恩格尔—普雷契特(Engel-Precht)碳酸钾方法中的非催化多相动力学

制造 K_2CO_3的恩格尔—普雷契特方法由于经济和技术上的原因,在德国已被弃之不用。本工作试图查明和解决过程的控制问题,并提供改变原始的间歇操作为连续流程所必须的动力学数据。研究了两个反应:即恩格尔盐(KHCO_3·MgCO_3·4H_2O)的生成反应和该不溶性盐分解为 KHCO_3溶液和 MgCO_3·3H_2O 固相的反应。在研究反应最佳条件的同时,还确定了恩格尔盐生成反应(KCO,CO_2和MgCO_3·3H_2O 在水溶液料浆中的反应)的动力学和机理。对恩格尔盐分解的动力学、机理和最佳条件也同样地做了测定。本文完成了恩格尔—普雷契特方法中所有反应的研究,并与以前两次发表的结果(MgO 的水合和 MgO 的碳化)一起提出了关于设计一个有效的连续的流程所需要的所有数据。     

Deep water circulation, residence time, and chemistry in a karst complex

We investigated the hydrochemistry of a complex karst hydrosystem made of two carbonate units along a coastal lagoon. Ground water emerges on the lagoon floor from a submarine spring. In addition, thermal waters circulate through the limestone and mix with karst water near the lagoon shore. A distinction between the water from the two carbonate units is related to marine influences and human activities. In one of the massifs, the data show an incongruent dissolution of dolomite with time. In the other system, a slight contamination by saline fluids from the thermal reservoir has led to high calcium and magnesium concentrations. 36Cl, 14C, and 3H data constrain the residence time of the water, and allow for the distinguishing of four circulation types: (1) shallow surface circulation (primarily above sea level) in the karstic units with short residence times (<20 years); (2) shallow subsurface circulation (approximately 0 to -50 m) below the karstic units with residence time in the order of 50 years; (3) deep circulation at depth of 700 to 1500 m in the Jurassic limestones below thick sedimentary cover, with residence time of several thousand years for a part of the water; and (4) deep circulation at a depth of approximately 2500 m, which represents the thermal reservoir in the Jurassic units with residence time of approximately 100,000 years. An interpretative hydrogeological framework is based on the constraints of the geochemical analyses of the deep thermal system, and by water flow from the surface to the deep parts of the carbonate formations.     

Kinetic partitioning of Co,Mn, Cs,Fe, Ag,Zn and Cd in fresh waters (Loire) mixed with brackish waters (Loire estuary): experimental and modelling approaches

To simulate the behavior of radionuclides along a salinity gradient, in vitro sorption and desorption kinetics of Co, Mn, Cs, Fe, Ag, Zn and Cd were studied in Loire river water and the macrotidal Loire estuarine water over two different seasons. Partitioning between the dissolved phase and suspended solids were followed up over 100 h after adding radioactive tracers to freshly collected freshwater (sorption stage); this stage was followed by desorption in fresh and estuarine waters. A kinetic model describing the interactions between trace metals and particles under a salinity gradient was developed and calibrated. Among parameters and/or processes that control the fate and behavior of contaminated particles during their transfer in estuarine systems, this study shows that the speciation of trace metals is controlled by: (i) the chemical water composition: for all the elements except for Fe, desorption increased with salinity; however, the amplitude of such an effect strongly depended on the element and/or on the composition of the particulate phase (and consequently on the season); (ii) the possibility for a given element to form (or not) stable surface particle moieties such as oxides or inner-sphere complexes; (iii) the distribution of a given element among different types of sites characterised by different binding forces that can lead (or not) to re-adsorption processes after mixing of contaminated particles with uncontaminated water.Our model enabled the quantification of the contribution and the characteristic time of reactions that took place over short and long periods on the global partitioning between particulate and dissolved phases during sorption and desorption and to determine the extent to which these reactions were modified by the salinity.     

