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一种基于线性零磁场的动脉血管扫描成像方法仿真

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电工技术学报 2024年第2期39卷 343-355页

作者：杨丹王雨忱李天兆徐彬吴莹东北大学信息科学与工程学院沈阳110819 智能工业数据解析与优化教育部重点实验室(东北大学) 沈阳110819 东北大学计算机科学与工程学院沈阳110169

基于磁电耦合效应的血流检测及血管成像是实现心血管疾病早期诊疗的有效方法之一。该文基于磁场与血流耦合电效应,设计一种用于动脉血管扫描成像的组合线圈结构,产生带有零磁场线(FFL)区域的线性梯度磁场;在此结构的基础上,通过控制激... 详细信息

基于磁电耦合效应的血流检测及血管成像是实现心血管疾病早期诊疗的有效方法之一。该文基于磁场与血流耦合电效应,设计一种用于动脉血管扫描成像的组合线圈结构,产生带有零磁场线(FFL)区域的线性梯度磁场;在此结构的基础上,通过控制激励电流驱动FFL实现成像区域双向扫描;结合卷积神经网络(CNN)实现磁电耦合信号与血管信息的非线性映射,进而提出一种基于线性零磁场的动脉血管扫描成像新方法。采用多物理场仿真软件COMSOL对基于线性零磁场的血管扫描成像方法进行建模,求解磁电耦合信号,验证了所提出方法的合理性和有效性。结果表明,线性梯度磁场模式下的磁电耦合信号含有血管位置、半径等信息;CNN重建血管位置误差平均值为1.5694 mm,重建血管半径的方均误差(MSE)和相关系数(CC)平均值分别为0.0548和0.9870。研究结果可用于血管成像装置设计及后续相关临床应用提供研究支撑。

关键词：心血管疾病磁场与血流耦合电效应零磁场线线性梯度磁场卷积神经网络 COMSOL

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基于热流固耦合的液膜密封动态追随性分析

振动与冲击 2024年第7期43卷 214-222,238页

作者：宋勇于博郝木明王陈寅李天照任宝杰西安航天动力研究所西安710100 中国石油大学(华东)新能源学院山东青岛266580 东营海森密封技术有限责任公司山东东营257081

为研究热流固耦合下液膜密封动态追随特性,基于小扰动法及热动力润滑理论,考虑非补偿环轴向振动、角向偏摆,建立补偿环三自由度运动方程,对比并分析纯流场和热流固耦合模型下力学元件参数、操作工况参数、结构参数对动态追随性的影响。... 详细信息

为研究热流固耦合下液膜密封动态追随特性,基于小扰动法及热动力润滑理论,考虑非补偿环轴向振动、角向偏摆,建立补偿环三自由度运动方程,对比并分析纯流场和热流固耦合模型下力学元件参数、操作工况参数、结构参数对动态追随性的影响。结果表明:在热流固耦合模型下求解的液膜密封扰动量略小于纯流场模型下求解的扰动量;增加激励振幅,弹簧刚度和O型圈阻尼均会导致扰动增大,动态追随性变差;减小转速、增加介质压力会导致动态特性系数增加,有利于提高动态追随性;减少槽数会提高动态追随性,且在槽数给定时,槽深17μm,槽坝比0.8,螺旋角22°的结构参数设定会得到更好的动态追随性。

关键词：液膜密封振动特性小扰动法热流固耦合

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基于柔性转子的液膜密封稳态性能研究

流体机械 2024年第6期52卷 90-98页

作者：张菊华郝木明李天照商凯杰宋凯亮王长钊任宝杰中国石油大学(华东)新能源学院山东青岛266580 东营海森密封技术有限公司山东东营257067

为了研究转子柔性状态下动力学特征对航空发动机附件机匣轴端液膜密封的影响,结合转子的振幅、弯曲角度和热流体动力润滑理论,建立了柔性转子-液膜密封稳态分析模型,探究柔性转子-液膜密封的成膜机理,研究偏心量、倾斜角度、结构参数和... 详细信息

为了研究转子柔性状态下动力学特征对航空发动机附件机匣轴端液膜密封的影响,结合转子的振幅、弯曲角度和热流体动力润滑理论,建立了柔性转子-液膜密封稳态分析模型,探究柔性转子-液膜密封的成膜机理,研究偏心量、倾斜角度、结构参数和工况参数对液膜密封性能影响规律。结果表明:当动环发生偏心时,液膜压力分布呈现不均匀性,随着偏心量由0.1 mm增至0.5 mm时,密封泄漏量上升了11.84%;倾斜角度的增加在一定程度上可以减弱膜压不均匀性,但对密封性能的影响不明显,当倾斜角度从1×10^(-5) rad升至3×10^(-5) rad时,泄漏量仅增加2.1%;在工况参数不变时,适当减少螺旋槽数,并选取合适的螺旋角度,可以有效抑制泄漏现象;在相同的结构参数条件下,适当降低转速及压差可以有效降低泄漏量;基于柔性转子的液膜密封由于较大偏心量的存在,会导致密封性能下降,此外,高转速与大压差会进一步增加泄漏量,工程应用中可通过减少槽数,修改螺旋角度的方式抑制泄漏。研究可为液膜密封的优化设计提供理论依据。

