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Numerical prediction of particle slip velocity in turbulence by CFD-DEM simulation

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Particuology 2023年第9期80卷 170-179页

作者： Zhixin Sun Xiaokang Yan lijun Wang xiaoheng li Ai Wang Haijun Zhang School of Chemical Engineering China University of Mining and TechnologyXuzhou221116China School of Low-Carbon Energy and Power Engineering China University of Mining and TechnologyXuzhou221116China National Engineering Research Center of Coal Preparation and Purification China University of Mining and TechnologyXuzhou221116China School of Engineering The University of NewcastleCallaghanNSW2308Australia

Turbulent environment improves the flotation recovery of fine particles by promoting the particle–bubble collision rate,which directly depends on the particle slip ***,the existing slip velocity models are not applicable to fine particles in *** mechanism of turbulence characteristics and particle properties on the slip velocity of fine particles in turbulence was *** this study,a coupled ANSYS FLUENT and EDEM based on computational fluid dynamics(CFD)and discrete element method(DEM)were used to simulate the slip velocity of fine particles in the approximately homogenous isotropic turbulence,which was excited by the *** reliability of the used CFD-DEM simulation method was validated against the slip velocity measured by the particle image velocimetry(PIV)*** particular,the effects of the particle shapes,particle densities,and turbulence intensities on the slip velocity have been investigated with this numerical *** results show that particle shapes have no significant effect on fine particles between 37 and 225μ*** slip velocity of the spherical particles increases with the turbulence intensity and particle *** on the simulated data,a model which has a correlation coefficient of 0.95 is built by using nonlinear fitting.

关键词： Slip velocity Fine particles Turbulence CFD-DEM

主动脉支架体外开窗与Castor分支型覆膜支架TEVAR重建LSA治疗主动脉弓部病变的临床疗效比较

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医学临床研究 2024年第6期41卷 842-845页

作者：李晓恒李燕平付晓可李斌洛阳市中心医院河南洛阳471000

【目的】比较主动脉支架体外开窗与Castor分支型覆膜支架主动脉腔内修复术(TEVAR)重建左锁骨下动脉(LSA)治疗主动脉弓部病变的临床疗效。【方法】选取2020年1月至2023年1月本院收治的71例主动脉弓部病变的患者,根据LSA重建方式不同将其... 详细信息

【目的】比较主动脉支架体外开窗与Castor分支型覆膜支架主动脉腔内修复术(TEVAR)重建左锁骨下动脉(LSA)治疗主动脉弓部病变的临床疗效。【方法】选取2020年1月至2023年1月本院收治的71例主动脉弓部病变的患者,根据LSA重建方式不同将其分为体外开窗组(主动脉支架体外开窗,n=51)和外分支组(Castor分支型覆膜支架TEVAR重建LSA,n=21)。比较两组患者围术期指标、手术成功率及术后并发症发生率,1年后随访预后情况,夹层术后的夹腔重塑情况及患者假腔血栓化情况。【结果】外分支组手术时间、器械释放成功率、手术费用均高于体外开窗组(P0.05)。【结论】主动脉支架体外开窗与Castor分支型覆膜支架TEVAR重建LSA治疗主动脉弓部病变均具有良好的安全性与有效性,Castor分支型覆膜支架TEVAR操作时间较短且支架近端重塑效果优于体外开窗TEVAR。

关键词：主动脉疾病/外科学支架治疗结果

右腋下小切口与胸骨正中切口两种入路方式治疗先天性心脏病患儿的效果观察

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临床研究 2024年第6期32卷 12-15页

作者：李晓恒李燕平付晓可李斌洛阳市中心医院心外科河南洛阳471000 洛阳市中心医院急诊科河南洛阳471000

目的探讨先天性心脏病患者采取不同入路手术治疗的临床价值。方法抽取洛阳市中心医院2021年1月至2023年12月收入的先天性心脏病患儿70例,依据不同手术方式分为对照组与观察组,各35例,对照组接受胸骨正中切口,观察组接受右腋下小切口,对... 详细信息

