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Crushing analysis and multi-objective optimization of bitubular hexagonal columns with ribs

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Journal of Central South University 2017年第5期24卷 1164-1173页

作者： ZOU Xiang GAO guang-jun DONG Hai-peng LI Jian ZHOU Xi-sai CHEN wei guan wei-yuan Key Laboratory of Traffic Safety on Track of Ministry of Education(School of Traffic&Transportation Engineering Central South University)Changsha 410075China

In order to improve the crashworthiness of thin-walled columns, the energy absorption characteristics of three columns under quasi-static axial crushing loads were analyzed through LS-DYNA. Numerical results show that the energy absorption capability of the bitubular hexagonal columns with middle to middle(MTM) ribs is the best, followed by the bitubular hexagonal columns with corner to corner(CTC) ribs and the bitubular hexagonal columns without(NOT) ribs, respectively. Then, the MTM rib was optimized by using multi-objective particle swarm optimization algorithm. Through the analysis of the Pareto front for specific energy absorption(SEA, A_(se)) and peak crushing force(PCF, F_(pc)), it is found that there is a vertex on the Pareto front. The vertex has the design parameters of t_1=1.2 mm, t_2=1.2 mm, A_(se)=11.3729 k J/kg, F_(pc)=235.8491 kN. When the PCF is in a certain size, on the left of the vertex, the point with t_2=1.2 mm has the biggest SEA, meanwhile on the right of the vertex, the point with t_1=1.2 mm has the biggest SEA. Finally, the global sensitivity analysis was conducted to investigate the effect of two design parameters. The result is obtained that both SEA and PCF for MTM are more sensitive to t_1 rather than t_2 in the design domain.

关键词： bitubular hexagonal column axial crushing crashworthiness optimization global sensitivity analysis

Recent research development of energy-absorption structure and application for railway vehicles

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Journal of Central South University 2020年第4期27卷 1012-1038页

作者： GAO guang-jun ZHUO Tian-yu guan wei-yuan Key Laboratory of Traffic Safety on the Track of Ministry of Education Central South UniversityChangsha 410075China Joint International Research Laboratory of Key Technology for Rail Traffic Safety Central South UniversityChangsha 410075China National&Local Joint Engineering Research Center of Safety Technology for Rail Traffic Vehicle Central South UniversityChangsha 410075China

As the application of energy-absorption structure reaches an unprecedented scale in both academia and industry, a reflection upon the state-of-the-art developments in the crashworthiness design and structural optimization, becomes vital for successfully shaping the future energy-absorption structure. Physical impacting test and numerical simulation are the main methods to study the crashworthiness of railway vehicles at present. The end collision deformation area of the train can generally be divided into two kinds of structural design forms: integral absorbing structure design form and specific energy absorbing structure design form, and different energy-absorption structures introduced in this article can be equipped on different railway vehicles, so as to meet the balance of crashworthiness and economy. In pursuit of improving the capacity of energy dissipation in energy-absorption structures, studies are increasingly investigating multistage energy absorption systems, searching breakthrough when the energy dissipation capacity of the energy-absorption structure reaches its limit. In order to minimize injuries, a self-protective posture for occupants is also studied. Despite the abundance of energy-absorption structure research methods to-date, the problems of analysis and prediction during impact are still scarce, which is constituting one of many key challenges for the future.

关键词： railway vehicle energy-absorption structure crashworthiness

Crushing analysis and multiobjective crashworthiness optimization of bitubular polygonal tubes with internal walls

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Journal of Central South University 2016年第11期23卷 3040-3050页

作者：李健高广军邹翔关维元 Key Laboratory of Traffic Safety on Track of Ministry of Education (School of Traffic & Transportation Engineering Central South University)

In order to reduce casualties and property losses in a collision accident, thin-walled structure has been extensively used as energy absorber in crashworthiness design of train. With the help of energy absorber, collision kinetic energy can be controllably dissipated by the plastic deformation of structures. A new kind of multi-cell thin-walled structure called as bitubular polygonal tubes with internal walls(BPTIW) was constructed. The crashworthiness characteristics of BPTIWs were investigated by LS-DYNA. It can be found that the BPTIW with 12 sides has the most excellent crashworthiness characteristics. Therefore, based on response surface method(RSM) and multiobjective particle optimization(MOPSO) algorithm, the BPTIW with 12 sides was selected to optimize the dimensions of cross-sectional configuration under different constraints of energy absorption(EA) and crushing peak force(CPF). The results show that the optimal designs of BPTIW12 under different constraints present excellent crashworthiness characteristics and can be used in the practical engineering.

