Defect Engineering:Can it Mitigate Strong Coulomb Effect of Mg^(2+)in Cathode Materials for Rechargeable Magnesium Batteries?

Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.

基于MBSE的地空导弹总体方案设计

为了适应未来大型复杂系统设计与功能分析需求,在导弹设计中引入基于模型的系统工程(MBSE)思想,提出了基于MBSE的地空导弹总体设计流程。首先,明确地空导弹利益相关者的需求,定义导弹任务场景;基于设计需求开展功能分析,利用导弹任务场景进行功能分解,完成需求到功能的转化;根据导弹的系统功能映射出导弹架构组成,开展地空导弹系统的逻辑架构设计和物理架构设计,最终得到导弹总体设计方案,并针对导弹方案进行验证及优化,初步实现了地空导弹的总体设计过程。

基于数字孪生和MBSE的铁路防灾监测仿真推演系统设计

针对既有铁路防灾监测系统灾害情景预测能力低、主动防控水平差,以及灾害风险发生、发展、演化的路径和应对策略效能评估能力不足等问题,采用数字孪生和基于模型的系统工程(MBSE)技术重新设计铁路防灾监测仿真推演系统架构,采用系统建模语言(SysML)定义系统需求分析、功能架构、逻辑架构和物理架构;研制集铁路环境情景数据采集、孪生监控、情景仿真、情景推演、情景应对、数据资源管理等功能为一体的铁路防灾监测仿真推演系统。结果表明:提出的基于数字孪生和MBSE的铁路防灾监测仿真推演系统可提供新的灾害在线推演预测能力,从根本上改变响应式的灾害防控模式,可为铁路防灾监测系统的数字化转型及预测性主动防控升级提供重要的架构指导和技术支撑。

面向MBSE的飞行器多学科模型集成仿真技术研究

飞行器等复杂产品涉及的专业学科众多,学科建模软件各不相同,导致MBSE在实施过程中建立的系统架构模型难以驱动不同学科软件建立的多源异构模型,不能以仿真方式验证系统模型。针对上述问题,梳理了多学科模型的集成仿真方法的优缺点,并以无控火箭试验弹为例,提出采用FMI标准将各学科模型进行标准化封装,并在GCAir软件中进行集成和仿真验证,实现了多学科模型与系统仿真架构的一体化集成和仿真验证,解决了不同学科之间模型交互障碍,提高了复杂产品系统仿真验证效率。

MBSE在直升机航材支持场景建模中的应用

介绍了基于Rhapsody的直升机航材支持场景建模与开发的流程与方法;通过模型的方式建立用例图、活动图、顺序图和可用于执行验证的状态机来描述航材支持场景;指导直升机航材支持方案设计过程中的需求分析、功能分析和设计综合;探索MBSE方法在直升机运营保障领域的指导作用,为直升机用户航材支持提供初始建议。

基于WordCloud技术的MBSE发展态势研究

基于IEEE及国际系统工程协会(International Council on Systems Engineering,INCOSE)社区会刊,提取与基于模型的系统工程(model based systems engineering,MBSE)领域相关的167篇顶刊的关键词和摘要。采用Python及其第三方库WordCloud技术,以可视化形式展示MBSE领域研究内容并对MBSE发展态势进行研究。研究结果表明,MBSE在产品研发全生命周期,应用建模技术来支持系统需求、设计、分析、验证与确认等活动,在系统架构设计方面具有重要作用,将MBSE与安全性分析、可靠性分析方法结合也是MBSE的重要研究内容;系统建模语言(system modeling language,SysML)和对象过程方法(object process method,OPM)分别是目前MBSE研究领域中最受欢迎的建模语言和建模方法;将MBSE方法与本体进行结合是规范MBSE模型表达的重要手段,将MBSE与信息物理系统、数字孪生、并行工程领域进行融合研究是MBSE的重要发展方向。所提研究为使用WordCloud文本分析技术来探索当前的MBSE研究提供了技术路线参考,有助于对MBSE的未来发展态势进行预测。

X语言、方法及工具——支持MBSE的新一代一体化建模仿真技术体系

在当前基于模型的系统工程(MBSE)实践中,基于现有的建模语言、方法与工具,仍难以实现系统设计与仿真验证之间真正的闭环,因此无法完整体现MBSE的全部价值。针对这一问题,本研究较为系统地介绍了新一代建模仿真语言——X语言及其技术体系,具体包括混合系统建模框架——XDEVS,X语言架构及基本要素,X语言支持下基于建模仿真的系统工程方法论——X-SEM,以及面向X语言的建模仿真软件——XLab。基于X语言技术体系可以实现全系统统一建模和一体化仿真验证。最后用一个案例展示了基于X语言及其工具并遵循X-SEM方法论的系统开发过程。

