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工业CT图像直接生成四边形网格的方法研究

工程力学 2024年第11期41卷 14-21页

作者：金恒陈杨喜刘杰黎玲龙超段黎明重庆大学光电技术及系统教育部重点实验室ICT研究中心重庆400044 重庆大学机械与运载工程学院重庆400044 重庆大学光电工程学院重庆400044

针对具有内腔结构工件任意指定截面或局部的应力-应变分析问题,提出了一种将工业CT图像直接生成四边形网格有限元模型的方法。首先使用四叉树对工业CT图像进行初始网格划分;然后生成边界网格;最后进行网格优化。在生成边界网格过程中,... 详细信息

针对具有内腔结构工件任意指定截面或局部的应力-应变分析问题,提出了一种将工业CT图像直接生成四边形网格有限元模型的方法。首先使用四叉树对工业CT图像进行初始网格划分;然后生成边界网格;最后进行网格优化。在生成边界网格过程中,结合二次误差函数与贝塞尔曲线,提出了准确定位网格边界点的方法;在四叉树邻域搜索算法基础上,提出了边界单元连接模板。为了提高边界网格质量,提出了优化模板进行优化。对生成网格进行质量评价,结果表明:网格边长比均小于2,倾斜度均小于0.6,满足实际工程要求。通过对汽车轮毂和阀体CT图像生成的四边形网格进行应力-应变分析,数值仿真结果验证了提出方法的正确性。

关键词：应力-应变分析工业CT图像四边形网格四叉树网格优化

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中国教育非均衡发展及其与经济的适配性研究

福建教育学院学报 2024年第7期25卷 42-47页

作者：陈希言祁新华福建师范大学地理科学学院、碳中和未来技术学院福建福州350007

教育发展的区域协调与均衡是教育现代化的重要议题。根据2000、2005、2010、2015、2019年教育和经济社会发展数据,论文运用标准化处理、等权重法、GIS空间分析技术和面板回归模型,对中国教育非均衡发展及其与经济的适配性研究进行分析,... 详细信息

教育发展的区域协调与均衡是教育现代化的重要议题。根据2000、2005、2010、2015、2019年教育和经济社会发展数据,论文运用标准化处理、等权重法、GIS空间分析技术和面板回归模型,对中国教育非均衡发展及其与经济的适配性研究进行分析,结果表明:(1)2000年-2019年我国教育均衡发展水平呈现类S型波动上升趋势,整体呈现出从东南部向西北部延伸的趋势,局部地区表现为上升型和下降型;从空间分布来看,中东部地区的教育均衡发展水平总体高于西部地区;教育均衡发展水平与经济发展水平整体趋于协调,但有非均衡发展态势。(2)地方经济发展水平、地方政府教育投入能力对教育均衡发展指数具有正向影响效应,而城乡差距有负面影响效应。

关键词：教育均衡发展指数经济适配性面板回归

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树脂基和陶瓷基复合材料拉伸变形和微观损伤机理对比研究

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风机技术 2024年第4期66卷 75-81页

作者：刘星琪杨晨曦中航复合材料有限责任公司中国航发动力股份有限公司

通过SEM对两种复材进行了微观形貌表征,对比分析两种复合材料微观结构的异同;结合拉伸试验应力-应变曲线与失效试样的断口形貌,分析了CFRP复合材料及2DC/SiC复合材料拉伸过程中的损伤行为和断裂机制。研究表明:2DC/SiC材料具有PyC界面层... 详细信息

通过SEM对两种复材进行了微观形貌表征,对比分析两种复合材料微观结构的异同;结合拉伸试验应力-应变曲线与失效试样的断口形貌,分析了CFRP复合材料及2DC/SiC复合材料拉伸过程中的损伤行为和断裂机制。研究表明:2DC/SiC材料具有PyC界面层,内部存在三种尺度的缺陷且随机分布。而树脂基复合材料没有明确边界,材料内部纤维排列紧密,无明显缺陷。两种材料拉伸变形过程分为三个损伤阶段,2DC/SiC材料损伤模式有三类,即基体开裂、界面脱粘、纤维断裂;树脂基复合材料损伤模式分为五种,即基体开裂、纤维基体界面脱粘、分层、纤维束抽拔、纤维断裂。

关键词：复合材料界面损伤机理微观结构

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Periodic Wave Solutions and Their Limits for the Modified Kd V–KP Equations

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Acta Mathematica Sinica,English Series 2015年第6期31卷 1043-1056页

作者： Ming SONG Zheng Rong LIU chen xi yang Department of Mathematics Shaoxing University Department of Mathematics Yuxi Normal University Department of Mathematics South China University of Technology

In this paper, we use the bifurcation method of dynamical systems to study the periodic wave solutions and their limits for the modified KdV-KP equations. Some explicit periodic wave solutions are obtained. These solutions contain smooth periodic wave solutions and periodic blow-up solutions. Their limits contain solitary wave solutions, periodic wave solutions, kink wave solutions and unbounded solutions.