关键词： crashworthiness optimization thin-walled structure energy absorption response surface method finite element analysis

Melting Evaluation of Phase Change Materials Impregnated into Cascaded Metal Foams with Regionalized Enhancement

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Journal of Thermal Science 2025年第1期34卷 223-241页

作者： wei Xinyi ZHANG Nan ZHANG Zhaoli CAO Xiaoling yuan Yanping School of Mechanical Engineering Southwest Jiaotong University

Metal foam promotes the heat transfer of phase change materials(PCMs) in the penalty of reducing the energy storage density of the composite *** this work,the effects of constant porosity(0.96,0.94,0.92,or 0.90) and pore density(PPI) of metal foam on heat transfer of composite PCMs are *** rate could be enhanced by employing with low porosity copper ***,aiming to the right bottom phase changing "dead region",a regionalized enhancement strategy of cascaded metal foams is *** dynamic melting performances of all the composite PCMs are comprehensively *** results reveal that the cascaded configuration is beneficial for *** show that the horizontal strategy enhances melting performance:a maximum of 17.98% reduction in total melting time could be reached when the rear part porosity is 90%.The energy storage density rate could be raised by 5.48%.Besides,the vertical strategy performs with a better average temperature uniformity of 0.441 and brings a lower temperature in the heated *** sum up,the regionalized enhancement of copper foam provides better performance in the phase change *** shows significant potential for solar heat storage and thermal protection.

关键词： copper metal foam heat transfer enhancement phase change materials regionalized enhancement

Resistance of Cement-based Grouting Materials with Nano- SiO_(2) Emulsion to Chloride Ion Penetration

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 114-119页

作者： LI Shuiping CHENG Jian wei Chao yuan Bin YU Chengxiao College of Architectural Science and Engineering Yangzhou UniversityYangzhou 225127China

The chloride penetration resistance of cement-based grout materials was improved by nano-silica *** of mixtures containing different nano-silica particles or emulsions were exposed in sodium chloride solutions of specific concentrations with different test *** properties of the mixes were assessed in terms of weight loss and compressive strength.X-ray diffraction(XRD)and scanning electron microscopy(SEM)of mixes were performed to analysis the phase evolution and *** results demonstrated that the introduction of nano-SiO_(2) emulsion significantly decreased the compressive strength loss and calcium hydroxide(CH)crystal content of hydration production,and then enhanced the resistance of cement-based grouting materials to chloride ion *** improvement derives from the filling and pozzolanic effects of nano-SiO_(2) particles,which were incorporated via an emulsion and attributed to a well dispersion in grouting matrix.

关键词： grouting materials nano-SiO_(2)emulsion chloride ion penetration,weight loss strength loss

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

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Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： Yi Wang Yuning Li Yakun Gu wei Ma Yuying guan Mengyuan Guo Qianqian Shao Xunming Ji Jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment

Endoplasmic reticulum stress and autophagy in cerebral ischemia/reperfusion injury:PERK as a potential target for intervention

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Neural Regeneration Research 2025年第5期20卷 1455-1466页

作者： Ju Zheng Yixin Li Ting Zhang Yanlin Fu Peiyan Long Xiao Gao Zhengwei Wang Zhizhong guan Xiaolan Qi wei Hong Yan Xiao Key Laboratory of Endemic and Ethnic Diseases Ministry of Education&Key Laboratory of Medical Molecular Biology of Guizhou ProvinceGuizhou Medical UniversityGuiyangGuizhou ProvinceChina Guizhou Center for Disease Control and Prevention GuiyangGuizhou ProvinceChina Department of Histology and Embryology Guizhou Medical UniversityGuiyangGuizhou ProvinceChina Collaborative Innovation Center for Prevention and Control of Endemic and Ethnic Regional Diseases Co-constructed by the Province and Ministry GuiyangGuizhou ProvinceChina

Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion *** occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains *** this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion *** found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced ***,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating *** autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion *** from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.

关键词： apoptosis ATF4 autophagy C/EBP homologous protein cerebral ischemia/reperfusion injury eIF2α endoplasmic reticulum stress PERK

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抗风浪网箱沉浮遥控装置的设计

福建水产 2007年第3期29卷 55-57页

作者：魏观渊福建省水产研究所福建厦门361012

深水网箱抗风浪核心技术之一是沉于水下一定深度处以躲避台风浪的破坏,应用无线电移动通讯技术所研发的沉浮遥控装置可成功实现远距离遥控网箱系统的沉浮,保证网箱系统在任何紧急状态下都能自动、安全地沉降到预先指定的水下深度。笔者... 详细信息

深水网箱抗风浪核心技术之一是沉于水下一定深度处以躲避台风浪的破坏,应用无线电移动通讯技术所研发的沉浮遥控装置可成功实现远距离遥控网箱系统的沉浮,保证网箱系统在任何紧急状态下都能自动、安全地沉降到预先指定的水下深度。笔者等在晋江围头海域深水网箱基地的多次试验表明,配备沉浮遥控装置的抗风浪网箱在岸上遥控指挥下,其沉浮的性能指标能满足设计要求:能在30分种内实现下沉;下沉过程中网箱框架倾斜角度不超过20°。

关键词：网箱沉浮遥控装置设计

工时管理在科研开发设计管理领域中的应用研究

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船舶工程 2012年第3期34卷 72-75页

作者：韩明管伟元张海彬戴菁中国船舶及海洋工程设计研究院上海200011

文章论述了科研设计管理领域工时管理体系的建立方法、工时管理的主要应用领域、工时管理信息系统的研制要求,分析了在科研设计管理领域推进工时管理面临的主要问题和解决问题的主要方法。

关键词：工时管理科研设计管理信息系统计划进度管理