硫化氢对遇水膨胀橡胶性能的影响

研究了不同浓度的H2S气体及其溶液对遇水膨胀橡胶(WSR)质量变化、力学性能和体积膨胀倍率的影响。结果表明,在不同浓度的H2S气体和H2S溶液中,WSR的拉伸强度、扯断伸长率和体积膨胀倍率均有较大程度降低,腐蚀时间越长、浓度越大,降低程度越大,但腐蚀时间达到20 d时,不同浓度的H2S气体或H2S溶液对WSR性能的影响差异明显减小。此外,在H2S气体中,WSR的质量逐渐增大,而在H2S溶液中,WSR的质量逐渐减小,但其质量损失率呈现先增加后减小的变化趋势。     

The source of hydrogen sulfide in anoxic sediment

Putrefactive hydrogen sulfide production in the upper 4 cm of sediment in two small freshwater and eutrophic Southeast Michigan, U.S.A., lakes ranged from 0.13 to 1.51 with an average of 0.46 mg S l^?1 day^?1. Sulfate reductive production of hydrogen sulfide at the same sites ranged from 0.7 to 3.2 with an average of 1.54 mg S l^?1 day^?1. Putrefactive hydrogen sulfide production represented 5.1–53% (average of 18.3–27.6%) of the total hydrogen sulfide produced at the two lakes over an April–October study period. ³⁵S labeled substrates were used to estimate hydrogen sulfide production rates.Proteolytic bacteria averaged 2.2 × 10⁴ cells ml^?1 sediment whereas sulfate reducers averaged 4.8 × 10² cells ml^?1 sediment. Putrefactive hydrogen sulfide production correlated highly with numbers of proteolytic bacteria (r² = 0.84) but the correlation between sulfate reduction and sulfate reducing bacteria was low (r² = 0.13).Interstitial soluble inorganic sulfate, protein and organic carbon were not closely correlated with hydrogen sulfide production rates or bacteria enumeration results. Natural substrate concentrations (S_n) used to estimate hydrogen sulfide production were supported by kinetic bioassay results.     

Iron and hydrogen sulfide interference in the analysis of soluble reactive phosphorus in anoxic waters

Anoxic water from eight lakes containing various amounts of ferrous iron, hydrogen sulfide, calcium and total phosphorus was analysed for soluble reactive phosphorus (SRP). Hydrogen sulfide concentrations higher than 1 mg l⁻¹ and ferrous iron concentration above 0.20 mg l⁻¹ produce interferences in the SRP analysis in many occasions (e.g. 80% underestimation of SRP). Interfering concentrations of these materials are shown to be present in anoxic water from a large number of lakes, groundwater springs and ocean basins.The mechanisms of the interferences are discussed and methods described to prevent these analytical errors. Ferrous iron is not problematic if the sample is kept anoxic before and during filtration. On the other hand vigorous aeration is obligatory if hydrogen sulfide is present. Simple methods to test for both the possible interfering compounds are presented. It is shown for the water from the anoxic hypolimnia of eight lakes that a modified analysis of total (unfiltered) reactive phosphorus (TRP) yields on average only 2% lower phosphorus concentrations than SRP analysis. TRP hence can replace the complicated SRP analysis in anoxic waters.     

Importance of speciation methods in analytical control of water treatment processes with application to fluoride removal from waste waters

Analytical methods of speciation for the control of water treatment processes, particularly for the removal of fluoride by aluminium hydroxide polymers as precipitant, have been discussed. It has been shown that combination of ultrafiltration with spectroscopic methods and fluoride ion-selective electrode offers a powerful means for the control of both the precipitant and pollutant, e.g. fluoride. ²⁷Al n.m.r. has been used for the identification of hydrolytic products of aluminium(III) and the ultrafiltration technique has been applied for the separation of the active polymer. The hydrolytic products were also characterized by timed spectrometric method. The interaction between aluminium hydroxide polymer and fluoride was studied by means of fluoride ion-selective electrode, ultrafiltration and atomic absorption spectrometry. The usefulness of these speciation methods for choosing the best conditions for water treatment process is discussed. By applying them for the removal of fluoride, it was found that the fluoride levels can be brought down to less than 10 mg l^?1, the limit set by Swiss regulatory body for discharge of waste water. The importance of using such speciation methods for evaluating the possible impact of the “products” of the water treatment (dissolved species in treated water, discharged solid) is also emphasized.     

