The Effect of Additives on Crystal Size of Sodium Sulphate     

ZHANG Lei  LIU Shanhe  XIANG Jun  CHENG Penggao  TANG N  WANG Xuekui 《《地质学报》英文版》2014,88(Z1):401-403

正1 Introduction Anhydrous sodium,mainly produced in the United States,Canada,Japan,is indispensable commodities and raw materials in daily life and industry.In recent years,anhydrous sodium sulfate of general size was much oversupplied[1].However particles anhydrous sodium sulphate of large size is not adequate to the demand for its  相似文献   

硫酸盐渍土盐胀特性试验及分析   总被引：3，自引：2，他引：1  

刘娉慧  王俊臣  蒋剑  王常明 《吉林大学学报(地球科学版)》2005,35(1):74-78

硫酸盐渍土分布广泛,其盐胀特性给工程建设带来诸多困难,以往许多这方面的研究多是通过向非盐渍土中掺入不同比例的盐分,人工制备成盐渍土样进行,且仅侧重于盐胀率的测试和分析,对盐胀压力的研究很少.结合硫酸盐渍土地区工程现场出现的渠道面板胀裂变形等问题,取样天然硫酸盐渍土,对单因素影响下的硫酸盐渍土膨胀率进行测试和分析,对各因素作用下的盐胀机理加以分析,并对法向膨胀力进行测试,与非盐渍土的冻胀力进行对比后,发现硫酸盐渍土具有较大的法向盐胀压力,建议设计分析中需在试验的基础上考虑盐胀的影响.  相似文献   

Host rock dolomitization and secondary porosity development in the Upper Devonian Cairn Formation of the Fairholme carbonate complex (South‐west Alberta,Canadian Rockies): diagenesis and geochemical modelling     

VEERLE VANDEGINSTE  RUDY SWENNEN  MARK H. REED  ROB M. ELLAM  KIRK OSADETZ  FRANÇOIS ROURE 《Sedimentology》2009,56(7):2044-2060

The Upper Devonian carbonate reefs in West‐central Alberta are important petroleum reservoirs that are well‐known for their extensive secondary porosity. An outcrop analogue study indicates that an early matrix‐selective dolomitization event occurred which is characterized by a major Late Devonian sea water component with increased salinity because of evaporation. It is interpreted that the matrix (replacive) dolomite formed during the Famennian as the result of a combination of both seepage and latent reflux dolomitization, although an additional type or overprinting of later intermediate burial dolomitization cannot be excluded. Formation of the moulds is attributed mainly to the dissolution of undolomitized fossil cores, most typically stromatoporoids. Geochemical modelling indicates that carboxylic acid fluids have the highest potential for dissolving residual calcite in this case. Geochemical models consistent with this analysis and interpretations can reproduce the secondary porosity and suggest a viable dolomitization process for the localities studied.  相似文献   

电感耦合等离子体发射光谱法测定地热水中的硫化物     

李清彩  赵庆令  安茂国  孙宁  张守文 《岩矿测试》2017,36(3):239-245

地热水中的硫化物(H_2S、HS~-和S~(2-))通常受到硫酸根、亚硫酸根、硫代硫酸根等硫元素的共存干扰,并且硫化物具有热、光、氧不稳定性,在水样保存、前处理、标准溶液配制等环节影响着测试的准确度和精密度。本文在现场采集的地热水水样中加入乙酸锌及氢氧化钠,使硫化物形成硫化锌沉淀而与溶液分离,将此沉淀溶于双氧水和逆王水,使低价态的S2-氧化成稳定的SO_4~(2-),选择易于纯化且性质稳定的硫酸钠配制硫标准储备液,以182.624 nm谱线作为硫元素分析谱线,应用电感耦合等离子体发射光谱法测定出地热水样中的硫化物含量。硫的浓度在0.1~100 mg/L范围内与其发射强度呈线性(相关系数为0.9994);方法检出限为0.009 mg/L,相对标准偏差(n=11)低于1.80%,实际水样中硫化物的加标回收率介于99.0%~103.0%。与前人相关测试方法相比,本方法的技术指标具有优势。  相似文献   

Use of heavy liquid density separation to remove pyrite from sediment samples for radiocarbon dating     

《Quaternary Geochronology》2015

Sample preparation protocols for concentrating organic material from sediments for radiocarbon dating often include a large number of steps and the use of hazardous chemicals. Thus, these protocols are often problematic for pollen-poor sediments as material can get lost or may become degraded. Pyrite in samples for radiocarbon dating hinders an effective graphitisation process and thus needs to be removed during sample preparation. Standard protocols require the use of nitric acid, a strong oxidant that corrodes organic material. Therefore, the use of nitric acid needs to be avoided when preparing pollen-poor but pyrite-rich sediments.We present a method that minimises the sample preparation steps by replacing acid treatment with heavy liquid separation. Using non-toxic LST at a density of 2.0 g cm⁻³ is shown to be effective for separating the organic fraction from sulphides, silicates and carbonates. We applied this method to pyrite-rich and pollen-poor sediments from Western Australia that had previously been problematic to date. The successful AMS radiocarbon dating of all samples pre-treated with LST demonstrates the effectiveness of this method.  相似文献   

