旋转电极法研究盐类溶解─LiCl、NaCl、KCl在水中的溶解动力学

利用旋转盘装置结合离子选择电极研究了ＬｉＣｌ、ＮａＣｌ、ＫＣｌ在２０℃～３５℃水中溶解动力学，得到了溶解动力学方程．     

旋转电极法研究盐类溶解—LiCl,NaCl,KCl在水中的溶解动力学

利用旋转盘装置结合离子选择电极研究了ＬｉＣｌ、ＮａＣｌ、ＫＣｌ在２０℃～３５℃水中溶解动力学，得到了溶解动力学方程．     

软钾镁矾溶解动力学研究

本文对软钾镁矾在水中不同粒度和１０～４０℃时的溶解过程进行研究，并建立溶解速率方程，获得该复盐的溶解动力学方程，探明它们的溶解和转化机理．     

氯化钠对钾光卤石溶解过程的影响

研究了不同温度下，不同浓度的ＮａＣｌ溶液对钾光卤石溶解转化的影响．得出ＮａＣｌ的浓度对溶解转化的影响不大，且温度对光卤石的溶解转化的影响不是简单线性关系的结论．计算了该体系光卤石的溶解动力学方程和氯化钾结晶动力学方程．     

钾光卤石溶解和氯化钾结晶动力学与机理研究

本文研究了易溶性复盐钾光卤石(KCl·MgCl_2·6H_2O)的溶解机理及动力学。利用相图控制在固相光卤石饱和区的情况下研究改变温度、浓度、搅拌速度及成块压力对光卤石溶解过程的影响,发现MgCl_2、KCl首先以近相等的速度且出现KCl:MgCl_2的摩尔比值>1进入溶液,随后KCl从溶液中结晶出来。KCl在整个溶解过程中明显分为两个阶段,即以溶解为主导的过程和以结晶为主导的过程;在溶解时,MgCl_2受扩散控制,KCl属化学溶解过程,KCl结晶受扩散控制,获得了动力学的方程计算出MgCl_2的溶解活化能和KCl的溶解和结晶活化能。     

软钾镁矾溶解动力学Ⅰ:对K~ ,Mg~(2 )/SO_4~(2-)—H_2O三元体系的研究(50-75℃)

前言青藏高原的诸多盐湖中存在大量的钾、钠、镁复盐,如KCI和KSO。这两种钾肥可以由盐湖中所含的钾钱复盐光卤石和软钾镁矾（K。SO。·MgSO。·sH刀）在水中溶解制得,因此,有必要对复盐溶解过程进行系统的研究,夏树屏等人‘’,‘’已对复盐氯碳酸镁和氯柱硼镁石等的溶解转化机理和动力学进行了较为详细的研究,解决了不同类型复盐的研究方法和数据处理方法。德国和独联体两国的学者对钾光卤石固体盐矿的工艺及基础研究曾进行过不少的工作H．H．Emons和HVo…等‘”对钾光卤石的天然单晶和压块光卤石不同条件下的溶解速度常数及…     

广西海湾红树林区海水中氮的生物地球化学特征及其生态效应

2008年1月、5月、8月和11月,对广西壮族自治区合浦县海湾3个红树林区进行调查,并采集水样,研究各区海水中不同形态氮的含量分布、形态特征、相互关系和氮磷比及其对生态环境的影响效应。结果表明,广西壮族自治区合浦县海湾红树林区海水中各形态氮主要以陆源的补充为主,以凋落物的释放补充为辅;其中,总氮、颗粒态氮、溶解态氮和溶解无机氮含量都具有春季、夏季偏高和秋季、冬季偏低的特征,只有溶解有机氮含量具有夏季最高、秋季和冬季次之、春季明显偏低的特征;研究区海水中氮的存在形态主要以溶解态氮为主,其占总氮的81.74%,但在溶解态氮中,溶解有机氮仅以55.06%略占优势;研究区海水中各形态氮含量之间多有显著正相关关系,但四季都能保持高度一致迁移、转化规律的只有总氮与溶解态氮、溶解无机氮和溶解态氮与溶解无机氮,溶解态氮和溶解无机氮无疑成为总氮的主导控制因子。研究区海水中各形态氮含量明显受到环境因子的影响,其中受悬浮物和总有机碳含量的影响较大,受透明度、总碱度、水温和叶绿素a含量的影响次之,受盐度和p H的影响相对较小;研究区海水中各形态氮含量对基础生物量(初级生产力、浮游植物总细胞数和浮游动物总个体数)和浮游生物结构(总种数、丰度、均匀度、多样性指数和多样性阀值)的影响明显,前者以正面影响为主,后者以负面影响为主,春季的影响程度尤为突出;除颗粒态氮与颗粒态磷含量的比值以12.23的明显低值显示氮的相对缺乏外,海湾红树林区海水中的其余4种形态氮含量的比值都在33.07~91.75之间,呈富足状态,尤以溶解无机氮最为显著,这与氮的来源途径较多、转化速率较高有关。     

