多房棘球蚴囊泡来源EVs及其emu-miR-10-5p促进小鼠肝星状细胞活化

目的明确多房棘球绦虫囊泡来源胞外囊泡(Extracellular vesicles,EVs)及其emu-miR-10-5p在体外调节HSCs活化中的作用。方法小鼠腹腔注射原头节构建继发性多泡型包虫病模型,以小鼠体内病灶为材料培养多房棘球绦虫囊泡并进行PCR鉴定。透射电镜观察培养囊泡组织中胞外囊泡结构。差速-超速离心法分离囊泡培养上清中EVs,透射电镜、纳米粒径以及Western blot对分离EVs进行鉴定。CCK-8检测不同浓度EVs作用后HSCs活力。EVs作用于HSCs后RT-qPCR和Western blot检测α-SMA、CollagenⅠ和CollagenⅢ表达水平。生物信息学分析确定emu-miR-10-5p为特异性miRNA。过表达emu-miR-10-5p后EdU检测HSCs增殖,RT-qPCR个Western blot检测细胞中α-SMA、CollagenⅠ和CollagenⅢ表达水平。干扰囊泡组织中emu-miR-10-5p后提取培养上清液中EVs作用于HSCs后,检测HSCs细胞中α-SMA、CollagenⅠ和CollagenⅢ表达水平。结果成功通过小鼠体内病灶材料培养出多房棘球蚴囊泡,经PCR扩增特异性基因证实为多房棘球绦虫来源。TEM观察培养囊泡表面有较多的囊状结构。通过差速-超速离心分离出多房棘球蚴囊泡来源EVs,并经TEM证实为球形、膜状结构。囊泡来源EVs能被HSCs内化,并促进HSCs增殖和活化。通过综合分析多房棘球绦虫感染小鼠血清、棘球蚴组织、棘球蚴囊泡来源EVs、生发层细胞、原头节miRNA测序结果,发现emu-miR-10-5p在上述成分中均存在表达,并通过RT-qPCR证实emu-miR-10-5p在多房棘球蚴囊泡来源EVs中存在的量较高。进一步研究证实过表达emu-miR-10-5p能促进HSCs增殖,增加HSCs中α-SMA、Collagen I和CollagenⅢmRNA及蛋白表达水平。而干扰囊泡中emu-miR-10-5p后从培养上清液中提取的EVs未增加α-SMA、Collagen I和CollagenⅢmRNA及蛋白表达水平。结论多房棘球蚴囊泡来源EVs及emu-miR-10-5p能够促进HSCs活化。

Matlab-Simulink Simulation Model of Electric Multiple Unit(EMU)Series ŽS 413/417 in Traction and Electric Braking Mode

In the paper,the Matlab-Simulink model of simulation of operation of theŽS 413/417 series EMU(electric multiple unit)in traction and braking mode is exposed where changes are observed:stator currents of three-phase traction motors,traction electric motor speeds and EMU,electromagnetic torque on the rotor shaft of the traction electric motor and DC(direct current)bus voltage.The model allowed review of the listed parameters for:different allowed values of contact network voltage and total voltage distortion at the place of connection of the EMU to the contact network,different mechanical loads of EMU and traction electric motor and different train speeds and rotation of traction electric motors.Appropriate conclusions were made through the analysis of the simulation results obtained.

Investigation on influencing factors of wheel polygonization of a plateau high-speed EMU train

Purpose–This study aims to investigate the cause of high-order wheel polygonization in a plateau high-speed electric multiple unit(EMU)train.Design/methodology/approach–A series of field tests were conducted to measure the vibration accelerations of the axle box and bogie when the wheels of the EMU train passed through tracks with normal rail roughness after re-profiling.Additionally,the dynamic characteristics of the track,wheelset and bogie were also measured.These measurements provided insights into the mechanisms that lead to wheel polygonization.Findings–The results of the field tests indicate that wheel polygonal wear in theEMUtrain primarily exhibits 14–16 and 25–27 harmonic orders.The passing frequencies of wheel polygonization were approximately 283–323 Hz and 505–545 Hz,which closely match the dominated frequencies of axle box and bogie vibrations.These findings suggest that the fixed-frequency vibrations originate from the natural modes of the wheelset and bogie,which can be excited by wheel/rail irregularities.Originality/value–The study provides novel insights into the mechanisms of high-order wheel polygonization in plateau high-speed EMU trains.Futher,the results indicate that operating the EMU train on mixed lines at variable speeds could potentially mitigate high-order polygonal wear,providing practical value for improving the safety,performance and maintenance efficiency of high-speed EMU trains.

