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thermodynamic conditions of framework grain dissolution of clastic rocks and its application in Kela 2 gas field

Science China Earth Sciences 2005年第1期48卷 21-31页

作者： LAI Xingyun, YU Bingsong, CHEN Junyuan, CHEN Xiaolin, LIU Jianqing, MEI Mingxiang, JING Weiguang & CHENG Suhua School of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083, China Key Laboratory of Lithospheric Tectonics, Deep-level Process and Exploration of Ministry of Education, Beijing 100083, China China University of Geosciences School of Earth Sciences and Mineral Resources Beijing China Key Laboratory of Lithospheric Tectonics Deep-level Process and Exploration of Ministry of Education Beijing China

Feldspar and clastic debris are the most important constituent framework grains of sedimentary clastic rocks and their chemical dissolution plays an essential role in the formation and evolution of the secondary pore in the reservoir rocks. On the basis of thermodynamic phase equilibrium, this study investigates the chemical equilibrium relationships between fluid and various plagioclase and K-feldspar in diagenesis of the sediments, particularly, the impact of temperature and fluid compositions (pH, activity of K+, Na+, Ca2+ and so on) on precipitation and dissolution equilibria of feldspars. Feldspar is extremely easily dissolved in the acid pore water with a low salinity when temperature decreases. The dissolution of anorthite end-member of plagioclase is related to the Ca content of the mineral and the fluid, higher Ca either in the mineral or in the fluid, easier dissolution of the feldspar. Moreover, the dissolution of albite end-member of plagioclase is related to Na of both the mineral and fluid, lower Na out of both the mineral and fluid, easier dissolution of the mineral. Similarly, lower-K fluid is more powerful to dissolve K-feldspar than the higher. The anorthite component of plagioclase is most easily dissolved in ground water-rock system, the albite is the secondary, and K-feldspar is the most stable. Selective dissolution of plagioclase occurs in diagenesis because of the plagioclase solid solution that is mainly composed of albite and anorthite end-members, Ca-rich part of which is preferentially dissolved by the pore water, in contrast to the Na-rich parts. Based on investigation of reservoir quality, secondary pore, dissolution structures of feldspar, clay minerals and ground water chemistry of the Kela 2 gas field of Kuqa Depression in the Tarim basin of Western China, we discovered that the secondary pore is very well developed in the highest quality section of the reservoir, and the plagioclase of which was obviously selectively dissolved, in contrast to the overgrowth of K-feldspar. Chemist

关键词： dissolution of feldspar, thermodynamic conditions, groundwater pore chemistry, Kela 2 gas field.

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thermodynamic analysis and simulation for gas baffle entrance collimator of EAST-NBI system based on thermo-fluid coupled method

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Nuclear Science and Techniques 2018年第1期29卷 90-95页

作者： Ling Tao Chun-Dong Hu Yuan-Lai Xie Institute of Plasma Physics Chinese Academy of Sciences

The world's first full Experimental Advanced Superconducting Tokamak(EAST) is designed with the auxiliary heating method of neutral beam injection(NBI)system. Beam collimators are arranged on both sides of the beam channel for absorbing the divergence beam during the beam transmission process in the EAST-NBI system.The gas baffle entrance collimator(GBEC) is a typical high-heat-flux component located at the entrance of gas baffle. An efficient and accurate analysis of its thermodynamic performance is of great significance to explore the working limit and to ensure safe operation of the system under a high-parameter steady-state condition. Based on the thermo-fluid coupled method, thermodynamic analysis and simulation of GBEC is performed to get the working states and corresponding operating limits at different beam extraction conditions. This study provides a theoretical guidance for the next step to achieve long pulse with highpower experimental operation and has an important reference to ensure the safe operation of the system.

