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Propagation Properties of Shock Waves in Polyurethane Foam based on Atomistic Simulations

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Defence Technology（防务技术） 2024年第1期31卷 117-129页

作者： Zhiqiang Hu Jianli Shao Shiyu Jia weidong song Cheng Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Porous materials are widely used in the field of protection because of their excellent energy absorption *** this work,a series of polyurethane microscopic models are established and the effect of porosity on the shock waves is studied with classical molecular dynamics ***,shock Hugoniot relations for different porosities are obtained,which compare well with the experimental *** pores collapse and form local stress wave,which results in the complex multi-wave structure of the shock *** microstructure analysis shows that the local stress increases and the local velocity decreases gradually during the process of pore collapse to complete ***,it leads to stress relaxation and velocity *** shock stress peaks can be fitted with two exponential functions,and the amplitude of attenuation coefficient decreases with the increase of ***,the pore collapse under shock or non-shock are discussed by the entropy increase rate of the *** energy is dissipated mainly through the multiple interactions of the waves under *** energy is dissipated mainly by the friction between atoms under non-shock.

关键词： Polyurethane foam Shock wave Attenuation Atomistic simulation

Damage evolution of rock-encased-backfill structure under stepwise cyclic triaxial loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 597-615页

作者： Xin Yu Yuye Tan weidong song John Kemeny Shengwen Qi Bowen Zheng songfeng Guo Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100089China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing100089China University of Chinese Academy of Sciences Beijing100049China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of High-Efficient Mining and Safety of Metal Mines(Ministry of Education of China) University of Science and Technology BeijingBeijing100083China Department of Mining and Geological Engineering University of ArizonaTucsonAZ86721USA

Rock-encased-backfill(RB)structures are common in underground mining,for example in the cut-andfill and stoping *** understand the effects of cyclic excavation and blasting activities on the damage of these RB structures,a series of triaxial stepwise-increasing-amplitude cyclic loading experiments was conducted with cylindrical RB specimens(rock on outside,backfill on inside)with different volume fractions of rock(VF=0.48,0.61,0.73,and 0.84),confining pressures(0,6,9,and 12 MPa),and cyclic loading rates(200,300,400,and 500 N/s).The damage evolution and meso-crack formation during the cyclic tests were analyzed with results from stress-strain hysteresis loops,acoustic emission events,and post-failure X-ray 3D fracture *** results showed significant differences between cyclic and monotonic loadings of RB specimens,particularly with regard to the generation of shear microcracks,the development of stress memory and strain hardening,and the contact forces and associated friction that develops along the rock-backfill *** important finding is that as a function of the number of cycles,the elastic strain increases linearly and the dissipated energy increases ***,compared with monotonic loading,the cyclic strain hardening characteristics are more sensitive to rising confining pressures during the initial compaction *** finding is that compared with monotonic loading,more shear microcracks are generated during every reloading stage,but these microcracks tend to be dispersed and lessen the likelihood of large shear fracture *** transition from elastic to plastic behavior varies depending on the parameters of each test(confinement,volume fraction,and cyclic rate),and an interesting finding was that the transformation to plastic behavior is significantly lower under the conditions of 0.73 rock volume fraction,400 N/s cyclic loading rate,and 9 MPa *** the findings have important practical implications on t

关键词： Rock and backfill Triaxial cyclic loading Volume fraction Damage evolution 3D visualization

Circadian rhythm dysfunction and psychopathology in the offspring of parents with bipolar disorder:a highrisk study in the Chinese population

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General Psychiatry 2024年第3期37卷 388-400页

作者： Binbin Lei Hongliang Feng Lulu Yang Jing Wang Jie Chen weidong song Chao Jiang Kun Zhang Qunfeng Wang Jessie Chi Ching Tsang Ngan Yin Chan Yaping Liu Joey W.Y.Chan Jiyang Pan Bin Zhang Tao Li Kathleen Ries Merikangas Jihui Zhang Yun Kwok Wing Guangdong Cardiovascular Institute Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouGuangdongChina Guangdong Mental Health Center Guangdong Provincial People's Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhouGuangdongChina Li Chiu Kong Family Sleep Assessment Unit Department of PsychiatryFaculty of MedicineThe Chinese University of Hong KongHong KongChina Center for Sleep and Circadian Medicine The Affiliated Brain Hospital of Guangzhou Medical UniversityGuangzhouGuangdongChina Department of Psychiatry Faculty of MedicineThe Chinese University of Hong KongNew TerritoriesHong KongChina Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China Guangzhou Medical UniversityGuangzhouGuangdongChina Shenzhen Nanshan Center for Chronic Diseases Control(Shenzhen Nanshan Mental Health Center) ShenzhenChina Department of Clinical Psychology Shenzhen Fuyong People's HospitalShenzhenChina Department of Mental Illness Prevention and Treatment Shenzhen Longgang Center for Chronic Diseases ControlShenzhenChina Department of Neurology Zhongnan Hospital of Wuhan UniversityWuhanHubeiChina Sleep Medical Center The First Affiliated Hospital of Jinan UniversityGuangzhouGuangdongChina Department of Psychiatry Nanfang HospitalSouthern Medical UniversityGuangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired IntelligenceGuangzhouGuangdongChina Department of Neurobiology Affiliated Mental Health Center&Hangzhou Seventh People's HospitalZhejiang University School of MedicineHangzhouZhejiangChina Genetic Epidemiology Research Branch Intramural Research ProgramNational Institute of Mental HealthBethesdaMarylandUSA

