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An adaptive cell-based domain integration method for treatment of domain integrals in 3D boundary element method for potential and elasticity problems

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Acta Mechanica Solida Sinica 2017年第1期30卷 99-111页

作者： Qiao Wang Wei Zhou Yonggang Cheng gang ma Xiaolin Chang Qiang Huang State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University

An adaptive cell-based domain integration method（CDIM） is proposed for the treatment of domain integrals in 3D boundary element method（BEM）. The domain integrals are computed in background cells rather than volume elements. The cells are created from the boundary elements based on an adaptive oct-tree structure and no other discretization is needed. Cells containing the boundary elements are subdivided into smaller sub-cells adaptively according to the sizes and levels of the boundary elements; and the sub-cells outside the domain are deleted to obtain the desired accuracy. The method is applied in the 3D potential and elasticity problems in this paper.

关键词： Cell-based domain integration method Domain integrals BEM Potential problems Elasticity problems

Experimental and numerical investigation of Weibullian behavior of grain crushing strength

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Geoscience Frontiers 2020年第2期11卷 401-411页

作者： Quanshui Huang Wei Zhou gang ma Tang-Tat Ng Kun Xu State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Wuhan UniversityMinistry of EducationWuhan 430072China University of New Mexico AlbuquerqueNM87131USA

The Weibullian behavior of single grain crushing strength was investigated experimentally and numerically with the aim of enhancing the understanding of rock grain *** morphologies of pebble grains were obtained using white light 3D laser scanning and image processing.A grain shape library was constructed for grain shape analysis with different shape *** use of the shape library and grain stability analysis is discussed for a suggested procedure to rotate a grain to its most stable *** grain crushing tests were performed for 30 pebbles to obtain force-displacement curves and fracture *** grain was compressed diametrically between flat *** expected,the values of the stress at bulk fracture follow a Weibull distribution.A procedure for generating crushable agglomerates with realistic particle shapes was demonstrated,which was accomplished in the discrete element modeling(DEM)of the single grain crushing *** work presented here is novel in that both the heterogeneous micro-structures and randomly distributed flaws are *** DEM results demonstrate that the proposed modeling approach and calibrated parameters are reliable and can reflect the crushing behavior of rock ***,three parametric studies were presented evaluating the effects of micro-crack density,micro-crack disorder,and grain morphology on the Weibullian behavior of the crushing strength,none of which has previously been thoroughly *** three studies provide a deeper insight into the origin of the Weibullian behavior of single grain crushing strength.

关键词： Rock grain Grain crushing test Discrete element modeling 3D scanning technique Grain stability Weibullian behavior

L-type Calcium Channels are Involved in Iron-induced Neurotoxicity in Primary Cultured Ventral Mesencephalon Neurons of Rats

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Neuroscience Bulletin 2020年第2期36卷 165-173页

作者： Yu-Yu Xu Wen-Ping Wan Sha Zhao Ze-gang ma Department of Physiology School of Basic MedicineQingdao UniversityQingdao 266071China Institute of Brain Science and Disorders Qingdao UniversityQingdao 266071China

In the present study,we investigated the mechanisms underlying the mediation of iron transport by Ltype Ca^2+ channels(LTCCs)in primary cultured ventral mesencephalon(VM)neurons from *** found that cotreatment with 100 lmol/L FeSO4 and MPP^+(1-methyl-4-phenylpyridinium)significantly increased the production of intracellular reactive oxygen species,decreased the mitochondrial transmembrane potential and increased the caspase-3 activation compared to MPP^+ treatment ***-treatment with 500 lmol/L CaCl2 further aggravated the FeSO4-induced neurotoxicity in MPP^+-treated VM ***-treatment with 10 lmol/L isradipine,an LTCC blocker,alleviated the neurotoxicity induced by co-application of FeSO4 and FeSO4/*** studies indicated that MPP^+treatment accelerated the iron influx into VM *** addition,FeSO4 treatment significantly increased the intracellular Ca^2+ *** effects were blocked by *** results suggest that elevated extracellular Ca^2+ aggravates ironinduced *** mediate iron transport in dopaminergic neurons and this,in turn,results in elevated intracellular Ca^2+ and further aggravates iron-induced neurotoxicity.