目的探讨先天性心脏病患者采取不同入路手术治疗的临床价值。方法抽取洛阳市中心医院2021年1月至2023年12月收入的先天性心脏病患儿70例,依据不同手术方式分为对照组与观察组,各35例,对照组接受胸骨正中切口,观察组接受右腋下小切口,对两组患儿临床指标(手术时间、体外循环时间、输血量、胸腔引流量、主动脉阻断时间、住院时间),疼痛程度,呼吸功能及并发症发生情况进行组间比较。结果两组患儿手术时间、体外循环时间、主动脉阻断时间相比,差异无统计学意义(P>0.05),观察组输血量、胸腔引流量均低于对照组,且住院时间短于对照组,差异有统计学意义(P0.05);观察组患儿各时间段疼痛程度评分均低于对照组,差异有统计学意义(P0.05)。结论两种手术入路方式均可治疗先天性心脏病,且与胸骨正中切口相比,右腋下小切口不会影响患儿呼吸功能,且可改善疼痛程度,促进患儿快速康复,安全性较高,值得临床应用。

关键词：先天性心脏病心脏直视手术右腋下小切口胸骨正中切口

2022年珠三角4个城市PM_(2.5)污染中金属元素吸入途径的健康风险评估

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上海预防医学 2024年第4期36卷 393-398页

作者：牛计伟黄素丽李晓恒张振季佳佳刘宁中国疾病预防控制中心现场流行病学培训项目北京100050 深圳市疾病预防控制中心广东深圳518055 广东省疾病预防控制中心广东广州511430

【目的】了解新型冠状病毒感染疫情下广东省珠三角城市空气中细颗粒物(PM_(2.5))污染特征及PM_(2.5)中金属元素吸入途径的健康风险。【方法】2022年在广州、深圳、佛山及珠海市等4个市10个区设置10个PM_(2.5)监测点,每月连续7 d采集空... 详细信息

【目的】了解新型冠状病毒感染疫情下广东省珠三角城市空气中细颗粒物(PM_(2.5))污染特征及PM_(2.5)中金属元素吸入途径的健康风险。【方法】2022年在广州、深圳、佛山及珠海市等4个市10个区设置10个PM_(2.5)监测点,每月连续7 d采集空气样品进行PM_(2.5)质量浓度及PM_(2.5)中12种金属元素成分分析。通过经典“四步法”对空气中PM_(2.5)金属元素与健康影响的致癌风险(CR)、慢性非致癌风险的评估。在CR评估中结合金属元素年龄敏感特征,引入年龄敏感因子,分析空气污染对人群健康影响。【结果】共采集样品818份,珠三角4个城市PM_(2.5)年均浓度(最小值~最大值,标准差)为30.17(1.00~166.00,21.06)μg·m^(-3),低于GB 3095—2012《环境空气质量标准》二级浓度限值。4个城市PM_(2.5)浓度差异有统计学意义(P锰(Mn)>铅(Pb)>砷(As)>镍(Ni)>铬(Cr)>硒(Se)>锑(Sb)>镉(Cd)>铊(Tl)>铍(Be)>汞(Hg)。AS、Mn具有人群慢性非致癌风险,Cr、As、Cd、Be、Ni存在人群CR。【结论】珠三角4个城市PM_(2.5)污染水平低且有差异性,临海城市低于非临海城市,全年呈先降后升的特征。4个城市PM_(2.5)中金属元素除Be、Ni外质量浓度排序基本相同。PM_(2.5)中As、Mn显示有一定程度的慢性非致癌风险,As、Cr、Cd、Ni、Be存在一定程度的CR。4个城市均须采取有效干预措施,继续加强空气中Cr、As、Cd、Mn的污染管控和健康防护,控制空气污染导致的健康负担。

关键词：金属元素 PM_(2.5) 空气污染健康风险吸入

Dlg1 Knockout Inhibits Microglial Activation and Alleviates lipopolysaccharide-Induced Depression-like Behavior in Mice

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Neuroscience Bulletin 2021年第12期37卷 1671-1682页