溶解动力学和结晶动力学研究的参数优化

溶解动力学和结晶动力学研究的参数优化对研究物质的溶解、结晶转化机理和热力学行为具有重要的意义。我们将Ｒｕｎｇｅ-Ｋｕｔｔａ法与单纯形优化法相结合,针对几种适合于该法求解的微分动力学方程进行了讨论,从而为动力学研究中机理模型参数的优化提供了一种行之有效的方法。     

软钾镁矾溶解动力学Ⅲ∶NaCl对软钾镁矾溶解转化影响的研究

本文利用合成纯软钾镁矾晶体，研究了不同浓度ＮａＣｌ（１．０２８、３．０５４％）溶液、不同温度（２５、５０、７５℃）对软钾镁矾溶解转化过程的影响。并且采用龙格—库塔微分数值法拟合求解其溶解过程和结晶过程动力学方程。结果表明在一定浓度ＮａＣｌ溶液中软钾镁矾是不相称溶解。ＭｇＳＯ４先于Ｋ２ＳＯ４溶解进入溶液中，温度越高，溶解速度越快，Ｋ２ＳＯ４结晶速度也越快，ＮａＣｌ的盐析作用越明显，软钾镁矾溶解达到Ｋ２ＳＯ４过饱和并析出所需时间缩短，溶解受扩散和表面反应控制，Ｋ２ＳＯ４结晶受扩散控制。     

北京汉石桥潜流湿地对总溶解性固体和浊度的去除效果分析

以北京汉石桥潜流湿地为研究对象,分析了2014-2015年水体中总溶解固体(Turb)与浊度(TDS)的去除率,研究潜流湿地对水中总溶解固体与浊度的去除效果。结果表明:①潜流湿地对浊度(TDS)和总溶解固体(Turb)在全年均具有一定的处理效果,1-12月去除率表现为先增加后降低的趋势,平均去除率分别为85.6%和6.4%;②温度成为制约潜流湿地污染物去除的重要因素,其中总溶解固体和浊度与温度的相关系数分别为0.669和0.489;③对总溶解性固体和浊度的比较发现,在估值背景浓度下,面积速率常数均高于零背景值时的面积速率常数,当污染负荷较低时,潜流湿地对总溶解性固体和浊度去除的面积速率常数随进水污染负荷的升高而增加。     

光卤石在芒硝溶液中溶解和转化动力学

本文研究了在恒速搅拌下，不同温度光卤石在芒硝溶液中溶解及转化机理，用溶解过程离子实验值拟合得到动力学方程，并求得了溶解反应的表观活化能，为生产硫酸钾提供了一定的基础。     

基于野外控制试验的不同持续时间干旱对喀斯特溶蚀的影响研究

溶蚀作用是喀斯特地区最根本的作用过程之一,与水密切相关,极易受到干旱的影响。过去研究表明,干旱对喀斯特溶蚀有重要的影响,但具体影响有多大尚不清楚。论文采用标准溶蚀试片法并通过野外控制试验的方式,定量地给出了12种不同持续时间干旱对黔中地区林地、灌草地和耕地及其地下不同土层深度喀斯特溶蚀的影响,并初步分析了其影响过程机理。研究表明：① 不同持续时间干旱对林地、灌草地和耕地喀斯特溶蚀的影响程度分别达到30.61%~83.33%、38.45%~88.82%和66.76%~95.14%,均随干旱持续时间的增加而呈明显的上升趋势;② 干旱对不同土层喀斯特溶蚀的影响不一致,较短持续时间干旱对林地、灌草地和耕地中下层喀斯特溶蚀的影响较大,而长持续时间干旱则对表层喀斯特溶蚀的影响较大;③ 土壤水分是干旱影响喀斯特溶蚀的关键要素,土壤pH随土壤水分变化而变化,而土壤有机质对喀斯特溶蚀的干旱影响则有一定的减缓作用。     

盐类溶解动力学的数学模型和热力学函数

总结了研究盐类溶解动力学的方法和数学模型。采用C语言编写了自动寻优的单线形法，实现了含4个参数的通用程序，并例举了研究实例。另外讨论了热力学函数的处理，也例举了研究实例。     

盐卤硼酸盐化学ⅩⅨ——氯柱硼镁石溶解及相转化研究

本文研究了温度、盐效应、晶体用量和搅拌速度对氯柱硼镁石在水中溶解过程及相转化的影响。实验结果表明,该复盐属不同步溶解,先溶脱MgCl·6H_2O,生成中间产物MgO·B_2O_3·4H_2O,随后发生相转化和结晶过程。最终产物在10—50℃时是多水硼镁石,在60℃时是柱硼镁石。提出了相转化机理,计算了溶解度、溶解热等热力学函数。     

Origin of the salt valleys in the Canyonlands section of the Colorado Plateau: Evaporite-dissolution collapse versus tectonic subsidence

