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ADAPTIVE RIGID-PLASTIC MESHLESS GALERKIN METHOD AND ITS APPLICATION IN ANALYSIS OF EXTRUSION PROCESSES

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Chinese Journal of Mechanical engineering 2007年第2期20卷 26-31页

作者： WU Xin ZHAO guoqun wang Weidong GUAN Yanjin LU Ping School of Mechanical Engineenng Hangzhou Dianzi University Hangzhou 310018 China engineering research {2. for Mould ＆ die technology Shandong University Jinan 250061 China Engineenng research center for Mould ＆ {2. technology Shandong University Jinan 250061 China

Under the hypothesis of the rigid-plastic material, specific efforts are placed on the developments of the key simulation techniques of the meshless Galerkin method because of the complexity of the deformation process as well as the generality and atomization of the simulation procedures for non-steady state large deformation plastic processes, therefore, an adaptive rigid meshless Galerkin method is developed. The influence domain control method is used in the least square approximation by dynamic evaluation of the magnitude of the influence domain and the effective control of the amount and the positions of the points in the least square approximation in order to improve approximation precision. The amount of the Gauss integration points in the discrete domain is maintained in a considerable magnitude in order to ensure the integration precision in the discrete domain. The length of the frictional boundary of the plastic deformation process may be getting longer when its deforma- tion is getting severe. Thus, the densities of the boundary points of some places get lower. The adaptive boundary points setting method is employed to improve the approximation precision of the boundary points and enhance the constraint of the boundary condition by adaptive control of boundary point density. Some typical extrusion processes are analyzed, detail simulation results such as the deformation field, velocity field, effective strain field, effective strain rate field, the volume loss curve and load-stroke curve are obtained. The effectiveness of the method developed is demonstrated and the precision of the meshless simulation is proved by overall comparison with the results obtained by using the commercial software deform.

关键词： Rigid-plastic Galerkin Adaptive Non-steady state Extrusion Severe deformation

A GPU accelerated Boussinesq-type model for coastal waves

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Acta Oceanologica Sinica 2022年第9期41卷 158-168页

作者： Kezhao Fang Jiawen Sun guangchun Song Gang wang Hao Wu Zhongbo Liu State Key Laboratory of Coastal and Offshore engineering Dalian University of TechnologyDalian116024China National Marine Environmental Monitoring center Dalian116023China Marine Geological Resources Survey center of Hebei Province Qinhuangdao066001China College of Transportation engineering Dalian Maritime UniversityDalian116026China

This study presents an efficient Boussinesq-type wave model accelerated by a single Graphics Processing Unit(GPU).The model uses the hybrid finite volume and finite difference method to solve weakly dispersive and nonlinear Boussinesq equations in the horizontal plane,enabling the model to have the shock-capturing ability to deal with breaking waves and moving shoreline *** code is written in CUDA *** achieve better performance,the model uses cyclic reduction technique to solve massive tridiagonal linear systems and overlapped tiling/shared memory to reduce global memory access and enhance data *** numerical tests are conducted to validate the GPU *** performance of the GPU model is evaluated by running a series of numerical simulations on two GPU platforms with different hardware *** with the CPU version,the maximum speedup ratios for single-precision and double-precision calculations are 55.56 and 32.57,respectively.

关键词： Boussinesq model GPU speedup ratio coastal waves

Migration to gliomas of bone mesenchymal stem cells transfected with cytosine deaminase gene following transplantation in vivo

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Neural Regeneration research 2011年第19期6卷 1462-1466页

作者： guangchun Ji Fei Song Qi Xing Jian Liu Kedong Song Daqing Zhang Zihan wang The Second Affiliated Clinical College of Dalian Medical university Dalian 116023 Liaoning Province China The First Affiliated Clinical College of Dalian Medical university Dalian 116011 Liaoning Province China Institute of Chemical engineering Dalian University of Technology/Dalian Stem Cell and Tissue Engineering Research and Development Center Dalian 116024 Liaoning Province China Dalian Central Hospital Dalian 116033 Liaoning Province China

This experiment sought to observe the migration and distribution of bone mesenchymal stem cells transfected with the cytosine deaminase gone （BMSCs-CD/eGFP） after transplantation in vivo through three pathways. In addition, we examined the tropism of these cells to glioma. Intracranial C6 glioma models were established in Sprague-Dawley rats using an intracranial stereotactic inoculation method. When tumors were 7 days old, rats were inoculated with lx106 BMSCs-CD/eGFP cells via the tumor-bearing internal carotid artery, the contralateral hemisphere and the tumor-bearing glioma. Fluorescence microscopy revealed that BMSCs-CD/eGFP exhibited a strong capacity for migration to tumors. BMSCs-CD/eGFP transplanted via the tumor-bearing intemal carotid artery were observed to distribute in glioma tissues. BMSCs-CD/eGFP inoculated via the ipsilateral glioma mainly located within and at the edge of glioma tissues. BMSCs-CD/eGFP inoculated via the contralateral hemisphere mainly distributed at the proximal end of the tumor at the incubation site.

