The Research and Application of the Anti-Interference Techniques of Electronic Device in Power System

This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[

Integrated power electronics module based on chip scale packaged power devices

High performance can be obtained for the integrated power electronics module（IPEM） by using a three-dimensional packaging structure instead of a planar structure. A three- dimensional packaged half bridge-IPEM （HB-IPEM）, consisting of two chip scale packaged MOSFETs and the corresponding gate driver and protection circuits, is fabricated at the laboratory. The reliability of the IPEM is controlled from the shape design of solder joints and the control of assembly process parameters. The parasitic parameters are extracted using Agilent 4395A impedance analyzer for building the parasitic parameter model of the HB- IPEM. A 12 V/3 A output synchronous rectifier Buck converter using the HB-IPEM is built to test the electrical performance of the HB-IPEM. Low voltage spikes on two MOSFETs illustrate that the three-dimensional package of the HB-IPEM can decrease parasitic inductance. Temperature distribution simulation results of the HB-IPEM using FLOTHERM are given. Heat dissipation of the solder joints makes the peak junction temperature of the chip drop obviously. The package realizes three-dimensional heat dissipation and has better thermal management.

Constructing Large Scale Cohort for Clinical Study on Heart Failure with Electronic Health Record in Regional Healthcare Platform:Challenges and Strategies in Data Reuse

Regional healthcare platforms collect clinical data from hospitals in specific areas for the purpose of healthcare management.It is a common requirement to reuse the data for clinical research.However,we have to face challenges like the inconsistence of terminology in electronic health records (EHR) and the complexities in data quality and data formats in regional healthcare platform.In this paper,we propose methodology and process on constructing large scale cohorts which forms the basis of causality and comparative effectiveness relationship in epidemiology.We firstly constructed a Chinese terminology knowledge graph to deal with the diversity of vocabularies on regional platform.Secondly,we built special disease case repositories (i.e.,heart failure repository) that utilize the graph to search the related patients and to normalize the data.Based on the requirements of the clinical research which aimed to explore the effectiveness of taking statin on 180-days readmission in patients with heart failure,we built a large-scale retrospective cohort with 29647 cases of heart failure patients from the heart failure repository.After the propensity score matching,the study group (n=6346) and the control group (n=6346) with parallel clinical characteristics were acquired.Logistic regression analysis showed that taking statins had a negative correlation with 180-days readmission in heart failure patients.This paper presents the workflow and application example of big data mining based on regional EHR data.

Electronic Cigarette Use Scale: Development and evaluation of a measure among Chinese students

Objective:To develop the Electronic Cigarette Use Scale(ECUS)based on social cognitive theory and test its reliability and validity,so as to provide a scientific tool for evaluating the use of e-cigarette smokers in China.Methods:Based on the review of social cognitive theory and literature analysis,the item pool of ECUS was constructed to form the initial version.From January to March in 2022,using the convenient sampling method,electronic questionnaires were distributed to college students in Guangdong Province through the questionnaire star platform,and a total of 1047 valid questionnaires were collected for item screening.The total sample was randomly divided into sample 1(n=517)and sample 2(n=530)for Exploratory Factor Analysis(EFA)and Confirmatory Factor Analysis(CFA)respectively to further test the reliability and validity of the scale and finally form a 24-item scale.Results:The formal ECUS included 24 items,6 factors were extracted by EFA,and the cumulative explanatory variance was 72.774%.CFA showed that the goodness-of-fit indices were acceptable:χ^(2)/df=2.61,CFI=0.938,TLI=0.928,RMSEA=0.055,90%CI(0.050,0.061),SRMR=0.046,AIC=34694.405,BIC=35036.235.The Cronbach’saof the 24-item scale was 0.898,and the Cronbach’saof each dimension was between 0.839 and 0.954.Both convergent validity and discriminant validity reached the standard.Conclusion:The 24-item ECUS developed in this study has been tested with good reliability and validity and is suitable for evaluating the use of e-cigarette smokers in China.

Relativistic Multichannel Theory:Scaling Behavior of Multichannel Quantum Defect Theory Parameters(μ_(α),U_(iα)) Along the Ne-Like Iso-electronic Sequence

The compact physical parameters(μ_(α),U_(iα))in multichannel quantum defect theory(MQDT)can be directly calculated with relativistic multichannel theory(RMCT).Here we report a systematic study of the MQDT parameters(fiay Uia)with RMCT along the Ne-like iso-electronic sequence(including Ca^(10+),Fe^(16+),Ge^(22+),Ag^(37+) ions).We find that the physical parameters(μ_(α),U_(iα))show a very interesting scaling behavior along the iso-electronic sequence.

