Applying ellipsometry to studying the effect of two kinds of rare earth metal salts on anodizing aluminum alloy

1.IntroductionDuringthepastyears,avarietyofsurfacetreatmentshavebeenusedtoincreasecorrosionresistanceofaluminumalloys.SinceHintonandhiscolleaguesfirstreportedthecorrosioninhibitionwithrareearthmetalsaltsforAA7075aluminumalloys[1],muchattentionhasbeenpaidtotheroleofrareearthadditivesintheareaofsurfacetreatmentsofaluminumanditsalloys.However,mostoftheseresearchesfocusedonrareearthconversioncoatingsformedbychemicalconversionmethods[2-8],theapplicationofrareearthmetalsaltsinanodizingofaluminumall…     

谈非金属含氧酸的氧化性

从物质结构、热力学、动力学角度出发,分析讨论了影响非金属含氧酸氧化性的因素．     

A Multi Proxy Investigation of Moisture,Salt, and Weathering Dynamics on a Historic Urban Boundary Wall in Oxford,UK

ABSTRACT

Boundary walls are neglected but important parts of historic urban environments, and they are often prone to serious deterioration. Understanding moisture and salt dynamics within boundary walls can help infer the causes and dynamics of deterioration. This investigation investigates the patterns of moisture, salt, and deterioration on a 300 year old limestone boundary wall in Worcester College, Oxford. Multiple methods to assess moisture and salts within and across the wall (electrical resistivity tomography, handheld resistivity-based moisture meter, paper pulp poultices, scanning electron microscopy, inductively coupled plasma optical emission spectrometry, and ion chromatography of small scale sampling of deteriorated limestone) were used in conjunction with decay mapping of both sides of the wall. The salt weathering strongly correlates with severely weathered zones at the wall and salts, mainly sulfates, seem to be the main agent of decay processes. The combined results demonstrate that the environmental influences driving stone decay can differ on a very small scale even at a comparatively simple structure like a boundary wall, and that repairs can have adverse effects if the patterns of salt and moisture dynamics are not sufficiently known.     

合成mPEG咪唑啉碘及其Pd催化制备芴衍生物

聚乙二醇单甲醚甲基咪唑啉碘盐(L)是聚乙二醇单甲醚(mPEG750)经磺酰化、碘化之后再与1-甲基咪唑反应得到,研究它在钯催化芳基硼酸和2,7-二溴芴衍生物的Suzuki偶联反应中的催化活性,结构经核磁共振表征为预期化合物.     

电导法测定黄土-古土壤序列易溶盐含量的方法学研究

尝试使用电导法测定黄土-古土壤序列中的易溶盐总量.着重考察配制溶液时的水土比例、溶解时间等具体实验条件对测试结果的影响.当水土比固定时,若溶解时间增加,电导率也随之增加;溶解时间固定时,随着水土比的增加,电导率则逐渐降低.水土比变化对电导率测量值的影响较震荡时间更高,是最重要、需要最先确定的实验条件.为了尽可能保证易溶盐溶解、避免难溶盐参与溶解,建议测定黄土-古土壤序列电导率时,使用5:1的水土比;选择至少10 min的震荡时间,30 min为最优.若样品年代较早,或地理位置偏东南,则建议更长的震荡时间.     

Rising moisture,salts and electrokinetic effects in ancient masonries: From laboratory testing to on-site monitoring

The investigation of capillary water rise mechanisms in old masonries is of great practical interest, as well as the investigation of the electrical effects accompanying such phenomenon. In fact, moisture presence facilitates all the decay processes in porous building materials and strongly threatens the preservation of materials in architectural heritage. Previous papers have shown that performing a correct and accurate measurement of spontaneous electric potential in masonries is very challenging due to several variables influencing these phenomena, such as materials microstructure, soluble salts nature and amount. In this paper, the influence of mortar joints on the capillary water rise and on the related electrokinetic effects was investigated on laboratory assemblies; then, the same measuring procedure was applied on site to a real XVI Cent. masonry building affected by rising damp.     

季铵盐-镧-蒙脱土复合材料的制备及性能研究

以龙岩膨润土为原料,氟化钠为改性剂制备钠基蒙脱土.采用水热离子交换法,将镧离子和十六烷基三甲基季铵阳离子交换到蒙脱土的层间得到改性蒙脱土,并对其结构和抗菌性能进行了表征.X-射线衍射法(XRD)分析发现,改性蒙脱土的层间距发生了变化;红外光谱测试(FT-IR)结果显示出相应的离子吸收峰,说明镧离子和十六烷基三甲基季铵阳离子确实交换到蒙脱土层中.抗菌实验结果表明,CTAB-La-MMT具有较好的抗菌性能,对金黄色葡萄球菌(Staphyloccus.aureus)和大肠杆菌(Escherichia.coli)的最小抑菌浓度(MICs)分别小于200mg/L和400 mg/L,其抗菌效果比Na-MMT、La-MMT和CTAB-MMT改性蒙脱土都好.     

Quality of effluents from Hattar Industrial Estate

Of 6634 registered industries in Pakistan, 1228 are considered to be highly polluting. The major industries include textile, pharmaceutical, chemicals （organic and inorganic）, food industries, ceramics, steel, oil mills and leather tanning which spread all over four provinces, with the larger number located in Sindh and Punjab, with smaller number in North Western Frontier Province （NWFP） and Baluchistan. Hattar Industrial Estate extending over 700 acres located in Haripur district of NWFP is a new industrial estate, which has been developed with proper planning for management of industrial effluents. The major industries located in Hattar are ghee industry, chemical （sulfuric acid, synthetic fiber） industry, textile industry and pharmaceuticals industry. These industries, although developed with proper planning are discharging their effluents in the nearby natural drains and ulti- mately collected in a big drain near Wah. The farmers in the vicinity are using these effluents for growing vegetables and cereal crops due to shortage of water. In view of this discussion, there is a dire need to determine if these effluents are hazardous for soil and plant growth. So, effluents from different industries, sewage and normal tap water samples were collected and analysed for pH electrical conductivity （EC）, total soluble salts （TSS）, biological oxygen demand （BOD）, chemical oxygen demand （COD）, total nitrogen, cations and anions and heavy metals. The effluents ofghee and textile industries are highly alkaline. EC and TSS loads of ghee and textile industries are also above the National Environmental Quality Standards （NEQS）, Pakistan. All the effluents had residual sodium carbonates （RSCs）, carbonates and bicarbonates in amounts that cannot be used for irrigation. Total toxic metals load in all the effluents is also above the limit i.e. 2,0 mg/L. Copper in effluents of textile and sewage, manganese in ghee industry effluents and iron contents in all the effluents were higher than NEQS. BOD and COD values of all the industries are also above the NEQS. On the whole, these effluents cannot be used for irrigation without proper treatment otherwise that may cause toxicity to soil, plants and animals as well add to the problems of salinity and sododicity. Similarly, these effluents cannot be used for fish farming.     

多巴胺在稀土杂多酸盐修饰电极上的电催化氧化

制备了稀土杂多酸盐修饰玻碳电极并研究了它对多巴胺的电催化特性。实验结果表明,该修饰电极对多巴胺有较好的电催化作用,且多巴胺在该修饰电极上的氧化受表面控制。稀土杂多酸盐修饰电极对多巴胺的催化氧化有良好的稳定性和重现性。     

完全沉淀被测组分所需沉淀剂的用量条件

以难溶盐的溶解度与活度积、活度系数的关系为依据,探讨完全沉淀被测离子所需沉淀剂的具体用量条件,并推导出相应的计算关系式,使沉淀剂的用量更加明确、具体和具有实用性．