关键词： Neutral beam injection High-heat-flux component Beam collimator Thermo-fluid coupled method thermodynamic analysis

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thermodynamic watershed hydrological model: Constitutive relationship

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Science China(Technological Sciences) 2008年第9期51卷 1353-1369页

作者： TIAN FuQiang HU HePing LEI ZhiDong State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China

The representative elementary watershed (REW) approach proposed by Reggiani et al. was the first attempt to develop scale adaptable equations applicable directly at the macro scale. Tian et al. extended the initial definition of REW for simulating the energy related processes, and re-organized the deriving procedure of balance equations so that additional sub-regions and substances could be easily incorpo-rated. The resultant ordinary differential equation set can simulate various hydro-logical processes in a physically reasonable way. However, constitutive and geo-metric relationships have not been developed for Tian et al.'s equation set, which are necessary for the thermodynamic watershed hydrological model to apply in hydrological modeling practice. In this work, the constitutive equations for mass exchange terms and momentum exchange terms were developed as well as geo-metric relationships. The closed ordinary differential equation set with nine equa-tions was finally obtained.

关键词： thermodynamics hydrological model constitutive relationship thermodynamic watershed hydrological model representative elementary watershed

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Separation of atropisomers by chiral liquid chromatography and thermodynamic analysis of separation mechanism

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Journal of Pharmaceutical Analysis 2017年第3期7卷 156-162页

作者： Ling Zhang Yue Hu Elizabeth Galella Frank P. Tomasella William P. Fish Chemical and Synthetic Development Bristol-Myers Squibb Co.New BrunswickNJ 08903USA Drug Product Science and Technology Bristol-Myers Squibb Co.New BrunswickNJ 08903USA

In the pharmaceutical industry, the analysis of atropisomers is of considerable interest from both scientific and regulatory perspectives. The compound of interest contains two stereogenic axes due to the hindered rotation around the single bonds connecting the aryl groups, which results in four potential configurational isomers(atropisomers). The separation of the four atropisomers was achieved on a derivatized β-cyclodextrin bonded stationary phase. Further investigation showed that low temperature conditions, including sample preparation(-70 °C), sample storage(-70 °C), and chromatographic separation(6 °C), were critical to preventing interconversion. LC-UV-laser polarimetric analysis identified peaks 1 and 2 as a pair of enantiomers and peaks3 and 4 as another. thermodynamic analysis of the retention data indicated that the separation of the pairs of enantiomers is primarily enthalpy controlled as indicated by the positive slope of the van't Huff plot. The difference in absolute Δ(Δ H), ranged from 2.20 k J/mol to 2.42 k J/mol.

关键词： Atropisomer separation Chiral HPLC thermodynamic parameters β-cyclodextrin stationary phase Chiral separation mechanism

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thermodynamic Calculation and Stability of Calcium Silicate Hydrate System

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Journal of Wuhan University of Technology(Materials Science) 2015年第1期30卷 147-151页

作者：段平严春杰 ZHOU Wei SHUI Zhonghe Faculty of Materials Science and Chemistry China University of Geosciences Engineering Research Center of Nano-Geomaterials of Ministry of Education China University of Geosciences Zhejiang Research Institute China University of Geosciences School of Materials Science and Engineering Wuhan University of Technology

Dissolution of cement clinker minerals involves a number of physical and chemical processes, and the simulation of dissolution processes helps to understand cement hydration conveniently. Dissolution model of cement clinker minerals was set up based on simulation theory of geochemical reaction equilibrium, PHREEQC simulation software provided by United States Geological Survey （USGS） was employed for thermodynamic calculation of C-S-H system. Stability of C-S-H system with low Ca/Si ratio at normal temperature was also explored. The results show that many phase assemblages coexist with the aqueous phase depending on its composition. The most stable product varies with different Ca/Si ratio of C-S-H system. Active SiO2 will consume excessive CH, so the Ca/Si ratios of C-S-H system decrease, C-S-H with low Ca/Si ratio becomes the most stable product, and this is the thermodynamic driving force of secondary pozzolanic reaction.