关键词： L-type Ca^2+channels Iron overload Parkinson’s disease Isradipine Dopamine neuron

Studies on the Mechanism of Methyl Methacrylate Polymerization Initiated　by　Volatile　and　Nonvolatile　Products　of　Methyl　Methacrylate　Plasma

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Chemical Research in Chinese Universities 1995年第3期11卷 250-255页

作者： Liu, Xiao-dong Li, Jing ma, Yu-gang Shen, Jia-cong NORmaN BETHUNE UNIV MED SCI BASIC MED COLLCHANGCHUN 130023PEOPLES R CHINA JILIN UNIV KEY LAB MOLEC SPECTRA & STRUCTCHANGCHUN 130023PEOPLES R CHINA

he volatile (VPP) and nonvolatile (NVPP) products of methyl methacrylate(Mma) reaction in plasma chamber were used as initiators of Mma polymeriza-tion. From the structure analyses of the two initiators, the measurement of poly-merization kinetics, and the determination of the molecular weight of resultantpolymers , we found tliat Mma polymerization initiated by NVPP is a typical radical mechanism of polymerization which undergoes a process of continuous initiationand bifunction termination , while VPP-initiated polymerization suggested a mech-anism of living radical process fpolymerization with instantaneous initiation , chain-transfer to monomer , without termination).

关键词： Plasma initiated polymerzation Methyl methacrylate Kinetics

Jacobian matrix for near-infrared remote sensing based on vector radiative transfer model

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Science China Earth Sciences 2020年第9期63卷 1353-1365页

作者： Wenguang BAI Peng ZHANG Wenjian ZHANG Jun LI gang ma Chengli QI Hui LIU National Satellite Meteorological Center Beijing 100081China

Due to the polarization effects of the Earth’s surface reflection and atmospheric particles’scattering,high-precision retrieval of atmospheric parameters from near-infrared satellite data requires accurate vector atmospheric radiative transfer *** paper presents a near-infrared vector radiative transfer model based on the doubling and adding *** new model utilizes approximate calculations of the atmospheric transmittance,reflection,and solar scattering radiance for a finitely thin atmospheric *** verify its accuracy,the results for four typical scenarios(single molecular layer with Rayleigh scattering,single aerosol layer scattering,multi-layer Rayleigh scattering,and true atmospheric with multi-layer molecular absorption,Rayleigh and aerosol scattering)were compared with benchmarks from a well-known *** comparison revealed an excellent agreement between the results and the reference data,with accuracy within a few ***,to fulfill the retrieval algorithm,a numerical differentiation-based Jacobian calculation method is developed for the atmospheric and surface *** is coupled with the adding and doubling process for the radiative transfer *** Jacobian matrix produced by the new algorithm is evaluated by comparison with that from the perturbation *** relative Jacobian matrix deviations between the two methods are within a few thousandths for carbon dioxide and less than 1.0×10-3%for aerosol optical *** two methods are consistent for surface albedo,with a deviation below 2.03×10-4%.All validation results suggest that the accuracy of the proposed radiative transfer model is suitable for inversion *** model exhibits the potential for simulating near-infrared measurements of greenhouse gas monitoring instruments.

关键词： Vector radiative transfer Jacobian matrix calculation Aerosol scattering

Assimilation of FY-3D MWTS-Ⅱ Radiance with 3D Precipitation Detection and the Impacts on Typhoon Forecasts

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Advances in Atmospheric Sciences 2023年第5期40卷 900-919页

作者： Luyao QIN Yaodeng CHEN gang ma Fuzhong WENG Deming MENG Peng ZHANG Key Laboratory of Meteorological Disaster of Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Earth System Modeling and Prediction Centre China Meteorological AdministrationBeijing 100081China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites(LRCVES/Cma) National Satellite Meteorological CenterChina Meteorological Administration(NSMC/CMA)Beijing 100081China

