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LA-ICP-MS in situ analyses of the pyrites in Dongyang gold deposit,Southeast China:Implications to the gold mineralization

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China Geology 2020年第2期3卷 230-246页

作者： Nan Xu Cai-lai Wu Sheng-rong Li Bo-qiang Xue Xiang He Yan-long Yu Jun-zhuang Liu Key Laboratory of Deep-Earth dynamics of Ministry Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China State Key laboratory of Geological Processes and Mineral Resources School of Earth Sciences and ResourcesChina University of Geosciences(Beijing)Beijing 100083China Yunnan Gold Mining group Co. LtdKunming 650200China China Renewable Energy Engineering Institute Beijing 100120China China National Gold group Co. LtdBeijing 100011China

The Dongyang gold deposit is a newly discovered epithermal deposit in Fujian Province,Southeast China,along the Circum-Pacific metallogenic ***,the authors present mineralogical,scanning electron microscope,and laser ablation inductively coupled clasma mass spectrometry analysis to reveal the relations between Au and Te,As,S,Fe,etc.,and discuss the gold precipitation *** pyrites in this deposit are Fe-deficient,and are enriched in Te and *** authors infer that As was mainly in form of As-complexes,and Te-Au-Ag inclusions/solid solution also exsits in the Py *** with the depletion of Te and As,they were less active chemically in the Py II,and Au may be incorporated into As-rich and Fe-deficient surface sites by chemisorption onto As-rich growth *** of the incorporation of new fluid,Te and As became the most active chemically in the Py III,which was the main elements precipitation stage,and As dominantly substituted for S in the lattice of pyrite,due to the more reducing *** authors propose Au was in form of invisible gold,and the incorporation of gold can be considered as post-pyrite event,while the Au-bearing minerals were result of post incorporation of gold in arsenian pyrite.

关键词： Gold deposit SEM LA-ICP-MS Invisible gold Pyrite Mineral exploration engineering Dongyang Fujian Province China

Numerical study on the aerodynamic performance and safe running of high-speed trains in sandstorms

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 971-978页

作者： Hong-bing XIONG Wen-guang YU Da-wei CHEN Xue-ming SHAO Department of mechanics Zhejiang University Hangzhou 310027 China National Engineering Laboratory for System Integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd. Qingdao 266111 China

The influence of sandstorms on train aerodynamic performance and safe running was studied in response to the frequent occurrence of sandstorm weather in north *** Eulerian two-phase model in the computational fluid dynamic (CFD) software FLUENT,validated with published data,was used to solve the gas-solid multiphase flow of a sandstorm around a *** train aerodynamic performance under different sandstorm levels and no sand conditions was then *** showed that in sandstorm weather,the drag,lift,side forces and overturning moment increase by variable *** on a numerical analysis of aerodynamic characteristics,an equation of train stability was also derived using the theory of moment balance from the view of dynamics.A recommended speed limit of a train under different sandstorm levels was calculated based on the stability analysis.

关键词： High-speed train Sandstorm Gas-solid multiphase Eulerian two-phase model Aerodynamic Safety Speed limit

Particle mixing rates using the two-fluid model

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Particuology 2018年第1期16卷 13-26页

作者： M. Banaei N.G. Deen M. van Sint Annaland J.A.M. Kuipers Multiphase Reactors group Deportment of Chemical Engineering & Chemistry Eindhoven University of Technology 5600 MB Eindhoven The Netherlands Dutch Polymer Institute (DPI) 5600 AX Eindhoven The Netherlands Multiphase and Reactive Flows group Department of Mechanical Engineering Eindhoven University of Technology 5600 MB Eindhoven The Netherlands

In this work, a new methodology is introduced to calculate the solids mixing rate in dense gas-fluidized beds using the two-fluid model. The implementation of this methodology into an existing two-fluid model code was carefully verified. The solids phase continuity equation was satisfied using our method, and the sensitivity of the computational results to the time step, computational cell size, and discretization scheme was investigated to determine the optimal simulation settings. Using these simulation settings, the degree of solids mixing was observed to rapidly （exponentially） increase with increasing operating pressure and linearly decrease with increasing bed diameter. Our novel methodology can be applied to analyze mixing processes in large lab-scale beds as an alternative to existing time-consuming simulation techniques such as computational fluid dynamics combined with the discrete element model.

关键词： Gas-solid fluidized bed Simulation Two-fluid model solids mixing Pressure Scale up

Development and validation of THM coupling model of methane-containing coal

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International Journal of Mining Science and Technology 2012年第6期22卷 868-872页

作者： Tao Yunqi Xu Jiang Liu Dong Liang Yongqing State Key Laboratory of Coal Mine Disaster dynamics and Control Chongqing University State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam Chongqing University

Based on nine necessary basic assumptions for THM coupling model,this research comprehensively applied the theories of elastic mechanics,seepage mechanics and heat transfer,and established a real three-field and two-way coupled mathematical model to reveal the connections among seepage field,deformation field and temperature field within the system of methane-containing *** comparison between numerical and analytical solutions,the coupling modeling for THM of methane-containing coal was proved to be correct by model application in the physical simulation experiment of coal and gas *** model established in this paper was the improvement of traditional seepage theory of methane-containing coal and fluid-solid coupled model theory,which can be widely used in prevention of coal and gas outburst as well as exploitation of coal bed methane.