MBSE在航空飞行控制系统的应用研究

现代飞机系统的复杂性不断增长,传统的开发方法在管理和维护方面变得越来越具有挑战性。首先,对航空飞控系统研发过程在当前系统工程实践方面进行了评估,阐述了传统开发方式的不足和基于模型的系统工程(MBSE)的核心原则和优点,以及在实现中常用的工具和方法;然后,展示了MBSE如何在飞行控制系统研发时使用模型来支持复杂系统的规范、设计、分析、验证和确认的过程;最后,结合先进的MBSE工具和方法的发展,MBSE结合敏捷的开发前景,以及提高MBSE实践的互操作性和标准化的需求对未来的研究方向进行了展望。本文研究为利用MBSE方法论和工具来改进飞行控制系统的设计、开发和性能感兴趣的航空工业专业人员、系统工程师提供资源和解决思路。

基于MBSE的卫星互联网仿真平台架构建模

针对传统基于文档的系统工程方法在高复杂度卫星互联网仿真平台开发中存在的系统设计协调性差及早期仿真验证不足等问题,提出采用基于模型的系统工程(model-based systems engineering,MBSE)方法开展卫星互联网仿真平台架构建模。首先,提出基于MBSE的双V模型(dual V model based on MBSE,DVMBSE)及与外部软件集成验证架构;然后,基于MBSE方法论对卫星互联网仿真平台顶层架构开展需求分析、功能分解及交互结构建模;最后,通过运行逻辑验证与外部模型集成验证实现了模型的有效性验证,从而支撑卫星互联网设计论证。

基于MBSE的空间引力波探测系统指标管理及其探测灵敏度分析

为了将空间引力波探测系统论证过程中顶层指标分解与系统级性能分析过程动态关联,提供对空间科学任务全生命周期信息的管理与应用分析能力,提出了基于模型的系统工程(MBSE)的空间引力波探测系统指标管理及其探测灵敏度分析方法。通过系统建模语言(SysML)构建空间引力波探测系统指标参数模型,并解析模型内容,筛选和记录指标参数,最后,通过探测灵敏度这一评价空间引力波探测系统探测能力的主要标准,实现空间引力波探测系统对不同科学目标的探测性能分析。结果表明,该方法可统一管理和追溯所有指标内容,为空间引力波探测系统顶层指标论证和系统级性能评价提供了支持。

MBSE在动车组转向架失稳检测系统架构设计中的应用

针对传统的动车组转向架失稳检测系统研制过程中出现设计数据追溯性差、模型复用性低、难以保证设计信息一致性,以及缺乏系统整体设计理念等一系列问题,将基于模型的系统工程(Modelbased system engineering,MBSE)应用于动车组转向架失稳检测系统的设计。在Arcadia建模方法的基础上,结合功能定义分析方法对动车组转向架失稳检测系统进行架构设计:通过运行分析、系统分析、逻辑架构分析和物理架构分析4个层次建立其失稳检测系统“黑盒”到“白盒”的架构模型;通过识别功能、表达功能和评估功能3个环节对功能进行定义分析,并借助状态机仿真方式验证最终架构的逻辑正确性。研究表明:在动车组转向架失稳检测系统架构设计过程中,采用基于模型的系统工程方法建立的模型具有可追溯性和可复用性,可以在设计早期对系统进行整体设计,降低决策风险,对动车组转向架的研发有着积极的推动作用。

基于MBSE的发动机DFMEA开发

本文介绍了DFMEA(Design Failure Mode and Effect Analysis,设计失效模式和效果分析)的概念、目前行业内发动机DFMEA的现状及发动机MBSE(Model Based System Engineering,基于模型的系统工程)。根据MBSE的思路将发动机分成4个层级,将层级划分引入FMEA流程,进行发动机DFMEA的开发,整个发动机DFMEA体系分成4个层级。以气门系统DFMEA为实例介绍了基于MBSE的DFMEA建模,根据气门系统的BLOCK图,完成气门系统模型化,在专业模型化工具中搭建气门系统模型。