Study of polymeric aluminium(III) hydroxide solutions for application in waste water treatment. Properties of the polymer and optimal conditions of preparation

The optimal conditions for the preparation of polymeric aluminium(III) hydroxide species for water treatment has been described. The partially hydrolysed aluminium(III) solutions were characterized by ultrafiltration method, ferron assay, ²⁷Al n.m.r. measurements, high pressure anion exchange chromatography and precipitation of polymeric aluminium hydroxo species with sodium sulphate. The results of these tend to suggest that the polymeric aluminium(III) hydroxide species have a size between 10–20 Å; these have an average residual positive charge of 0.54, and constitute about 80% of the total aluminium in the hydrolysed solution. They are retained by UM05 membrane. ²⁷Al measurements indicate that Al₁₃O₄(OH)₂₄^7? ion are the predominant polymeric species in these solutions. In addition to these the hydrolysed aluminium(III) solutions contain low proportions of monomeric aluminium hydroxo species and inert micro-crystalline aluminium hydroxide. The effect of ageing, dilution and pH on the stability and characteristics of the aluminium hydroxide polymer were also studied in detail.     

广西大厂矿田C、H、O同位素及成矿流体来源研究

桂西北南丹县境内的大厂矿田由锡石硫化物型锡多金属矿、夕卡岩型锌铜矿和热液脉型钨锑矿组成。通过系统研究大厂矿田不同矿化类型矿石以及围岩的C、H、O同位素组成,得出结果显示:从远离矿体无蚀变围岩→近矿蚀变围岩→矿体,δ¹³C平均值分别为0.88‰、-0.74‰、-7.09‰,δ18O平均值分别为22.58‰、16.00‰、14.42‰,δ13C值与δ18O值均表现出依次降低的特点;夕卡岩型锌铜矿、锡多金属矿和钨锑矿的δ18OH₂O值与δD值的关系则显示,大厂矿田的成矿流体是具有多来源的。C、H、O同位素的组成特征表明,大厂矿田锌铜矿和锡多金属矿的成矿作用均与龙箱盖岩体有关,这为进一步探讨大厂矿田夕卡岩型锌铜矿、锡多金属矿、钨锑矿成矿流体来源及成矿热液的运移方向提供了参考资料。     

上海市GPS校准基线场的建立和测量不确定度评定

本文简要介绍了上海市GPS校准基线场的建立,对该场的测量不确定度进行了评定。     

如何做好泰山景区九小场所消防安全管理工作

分析了泰山九小场所消防安全管理工作的现状,提出了解决问题的对策,并全方位的落实消防安全责任,消除火灾隐患,确保平安泰山建设大局的安全和稳定。     

浅谈南水北调中控制水准网及平面控制网测量

详细介绍了南水北调中控制水准网及平面控制网的测量过程,重点阐述了施工GPS控制网布设方案及观测,水准路线及水准网的布设及观测,以完善控制网测量方案,积累控制网测量经验。     

电法勘探技术在清水宋墓水害勘测中的应用

清水宋墓是发现在清水县境内宋(金)时期四座小型平民墓的合称,位于甘肃省清水县赵充国陵园内。受自然因素和人为因素的影响,清水宋墓渗水严重,水害普遍发育,并衍生出砖画颜料褪色、表层风化剥落等多种病害。本次勘测工作根据土体含水率不同存在的电性差异原理,采用高密度电阻率法、自然电场法两种电法勘探方法,查明了清水宋墓渗水病害分布情况及墓室区域土体表层渗流补给方向,为清水宋墓水害的治理和保护提供了依据。