Assessment of urban and industrial contamination levels in the bay of Cádiz,SW Spain

Measuring the amount of pollution is of particular importance in assessing the quality and general condition of an ecosystem. In this paper, some of the results obtained as a consequence of the specific agreement between the Environmental Agency (Consejería de Medio Ambiente, Junta de Andalucía) and the University of Cadiz to assess the environmental condition of the marine bottom and waters are showed. Physical and chemical analyses in water and sediments were undertaken at various sampling sites close to urban and industrial locations. Later on, these results were studied under statistical analysis to reveal any possible relationships between the parameters employed, and to identify any analogous behaviour between the sampling sites. Physical-chemical data revealed that sediments and waters analysed were moderately contaminated and, in addition, no great differences were found between in rising and ebbing tide conditions. Finally, considering only the pollution level, from the cluster analysis of sediments two major groups appear, one of which corresponded to those sites located in the outer bay, and the other to those situated in the inner bay. However, number 6 and 14 sampling sites cannot be associated to those groups due to be related to points with important local discharges.     

Box coring artifacts in sediments affected by a waste water outfall

Variations in porosity of surface sediments are often the major cause of sediment loss during gravity and box coring. Sediments with a high content of organic matter usually have higher porosity, and thus, lower resistance (strain) towards mechanical disturbance. Here, we demonstrate that box coring artifacts (i.e. sediment loss and core shortening) can be produced in sediments from the Palos Verdes (PV) shelf, which in the past had received relatively high loads of organic carbon (OC) enriched particulate matter originating from the Whites Point outfall that had created a high porosity layer at depth. This has been overlooked as a possibility for obtaining low estimates of sediment and pollutant accumulation rates. Since any such sediment loss during coring can lead to serious underestimates of sedimentation rates, our results here may have important implications for any attempts at reconstructing pollutant fluxes and histories in these coastal marine sediments.     

自由流式砂石泵应用中须注意的几个问题

本文重点阐述了在钻探施工中，使用自由流式砂石泵时，在选型过程中应注意合理选择技术参数。     

美国亚利桑那州凤凰市地面沉降和地面裂缝的起源

1980年1月，凤凰市出现首例地裂缝。该区水位下降已超过90m，测得沉降量是1.05m，间接沉降证据为1.5m，地下水位埋深达170多m，最大沉降速率为0.13m/a。地下水位上降始于50年代中期，10年后，当地下水位下降30m～45m后，沉降开始发生，沉降漏斗每年扩大5km^2，先是向西，最近向北向东发展，沉降漏斗还将继续扩大，沉降量可能要超过3m。     

藏南帕里至达吉地带的上地壳结构特征──REFTEK顺带广角地震观测结果分析

本文主要介绍１９９２年中美喜马拉雅和青藏高原深剖面与综合研究项目第一阶段（ＩＮＤＥＰＴＨＩ－１）广角地震观测资料利用Ｓｅｉｓ８１程序（Ｃｅｒｖｅｎｙ，１９８１）进行二维解释所获得的帕里一达吉地带的上地壳结构特征。主要成果为：（１）前寒武结晶基底之顶界表现为Ｒ１界面。据本项目地质调查，藏南拆离系（ＳＴＤＳ）在帕里以北约１０ｋｍ处出露，向北缓倾并向地下延伸。认为Ｒ１界面不仅是结晶基底之顶界的反映，而且ＳＴＤ可能沿着Ｒ１界面展布，也即Ｒ１界面同时是一条沉积盖层和基底之间的拆离层。Ｒ１界面埋深３±０．６—１１±０．６ｋｍ。（２）上述拆离层在萨马达一达吉之间，以Ｒ１界面之上的负速度梯度楔状体（ＬＶＬ）为特征。ＬＶＬ可能是ＳＴＤＳ活动时拖带下沉的中生代特提斯沉积，或可能是含水破碎带。（３）在结晶基底内部存在第二条拆离带（ＬＶＺ），表现为Ｔ２反射波组。ＬＶＺ在帕里埋深８．５±０．６ｋｍ，向北陡倾，至萨马达为２２．５±０．６ｋｍ深；再向北，倾角变缓，至达吉之下，达２７±０．６ｋｍ深。ＬＶＺ在帕里─萨马达之间，厚仅０．５ｋｍ；至达吉，增厚至５ｋｍ；也具楔形负速度梯度带性质；它可能是花岗岩局部融熔体之反映...更多。（４）在萨马达─达吉。