The design and engineering strategies of metal tellurides for advanced metal-ion batteries

Owning various crystal structures and high theoretical capacity,metal tellurides are emerging as promising electrode materials for high-performance metal-ion batteries(MBs).Since metal telluride-based MBs are quite new,fundamental issues raise regarding the energy storage mechanism and other aspects affecting electrochemical performance.Severe volume expansion,low intrinsic conductivity and slow ion diffusion kinetics jeopardize the performance of metal tellurides,so that rational design and engineering are crucial to circumvent these disadvantages.Herein,this review provides an in-depth discussion of recent investigations and progresses of metal tellurides,beginning with a critical discussion on the energy storage mechanisms of metal tellurides in various MBs.In the following,recent design and engineering strategies of metal tellurides,including morphology engineering,compositing,defect engineering and heterostructure construction,for high-performance MBs are summarized.The primary focus is to present a comprehensive understanding of the structural evolution based on the mechanism and corresponding effects of dimension control,composition,electron configuration and structural complexity on the electrochemical performance.In closing,outlooks and prospects for future development of metal tellurides are proposed.This work also highlights the promising directions of design and engineering strategies of metal tellurides with high performance and low cost.

Constitutive modeling for mechanical behaviors of geomaterials, newdesigns and techniques in geotechnical engineering

This Special Issue of the Journal of Rock Mechanics and GeotechnicalEngineering （JRMGE） contains 13 papers prepared by internationalexperts on various general topics in geomechanics, rockmechanics and geotechnical engineering. It represents a usefulmix of theoretical developments, testing and practical applications.We present in the following brief details in the papers, alphabeticallyin accordance with the last name of the first author.Barla presents a review of tunneling techniques with emphasison the full-face method combining full-face excavation and facereinforcement by means of fiber-glass elements with a yieldcontrolsupport. This method has been used successfully in difficultgeologic conditions, and for a wide spectrum of ground situations.The validation of the method with respect to the Saint Martin LaPorte access adit along the LyoneTurin Base tunnel experiencingseverely squeezing conditions during excavation is also includedin the paper. The numerical modeling with consideration of therock mass time-dependent behavior showed a satisfactory agreementwith monitoring results.

Application of Parametric Design to Mechanical Engineering

The definition and functions of parametric design were introduced. According to the practical condition of mechanical engineering design, the necessity and feasibility of parametric design for complex mechanical engineering design was analyzed. The related key technologies and methods were also discussed by a project example based on Inventor platform.

Materials Design of Microstructure in Grain Boundary and Second Phase Particles

A concept of microstructure design for materials or materials microstructure engineering is proposed. The argument was suggested based on literature review and. some our new research work on second phase strengthening mechanisms and mechanical property modeling of a particulate reinforced metal matrix composite. Due to development of computer technology, it is possible now for us to establish the relationship between microstructures and properties systematically and quantitatively by analytical and numerical modeling in the research scope of computerization materials. Discussions and examples on intellectual optimization of microstructure are presented on two aspects: grain boundary engineering and optimal geometry of particulate reinforcements in two-phase materials.

Design methodology for the safety of underground rock engineering

In order to optimise the safety of underground rock engineering construction and the long-term security of the resultant facilities, it is necessary to have a knowledge of the likely hazards. These risks or hazards fall into the four categories of 'known beforehand and relatively easily addressed', 'known beforehand and not easily addressed', 'not known beforehand and relatively easily addressed', and 'not known beforehand and not easily addressed'. This paper describes how these four types of hazard can be incorporated into a design methodology approach, including the process by which the relevant mechanical rock mass parameters can be recognised for modelling and hence predictive purposes. In particular, there is emphasis on the fact that information and judgement are the keys to safety——whether the hazards are known or unknown before construction proceeds.

An Analysis of the Kinetic Features of Scissor Elevator Mechanism and Its Optimized Design

A mathematical model has been established for the research on scissor elevator for ship passenger stairs.The kinematical and kinetic simulation analyses were carried out with MATLAB/Simulink.The relative kinetic relation between hydraulic cylinder and other parts,as well as its rules of change has been found.A 3-D model of ship scissor elevator was established with Pro/E.The design of the mechanism was optimized in Pro/MECHANICA based on the findings from simulation analysis.Practice has proved that the design is scientific and reasonable and could serve as the theoretical guidance and reference for the design of scissor mechanism of other uses.