基于MBSE的民机飞行控制系统架构设计

基于模型的系统工程(model-based systems engineering,MBSE)已被广泛应用于复杂系统设计之中。通过构建功能、行为和结构之间的关系,提出一种基于MBSE的多层级递进式架构设计流程。随后,以高度控制需求为导向,对民机飞行控制系统进行了示例化建模。结果表明,基于MBSE的民机飞行控制系统多层级递进式架构设计能够充分发挥数字模型可重用的优势,保证需求与功能、逻辑和物理架构的紧密结合,提高系统设计的可追溯性,可为后续领域层阶段模型设计提架构参考。

基于MBSE的鱼雷全电子安全系统安全性与任务可靠性分析

随着武器装备研究的深入推进,传统方法难以满足复杂系统安全性与可靠性分析的需求;为提升系统研发与评估效率,以形式化的系统建模语言分析鱼雷全电子安全系统的安全性、可靠性成为必然趋势;文章在传统安全性与可靠性分析的基础上,基于系统工程开展安全系统建模过程,以功能需求、系统架构、活动视图以及时序逻辑控制作为安全性与作用可靠性分析的构成元素,对系统功能模型进行故障传播建模;最后以安全建模语言构建事故树模型得出安全性与可靠性的影响因素,为引信系统的安全性与可靠性分析工作提供一定参考价值。

Biomimetic natural biomaterials for tissue engineering and regenerative medicine:new biosynthesis methods,recent advances,and emerging applications

Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative medicine.This paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future challenges.We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM.Moreover,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications.Finally,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.

Compositional and Hollow Engineering of Silicon Carbide/Carbon Microspheres as High-Performance Microwave Absorbing Materials with Good Environmental Tolerance

Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow Si C/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach-60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.

基于MBSE的卫星能源系统设计与验证

卫星的能源分系统设计和验证是卫星设计的关键环节。能源分系统具有高安全和高可靠的要求,其设计过程与卫星轨道、光照、工作模式等多重因素耦合,同时需要与机械、热、供电、控制等多学科关联设计。为快速、便捷、全面实现复杂系统的设计和仿真,提出基于模型的系统工程(model-based system engineering,MBSE)方法,通过模型实现能源分系统多耦合、多产品、高安全系统的显式一体化表达,围绕需求展开多个功能点和性能点的设计、验证与优化。结果表明,所提方法构建的设计验证一体能源设计模型可对系统需求做精细化分析,进而进行功能和结构设计,实现和优化系统性能指标设计,并完成对需求的闭环和验证,在工程中具有高效、明确的应用价值。

Defect engineering in transition-metal(Fe,Co,andNi)-based electrocatalysts for water splitting

Electrocatalytic water splitting seems to be an efficient strategy to deal with increasingly serious environmental problems and energy crises but still suffers from the lack of stable and efficient electrocatalysts.Designing practical electrocatalysts by introducing defect engineering,such as hybrid structure,surface vacancies,functional modification,and structural distortions,is proven to be a dependable solution for fabricating electrocatalysts with high catalytic activities,robust stability,and good practicability.This review is an overview of some relevant reports about the effects of defect engineering on the electrocatalytic water splitting performance of electrocatalysts.In detail,the types of defects,the preparation and characterization methods,and catalytic performances of electrocatalysts are presented,emphasizing the effects of the introduced defects on the electronic structures of electrocatalysts and the optimization of the intermediates'adsorption energy throughout the review.Finally,the existing challenges and personal perspectives of possible strategies for enhancing the catalytic performances of electrocatalysts are proposed.An in-depth understanding of the effects of defect engineering on the catalytic performance of electrocatalysts will light the way to design high-efficiency electrocatalysts for water splitting and other possible applications.

Interface Engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature

Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.

基于MBSE的铅冷快堆非能动余热排出系统设计需求分析

针对传统的铅冷快堆非能动余热排出系统设计中存在开发效率低、迭代周期长、模型二义性等前期需求问题,本研究将基于模型的系统工程(Model-based System Engineering,MBSE)方法应用于铅冷快堆非能动余热排出系统设计需求中,结合设计流程进行系统架构的初步设计,该系统架构由需求分析、功能分析和设计综合三部分组成。结果表明:需求分析阶段生成的需求图和用例图可捕获系统需求并确定系统顶层用例;功能分析阶段绘制的时序图、活动图和状态机图可形成系统功能模型并提供早期确认与验证;设计综合阶段建立的白盒模型最终实现系统架构的分析与设计。采用该方法设计的系统架构可确保前后设计需求一致性,进一步降低设计风险并提高设计效率,可为数字化铅冷快堆非能动余热排出系统设计与优化提供应用参考。