Precipitation detection is an essential step in radiance assimilation because the uncertainties in precipitation would affect the radiative transfer calculation and observation *** traditional precipitation detection method for microwave only detects clouds and precipitation horizontally,without considering the three-dimensional distribution of *** precipitation detection from 2D to 3D is expected to bring more useful information to the data assimilation without using the all-sky *** this study,the 3D precipitation detection method is adopted to assimilate Microwave Temperature Sounder-2(MWTS-Ⅱ)onboard the Fengyun-3D,which can dynamically detect the channels above precipitating clouds by considering the near-real-time cloud *** data assimilation and forecasting experiments for Typhoons Lekima(2019)and Mitag(2019)are carried *** with the control experiment,the quantity of assimilated data with the 3D precipitation detection increases by approximately 23%.The quality of the additional MWTS-Ⅱradiance data is close to the clear-sky *** case studies show that the average root-mean-square errors(RMSE)of prognostic variables are reduced by 1.7%in the upper troposphere,leading to an average reduction of4.53%in typhoon track *** detailed diagnoses of Typhoon Lekima(2019)further show that the additional MWTS-Ⅱradiances brought by the 3D precipitation detection facilitate portraying a more reasonable circulation situation,thus providing more precise *** paper preliminarily proves that 3D precipitation detection has potential added value for increasing satellite data utilization and improving typhoon forecasts.

关键词： numerical weather prediction radiance assimilation microwave temperature sounding FY-3D MWTS-II precipitation detection

Preface to special issue:dedicated to Professor Wenqing Shen in honor of his 80th birthday

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Nuclear Science and Techniques 2024年第12期35卷 209-216页

作者： De-Qing Fang Xiang-Zhou Cai Hong-Wei Wang Yu-gang ma Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai200438China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China

We are honored to dedicate this issue to Professor Wenqing Shen to celebrate his 80th birthday,along with his distinguished career,great achievements in nuclear science,and fruitful contributions to science and technology *** Wenqing Shen was born in Shanghai on August 21,*** graduating from middle school with outstanding grades,he was admitted to the preparatory program of Fudan University;this marked the frst turning point in his life.

关键词： admitted turning birthday

Re-examination of Finite-Size Effects in Isobaric Yield Ratios Using a Statistical Abrasion-Ablation Model

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Chinese Physics Letters 2013年第5期30卷 44-47页

作者： ma Chun-Wang WANG Shan-Shan WEI Hui-Ling ma Yu-gang Department of Physics Henan Normal UniversityXinxiang 453007 Department of Nuclear Physics Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800

The"finite-size"effects in the isobaric yield ratio(IYR),which are shown in the standard grand-canonical and canonical statistical ensembles(SGC/CSE)method,are claimed to prevent the actual values of physical parameters from being *** conclusion of SGC/CSE may be questionable for neutron-rich nucleus-induced *** investigate whether the IYR has finite-size effects,we re-examine the IYR for the mirror nuclei[IYR(m)]using a modified statistical abrasion-ablation(SAA)*** is found that when the projectile is not so neutron-rich,the IYR(m)depends on the isospin of the projectile,but size dependence can not be *** reactions induced by the very neutron-rich projectiles,contrary results to those of the SGC/CSE models are obtained,i.e.,the dependence of the IYR(m)on the size and the isospin of the projectile is weakened and disappears in both the SAA and experimental results.

关键词： canonical finite mirror

Efficient allocation of coal de-capacity quota among Chinese provinces:a zero-sum gains data envelopment model

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Chinese Journal of Population,Resources and Environment 2019年第3期17卷 229-240页

作者： gang ma Xu Li Jianping Zheng School of management Fudan UniversityShanghaiChina

An efficient coal de-capacity quota allocation scheme is key for accelerating China's coal supplyside structure *** paper allocates the coal de-capacity quota from the perspective of efficiency to seek the optimal capacity allocation in each Chinese ***,we estimate the coal capacity of 24 coal-producing provinces based on boundary production function *** to the actual coal overcapacity in each province,we initially allocate the coal decapacity quota of reducing 0.8 billion tons among ***,we optimize the initial allocation plan by using the zero-sum gains data envelopment model(ZSG-DEA)considering backward coal capacity,coal economic output,and coal resource endowment of each *** results indicate that:First,there is coal overcapacity all over China,and there are obvious differences among the ***,the optimal allocation results show that the large coal producing provinces,including Shanxi,Inter Mongolia,Shaanxi,etc.,need to undertake most of the coal decapacity tasks,while the old coal producing provinces in northeast and west China should undertake a heavier burden of coal ***,the“one-size fits-all”approach burdens the small coal producing provinces with reducing coal capacity,leading to a general low enthusiasm for coal de-capacity in these regions.

关键词： Coal de-capacity ZSG-DEA model Chinese provinces quota allocation