Customized High-speed EMU Design Practice for Jakarta-Bandung HSR

The high-speed EMUs for Jakarta-Bandung high-speed railway(HSR)represent an important image and symbol of the Jakarta-Bandung HSR Project.By relying on the technical platform of the model CR400 EMU,the EMU is upgraded for the customized design in terms of adaptability to geographical environment and track conditions,integration of Indonesian cultural characteristics,etc.In the course of development,in order to accurately grasp the boundary conditions and solve matching adaptation problems,studies are conducted on the exploration of design boundary and the related special technology.With the systematic analysis and design experience summary of the high-speed EMUs for Jakarta-Bandung HSR,the paper aims to provide reference for the O&M of high-speed EMUs for Jakarta-Bandung HSR and the other similar overseas HSR projects.

基于EMU8086的微机原理教学实践探索——以8086数据寻址方式为例

从微机原理课程特点及教学现状出发,分析传统教学方式的弊端。探讨了EMU8086在微机原理课程线上线下混合式教学模式中的应用,以8086的数据寻址方式的教学为例,介绍了EMU8086仿真软件的特点和功能,分析了8086数据寻址方式在该课程中的重要性。通过实际案例介绍如何使用EMU8086进行8086数据寻址方式的教学。实践表明,在混合式教学模式下,通过使用EMU8086辅助教学,学生可以更直观地理解8086处理器的工作原理和数据寻址方式,能够有效提高学生对微机原理的理解和实际操作能力。

Identification of a Newly Isolated Getah Virus in the China-Laos Border,China

In this study, we isolated a virus strain （YN12031） from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect （CPE） 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers.

An abnormal carbody swaying of intercity EMU train caused by low wheel-rail equivalent conicity and damping force unloading of yaw damper

Low-frequency carbody swaying phenomenon often occurs to railway vehicles due to hunting instability,which seriously deteriorates the ride comfort of passengers.This paper investigates low-frequency carbody swaying through experimental analysis and numerical simulation.In the tests,the carbody acceleration,the wheel-rail profiles,and the dynamic characteristics of dampers were measured to understand the characteristics of the abnormal carbody vibration and to find out its primary contributor.Linear and nonlinear numerical simulations on the mechanism and optimization measures were carried out to solve this carbody swaying issue.The results showed that the carbody swaying is the manifest of carbody hunting instability.The low equivalent conicity and the decrease of dynamic damping of the yaw damper are probably the cause of this phenomenon.The optimization measures to increase the equivalent conicity and dynamic damping of the yaw damper were put forward and verified by on-track tests.The results of this study could enrich the knowledge of carbody hunting and provide a reference for solving abnormal carbody vibrations.

Visit China-Laos Year

Visit China-Laos Year 2019 was launched on January 25 in Vientiane, the capital of Laos.

Maintenance Optimization for EMU Trains Considering Environmental Impacts and Correlations

The complexity of the actual operating environment of EMU trains and the interaction between the reliability of system components have become a huge challenge for the maintenance scheduling of EMU trains. In response to these problems, the evolution of reliability and failure rate under the influence of environmental factors, failure correlations and economy correlations is analyzed. We assume bogie systems form the EMU train in series. The failure correlation matrix of the bogie systems is modeled. With the lowest total maintenance cost as the optimization objective, a decision-making model for EMU train maintenance is established. A dynamic maintenance strategy is proposed for the model, which can improve maintenance plans efficiently. Artificial bee colony algorithm is applied to further iteratively optimize the threshold parameters in the strategy. The results are calculated and verified by a numerical example. The results show the effectiveness of the maintenance decision model. The dynamic maintenance strategy in this paper is compared with the traditional opportunistic maintenance strategy. The proposed maintenance strategy outperforms the traditional opportunistic maintenance strategy in the numerical example.