Organic matter mineralisation in the hypolimnion of an eutrophic Maar lake   总被引：2，自引：0，他引：2  

Sven Fahrner  Michael Radke  Dorothée Karger  Christian Blodau 《Aquatic Sciences - Research Across Boundaries》2008,70(3):225-237

  相似文献   

藻酸双酯钠片剂的薄膜包衣工艺研究     

黎华  赵峡  赛向阳 《中国海洋大学学报(自然科学版)》2005,35(2):306-308

为了提高产品质量的稳定性,实验研究了采用新菲尔对藻酸双酯钠片剂进行薄膜包衣的方法,并运用正交试验确定了薄膜包衣的最佳工艺条件为：藻酸双酯钠片剂硬度为3～4kg／mm^2,包衣液浓度为11％,喷液流量为0．19kg／min,片芯水分为5．0％。采用新菲尔包制的薄膜衣片与藻酸双酯钠糖衣片相比较具有阻湿性能好,片剂增重小,工时短等优点。  相似文献   

The Origin and Distribution of Salts on Alluvial Fans in The Atacama Desert,Northern Chile     

I. A. Berger  R. U. Cooke 《地球表面变化过程与地形》1997,22(6):581-600

The Atacama Desert has been predominantly hyperarid since the middle Miocene. Combined ionic and X-ray diffraction analysis shows that calcium sulphate is prevalent on three similar alluvial fans in salar basins across a transect of different environments in Antofagasta Province, northern Chile. Differences between the fans were largely due to the effect of local factors on salt input, secondary redistribution and deposit preservation. Thus carbonate was notable in the High Andes (fan C) and Pre-Cordillera (fan B), whereas in the Central Valley (fan A) greater qualities of the more soluble salts (chlorides and nitrates) probably reflect the higher level of aridity and an oceanic source (the camanchaca). Calcium sulphate distribution on the alluvial fans and on adjacent hilltops indicates an aeolian origin. Evidence from the Pre-Cordillera (fan B), however, suggests that salt input may have been episodic, related to changes in conditions within the general aridity and possibly to stone pavement and soil development. Calcium sulphate sources range from an input in Andean precipitation and the camanchaca to abundant regional evaporite deposits. It is probable, however, that products of Andean volcanism constitute the dominant primary source of calcium sulphate, and that the salt has subsequently been distributed widely within the endoreic basins of the region by a combination of groundwater, surface flow and the wind. © 1997 John Wiley & Sons, Ltd.  相似文献   

INTERRELATIONSHIP BETWEEN WATER QUALITY AND GROUNDWATER FLOW DYNAMICS IN A SMALL WETLAND SYSTEM ALONG A SANDY HILL RIDGE     

H. DE MARS  A. C. GARRITSEN 《水文研究》1997,11(4):335-351

Detailed modelling of the hydrological setting of fen meadows appears to be possible provided that detailed information on geomorphology, hydrochemistry and piezometric heads is available for a number of years. In the Laegieskamp, a small wetland reserve located in the central part of The Netherlands, a piezometric monitoring network was sampled for water quality analysis and piezometric heads between 1986 and 1992. Average yearly discharge and recharge periods were used for FLOWNET calculations. First, the models were used to determine, with the help of information on water quality, the hydrological systems in the study area. Secondly, they were used to define the present and past hydrological setting of a fen meadow in the reserve. The hydrological systems and water quality in the study area have changed considerably over the past 65 years. At present the fen meadow is mainly fed by precipitation. The mineral-rich conditions favouring the fen meadow vegetation are thought to be maintained thanks to a clayey peat layer and an oscillating shallow water body that prevents rapid leaching of minerals. The sulphate content in the fen exhibits a pattern of temporal variation, which is related to the severity of the annual drought. Our study showed that groundwater flow is mainly lateral, instead of the assumed vertical infiltration of groundwater in previous regional studies. This led us to the conclusion that conservation and restoration perspectives are much better than previously expected. The polluted middle, deep groundwater is not a major threat to this fen at the moment. © 1997 John Wiley & Sons, Ltd.  相似文献   

The Role of Multiphase Chemistry in the Oxidation of Dimethylsulphide (DMS). A Latitude Dependent Analysis     

F. Campolongo  A. Saltelli  N. R. Jensen  J. Wilson  J. Hjorth 《Journal of Atmospheric Chemistry》1999,32(3):327-356

A kinetic model for the OH-initiated homogeneous gas phase oxidation of dimethylsulfide (DMS) in the atmosphere (Saltelli and Hjorth, 1995), has been extended here to include the liquid phase chemistry. The updated model has then been employed to predict the temperature dependency of the MSA/nss-SO42- ratio. Model predictions have been compared with observational data reported in Bates et al. (1992). Sensitivity and uncertainty analysis has been performed in a Monte Carlo fashion to identify which are the important uncertainties on the input parameters and which are the possible combinations of parameter values that could explain the field observations. Results of the analysis have indicated that the temperature dependencies of the interactions between gas phase and liquid phase chemistry may to a large extent explain the observed T-dependence of the MSA/nss- SO42- ratio. The potential role of multi-phase atmospheric chemistry, not only in the case of SO2 but also of other oxidation products of DMS and, particularly, of DMS itself, has been highlighted.  相似文献