Background Understanding the evolution of circadian rhythm dysfunction and psychopathology in the high-risk population has important implications for the prevention of bipolar ***,some of the previous studies on the emergence of psychopathologies and circadian dysfunction among high-risk populations were inconsistent and *** To examine the prevalence rates of sleep and circadian dysfunctions,mental disorders and their symptoms in the offspring of parents with(O-BD)and without bipolar disorder(O-control).Methods The study included 191 O-BD and 202 O-control subjects aged 6-21 years from the Greater Bay Area,*** diagnoses and symptoms of sleep/circadian rhythm and mental disorders were assessed by the Diagnostic Interview for Sleep Patterns and Disorders,and the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version,*** estimating equations and shared frailty proportional hazards models of survival analysis were applied to compare the outcomes in the *** Adjusting for age,sex and region of recruitment,there was a significantly higher risk of delayed sleep phase symptoms(9.55%vs 2.58%,adjusted OR:4.04)in O-BD than in O-control.O-BD had a nearly fivefold higher risk of mood disorders(11.70%vs 3.47%,adjusted OR:4.68)and social anxiety(6.28%vs 1.49%,adjusted OR:4.70),a fourfold higher risk of depressive disorders(11.17%vs 3.47%,adjusted OR:3.99)and a threefold higher risk of mood symptoms(20.74%vs 10.40%,adjusted OR:2.59)than *** analysis revealed that O-BD children(aged under 12 years)had a nearly 2-fold higher risk of any mental and behavioural symptoms than O-control,while there was a nearly 4-fold higher risk of delayed sleep phase symptoms,a 7.5-fold higher risk of social anxiety and a 3-fold higher risk of mood symptoms in O-BD adolescents(aged 12 years and over).Conclusions There was an increase in delayed sleep phase symptoms in O-BD

关键词： prevention dysfunction bipolar

应力–渗流耦合下深部花岗岩力学行为及破坏特征

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工程科学学报 2024年第4期46卷 600-613页

作者：张超杜翠凤宋卫东付建新北京科技大学土木与资源工程学院北京100083 金属矿山高效开采与安全教育部重点实验室北京100083

在矿山深部开采过程中,高应力与高水压耦合作用导致岩石的力学特性演化机理更加复杂.为分析深部复杂条件下花岗岩的力学行为及破坏特征,利用低场核磁共振核技术(NMR)进行花岗岩初始孔隙率测量,借助岩石高温三轴流变系统开展应力–渗流... 详细信息

在矿山深部开采过程中,高应力与高水压耦合作用导致岩石的力学特性演化机理更加复杂.为分析深部复杂条件下花岗岩的力学行为及破坏特征,利用低场核磁共振核技术(NMR)进行花岗岩初始孔隙率测量,借助岩石高温三轴流变系统开展应力–渗流耦合试验,引入耗能比实现花岗岩破坏过程的能量演化分析.研究结果表明:岩石的峰值强度、峰值应变随孔隙水压的增大呈线性减小且减小速率逐渐提升,随围压的增大呈线性增加且增大速率逐渐变缓;峰值渗透率随着孔隙水压的增大呈线性增大,随围压的增大呈线性减小;岩石破坏应变能表现出明显的围压效应和孔隙水压效应,峰值应力点为弹性能极值点,峰值点之后弹性能迅速转化为岩石损伤的耗散能,岩石耗能比整体呈现增大→减小→增加的“S”型变化规律;引入花岗岩初始孔隙率,将岩石视为固体骨架和孔隙两部分组成,综合考虑变形特征并构建应力–渗流耦合本构模型,与试验对比后认为该模型具有较高普适性.