Mechanism for Integrating Sustainability in Engineering Design

This paper proposes an integration mechanism to help the owners and designers to integrate sustainability issues into design process, communicate with stakeholders and achieve consensus. Literature concerning engineering design, decision making and environment assessment were reviewed. Sustainability disputes in construction projects were analyzed and owners and designers were interviewed to understand the evolvement of these issues. Key success factors of other successful integration projects were also referenced. An integration mechanism including procedures was established along with traditional design process. Four integration steps were developed： organize integration team, propose integration issues, determine acceptance criteria, and evaluate alternatives; and four integration dimensions were also identified： appeals, decision making and execution, stakeholders, and experts. A matrix was formed by the four integration steps and four dimensions. A rigor index was proposed to measure the quality of the integration process. Finally, the mechanism was tested on a construction project with sustainability controversy to check its validity. The study results show that the integration mechanism can help incorporate sustainability issues and achieve consensus if followed rigorously. The integration matrix systematically examines the eight key integration factors under the four dimensions. The rigor index can explain the quality in integrating sustainability issues into engineering design. The mechanism provides a useful tool for the owners and designers to cope with the sustainability decision making difficulties.

The Principle of Square Hole Machining and It＇s Tooling Structure Design

In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and process with computer graphics parameters design. The results that, as long as the appropriate parameters, using the above method not only can punch the square hole, can also be processed triangle, the five angle and hexagonal regular polygon holes. The square hole processing method can provide theoretical basis and engineering reliable reference for related engineering and technical personnel.

考虑锚杆预应力作用下隧道围岩力学分析及参数设计

隧道工程中锚杆设计多依靠经验法和类比法,为研究预应力锚杆支护体系下围岩的力学效应,建立预应力锚杆与围岩力学耦合模型,考虑围岩开挖损伤效应,通过弹塑性力学理论推导出隧道开挖后围岩应力分布及径向位移解析表达式,采用有限差分软件FLAC3D进行算例验证并分析预应力锚杆参数对围岩状态的影响。研究结果表明:理论解析和数值模拟中最大切向应力和围岩塑性区半径分别为4.77 MPa、15 m和4.49 MPa、15.86 m,理论解析与数值模拟所计算隧道围岩应力分布、位移基本一致,在Ⅳ、Ⅴ级围岩地层中验证了理论解析解的合理性;随着预紧力增大,处于塑性区的围岩径向位移及塑性区半径逐渐减小,弹性区基本不受影响;当锚杆自由段长度位于塑性区时,随着锚杆长度增加,围岩塑性区径向位移及塑性区半径逐渐减小。在实际工程中应尽量增大锚杆预紧力,锚杆长度增加对围岩位移以及塑性区的发展控制效果有限,应控制锚杆自由段长度在塑性区内。

深层、超深层定向钻井中若干基础研究进展与展望

深层、超深层定向钻井具有“垂深大与水平延伸远”的双重特征,受到复杂地层、高温高压、超长裸眼等多重因素约束,其安全高效作业面临着更大的全方位技术挑战。为此,着眼于深层、超深层定向钻井的提速提效问题,系统总结了定向钻井的发展概况与技术特点,选取了深层、超深层定向钻井中力学方面的几个重要基础问题,分析了国内外专家学者的相关研究进展和最新研究成果,最后展望了深层、超深层定向钻井基础理论研究发展趋势并提出相关建议。研究结果表明:①大小偏差融合控制算法兼顾了井眼轨迹的控制精度、光滑度等多目标约束,适应于深层、超深层条件下井眼轨迹实时控制要求;②合理优化振动减阻工具个数、安放位置及其激励力幅值,可显著降低井下管柱摩阻,并有效提高机械钻速;③基于误差补偿机制的机械钻速融合预测模型既保留了机理模型的可解释性,又具有较高的预测精度;④套管复合磨损预测模型突破了经典“单月牙”模式的局限性,实现了复合模式下套管磨损形状与深度的同步预测。结论认为,深层、超深层定向井和水平井是未来油气井工程的重要发展方向之一,需要加强多因素耦合机理、钻井延伸极限、机理与数据融合驱动等方面的基础研究,以推动复杂油气井工程基础理论的创新与发展,为深层、超深层钻井工程技术进步提供必要的基础理论支撑。