关键词： Coal containing methane Temperature field Seepage field Stress field fluid-solid-heat coupling

An effective thermal conductivity model for unsaturated compacted bentonites with consideration of bimodal shape of pore size distribution

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Science China(Technological Sciences) 2015年第2期58卷 369-380页

作者： CHEN Yi Feng WANG Min ZHOU Song HU Ran ZHOU Chuang Bing State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Key Laboratory of Rock mechanics in Hydraulic Structural Engineering (Ministry of Education) Wuhan University School of Civil Engineering and Architecture Nanchang University

An effective thermal conductivity model was proposed for unsaturated compacted bentonites with consideration of the bimodal shape of pore size distribution curves. The pores of soils were grouped into two dominant pore size modes corresponding to the intra- and inter-particle pores, and were simulated with randomly distributed spheroidal inclusions of different aspect ratios. With the assumption of preferential invasion of the wetting fluid （water） into pores of smaller sizes and by virtue of the analyt- ical solution to the inhomogeneous inclusion problem in heat conduction, the model was developed using the Mori-Tanaka （MT）, Ponte Castafieda-Willis （PCW） and self-consistent （SC） homogenization approaches for different considerations of the interactions between pores and the solid phase. The proposed model is functions of the thermal conductivities of the solid, liq- uid and gas phases, porosity, the degree of saturation, the aspect ratios of pores and/or soil particles, and the fraction of the smaller group of pores. The proposed model was validated against five sets of laboratory measurement data on the MX-80, FEBEX, KunigeI-V1 and GMZ01 bentonites, showing a good agreement between the model predictions and the laboratory measurements. The responses of the model with respect to the geometries of pores and solid particles were examined. Com- pared to series-parallel structural models, the proposed model may overall exhibit better performance if proper homogenization schemes are adopted, but as an advantage, the model has clearer physical mechanisms and a smaller number of parameters.

关键词： thermal conductivity homogenization schemes compacted bentonite unsaturated soil pore size distribution three-phase media

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Acta Mechanica Sinica 2023年第1期39卷 1-3页

作者： Xiaoyan Ye Hongyang Cheng College of Civil Engineering and mechanics Lanzhou UniversityLanzhou 730000China Department of Civil Engineering Faculty of Engineering TechnologyMESA+University of Twente7500 AE EnschedeThe Netherlands

Granular matter is the second most handled material after water in the global *** macroscopic behavior arises from a collisional to a collective motion of the constituent grains,with varying lengths and time *** fluid-like and solid-like behaviors of granular materials and their transitions[1]are relevant to many industrial problems,such as mining excavation[2],selective laser sintering and powder spreading[3],thawing-induced slope failure[4],and granular impact[1].Designing and optimizing these processes require a synergy of understandings obtained from studies of contact theories[5],particle morphology or shape representation[5,6],interparticle friction[7],and micro-tomacro[4,7,8]and discrete-to-continuum transitions[1,2].

关键词： friction transitions collective

mechanics OF EXPLOSIVE WELDING

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MECHANICS OF EXPLOSIVE WELDING

Lattice Boltzmann Method for Reacting Flows in Porous Media

作者：郑哲敏 Institute of mechanics CAS

1. INTRODUCTIONThis paper is a summary of work done in recent years at the Institute of mechanics, Chinese Academy of Sciences, on several problems of theoretical interest in explosive welding from the point of view of hydro-elasto-plastic dynamics, where the medium or media have to be regarded as exhibiting both fluid-like and solid-like properties. Ex-

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Advances in Applied Mathematics and mechanics 2010年第5期2卷 545-563页

作者： Qinjun Kang Peter C.Lichtner David R.Janecky Computational Earth Sciences group Los Alamos National LaboratoryLos AlamosNM 87545U.S.A Ecology and Air Quality group Los Alamos National LaboratoryLos AlamosNM 87545U.S.A

We review recent developments in lattice Boltzmann method for reacting flows in porous *** present the lattice Boltzmann approaches for incompressible flow,solute transport and chemical reactions in both the pore space and at the fluid/solid *** discuss in detail the methods to update solid phase when significant mass transfer between solids and fluids is involved due to dissolution and/or *** in different areas are presented and perspectives of applying this method to a few important fields are discussed.

关键词： Reactive flows lattice Boltzmann method porous media pore scale

A stability condition for turbulence model:From EMMS model to EMMS-based turbulence model

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Particuology 2014年第5期12卷 142-154页

作者： Lin Zhang Xiaoping Qiu Limin Wang Jinghai Li The EMMS group State Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of Sciences University of Chinese Academy of Sciences

The closure problem of turbulence is still a challenging issue in turbulence modeling. In this work, a stability condition is used to close turbulence. Specifically, we regard single-phase flow as a mixture of turbulent and non-turbulent fluids, separating the structure of turbulence. Subsequently, according to the picture of the turbulent eddy cascade, the energy contained in turbulent flow is decomposed into different parts and then quantified. A turbulence stability condition, similar to the principle of the energy-minimization multi-scale （EMMS） model for gas-solid systems, is formulated to close the dynamic constraint equa- tions of turbulence, allowing the inhomogeneous structural parameters of turbulence to be optimized. We name this model as the ＂EMMS-based turbulence model＂, and use it to construct the corresponding turbulent viscosity coefficient. To validate the EMMS-based turbulence model, it is used to simulate two classical benchmark problems, lid-driven cavity flow and turbulent flow with forced convection in an empty room, The numerical results show that the EMMS-hased turbulence model improves the accuracy of turbulence modeling due to it considers the principle of compromise in competition between viscosity and inertia.

关键词： Stability condition Mathematical modeling Turbulence EMMS Hydrodynamics Computational fluid dynamics