关键词：应力–渗流耦合低场核磁共振本构模型破裂特征能量耗散

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基于机器学习的空气源热泵干燥能耗回归预测

农业工程学报 2024年第2期40卷 41-51页

作者：杨仕陈维汉杨明金张原李守太蒲应俊杨玲宋卫东西南大学工程技术学院重庆400715 丘陵山区农业装备重庆市重点实验室重庆400715 农业农村部南京农业机械化研究所南京210014

为了降低空气源热泵干燥过程能耗,研究了空气源热泵干燥能耗特性,采用多元线性回归模型(multivariate linear regression model, MLRM)和BP神经网络(back propagation neural network, BPNN)模型来预测干燥工艺能耗。在分析干燥能耗影... 详细信息

为了降低空气源热泵干燥过程能耗,研究了空气源热泵干燥能耗特性,采用多元线性回归模型(multivariate linear regression model, MLRM)和BP神经网络(back propagation neural network, BPNN)模型来预测干燥工艺能耗。在分析干燥能耗影响特征参数的基础上,提出将干燥工艺过程进行切分处理的方法以降低数据获取难度。选取烘房设定温度、烘房设定湿度、烘房初始温度、烘房初始湿度、环境平均温度、环境平均湿度、物料质量和初始含水率8个特征参数作为模型输入,能耗和物料结束含水率作为模型输出。使用MLRM模型、BPNN模型和其他机器学习模型进行能耗预测,MLRM模型对能耗拟合的决定系数为0.739,对物料结束含水率拟合的决定系数为0.931;BPNN模型使用Sigmoid函数作为激活函数时对能耗拟合的决定系数最高,为0.828,使用Identity函数作为激活函数时对物料结束含水率拟合的决定系数最高,为0.942,拟合效果优于其他机器学习模型,能够满足实际生产需求。以复水豌豆为干燥对象设计加载物料65 kg、持续时间4 h的完整变温变湿干燥工艺进行验证试验,结果表明:试验总能耗为15.066 kW·h,MLRM模型和BPNN模型的预测总能耗分别为14.476 kW·h、15.183 kW·h,预测精度分别为96.08%、99.23%;试验结束含水率为8.541%,MLRM模型和BPNN模型的预测结束含水率分别为9.560%、8.889%,预测精度分别为88.07%、95.93%。该研究提出了一种使用MLRM模型和BPNN模型对空气源热泵干燥能耗进行分段精准预测的有效手段,对于优化干燥工艺和降低干燥能耗具有实际意义。

关键词：热泵干燥能耗模型回归预测机器学习工艺切分

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解剖型锁定钛板与髓内钉治疗胫骨远端骨折的疗效比较

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中山大学学报（医学科学版） 2024年第1期45卷 108-113页

作者：马梦君陈彦博曾钢陈宸宋卫东刘文宙中山大学附属第八医院骨外科广东深圳518033 中山大学孙逸仙纪念医院骨外科广东广州510000

【目的】对比应用解剖型锁定钛板与髓内钉治疗胫骨远端骨折的临床疗效与并发症情况。【方法】自2019年9月至2021年9月,于中山大学孙逸仙纪念医院诊断为胫骨远端AO-A型骨折的手术患者纳入本研究,共32例。其中15例采用钛板螺钉治疗,17例... 详细信息

【目的】对比应用解剖型锁定钛板与髓内钉治疗胫骨远端骨折的临床疗效与并发症情况。【方法】自2019年9月至2021年9月,于中山大学孙逸仙纪念医院诊断为胫骨远端AO-A型骨折的手术患者纳入本研究,共32例。其中15例采用钛板螺钉治疗,17例采用髓内钉治疗。比较两组一般手术指标、骨折愈合时间、术后并发症发生情况、手术前后VAS评分及术后踝关节功能。【结果】患者均获得随访,随访时间10~20个月,平均12个月。髓内钉组手术时间、术中透视次数均长于钛板螺钉组,但术前等待时间、住院天数少于钛板螺钉组,统计学差异显著(P0.05);术后6周,两组VAS评分均低于术前,统计学差异显著(P0.05);术后6月AOFAS评分、术后1年踝关节活动度、并发症发生率髓内钉组优于钛板螺钉组,统计学差异显著(P0.05)。【结论】钛板螺钉与髓内钉均是治疗胫骨远端AO-A型骨折的有效术式,远期临床疗效无明显差异。髓内钉的软组织并发症较少,对踝关节活动度影响更小,康复更快,安全性更高,而钛板螺钉发生术后软组织感染的概率较大。我们建议在临床工作中,应该做好患者的术前评估,在把握适应症的前提下,髓内钉并发症更少,有一定优势。