The salt valleys over the axis of the salt-cored anticlines in the Paradox fold and fault belt (Canyonlands, Utah and Colorado) are created by subsidence of the anticline crests. Traditionally, the collapse of the anticlinal crests was attributed to dissolution of the salt walls (diapirs) forming the anticline cores. Recent studies based on scaled physical models and field observations propose that the salt valleys are a result of regional extension and that salt dissolution had only a minor influence in the development of the axial depressions. This paper presents several arguments and lines of evidence that refute the tectonic model and support the salt dissolution subsidence interpretation.The development of contractional structures in salt dissolution experiments led the advocates of the tectonic interpretation to reject the dissolution-induced subsidence explanation. However, these salt dissolution models do not reproduce the karstification of salt walls in a realistic way, since their analog involves removal of salt from the base of the diapirs during the experiments. Additionally, numerous field examples and laboratory models conducted by other authors indicate that brittle subsidence in karst settings is commonly controlled by subvertical gravity faults.Field evidence against the regional extension model includes (1) a thick cap rock at the top of the salt walls, (2) the concentration of subsidence deformation structures along the crest of the anticlines (salt walls), (3) deformational structures not consistent with the proposed NNE extension, like crestal synforms and NE–SW grabens, (4) dissolution-induced subsidence structures controlled by ring faulting, revealing deep-seated dissolution, (5) large blocks foundered several hundred meters into the salt wall, (6) evidence of recent and active dissolution subsidence, and (7) the aseismic nature of the recently active collapse faults. Although underground salt dissolution seems to be the main cause for the generation of the salt valleys, this phenomenon may have been favored by regional extension tectonics that enhance the circulation of groundwater and salt dissolution.     

Differential diatom dissolution in Late Quaternary sediments from Lake Manyara,Tanzania: an experimental approach

Diatom dissolution in saline lakes represents an important obstacle to the quantitative reconstruction of water chemistry and climate from lake sediment archives. This problem is here approached experimentally by artificially dissolving diatom-bearing core sediment from Lake Manyara, Tanzania. Manyara holds one of the longest continuous palaeolimnological records from tropical Africa although its interpretation is based on a fragmentary diatom record due to frustule dissolution. These experiments have revealed clear changes in assemblage composition as dissolution operated differentially with respect to diatom taxa. Differential dissolution has considerable impact on the water chemistry estimates derived from transfer functions. Taphonomy, rather than environmental change, may have been responsible for minor fluctuations in the diatom assemblages from Manyara, although major palaeohydrological changes during the Late Pleistocene and Early Holocene can be identified. Particularly well represented by MANE-87 is a period of intermediate lake level between 27 500 and 23 000 ¹⁴C yr BP which has regional palaeohydrological significance.     

Effects of Fe3+ on Dissolution Dynamics of Carbonate Rocks in a Shallow Burial Reservoir

Dissolution of carbonates in acidic fluids, which has attracted much research attention in recent years, is of great significance for the formation of high-quality reservoirs. The dissolution stage under low temperature and low pressure in shallow burial is one of the most important processes of reservoir dissolution and transformation. However, the dissolution dynamics of carbonate rocks in shallow burial and their formation have been controversial for a long time, and there are still disputes in the dissolution processes about how associated minerals and accessory minerals (e.g., pyrite) in carbonate reservoirs influence the formation of secondary pores. Additional metal ions in acidic fluids can change fluid properties and dissolution processes, and consequently affect reservoir quality. However, there are few laboratory studies done on the effect of associated minerals on the dissolution dynamics of carbonates. To clarify the specific impact of Fe-bearing associated minerals and Fe³⁺ on the dissolution of carbonates in shallow burial reservoirs, six samples of typical carbonate rocks in the Zigui area of Hubei Province, China were studied. The dissolution kinetics of carbonates in dilute hydrochloric acid and sulfuric acid solutions containing metal ions (Fe³⁺/Ca²⁺/Mn²⁺) at ambient temperature and pressure (T?=?25 °C, P?=?1 atm) were studied, by laboratory dissolution experiments combined with numerical simulations using PHREEQC. The results show that the Fe³⁺ is of great significance on the dissolution of carbonate rocks, while the influences of Ca²⁺ and Mn²⁺ are relatively weak. The dissolutions degrees of micritic limestone (ZG-L25), dolomitic limestone (ZG-L7) and dolomite (ZG-D9) were better than the other carbonates under the influence of metal ions (Fe³⁺/Ca²⁺/Mn²⁺) in acid solutions. Therefore, the dolomite reservoir of the Cambrian Qinjiamiao Formation, the dolomitic limestone reservoir of the Tianheban Formation and the limestone reservoir of the Triassic Daye Formation in the Zigui area are potential high-quality reservoirs. The carbonate reservoirs associated with Fe-bearing minerals were easier to dissolve and formed secondary pores under shallow burial. This process is beneficial to the formation of high-quality reservoirs. Moreover, the addition of Fe³⁺ into hydrochloric acid solution may be conducive to improving the reservoirs acidizing effect. Furthermore, the results gave innovative results from multiple perspectives of geo-material science and computational geosciences, which may provide new avenues for in-depth study of carbonate dissolution in shallow burial based on water–rock reaction, chemical dissolution, computational simulation, and geological background.