求解多维复杂函数及真实世界工程设计问题的高效海洋捕食者算法

针对海洋捕食者算法在面对复杂函数和工程设计优化问题时存在的自适应能力有限、寻优精度有时较低、局部桎梏概率较高等缺点,提出一种新的高效自适应海洋捕食者算法.首先在海洋记忆存储阶段引入学习自动机引导的教与学搜索机制,更好地平衡算法在不同迭代时期对探索和挖掘能力的不同需求;然后在局部开发阶段,引入对数螺旋探索机制,加强算法在最优解附近的精细挖掘能力,进一步提高收敛精度;最后在算法中每次迭代末尾处加入改进的自适应相对反射策略,提升种群跳出局部最优的能力,降低局部桎梏概率.为了分析和验证该改进算法的性能,将其和6种代表性算法在进化计算大会(CEC)2017测试套件上进行100维的函数极值测试,并在4个具有挑战性的工程设计优化问题上进行测试.测试结果表明在求解多维复杂函数和工程设计优化问题时,本文改进算法的寻优精度、收敛性能和求解稳定性明显优于其他6种代表性算法,尤其在高维复杂函数下,其寻优性能的优越性更为显著.

基于工程经济性的公路悬索桥主缆最优垂跨比研究

为寻求工程经济性最优的公路悬索桥主缆垂跨比,以我国近年多座采用混凝土桥塔的单跨公路悬索桥为背景,建立主缆、锚碇、桥塔基础工程量的直接函数模型和桥塔塔身工程量的非线性函数拟合模型,对跨度750~2250 m、单层车道数4~8及双层车道数6+4、垂跨比1/14~1/6共952种布置形式的悬索桥进行大范围关于主缆垂跨比的工程经济性研究,并以2座实桥为算例分析主缆垂跨比对悬索桥静、动力性能及抗风性能的影响。结果表明:主缆垂跨比对悬索桥工程经济性影响显著;悬索桥主缆最优垂跨比与跨度相关,而车道数、加劲梁荷载集度的影响相对较小,涉水和不涉水的差异也不显著;基于工程经济性考虑,跨度750~2250 m的悬索桥主缆最优垂跨比为1/6.5~1/8.5,比经验值增大较多。2座实桥算例分析表明随着垂跨比增加,加劲梁挠度和活载应力有所增加,抗风性能略有提升,建议方案设计阶段加大垂跨比研究范围、对工程经济性和桥梁力学性能进行综合比选。

以工程案例驱动材料力学双语教学的探索与实践

该文针对机械类专业基础课程材料力学的特点,结合教学实践,从教学内容、教学设计、教学实施、思政融入几方面,探讨如何进行材料力学课程教学的改革,特别是通过全过程工程案例驱动材料力学教学的教学设计,使得课程学习目标明确,提高学生的学习兴趣,达到不断提升教学质量的目的,使得学生在掌握构件强度、刚度以及稳定性的计算与分析方法、培养解决工程复杂问题能力的同时,树立辩证与多视角思维的科学发展观,以促进人才培养能力全面提升。

关于医院建筑机电工程创新的思考

现今医院建筑机电工程模式与当今快速发展的时代背景不协调,妨碍了机电工程实现功能需求和“双碳”目标的要求,需要创新。分析了现今医院建筑机电工程模式的弊病;提出了在完成机电系统综合的基础上,与建筑工程剥离,作为完整独立的工程项目单独实施,在整个过程中以运维作引导,充分发挥设计龙头作用;基于医院建筑电气化、电力需求响应,探讨了医院建筑机电工程实现功能目标且经济低碳的运维策略;最后指出医院建筑机电工程创新的直接受益者和主导者是医院。