关键词： Bifurcation method modified KdV-KP equation periodic wave solutions limits

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Some New Expressions of Compactons in Compressible Elastic Rods

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Acta Mathematicae Applicatae Sinica 2006年第3期22卷 487-494页

作者： chen-xi yang Min-ying Tang Department of Mathematics of Yuxi Normal College Yuxi 653100 China School of Mathematical Sciences and Center for Nonlinear Science Studies South China University of Technology Guangzhou 510640

In this paper, we use phase plane analysis to study the compactons of the nonlinear equation. Four new implicit expressions of the compactons are obtained. These new implicit expressions are given by inverse tangent functions. Our work extends previous results. For two sets of the data, the graphs of the implicit functions are drawn and numerical simulations are given to test the correctness of our theoretical results.

关键词： Compactons bifurcation method implicit expressions numerical simulations

Progress in research on diffusional phase transformations of Fe–C alloys under high magnetic fields

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Journal of Iron and Steel Research International 2022年第5期29卷 707-718页

作者： Kai Wang Chao-jie Yan chen-hua Yuan xi-chen yang Li-jia Zhao Qiang Wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina School of Materials Science and Engineering Northeastern UniversityShenyang110819LiaoningChina

The solid-phase transformations of metal materials under high magnetic fields are an important topic in research on the electromagnetic processing of *** in research on the diffusional phase transformations of Fe–C alloys under high magnetic fields is *** effects of high magnetic fields on the microstructural evolution in diffusional phase transformations in Fe–C alloys are *** kinetics of ferrite transformations,pearlite transformations,and the precipitation of carbides under high magnetic fields are reviewed in terms of the thermodynamics of phase transformations and the diffusion behavior of carbon ***,future trends in research on diffusional phase transformations of Fe–C alloys under high magnetic fields are discussed.

关键词： High magnetic field Diffusional phase transformation Fe–C alloy Microstructure Thermodynamics Kinetics

Regioselective Oxidation Approaches to Concise Synthesis of （±）-Canabisin D

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Chinese Journal of Chemistry 2015年第7期33卷 717-722页

作者： Wenling Li Qian Liu Hao Liu PeUan chen xi yang Yingying Liu School of Chemical and Biological Engineering Lanzhou Jiaotong University Lanzhou Gansu 730070 China

The regioselective effects of tert-butyl or bromine as the position-protecting group of feruloytyamide on the oxidative coupling reactions for the synthesis of natural （±）-canabisin D were investigated in detail. The coupling yield of 8-8-coupled aryldihydronaphthalene product of 5-Br-feruloytyamide was higher than that of tert-butyl substituted precursor under FeCl3·6H2O-acetone-water oxidative condition.

关键词： oxidative coupling biomimetic synthesis regioselectivity liganamides canabisin D

Investigation of cavitation erosion caused by laser-induced single bubble collapse near alloy coating surface

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Journal of Hydrodynamics 2023年第5期35卷 876-886页

作者： Hai-gang Wen Zhi-feng Yao Qin Wu Yu-rong Sun chen-xi yang Qiang Zhong College of Water Resources and Civil Engineering China Agricultural UniversityBeijing100083China Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing100083China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

To investigate the mechanism of cavitation erosion caused by laser-induced single bubble near the surface coating alloy coating material, we utilized a nanosecond resolution photography system based on a Q-switched Nd: YAG laser and conventional industrial camera to carefully observe the transient process of bubble collapse under different conditions. We analyzed the generation of collapse microjets and the emission of collapse shock waves and explored the cavitation erosion characteristics caused by laser-induced single bubble collapse. We discovered that even on surfaces of highly hard and corrosion-resistant alloy coatings, severe cavitation erosion occurred, and there was a phenomenon of mismatch between the cavitation erosion location and the bubble projection position. The intensity of cavitation erosion depended on the energy self-focusing effect of the collapse shockwaves. In the experiments, we also observed the self-focusing phenomenon of collapse shockwaves under different conditions. The self-focusing effect of collapse shockwaves weakened as the distance between the bubble and the material surface increased, which may be the cause of cavitation erosion induced by a laser-induced single bubble.

关键词： Cavitation erosion bubble collapse laser-induced shock wave self-focusing effect

Accelerating the solving of mechanical equilibrium caused by lattice misfit through deep learning method

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Advances in Manufacturing 2024年第3期12卷 512-521页

作者： chen-xi Guo Hui-Ying yang Rui-Jie Zhang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083People’s Republic of China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing100083People’s Republic of China

Precipitation is a common phenomenon that occurs during heat *** is internal stress around the precipitate owing to the lattice misfit between the precipitate and *** internal stress has a significant influence not only on the precipitation kinetics but also on the material *** misfit stress can be obtained by numerically solving the mechanical equilibrium ***,this process is complex and *** developed a new approach based on deep learning to accelerate the solution *** training data were first generated by a phase-field model coupled with elastic mechanical equilibrium equations,which were solved using the finite difference *** obtained precipitate morphologies and corresponding stress distributions were input data for training the physics-informed(PI)UNet *** well-trained PI-UNet model can then be applied to predicting stress distributions with the precipitate morphology as the *** accuracy and efficiency are discussed in this *** results showed that the PI-UNet model was an appropriate approach for quickly predicting the misfit stress between the precipitate and matrix.

关键词： Precipitate Mechanical equilibrium Heat treatment Deep learning