as surface area, crystallinity and crystal phase on the photocatalytic activity of TiO₂ were discussed.     

Y2O3:Eu3+纳米线阵列的制备与表征

Y2O3:Eu3+红色荧光粉由于色纯度高、化学性质稳定和量子效率接近100%而广泛用于荧光灯和投影电视等方面.近年来,Y2O3:Eu3+的大量研究工作主要集中于纳米粉末的制备方法及其与体相材料不同的发光特性[1～3].最近,有关Y2O3:Eu3+及其稀土化合物的纳米管、纳米线和纳米带一维材料的制备成为研究热点.Wu Changfeng等[4,5]利用表面活性剂合成了Y2O3 : Eu3+纳米管.激光格位选择激发测试结果表明,Eu3+在纳米管中占据3个不同的格位,其611 nm处的红色发光峰出现了宽化.He Yu等[6]采用水热法及退火处理制备出了Y2O3:Eu3+纳米带,发现Eu3+的发射峰不仅宽化,而且出现了625 nm的新峰.Li Yadong等[7～9]采用水热法制备了稀土氧化物、硫氧化物和氢氧化物等的纳米线和纳米管,并探索了其形成机理,同时发现Y2O3S : yb3+,Er3+具有上转换的性质.     

过氧化氢氧化酸碱滴定法测定苯甲醛的含量

本文提出和建立了一种分析醛类化合物的方法，并用此方法测定了分析纯苯甲醛的含量为９９．４％，相对标准偏差为０．２１％，实验苯甲醛中所带的寻质苯甲醇以及乙醇，甲醇均不干扰测定，苯甲酸的干扰可以扣除，本法操作简单，终点易于掌握，推广应用方便。     

季铵盐用于示波极谱滴定法测定培氟沙星和环丙沙星

介绍采用季铵盐 十六烷基三甲基溴化铵作滴定剂的示波极谱滴定法测定培氟沙星和环丙沙星含量的方法。在pH 4 .8HAc NaAc缓冲溶液中 ,培氟沙星和环丙沙星均能与四苯硼钠 (Na TPB)作用生成沉淀 ,干过滤后 ,用十六烷基三甲基溴化铵标准溶液代替在示波极谱滴定法中常用的有毒硫酸亚铊作为滴定剂 ,回滴滤液中过量的Na TPB ,由示波极谱图 [dE dt=f(E)曲线 ]上TPB的切口消失指示终点。本法终点直观、灵敏 ,操作简便、快速 ,应用于多批原料药样品的测定 ,均获得满意的结果 ,其回收率在 99.9%～ 10 0 .3%之间 ,最大相对误差 <± 0 .3% ,与非水滴定法测得结果基本吻合。     

New Host Molecules with Imidazoliums as Functional Arms:Syntheses and Anion Recognition

The bridged tri-imidazoliums 3.3X^--5.3X^-(X^-=PF6^-,Br^-,I^-)and bis-imidazoliums 6.2PF6^- were synthesized by N-quaternization of imidazole derivative 1 in acetonitrile under reflux.UV spectroscopic titration experiments showed that the halide salts and hexafluorophosphate salts of these imidazoliums exhibited good recognition toward anions in water and in acetonitrile,respectively.     

Molecular imprinting in ultrathin titania gel films via surface sol-gel process

Recent progresses of molecular imprinting in metal oxide matrices were summarized. Application of the surface sol-gel process to mixtures of organic carboxylic acids and titanium alkoxide provides ultrathin layers of titania gel (10-20 nm thick), in which molecule-sized cavities are kept intact upon removal of the organic templates. The imprinted cavity reflects the structural and functional features of the template molecule, and the enantioselective imprinting of dipeptide isomers is observed. Robustness and flexibility of the ultrathin titania layer is demonstrated by the formation of interconnected titania hollow structures. Possible practical applications and unsolved problems of this technique are discussed.     

库仑滴定法测定有机硅样品中的氮含量

本文利用库仑滴定法研究了高分子和低分子硅氮化合物及含氮有机硅样品中氮含量的测定,并研究和讨论了影响测定结果准确性的因素。     

Molecular structure of potassium [N,N′-bis(salicylideneamino)nitroguanidonate-N,N′,-O,O′]nickel(ii), the product of condensation of (salicylideneamino)nitroguanidine with salicylaldehyde on a Ni2+ ion template

The crystal structure of the product of the condensation of (salicylideneamino)nitroguanidine with salicylaldehyde on a Ni²⁺ ion template, K[Ni(C₁₅H₁₀N₅O₄)] · DMF, has been studied. It was established that a planar Ni complex, consisting of isolated [NiL]^– anions and solvated [K⁺ · DMF] cations, is formed. The negative charge of the anion is localized mainly on the O atoms of the nitro group. The nitroguanidine fragment of the ligand occurs in the tautomeric form, which was not reported previously.Deceased in 1995Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2273–2277, September, 1996.