课程思政在三维机械设计课程教学中的实践与认识

立德树人、思政先行,开展课程思政建设是专任教师的重要任务。从提高学生思想道德素质、培养学生创新能力和实践能力等方面,分析了课程思政在三维机械设计课程教学中的重要性和必要性。通过设计项目、创新设计竞赛和实践课程的应用,列举了在三维机械设计课程教学中引入课程思政的实践案例。从教师引导与学生自主、理论与实践相结合、团队合作与交流分享等方面,针对思政教学过程中的教学方法和策略给出了若干建议。期望通过对课程思政在三维机械设计课程教学中的实践与认识进行探讨,为相关科目教学中的课程思政建设提供指导和支持。

工程流体力学叙事型课堂设计及实施研究

鉴于新工科对高等教育的要求,结合注意力经济时代学生难以被课堂吸引的现状,提出了基于三幕式叙事模式的课堂设计思路,从时长分配、内容安排和注意力抓取3个方面,探究了工程流体力学课程的宏观课程编排和具体课堂设计改进思路,并以伯努利方程章节为例,给出了叙事型课堂具体的实施流程,激发学生课上课下自主学习的兴趣,提高学生的创新动力和解决实际工程问题的能力。

新工科背景下融入TRIZ的大学生机械创新设计实训路径

在新工科背景下,培养学生面向工程问题的创新设计能力是机械专业人才培养的关键。文中以“CDIO(Conceive-Design-Implement-Operate)创新设计”项目式实践课程为依托,将TRIZ(Theroy of Inventive Problem Solvling)创新方法和设计流程引入到大学生机械创新设计实训教学环节中。学生通过对TRIZ理论的基本原理和设计流程的学习,以具体项目为依托,运用TRIZ理论开展项目问题分析,解决设计过程中存在的技术冲突与矛盾问题,使学生在创新设计过程中有章可循,为本科生机械创新设计能力的提升提供借鉴思路。

基于生态设计原则与生命周期评估的可持续性机械设计

面对全球可持续发展的挑战机械设计需转型以降低环境影响并提升资源效率。探讨生态设计原则与生命周期评估(LCA)在实现设计可持续性中的应用。首先强调在设计初期考虑材料选择、能源效率和系统整合等生态原则的重要性。接着,通过LCA工具量化从原材料到废弃各阶段的环境影响,案例分析展示如何根据LCA结果优化设计。最后讨论实施中的挑战与对策,工程领域的可持续性设计提供策略和参考。

基于眼动生理测量的高原工程机械显示交互认知负荷研究

目的探究工程机械驾驶员在平原和高原地区进行显示交互操作的认知负荷,并基于认知负荷对工程机械显示交互装置的不同功能模块进行评价,提出改进建议。方法设计并实施作业地区(高原和平原)×任务类型(4种功能模块)双因子混合实验,15名平原驾驶员和12名高原驾驶员分别在平原和高原工地进行了实车实验,采用眼动仪测量指标为注视点持续时间、瞳孔直径、瞳孔直径变化率及操作完成时间。结果方差分析的结果表明,作业地区和任务类型均会对眼动指标和操作时间产生显著性影响。高原的总操作时间为235.77±81.14 s,平原为170.62±28.72 s,平原与高原的瞳孔直径差值为-0.198(P<0.05),瞳孔直径变化率差值为-0.010(P<0.05)。结论高原环境会增加工程机械驾驶员进行显示交互操作的认知负荷。装载机显示屏的电机和电池模块的认知负荷较高,且在高原环境中这一影响更为显著,对此提出了通过简化、抽象化设计等方式进行改进的建议。

基于实践人才培养的“5E”+OBE教学模式探讨

针对机械设计基础课程的教学痛点,提出“学生中心,应用导向,产教融合,持续创新”的教学思路,在“教学内容模块化,教学过程项目化,教学目标实践化”的CDIO(构思、设计、实现、运作)工程教育模式基础上,融入“5E”+OBE的教学模式,以具体案例为切入点,将理论知识与实际应用有机融合,引导学生自主思考,旨在培养应用型科学技术人才。