Recent advances on thermal analysis of stretchable electronics

Stretchable electronics, which offers the performance of conventional wafer-based devices and mechan- ical properties of a rubber band, enables many novel applications that are not possible through conven- tional electronics due to its brittle nature. One effective strategy to realize stretchable electronics is to design the inorganic semiconductor material in a stretchable format on a compliant elastomeric substrate. Engineering thermal management is essential for the development of stretchable electronics to avoid adverse thermal effects on its performance as well as in applications involving human body and biological tissues where even 1-2℃ temperature increase is not allowed. This article reviews the recent advances in thermal management of stretchable inorganic electronics with focuses on the thermal models and their comparisons to experiments and finite element simulations.

Visualization of atomic scale reaction dynamics of supported nanocatalysts during oxidation and ammonia synthesis using in-situ environmental(scanning) transmission electron microscopy

Reaction dynamics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas-solid catalyst reactions and are crucial to the catalyst function.Supported noble metal nanocatalysts such as platinum are of interest in fuel cells and as diesel oxidation catalysts for pollution control,and practical ruthenium nanocatalysts are explored for ammonia synthesis.Graphite and graphitic carbons are of interest as supports for the nanocatalysts.Despite considerable literature on the catalytic processes on graphite and graphitic supports,reaction dynamics of the nanocatalysts on the supports in different reactive gas environments and operating temperatures at the single atom level are not well understood.Here we present real time in-situ observations and analyses of reaction dynamics of Pt in oxidation,and practical Ru nanocatalysts in ammonia synthesis,on graphite and related supports under controlled reaction environments using a novel in-situ environmental(scanning) transmission electron microscope with single atom resolution.By recording snapshots of the reaction dynamics,the behaviour of the catalysts is imaged.The images reveal single metal atoms,clusters of a few atoms on the graphitic supports and the support function.These all play key roles in the mobility,sintering and growth of the catalysts.The experimental findings provide new structural insights into atomic scale reaction dynamics,morphology and stability of the nanocatalysts.

基于物联网技术的鸡智能育种平台研究与应用

为解决鸡规模化生产过程中个体精细化数据采集难度大、成本高、选育配种效率低等问题,研究设计基于物联网的包括适用于鸡全生命周期佩戴的电子标签、自动称重台、移动终端采集系统及鸡智能育种管理系统的鸡智能育种平台。结果显示:该平台实现鸡育雏、育成、产蛋到淘汰各阶段个体外貌、生产性能、调群等数据的精准采集,以及系谱跟踪、报表生成、智能选配等功能;较传统铝质翅标佩戴效率提升40%,个体身份识别正确率超过98%,产蛋、体重、外貌等数据采集准确率超过99%,通过种鸡智能选种选配模型实现了种鸡的快速优选,避免近亲繁殖。研究表明,建立的鸡智能育种平台能满足不同规模养殖企业的生产需求,有效减少人力成本、提升育种效率。

体电子显微学前沿

电子显微成像技术的快速发展使得对完整细胞、组织乃至整个机体进行高分辨三维结构解析研究成为可能,这些可进行大尺度生物样品三维结构研究的电子显微成像技术统称为体电子显微学技术(volume electron microscopy,vEM)。近年来,v EM在研究尺度、分辨率、吞吐量和易用性等方面发展迅速,在整个生命科学领域的应用呈爆炸式增长,该技术因此被《自然》(Nature)评为2023年最值得关注的七项前沿技术之一。然而,vEM相关技术的发展和应用在国内起步较晚,亟待进一步推广。本综述涵盖了vEM的发展历程、技术分类、样品制备、数据收集、图像处理等全方位的内容,便于生命科学、医学等领域研究人员去了解、学习、应用和进一步发展该技术。