关键词： cytosine deaminase gone bone mesenchymal stem cells glioma transduction migration

Numerical Simulation of Viscoelastic Extrudate Swell Through Elliptical Ring die

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Chinese Journal of Chemical engineering 2011年第1期19卷 10-17页

作者：许星明赵国群秦升学王威 College of Mechanical and Electrical engineering Shandong University Of Science and Technology Tai'an 271019_ China engineering research {2. for Mold & die Technologies Shandong University Jinan 250061 China College of Mechanical and Electrical engineering Shandong University of Science and Technology Qingdao 266510 China

The numerical simulation of extrudate swell is significant in extrusion *** prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional（3D）viscoelastic flow through elliptical ring die for polymer extrusion was *** penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion *** discrete elastic viscous split stress（DEVSS）and streamline-upwind PetrovGalerkin（SUPG）technology were used to obtain stable simulation *** surface was updated by updating the streamlines which needs less memory *** to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased ***,the numerical simulation of extrudate swell flow for low-density polyethylene（LDPE）melts was investigated and the results agreed well with others’*** conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape.

关键词： viscoelastic fluid extrudate swell finite element method polymer extrusion

高等工程教育虚拟仿真实验教学的分析与思考——基于2.8项国家级虚拟仿真实验教学项目的描述性研究

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实验技术与管理 2022年第12期39卷 199-204页

作者：董桂伟赵国群王桂龙毕见强胡蔓山东大学材料科学与工程学院山东济南250061 山东大学工程训练中心山东济南250002

通过对2.17—2.19年认定的2.8项高等工程教育领域国家级虚拟仿真实验教学项目的描述性研究发现:我国高等工程教育领域虚拟仿真实验教学存在地区间分布的不平衡,目前主要集中在高等教育资源丰富的东部地区;负责人主体是教授,且大都具有... 详细信息

通过对2.17—2.19年认定的2.8项高等工程教育领域国家级虚拟仿真实验教学项目的描述性研究发现:我国高等工程教育领域虚拟仿真实验教学存在地区间分布的不平衡,目前主要集中在高等教育资源丰富的东部地区;负责人主体是教授,且大都具有行政职务,从事一线实验教学的工程和实验技术人员参与很少;主题相对集中,传统专业基础类教学项目比重较大,面向新工科的项目偏少。基于此,未来工程领域虚拟仿真实验教学应注重突出中西部学校的学科特点,鼓励和发挥年轻教师特别是实验教学教师在项目建设中的主观能动性,并通过引入产学研用协同模式,打造虚拟仿真实验教学良性发展新范式。

关键词：高等工程教育虚拟仿真实验教学描述性研究分析思考

两阶段调控葡萄糖质量浓度强化赤藓糖醇发酵的研究

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中国酿造 2020年第6期39卷 88-92页

作者：刘金龙孙锡友赵国群王勇白敬孙旭河北科技大学生物科学与工程学院河北石家庄050000 河北省发酵工程技术研究中心河北石家庄050000

该研究在5 L发酵罐水平上研究了不同初始葡萄糖质量浓度对解脂耶氏酵母(Yarrowia lipolytica)JZ-2.4生长和发酵产赤藓糖醇的影响。结果表明,100 g/L初始葡萄糖质量浓度有利于菌体生长,高初始葡萄糖质量浓度(300 g/L和400 g/L)有利于赤... 详细信息

该研究在5 L发酵罐水平上研究了不同初始葡萄糖质量浓度对解脂耶氏酵母(Yarrowia lipolytica)JZ-2.4生长和发酵产赤藓糖醇的影响。结果表明,100 g/L初始葡萄糖质量浓度有利于菌体生长,高初始葡萄糖质量浓度(300 g/L和400 g/L)有利于赤藓糖醇合成。基于此,提出两阶段葡萄糖质量浓度调控策略,即0 h时以初始葡萄糖质量浓度为100 g/L,2. h后通过补加葡萄糖使总糖量达300 g/L进行发酵。结果表明,与分批发酵相比(100 g/L、2.0 g/L、300 g/L、400 g/L),采用该调控策略,赤藓糖醇产量达到最高水平92.66 g/L,分别比分批发酵提高了1347.81%、84.54%、14.66%、7.57%;生产强度达到最高的0.48 g/(L·h),分别比分批发酵提高了300%、37.14%、2..73%、2..00%。该调控策略为赤藓糖醇的高效发酵合成提供参考。

关键词：解脂耶氏酵母赤藓糖醇葡萄糖质量浓度比生长速率比合成速率