关键词：航空发动机柔性转子转子动力学特性液膜密封密封性能

Leaching kinetics of fluorine during the aluminum removal from spent li-ion battery cathode materials

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Journal of Environmental Sciences 2024年第4期138卷 312-325页

作者： Shengjie li Jianxin Zhu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

The high content of aluminum(Al)impurity in the recycled cathode powder seriously affects the extraction efficiency of Nickel,Cobalt,Manganese,and lithium resources and the actual commercial value of recycled materials,so Al removal is crucially important to conform to the industrial standard of spent li-ion battery cathode materials.In this work,we systematically investigated the leaching process and optimum conditions associated with Al removal from the cathode powder materials collected in a wet cathode-powder peeling and recycling production line of spent li-ion batteries(liBs).Moreover,we specifically studied the leaching of fluorine(F)synergistically happened along with the removal process of Al,which was not concerned about in other studies,but one of the key factors affecting pollution prevention in the recovery process.The mechanism of the whole process including the leaching of Al and F from the cathode powder was indicated by using NMR,FTIR,and XPS,and a defluoridation process was preliminarily investigated in this study.The leaching kinetics of Al could be successfully described by the shrinking core model,controlled by the diffusion process and the activation energy was 11.14 kJ/mol.While,the leaching of F was attributed to the dissolution of liPF6and decomposition of PVDF,and the kinetics associated was described by Avrami model.The interaction of Al and F is advantageous to realize the defluoridation to some degree.It is expected that our investigation will provide theoretical support for the large-scale recycling of spent liBs.

关键词： Al removal F leaching Cathode powder Heating alkali leaching Leaching kinetics

Additives strategies to improving cycling stability of li metal batteries by modifying electrode electrolyte interphases

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Progress in Natural Science:Materials International 2024年第2期34卷 338-344页

作者： Yuan li Pengfei Huang Chunyu Cui Xiaoyuan Ma li Chen Zekun li linhai li Yuhong Tian School of Biological and Chemical Engineering Guangxi University of Science and Technology School of College of Chemistry and Chemical Engineering Hunan University Isky Future Energy Institute

li metal batteries（LMBs） have attracted much attention due to the ultra-high theoretical capacity of the li metal anode（LMA）.However,the uncontrollable dendrites growth and low coulombic efficiency hinder their practical application.Here,we explore 3,5-difluoropyridine（2F-BD） as a novel electrolyte additive to enable highperformance LMBs.The 2F-BD additive participates in and modifies the solvation structure of li ions by reducing the coordinated number of PF6-at the electrode surface,leading to the formation of a liF and li3N-rich solid electrolyte interphase（SEI）.The liF component increases the robustness of SEI and suppresses the formation of li dendrites,while the li3N component facilitates the transportation and reaction kinetics of li ions.As a result,the li‖li symmetric cell presents a stable cycling performance of up to 500 h at a current density of 1 mA cm-2.After coupling with liFePO4cathode,the obtained full cell achieves high specific capacities of 106.06 mA h g-1and 84.98 mA h g-1at 2.55 mA cm-2and 5.10 mA cm-2,respectively,and maintains a high capacity retention of84.0% after 1000 cycles at 0.13 mA cm-2,with an average cycling CE of 99.58%.

关键词： Electrolyte additive li dendrites li metal batteries liF and li3N-Rich electrode-electrolyte interphase liFePO4 cathode

涡轮泵用球面装配机械密封热变形及磨损特性实验研究

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中国机械工程 2023年第13期34卷 1550-1558页

作者：李勇凡宋勇郝木明庄宿国周芮李天照王陈寅任宝杰李小卒中国石油大学(华东)新能源学院青岛266580 西安航天动力研究所西安710199 东营海森密封技术有限责任公司东营257067

以少量常压煤油介质条件下涡轮泵用球面装配机械密封为对象,通过实验测试分析端面磨损形成机理。设计实验工装,实现金属环截面9点温度矩阵和石墨环座3位置轴向位移的测试,得到两种弹簧力条件下温升和位移演变数据,并对磨损端面进行光学... 详细信息

以少量常压煤油介质条件下涡轮泵用球面装配机械密封为对象,通过实验测试分析端面磨损形成机理。设计实验工装,实现金属环截面9点温度矩阵和石墨环座3位置轴向位移的测试,得到两种弹簧力条件下温升和位移演变数据,并对磨损端面进行光学显微观测和径向轮廓测量。结果表明:磨损深度以内径处最大,至靠近外径处一定宽度内无磨损;随转速的升高密封环轴向及径向温度梯度不断增大;两工况下密封环倾转热变形造成的端面间隙锥度约为2.5 mrad和7.5 mrad。对于该型式密封,有必要通过端面开设流体动压槽以形成主动泵入润滑等方法来改善流体静压润滑效应缺失造成的严重磨损。

