非离子表面活性剂非均相光催化降解试验研究

以非离子型表面活性剂－脂肪醇聚氧乙烯醚为目标污染物,投加适量光敏半导体为催化剂,在高压汞灯照射下进行实验,在探讨各种影响因素作用的基础上,提出了在弱紫外辐照下使ＡＥＯ－９降解的最佳条件组合,为逐步利用自然光源催化氧化表面活性剂提供科学依据。     

TiO2制备条件对光催化氧化活性的影响

半导体光催化剂,如ＴｉＯ２,在紫外光照射下,生成具有强氧化还原活性的电子和空穴,可使许多有机物降解为ＣＯ２和Ｈ２Ｏ,用于处理工业废水具有成本低,无二次污染等优点,是一种很有应用前景的废水催理方法［１,２］．制备高活性的ＴｉＯ２光催化剂是这种过程在处理...     

四氢吡喃醚的形成、裂解和转化

对四氢吡喃醚的形成、裂解和转化方法进行了综述,参考文献１１１篇。     

High-temperature TG/DSC/QMS applications in environmental protection

The decomposition reactions of polystyrene, phenolic resin and a protective undercoating material for automobiles which contains PVC were tested using a new type of thermal analysis — mass spectrometry coupling system for measurements to 1500C or 2000C, which is based on the principle of a two-step skimmer orifice system. The results will be presented, with particular emphasis on the detection sensitivity of the new system for the products of decomposition.The capability of this coupling system to detect even heavy metals such as lead and silver in the waste gases from decomposition or after evaporation at high temperatures will also be demonstrated.     

High Performance Varistor Discs Obtained from Chemically Synthesized Doped Zinc Oxide Powder

The ceramic microstructure, the chemical homogeneity of specific dopants and the mechanical integrity of a varistor disc are critical parameters in determining the transient voltage suppression features of these devices. The material properties and overall quality of the starting ceramic powders used to produce such components are essential in achieving the desired properties. The present work describes a novel chemical method developed to produce doped zinc oxide powders and an industrial scale manufacturing process for the production of final varistor blocks for surge arrester applications. The results are compared with those obtained when using standard varistor powder made by the mixed oxide route is used. All the fundamental electrical properties of the discs have been determined and correlated with the relevant manufacturing steps.     

Alkylsulfamoyl Chlorides as Key Units in the Synthesis of Novel Biologically Active Compounds for Crop Protection

Due to their bifunctional character, alkylsulfamoyl chlorides are versatile units for the synthesis of heterocycles, polar sulfamates, and sulfonamides. In the last decade, synthetic methods of general preparative use have been developed, by means of which amine hydrochlorides, isocyanates, aziridines or tertiary alcohols can be reacted with suitable sulfuric acid derivatives to give novel, variously substituted alkylsulfamoyl chlorides. These compounds can subsequently be converted either to previously unobtainable N-alkoxyalkyl-N-alkylsulfamoyl chlorides or to novel heterocycles of the type 1H-2,1,3-benzothiadiazin-4-one-2,2-dioxide, 2H-1,2,6-thiadia-zin-3-one-1,1-dioxide and 2H-1,2,4,6-thiatriazin-5-one-1,1-dioxide; these compounds are examples of interesting models which illustrate the relation between the structure and the action of the compound, and in some cases lead to highly selective, ecologically unobjectionable herbicides. On the other hand, the alkylsulfamoyl chlorides themselves can be N-acylated to give further 3- to 5-atom bifunctional synthesis units, with which novel heterocyclic syntheses can be carried out. Further uses of the alkylsulfamoyl chlorides include the preparation of biologically active sulfamates, and cycloaddition reactions of N-sulfonylamines prepared in situ.     

Sol-gel ZrO2 coatings for chemical protection of stainless steel

ZrO₂ coatings deposited on 316 L stainless steel sheets were synthesized by sol-gel method using Zr(OC₃H₇)₄ as precursor and isopropanol, glacial acetic acid, and water as solvents for application with ultrasounds. Different solutions for dip-coating were prepared with compositions varying between 0.025 and 0.9 mol/dm³ of ZrO₂. X-ray diffraction shows that the films densified at 800°C are crystalline with a tetragonal structure. The thickness of the coatings varied from 0.35–0.75 m. The influence of the ZrO₂ coatings on the corrosion behavior of stainless steel substrates in aqueous NaCl was studied through potentiodynamic polarization curves at 1 mV/s. The values of the electrochemical parameters allow for an explanation of the role of the films in the increased resistance of steel against corrosion in moderately aggressive environments.     

Protective properties of redox polymer film deposited on stainless steel

We propose a novel composite organic-inorganic coating in the form of a redox polymer film for protection of stainless steel against general corrosion in strong acid medium (2 M H₂SO₄). We utilize an anion exchange polymer, protonated poly(4-vinylpyridine), into which hexacyanoferrate anions have been introduced. Owing to the presence of Fe(CN)₆^3–/4– at the interface formed by the film and the steel, a sparingly soluble metal hexacyanoferrate (mostly Prussian blue, PB) is formed as an overcoating on the steels surface, presumably on the passive (metal oxide) layer. The redox polymer film on the steel seems to act as a composite three-dimensional bilayer-type coating in which hexacyanoferrate(III,II) anions (that are capable of effective charge storage) exist in the outer portions of the film, whereas the inner PB layer improves the systems overall adherence and stability. By analogy to a conducting polymer (e.g. polyaniline, polypyrrole), introduction of the redox polymer composite film leads to stabilization of the steel substrates potential within the passive range.Contribution to the 3rd Baltic Conference on Electrochemistry, Gdansk-Sobieszewo, Poland, 23–26 April 2003Dedicated to the memory of Harry B. Mark, Jr. (28 February 1934–3 March 2003)     

铁掺杂TiO2纳米管阵列对不锈钢的光生阴极保护

在含FeSO4的HF、H2SO4/HF、NaF/Na2SO4溶液中,通过电化学阳极氧化直接在纯钛表面制备Fe 掺杂的TiO2(Fe-TiO2)纳米管阵列. 应用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱(UV-Vis)、X 射线光电子能谱(XPS)等手段对纳米管阵列的结构、形貌及化学组成进行表征. 利用光电化学测量研究Fe-TiO2纳米管阵列在不同波长范围内的光电响应特性和光生阴极保护行为. 考察了温度、时间、掺杂含量等参数对TiO2纳米管阵列的几何尺寸、形貌和光电性能的影响. 结果表明, Fe掺杂可有效减缓TiO2纳米管阵列载流子的复合, 窄化TiO2带隙宽度, Fe-TiO2在410-650 nm范围显示强吸收, 并使光谱响应扩展到波长大于400 nm 的可见光区. 实验结果还表明, Fe-TiO2纳米管阵列对316不锈钢(316L)具有良好的光生阴极保护作用, 暗态下阴极保护作用可继续维持.     

Analysis and Protection of One Thousand Hand Buddha in Dazu Stone Sculptures

The components of the rock, the pigments, the gold foils and the adhesive of One Thousand Hand Buddha in Dazu stone sculptures, Chongqing, China, have been analyzed by X-ray diffraction (XRD), X-ray fluorescence (XRF), infrared spectroscopy (IR), energy dispersive X-ray analysis (EDX) and fiber optics reflectance spectroscopy (FORS). Furthermore, the weathering and degeneration of One Thousand Hand Buddha have been discussed and the protective methods have been provided. In this work some useful information to study on conservation of stone relics is given.