关键词：胫骨远端骨折解剖型锁定钛板髓内钉治疗疗效

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混合储能微电网新能源多时段动态调度方法

电子设计工程 2024年第9期32卷 11-14页

作者：周晓东宋卫东朱柯许继电气股份有限公司河南许昌461000

由于对电量的需求不断增大,混合储能微电网的日常发电成本不断增长,为有效降低发电成本,优化发电的经济效益性,提出混合储能微电网新能源多时段动态调度方法。以柴油发电系统、可再生能源发电系统运行成本与负荷收益为优化目标,设定发... 详细信息

由于对电量的需求不断增大,混合储能微电网的日常发电成本不断增长,为有效降低发电成本,优化发电的经济效益性,提出混合储能微电网新能源多时段动态调度方法。以柴油发电系统、可再生能源发电系统运行成本与负荷收益为优化目标,设定发电容量与系统平衡约束;利用日前优化调度结果,将调度时间区间缩短至15 min,细化预测结果,实现日内循环调度;结合烟花算法和多目标灰熵算法,求解日内循环调度模型,完成新能源多时段动态调度。经实验验证可知,通过该方法调度后的柴发机组在峰时段发电功率得到显著降低,同时风电机组与光伏机组可以在不同时段完成有效配合,使两者调度后的功率降低,能够保障不同时段下的备用容量。

关键词：混合储能微电网新能源多时段动态调度发电功率

Phase formation,texture evolutions,and mechanical behaviors of Al0.5CoCr0.8FeNi2.5V0.2 high-entropy alloys upon cold rolling

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Progress in Natural Science:Materials International 2022年第2期32卷 196-205页

作者： Tongtong Sun weidong song Feilong Shan Kaikai song Kun Zhang Chuanxiao Peng Honggang Sun Lina Hu School of Mechanical Electrical & Information Engineering Shandong University State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology CAS Key Laboratory of Microgravity (National Microgravity Laboratory) Institute of Mechanics Chinese Academy of Sciences Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education) Shandong University

The cold rolling(CR) reduction dependence of microstructure evolutions and mechanical properties for Al0.5CoCr0.8FeNi2.5V0.2high-entropy alloy(HEA) were *** HEA remains FCC structures consisting of nanoscale ordered L12phase,confirming the phase formation *** increasing CR reduction,the textures transform from random ones to FCC rolling ones accompanied by dense slip bands and deformation *** a 50% CR reduction,the deformation textures started to become evident and were governed by typical {111}F,{110}Goss and {112}Cu texture *** the CR reduction approached 90%,the deformation textures mainly contained the {110}A,{114}X,and {112}Cu texture *** a result,both Vickers hardness and ultimate strength increased,but the ductility decreased *** enhanced strength should be attributed to the anisotropy and work hardening behavior from *** plastic deformation for the samples under low CR reductions was dominated by deformation twins and slip ***,under high CR reductions,the textures severely impeded the further propagation of pre-existing slip bands,leading to the rapid decrease of ***,the CR reduction should be carefully designed before optimal heat treatments to enhance the strength and ductility synergy.

关键词： High-entropy alloys Cold rolling Texture Mechanical property Ductility

基于多源信息融合的海底矿山开采及治理稳定性评价

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金属矿山 2024年第3期 29-36页

作者：李杨夏文浩宋卫东康明超杜云龙张开诚山东黄金集团有限公司山东济南250101 北京科技大学土木与资源工程学院北京100083 金属矿山高效开采与安全教育部重点实验室北京100083 山东黄金矿业(莱州)有限公司三山岛金矿山东莱州261442

地下开采是金属矿山开采的主要方式,在长期开采过程中,所形成的采空区以及不稳定区域需要进行充填注浆处理。针对三山岛金矿新立矿区在治理后的稳定性评价问题,首先通过数值模拟对该矿区开采及治理后全过程稳定性进行分析,其次采用层次... 详细信息

地下开采是金属矿山开采的主要方式,在长期开采过程中,所形成的采空区以及不稳定区域需要进行充填注浆处理。针对三山岛金矿新立矿区在治理后的稳定性评价问题,首先通过数值模拟对该矿区开采及治理后全过程稳定性进行分析,其次采用层次分析法对影响岩体稳定性的各种因素进行权重计算,将影响较大的因素作为D-S证据理论的评判指标,进行治理后的岩体稳定性评价。结果表明:治理后整体的变形量增长缓慢,塑性区变形处于稳定状态,充填治理效果良好,达到预期效果;治理情况、治理后围岩力学状态对岩体稳定性影响最大,治理前稳定性次之,地质因素影响最小。因子层中,采空区治理率影响最大。通过D-S证据理论证明所有水平在治理后处于稳定状态,其中-165 m水平稳定性相对较差,-240 m水平次之。

关键词：地下开采层次分析法 D-S证据理论稳定性评价