计及多重差异的交直流混合多能微网多时间尺度优化调度

近年来,可再生能源发电、热电联产、储能和电力电子变压器(PET)等技术发展迅速,有利于构建多能互补、清洁高效的交直流混合多能微网(MEMG),但不成熟的PET模型和复杂的不确定性为系统的优化调度带来了挑战。为此,首先构建了一种基于三级式PET的交直流混合MEMG结构,建立了包括PET在内的设备模型和不确定性模型;其次,提出了计及多重差异的MEMG多时间尺度优化调度策略,明确了日前-日内-实时三时间尺度调度的协调机制,其中,多重差异包含需求响应资源、系统调度目标和源荷预测精度在时间尺度上的差异,以及不同能量的响应特性差异;再次,建立了对应的多时间尺度优化调度模型,包括日前鲁棒机会约束优化模型、日内随机优化模型和实时分层滚动修正模型,并在日前调度中,改进了传统储能和电热耦合设备的备用模型,设计了基于PET的交直流系统备用共享机制,将调度模型转换为混合整数线性规划模型,给出了利用CPLEX求解器求解多时间尺度调度模型的步骤;最后,通过算例分析表明,所提调度策略可以通过逐级修正调度计划应对不确定性,且所设计备用方案兼具可靠性和灵活性。

基于COSMIC掩星观测的顶部电离层标高特征分析

顶部电离层是指F2层电子密度最大值所在高度以上的电离层区域。掩星观测能够提供地面到低轨卫星轨道高度处的整个电离层电子密度剖面,对于顶部电离层的研究具有重要作用。标高是构建顶部以上电离层电子密度剖面模型的重要参数。本文使用2007—2020年的气象、电离层和气候星座观测系统(Constellation Observing System for Meteorology,Ionosphere and Climate,COSMIC)掩星观测数据,提取有效电子密度剖面数据的顶部标高,分析了其随地方时、季节、经纬度和太阳活动水平的变化特性。结果表明:顶部标高具有明显的日变化和季节变化规律,并且表现出强烈的太阳活动依赖性;顶部标高在纬度上的变化强烈依赖于地方时,同时在东西经向上表现出明显的波状结构,且这种经度波状结构在南北半球具有不同的形态;顶部标高在夏季半球具有显著的东西经向差异,南半球夏季更为明显。

多种水等效材料的医用电子束修正因子研究

针对水等效材料在医用电子束剂量测量中修正因子的测量和使用问题,通过扫描医用电子束在水中和水等效材料中的百分深度剂量(percentage depth dose,PDD)曲线,计算获得深度缩放因子c_(pl)、注量缩放因子h_(pl)及总修正因子k_(pl)的实验值。结果表明,通过c_(pl)和h_(pl)组合或仅使用k_(pl)均可将水等效材料测量结果转换为水吸收剂量。比较PDD曲线表明,在10~20 MeV电子能量下3种水等效材料通过c_(pl)-h_(pl)修正后的R_(50),较水中测量最大偏差分别为0.19%、0.28%、0.22%;经k_(pl)修正得到的R_(50),较水中测量最大偏差分别为0.23%、0.29%、0.18%。结论:研究提供了多种材料c_(pl)-h_(pl)、k_(pl)的实验值,可方便用户快速完成电子束水吸收剂量的测量,相比于c_(pl)-h_(pl),使用k_(pl)更加简单高效。

小尺寸金属纳米线力学行为的原位电镜研究进展

金属纳米线在信息采集、存储以及超灵敏传感器等方面被广泛应用。在实际应用中,金属纳米线常处于应力状态下,对关键器件的性能稳定性有直接影响。原位研究金属纳米线在应力作用下的塑性变形原子机制是确保重要元器件在复杂环境下依旧保持稳定的物理性能输出的实验依据。本文介绍了纳米力学原位实验技术的研究进展和纳米材料力学性能曲线的测量策略;在此基础上,从材料的尺寸效应出发,总结了不同直径尺寸金属纳米线的位错、孪晶、表面原子扩散等变形机制与纳米线力学性能之间的相关性;展望了小尺寸金属纳米线原位纳米力学技术和原位实验研究的发展方向。

基于电测法的电子秤设计与标定实验

基于电测法的基本原理,结合材料力学中梁弯曲变形的理论知识,通过对静态应变仪参数的标定与校准,将静态应变仪改造成电子秤,从而实现对标定物重量的准确测量。该实验选择梁作为受力的载体,将应变片黏贴在梁上下表面,通过对灵敏系数的调整建立静态应变仪所测得的应变与标定物重量之间的关系。实验结果表明,改造后的静态应变仪作为电子秤使用时,能够准确测量出标定物的重量,实验数据的稳定性和重复性均得到了验证。实验将材料力学的理论知识与电测法相结合,拓宽了电测法在材料力学实验教学中的应用范围,也激发了学生的创新思维,具有研究性、综合性和创新性。