关键词： C-S-H equilibrium phase stability thermodynamic PHREEQC

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thermodynamic Stability of Sulfate Ions on Calcium Aluminosilicate Hydrate Microstructure

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Journal of Wuhan University of Technology(Materials Science) 2019年第3期34卷 638-647页

作者：胡晨光 DING Qingjun WANG Huan FENG Xiaoxin College of Materials Science and Engineering North China University of Science and TechnologyTangshan063210China Hubei Key Laboratory of Roadway Bridge and Structure Engineering(Wuhan University of Technology) Wuhan430070China College of Materials Science and Engineering Wuhan University of TechnologyWuhan430070China Hubei Communications Investment Intelligent Detection Co. LtdWuhan430051China

The thermodynamic stability of sulfate ions on synthesized calcium aluminosilicate hydrate (C-A-S-H) microstructure with different Ca/Si ratios and Al/Si ratios was investigated by XRD, SEM-EDS, 29Si and 27A1 nuclear magnetic resonance (NMR) and thermodynamic modeling. The results indicate that sulfate attack leads to both decalcification and dealumination for C-A-S-H gels, and the amount of corrosion products (gypsum and ettringite) decreased gradually with decreasing Ca/Si ratios of C-A-S-H. Sulfate ions can also promote the polymerization degree of C-A-S-H gels, improving its resistance to sulfate attack. Moreover, the 4-coordination aluminum (Al[4]) in C-A-S-H, 5-coordination aluminum (Al[5]), 6-ccordination aluminum (A1[6J) in TAH (third aluminum hydrate) and Al[6] in monosulfate or C-A-H (calcium aluminate hydrate) can be transformed into Al[6] in ettringite by sulfate attack. Furthermore, through thermodynamic calculation, the decrease of Ca/Si ratios and increase of Al/Si ratios can improve the thermodynamic stability of C-A-S-H gels under sulfate attack, which agrees well with the experiment results.

关键词： sulfate attack calcium aluminosilicate hydrate thermodynamic stability microstructure

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Acid Blue 25 adsorption on base treated Shorea dasyphylla sawdust:Kinetic,isotherm,thermodynamic and spectroscopic analysis

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Journal of Environmental Sciences 2012年第2期24卷 261-268页

作者： Megat Ahmad Kamal Megat Hanafiah Wan Saime Wan Ngah Shahira Hilwani Zolkafly Lee Ching Teong Zafri Azran Abdul Majid Department of Chemistry Faculty of Applied SciencesUniversiti Teknologi MARA School of Chemical Sciences Universiti Sains Malaysia Kulliyyah of Allied Health Sciences International Islamic University Malaysia

The potential of base treated Shorea dasyphylla（BTSD） sawdust for Acid Blue 25（AB 25） adsorption was investigated in a batch adsorption process.Various physiochemical parameters such as pH,stirring rate,dosage,concentration,contact time and temperature were studied.The adsorbent was characterized with Fourier transform infrared spectrophotometer,scanning electron microscope and Brunauer,Emmett and Teller analysis.The optimum conditions for AB 25 adsorption were pH 2,stirring rate 500 r/min,adsorbent dosage 0.10 g and contact time 60 min.The pseudo second-order model showed the best conformity to the kinetic data.The equilibrium adsorption of AB 25 was described by Freundlich and Langmuir,with the latter found to agree well with the isotherm model.The maximum monolayer adsorption capacity of BTSD was 24.39 mg/g at 300 K,estimated from the Langmuir model.thermodynamic parameters such as Gibbs free energy,enthalpy and entropy were determined.It was found that AB 25 adsorption was spontaneous and exothermic.