作者： Zhixin Peng xiaoheng li Jun li Yuan Dong Yuhao Gao Yajin liao Meichen Yan Zengqiang Yuan Jinbo Cheng Institute of Neuroscience Hengyang Medical CollegeUniversity of South ChinaHengyang 421001China The Brain Science Center Beijing Institute of Basic Medical Sciences27 Taiping RoadHaidian DistrictBeijing 100850China Beijing Institute for Brain Disorders Capital Medical UniversityBeijing 100069China Institutes of Brain Sciences and Disease Medical CollegeQingdao UniversityQingdao 266071China Center on Translational Neuroscience College of Life and Environmental ScienceMinzu University of ChinaBeijing 100081China

Microglia-mediated neuroinflammation is widely perceived as a contributor to numerous neurological diseases and mental disorders including *** large homolog 1(Dlg1),an adaptor protein,regulates cell polarization and the function of K?channels,which are reported to regulate the activation of ***,little is known about the role of Dlg1 in microglia and the maintenance of central nervous system *** this study,we found that Dlg1 knockdown suppressed lipopolysaccharide(LPS)-induced inflammation by downregulating the activation of nuclear factor-jB signaling and the mitogen-activated protein kinase pathway in ***,using an inducible Dlg1 microglia-specific knockout(Dlg1flox/flox;CX3CR1CreER)mouse line,we found that microglial Dlg1 knockout reduced the activation of microglia and alleviated the LPS-induced depressionlike *** summary,our results demonstrated that Dlg1 plays a critical role in microglial activation and thus provides a potential therapeutic target for the clinical treatment of depression.

关键词： Dlg1 Microglia Neuroinflammation Depression

Wireless Power Supply Based on MNG-MNZ Metamaterial for Cardiac Pacemakers

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 103-112页

作者： Weihua Chen Jingtao Jia xiaoheng Yan Yuhang Song Jiayi li Faculty of Electrical and Control Engineering Liaoning Technical UniversityNo.188Longwan South StreetXingchengHuludao 125105China CES

To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-negative(MNG) and mu-nearzero(MNZ) metamaterials. First, a hybrid metamaterial consisted of central MNG unit for magnetic field concentration and surrounding MNZ units for magnetic leakage shielding was established by theoretical calculation. Afterwards, the magnetic field distribution of wireless power supply system with MNG-MNZ metamaterial slab was acquired via finite element simulation and verified to be better than the distribution with conventional MNG slab deployed. Finally, an experimental platform of wireless power supply system was established with which power transfer experiment and system temperature rise experiment were *** and experimental results showed that the power transfer efficiency was improved from 44.44%,19.42%, 8.63% and 6.19% to 55.77%, 62.39%, 20.81%and 14.52% at 9.6 mm, 20 mm, 30 mm and 50 mm,respectively. The maximum SAR acquired by SAR simulation under human body environment was-7.14 dbm and maximum reduction of the magnetic field strength around the receiving coil was 2.82 A/m. The maximum temperature rise during 30min charging test was 3.85℃,and the safety requirements of human bodies were met.

关键词： Cardiac pacemaker MNG metamaterial MNZ metamaterial Wireless power supply system

微细粒锡石涡流强化浮选及CFD数值模拟研究

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矿产保护与利用 2024年第1期44卷 16-23页

作者：葛昱谦李晓恒孙志新韩鑫定张明青闫小康中国矿业大学化工学院江苏徐州221116 中国矿业大学国家煤加工与洁净化工程技术研究中心江苏徐州221116 中国矿业大学环境与测绘学院江苏徐州221116

为提高微细粒锡石矿物的浮选回收效果,采用基于湍流涡调控技术的新型涡流浮选装置对微细粒锡石(d50=16.45μm)进行了浮选实验研究,考察了涡流发生器结构及矿浆循环量对微细粒锡石浮选的影响。通过涡流矿化管内部流场CFD数值模拟,分析了... 详细信息