基于人工智能技术的铁路电子公文数据智能化分析及关联方法研究

利用大数据、人工智能、超大规模预训练模型等技术,研究铁路行业复杂场景下电子公文数据智能化分析及关联方法。介绍电子公文智能化提升总体架构、关键技术,为铁路电子公文数据智能化分析的远期场景提供方法性探索,从而充分挖掘铁路电子公文资源价值,提升公文办理质量和效率。

电子汽车衡检定分析

电子汽车衡作为测量大型货物计量的主要设备,是贸易往来的主要计量设备。在使用一段时间后,相关人员需要根据国家相关标准和规定对其进行检定,以减少使用过程中数据误差的产生,这也是保障行业进步与发展的关键。本文主要针对现阶段电子汽车衡检定工作开展的重要性以及检定工作要点进行分析,希望能够为电子汽车衡的使用提供参考。

国际直接投资与高新技术企业自主创新关系的实证分析

为充分发挥国际直接投资对高新技术企业自主创新的促进作用,本文以2010~2022年的电子及通信设备制造业面板数据为基础,就国际直接投资与高新技术企业自主创新的关系进行实证研究。通过选取自变量、因变量、控制变量、门限变量,进行描述性统计、回归分析、稳健性检验和内生性检验,分析因变量和自变量之间的关系。结果表明:电子及通信设备制造业自主创新存在明显差异,其中,技术投入资金反向抑制其自主创新,而国际直接投资、研发人力资本、研发人员报酬、企业规模、国家研发补贴、市场经营状况、对外开放水平正向促进其自主创新;电子及通信设备制造业与技术投入资金之间存在一对协整关系,与国际直接投资、研发人力资本、企业规模、研发人员报酬、国家研发补贴、市场经营状况、对外开放水平均存在两对协整关系,且均在1%显著性水平下显著相关;国际直接投资可正向促进电子及通信设备制造业自主创新,并随着研发人力资本门限值的增大,促进作用表现为先下降后上升的特点;将研发人力资本的门限值设定为小于11.364,可更好发挥国际直接投资对电子及通信设备制造业的自主创新促进作用。基于实证结果得出,要进一步发挥国际直接投资对高新技术企业自主创新的促进作用,需要从改善投资环境、引进研发人员、加大投入资金、营造自主创新氛围、加强行业对外开放、开展良性行业竞争等对策入手。

星载电子器件温控的系统多尺度分析

为提高星载电子器件热分析的模拟分辨率和精度以及被动热控装置的控温效果,本文建立系统多尺度模型获得不同尺度下卫星内部电子器件的温度场和热流信息.结果表明:系统多尺度模型在系统级尺度模拟精度与实际模型相对误差小于9%,并且可消耗较少的计算资源获得器件级尺度芯片微小结构的热信息.系统级模型可从宏观尺度评估星载被动热控材料的控温隔热性能,采用复合相变隔热材料可将载荷舱室温度波动幅值降至2.43 K,相比平台舱室温度波动幅值降低约69.43%,通过复合相变隔热材料隔热后的温度波动信号呈现向高频域部分转移的特征.基于多元回归分析选定需要进行重点隔热控温的舱室后,采用器件级简化模型得到不同热控装置布局下的温度场信息形成训练数据集,采用神经网络遗传算法在器件尺度预测被动热控装置的最佳安装位置,并得到减小器件最大温度波动的热控布局方案,最大温度波动降低2.74 K.

电子汽车衡安装调试的常见问题分析及质量控制措施

电子汽车衡作为一种国际上重要的计量工具,可实现对大宗物品称重计量,并用于贸易结算功能。在电子汽车衡生产加工中,安装调试过程会对电子汽车衡功能产生直接影响,并最终决定称重结果的可靠性。基于电子汽车衡存在问题,本文以电子汽车衡安装调试为研究重点,深入分析并揭示电子汽车衡中常见的一些问题。在此基础上,进一步提出了对应的质量控制措施。

“双高”配电系统的挑战与应对措施探讨

随着风光等可再生能源及多变流器等电力电子设备在配电系统中渗透率逐步提高,“双高”配电系统面临诸多问题与挑战。高比例可再生能源出力的不确定性及波动性,高比例电力电子设备大量存在于控制环节带来的低惯性及弱阻尼等新问题均为配电系统安全运行带来了新的挑战。该文从“双高”特性对配电系统影响的不同时空尺度出发,归纳配电系统新形势下面临的问题,分析这些新问题的产生机理,并针对现有的解决方案展开探讨。最后尝试对“双高”配电系统的发展进行展望。