关键词： Acid Blue 25 adsorption Shorea dasyphylla sawdust spectroscopy thermodynamic

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thermodynamic properties of under-cooled silver melts

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Science China(Physics,Mechanics & Astronomy) 2010年第1期53卷 76-80页

作者： ZHU YuYing 1 , LI Qiang 1,2,3, WANG Ge 1 , JING Qin 2 , WANG Xu 1 , GAO Ying 3 & GAO JingNa 3 1 Department of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China 2 Key Laboratory of Metastable Materials Science & Technology, Yanshan University, Qinhuangdao 066004, China 3 Department of Materials Science & Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China Department of Mechanical Engineering Yanshan University Qinhuangdao China Key Laboratory of Metastable Materials Science & Technology Yanshan University Qinhuangdao China Department of Materials Science & Engineering Hebei University of Science and Technology Shijiazhuang China

Differential scanning calorimeter technique combined with the traditional fluxing treatment was used to investigate the specific heat and related thermodynamic properties of under-cooled pure silver melts. The specific heat of the under-cooled melt showed a linear dependence on the temperature in the range of the obtained under-cooling from 0 to 198 K. The related thermodynamic properties of silver, such as the entropy change, the enthalpy change and the Gibbs free energy difference between the under-cooled melt and the solid phase, were derived from the measured specific heat. The relations between the temperature and the thermal diffusion or the thermal conductivity of the under-cooled melt were analyzed respectively.

关键词： under-cooled silver melts specific heat thermodynamic properties

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thermodynamic properties of cubic ZrC under high pressure from first-principles calculations

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Science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 1039-1042页

作者： ZHU Jun ZHU Bo QU JianYing GOU QingQuan CHEN Fang College of Physical Science and Technology Sichuan UniversityChengdu 610065China Southwest Jiaotong University-Emei Campus Emei 614202China

The elastic and thermodynamic properties of Zirconium carbide (ZrC) are investigated by ab initio plane-wave pseudopotential density function theory method. The obtained lattice constant, elastic constant and bulk modulus B are consistent with the experimental and theoretical data. Through the quasi-harmonic Debye model, the dependences of the normalized volume V/V0 and the bulk modulus B on pressure P, as well as the specific heat CV on the temperature T are obtained successfully. The relationships of the thermal expansion α with temperature and pressure are also investigated, which indicate the temperature hardly has any effect on the thermal expansion α at high pressure.

关键词： elastic properties thermodynamic properties ZrC

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Kinetic and thermodynamic studies on partitioning of polychlorinated biphenyls (PCBs) between aqueous solution and modeled individual soil particle grain sizes

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Journal of Environmental Sciences 2019年第2期31卷 100-110页

作者： Gbadebo Clement Adeyinka Brenda Moodley School of Chemistry and Physics College of AgricultureEngineering and SciencesUniversity of KwaZulu-Natal

The significance of soil mineral properties and secondary environmental conditions such as pH, temperature, ionic strength and time in the partitioning of eight selected polychlorinated biphenyl(PCB) congeners between aqueous solution and soil particles with different grain sizes was studied. The mineral properties of a model soil sample were determined, and Brunauer–Emmett–Teller(BET) adsorption–desorption isotherms were employed to observe the surface characteristics of the individual modeled soil particles.Batch adsorption experiments were conducted to determine the sorption of PCBs onto soil particles of different sizes. The results revealed that the sorption of PCB congeners onto the soil was dependent on the amount of soil organic matter, surface area, and pore size distribution of the various individual soil particles. Low pH favored the sorption of PCBs,with maximum sorption occurring between pH 6.5 and 7.5 with an equilibration period of 8 hr.Changes in the ionic strength were found to be less significant. Low temperature favored the sorption of PCBs onto the soil compared to high temperatures. thermodynamic studies showed that the partition coefficient(K_d) decreased with increasing temperature, and negative and low values of ΔH° indicated an exothermic physisorption process. The data generated is critical and will help in further understanding remediation and cleanup strategies for polluted water.

关键词： Partitioning PCBs Soil particle grain sizes Kinetics thermodynamic studies pH

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