为提高微细粒锡石矿物的浮选回收效果,采用基于湍流涡调控技术的新型涡流浮选装置对微细粒锡石(d50=16.45μm)进行了浮选实验研究,考察了涡流发生器结构及矿浆循环量对微细粒锡石浮选的影响。通过涡流矿化管内部流场CFD数值模拟,分析了涡流矿化改善微细粒浮选效果的原因。浮选实验表明,使用矩形涡流发生器诱导方式且在循环量0.6 m3/h(Re=21 220)时锡石的回收率为92.96%,精矿锡品位为3.32%。在获得精矿锡品位几乎相同的情况下,回收率相较于光管提高了25.73个百分点;CFD模拟分析结果表明内置矩形涡流发生器的矿化管内平均湍流耗散率和平均湍流动能最高,分别是光管的13.01倍和7.03倍,碰撞概率从1.07%提高到2.32%,矩形涡流发生器能显著改善矿化管的湍流环境,增大了微细颗粒-气泡的碰撞概率,从而起到强化微细粒锡石浮选的作用。

关键词：锡矿微细粒浮选涡流发生器数值模拟

The role and applications of extracellular vesicles in osteoporosis

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Bone Research 2024年第1期12卷 62-77页

作者： Fei Fang Jie Yang Jiahe Wang Tiantian li Erxiang Wang Demao Zhang xiaoheng liu Chenchen Zhou Institute of Biomedical Engineering West China School of Basic Medical Sciences&Forensic MedicineSichuan UniversityChengdu 610041China State Key Laboratory of Oral Diseases National Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengdu 610041China

Osteoporosis is a widely observed condition characterized by the systemic deterioration of bone mass and microarchitecture,which increases patient susceptibility to fragile *** intricate mechanisms governing bone homeostasis are substantially impacted by extracellular vesicles(EVs),which play crucial roles in both pathological and physiological *** derived from various sources exert distinct effects on ***,EVs released by osteoblasts,endothelial cells,myocytes,and mesenchymal stem cells contribute to bone formation due to their unique cargo of proteins,miRNAs,and ***,EVs secreted by osteoclasts and immune cells promote bone resorption and inhibit bone ***,the use of EVs as therapeutic modalities or biomaterials for diagnosing and managing osteoporosis is ***,we review the current understanding of the impact of EVs on bone homeostasis,including the classification and biogenesis of EVs and the intricate regulatory mechanisms of EVs in ***,we present an overview of the latest research progress on diagnosing and treating osteoporosis by using ***,we discuss the challenges and prospects of translational research on the use of EVs in osteoporosis.

关键词： osteoporosis homeostasis biomaterials

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铜电解精炼技术研究现状及展望

绿色矿冶 2024年第3期40卷 41-49页

作者：陈晨程楚刘海涛田静卢伟伟李晓恒李彦坤崔育涛宋克兴河南科技大学材料科学与工程学院河南洛阳471023 河南科技大学化学化工学院河南洛阳471023 河南省科学院材料研究所河南省先进导体材料重点实验室河南郑州450046 河南中原黄金冶炼厂有限责任公司河南三门峡472100

铜电解精炼是铜产业链中决定铜产品质量和性能的重要环节。本文总结和分析了传统电解精炼法、永久不锈钢阴极法、周期性反向电流法、脉冲电流法、平行流电解精炼法、外场强化电解精炼法等阴极铜电解精炼技术和一次或多次电解精炼制备高... 详细信息

铜电解精炼是铜产业链中决定铜产品质量和性能的重要环节。本文总结和分析了传统电解精炼法、永久不锈钢阴极法、周期性反向电流法、脉冲电流法、平行流电解精炼法、外场强化电解精炼法等阴极铜电解精炼技术和一次或多次电解精炼制备高纯铜电解精炼技术的原理、研究进展及存在问题,并对铜电解精炼技术进行了展望,指出阴极铜电解技术将朝着原料适应性强、金属回收率高、生产成本和能耗低以及环境友好等方向发展,而高纯铜电解精炼技术则朝着工艺简单化、节能减排、大规模生产以及产品高纯化等方向发展。

关键词：电解精炼阴极铜高纯铜