关键词：机械端面密封电涡流位移传感器温度梯度磨损机理

Highly-chlorinated inert and robust interphase without mineralization of oxide enhancing high-rate li metal batteries

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Chinese Chemical Letters 2024年第6期35卷 239-243页

作者： Long li Kang Yang Chenpeng Xi Mengchao li Borong li Gui Xu Yuanbin Xiao Xiancai Cui Zhiliang liu lingyun li Yan Yu Chengkai Yang Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesSchool of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China College of Material Sciences and Chemical Engineering Harbin Engineering UniversityHarbin 150001China

Side reactions and dendrite growth triggered by the unstable interface and inhomogeneous deposition have become the biggest obstacle to the commercialization for lithium metal batteries.In this study,a highly-chlorinated organic-inorganic hybrid interfacial protective layer is developed by rationally tuning the interfacial passivation and robustness to achieve the convenient and efficient li metal anode.The polyvinyl chloride(PVC)can effectively resist water and oxygen,which is confirmed by density functional theory.The organic-dominant solid electrolyte interphases(SEI)with lithium chloride are investigated by the X-ray photoelectron spectroscopy(XPS)with little mineralization of oxide,such as li_(2)O and li_(2)CO_(3).With such artificial SEI,a uniform and dense lithium deposition morphology are formed and an ultra-long stable cycle of over 500 h are achieved even at an ultra-high current density of 10 m A/cm^(2).Moreover,the simple and convenient protected anode also exhibits excellent battery stability when paired with the liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)and liFePO_(4)(LFP)cathode,showing great potential for the commercial application of lithium metal batteries.

关键词： Highly-chlorinated Water/oxygen resistance Stable interphase Dendrite-free lithium metal batteries High-rate

接触式机械密封混合润滑状态摩擦演化规律研究

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摩擦学学报 2023年第11期43卷 1241-1253页

作者：毕浩程郝木明任宝杰孙鑫晖李勇凡李天照刘馥瑜厉晓英中国石油大学(华东)新能源学院山东青岛266580 东营海森密封技术有限公司山东东营257067

接触式机械密封在运转中主要处于混合润滑状态,为探究其混合润滑状态下摩擦机理,结合粗糙面弹塑性模型,求解考虑密封端面粗糙度效应的雷诺方程,探究了转速和介质压力等工况条件对密封混合润滑状态密封摩擦参数的影响,推导了密封声发射... 详细信息

接触式机械密封在运转中主要处于混合润滑状态,为探究其混合润滑状态下摩擦机理,结合粗糙面弹塑性模型,求解考虑密封端面粗糙度效应的雷诺方程,探究了转速和介质压力等工况条件对密封混合润滑状态密封摩擦参数的影响,推导了密封声发射波能量公式,将密封混合润滑状态分为磨损期和稳定期,应用1.5维谱理论提取密封特征频率,探究混合润滑状态摩擦演化规律.研究结果表明摩擦参数影响密封声发射波能量幅值且密封摩擦形式随混合润滑状态发生变化:在磨损期,微凸体接触特征频率幅值较大,密封端面间摩擦以微凸体接触为主;在稳定期,流体膜黏性剪切摩擦特征频率幅值变大,黏性剪切效应增强,密封端面只存在局部微凸体接触.所得结论对接触式机械密封混合润滑状态摩擦机理的研究具有一定的理论指导意义.

关键词：接触式机械密封混合润滑摩擦参数 1.5维谱演化规律

Accelerating lithium-sulfur battery reaction kinetics and inducing 3D deposition of li2S using interactions between Fe3Se4 and lithium polysulfides

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Journal of Energy Chemistry 2024年第8期95卷 540-553页

作者： Yihan lin liheng li Longjie Tan Yongliang li Xiangzhong Ren Peixin Zhang Chuanxin He lingna Sun College of Chemistry and Environmental Engineering Shenzhen University

Although lithium-sulfur batteries（LSBs） exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of li2S.To address these issues,a novel composite,using electrospinning technology,consisting of Fe3Se4and porous nitrogen-doped carbon nanofibers was designed for the interlayer of LSBs.The porous carbon nanofiber structure facilitates the transport of ions and electrons,while the Fe3Se4material adsorbs lithium polysulfides（liPSs） and accelerates its catalytic conversion process.Furthermore,the Fe3Se4material interacts with soluble liPSs to generate a new polysulfide intermediate,lixFeSycomplex,which changes the electrochemical reaction pathway and facilitates the three-dimensional deposition of li2S,enhancing the reversibility of LSBs.The designed LSB demonstrates a high specific capacity of1529.6 mA h g-1in the first cycle at 0.2 C.The rate performance is also excellent,maintaining an ultra-high specific capacity of 779.7 mA h g-1at a high rate of 8 C.This investigation explores the mechanism of the interaction between the interlayer and liPSs,and provides a new strategy to regulate the reaction kinetics and li2S deposition in LSBs.

关键词： Adsorption Catalysis Electrostatic spinning Interlayers li2S electrodeposition lithium-sulfur batteries Polysulfide intermediates