底线思维与科技审度:高风险社会治理的要义与进路

当前AI大爆发及其应对乏力表明,西方科技发展模式的缺陷与人类社会的脆弱及学界研究的薄弱,更加凸显人类风险防控机制存在诸多漏洞及其引发的科技危机与人类安全危机,已把人类带入高风险社会。用底线思维与刘大椿提出的科技审度予以破解:底线思维解决非共识下的议而不决;科技审度和审度思维所特有的执两用中、包容互补、多元开放、整合升级、共识决策等,可提供有效的治理对策。科技转型是治理科技风险的根本解决之道,科技审度可发挥重要的启发与引导作用,以构建真善美的新型科技发展模式,加快世界科学中心建设,据此总结出高风险社会治理的要义与进路,以作为科技风险治理的研究指南。

高速动车组车体整备垂弯频率优化研究

提出采用2种不同方法对高速动车组进行模态分析研究。以车体各个部件厚度参数为设计变量进行模态及质量的灵敏度分析,研究不同部件厚度对车体一阶垂弯频率的影响规律,并筛选8个部件作为最终设计变量,建立优化数学模型;以车体与车下主要设备连接处弹性元件的刚度参数为设计变量进行响应面分析,研究弹性元件刚度对车体一阶垂弯频率的影响规律,并对弹性元件刚度进行优化。结果表明:2种方法均取得了一定的效果,基于灵敏度分析的部件优化,使车体整备一阶垂弯频率提升了4.88%;基于响应面分析的弹性元件优化,使车体整备一阶垂弯频率提升了28.05%,大于相关标准中规定的10Hz,优化效果明显。

动车组抗蛇形减震器底座裂纹原因分析

针对动车组抗蛇形减振器在例行维修中发现的裂纹缺陷,借助显微镜、扫描电镜、能谱分析对裂纹缺陷区域的显微组织进行观察和分析。结果表明,构件裂纹附近存在多处晶间腐蚀缺陷;裂纹的开裂方式以沿晶疲劳开裂为主,并伴生应力腐蚀开裂;因断口经历了腐蚀过程,不能排除裂纹是源于腐蚀开裂;未腐蚀的断口界面则表现出疲劳失效开裂行为。

轻量化动车组车载牵引变压器的研制

车载牵引变压器是动车组单体最重的电气设备,其轻量化有助于动车组节能降耗与运输效率提升。现有车载牵引变压器均为油浸式,干式变压器是其轻量化的主要方案,但目前干式变压器采用的环氧树脂绝缘易开裂、散热无法满足要求。为此,以具有良好力学性能的硅橡胶为基体材料,首先通过温升分析研究绝缘材料热导率需求,然后制备样品开展实验,以电学性能和力学性能为约束条件研究绝缘材料导热性能改进方法,进而研究车载牵引变压器轻量化设计方法,最后依据研制的绝缘材料与轻量化设计方法,设计并研制了一台容量为250 kVA的小型轻量化车载牵引变压器样机。结果表明:制备的高导热硅橡胶复合绝缘材料性能满足干式车载变压器对绝缘和力学性能的要求;研制的小型变压器样机质量为780 kg,相比同容量油浸式车载牵引变压器质量减少了46.2%,经试验测试得在额定条件下样机的热点温度值为167.68℃,满足车载牵引变压器运行需求。

车端侧滚减振装置对高速双层动车组动力学性能的影响分析

双层动车组设置较大的二系横向阻尼来抑制一次蛇行引起的共振,而较大的二系横向阻尼会使车辆的横向平稳性变差。针对某型高速双层动车组横向平稳性差的问题,基于车端侧滚减振装置的工作原理建立了车端侧滚减振装置在车体滚摆和摇头运动状态下的数学模型,并将AMEsim软件中建立的减振器仿真模型与台架试验进行验证。最后通过建立车端侧滚减振装置与被试车辆的联合仿真模型,在不改变车辆现有悬挂参数的基础上对车端侧滚减振装置的关键参数进行优化选取。仿真结果表明,车端侧滚减振装置可以在不影响车辆垂向平稳性、保证曲线运行安全性的前提下有效改善双层动车组的横向平稳性。

基于机器学习的长编重联动车组碰撞能量管理方案优化

为有效缓解交通运输压力,采用动车组重联运行可以成倍提高载客量,然而一旦发生碰撞事故,巨大的碰撞能量将造成严重的乘员损伤和财产损失,长编重联动车组碰撞能量管理已成为重点研究对象。本文提出均匀耗散和集中耗散2种碰撞能量管理模式,以头车和中间车车端的吸能装置平台力和压缩行程为设计参数,基于KNN、MLS、RBF和RF的4种机器学习算法,开展长编重联动车组碰撞能量管理方案优化设计。研究结果表明:预测头车吸能量和中间车自身耗散能量方差的最优机器学习模型分别是MLS和RBF,相对误差均在4%以内;头车和中间车的吸能元件平台力是影响头车界面吸能量的主要参数,中间车吸能装置参数是影响中间车界面碰撞能量分布是否均匀的主要参数;集中耗散模式下头车和重联界面吸收了碰撞能量48.24%,中间车界面吸收了碰撞能量51.76%,该能量分配模式要求头车前端吸能装置具有更高的吸能量;均匀耗散模式下头车和重联界面吸收了22.75%的碰撞能量,中间车界面吸收了77.25%的碰撞能量,该能量分配模式会增大车间距导致列车长度增加;优化获得的2种碰撞能量管理方案都能在时速36 km/h对撞工况下保证长编重联动车组车体结构完整,且车体120 ms最大平均加速度分别为2.64g和2.36g。

动车组轮对故障模式分析及风险评估

动车组转向架的检修质量直接关乎行车安全,轮对是转向架重点部件,为提高其检修品质,将轮对装配结构的可靠性进行分解研究,根据实车故障数据分析制定轮对故障先验模式,再结合三维仿真分析和实车数据完善轮对故障后验模式,同时推导出轮对故障风险顺序数RPN的计算权重,将实车故障数据按故障模式和RPN进行归纳整理,得出轮对装配结构中车轮故障发生频次高且危害大的结论,针对性地分析了车轮检修的重点部位和操作工序,优化了轮对的维修策略,提高了检修品质。

动车组轮对故障模式分析及风险评估

动车组转向架的检修质量直接关乎行车安全,轮对是转向架重点部件,为提高其检修品质,将轮对装配结构的可靠性进行分解研究,根据实车故障数据分析制定轮对故障先验模式,再结合三维仿真分析和实车数据完善轮对故障后验模式,同时推导出轮对故障风险顺序数RPN的计算权重,将实车故障数据按故障模式和RPN进行归纳整理,得出轮对装配结构中车轮故障发生频次高且危害大的结论,针对性地分析了车轮检修的重点部位和操作工序,优化了轮对的维修策略,提高了检修品质。

考虑个体差异的车轮二元相关退化可靠性分析

由于动车组车轮受加工装配及工况载荷等不确定因素的影响,车轮退化过程复杂,存在显著的个体差异及多个性能退化特征量,且多个退化特征量间相互耦合,仅考虑单个性能特征量难以全面反映其退化过程。因此,以轮缘和轮径作为车轮退化特征量,通过随机化尺度参数表征车轮个体差异,采用Gamma过程和Copula函数建立二元相关退化模型,并根据赤池信息准则(Akaike Information Criterion, AIC)筛选Copula函数,得到可靠度解析式。基于某型动车组车轮实测磨耗数据,对车轮进行可靠性分析,同时通过车辆动力学模型进行仿真验证。结果显示:考虑二元相关时的可靠性结果比仅考虑一元退化更贴近车辆实际运行情况;根据动力学仿真结果体现了考虑个体差异的必要性,表明所提模型能够更准确地表征车轮退化过程,可为可靠性分析以及维修决策优化提供理论支撑。

动车段高级修主要工艺及总平面布置研究

动车段是承担动车组高级修的场所,是保证动车组安全、高效运营的重要基础设施,动车组高级修工艺流程复杂,合理的工艺设计是实现检修功能、提升检修能力的重要因素。对动车段高级修主要工艺及总平面布置进行研究,首先探讨了动车组高级修工作量及设施规模确定方法,提出了工作量及设施规模计算公式;然后对动车组三、四、五级修主要工艺进行分析,并列举了动车组五级修工艺流程;最后结合工艺流程,对动车组高级修总平面布置进行研究,创新提出了四、五级修联合厂房布置方案,系统阐述了动车组高级修设施布置要点。

上海动车段高级修扩能改造总体设计

从上海动车段既有工艺布局及设备配置存在的问题入手,通过对上海动车段近远期检修能力测算分析,深层次发掘三级修检修、三四五级修调试、转向架检修能力不足、淋雨试验工位设置不合理等问题。对扩能改造的必要性进行分析研究,提出扩能改造的原则、思路和方案。改造方案中,提出兼容性改造既有三级修库架车机,新建4线三级修及调试库,新增淋雨试验装置,新增一台转向架静载试验设备。改造后,工艺布局顺畅合理,极大提高了上海动车段高级修检修能力,年检修套数可由400标准组提升至600标准组;转向架日均产能由12个/天提升至16个/天。