摘要：3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent *** the computational accuracy and efficiency,the optimal choices of numerical parameters and algorithms in FE modelling were *** formation mechanisms of cross-section distortion and springback were *** effects of pre-stretching,post-stretching,friction,and the addition of internal fillers on forming quality were *** results show that the stress state of profile in stretch-bending is uniaxial with only a circumferential *** stress distribution along the length direction of profile is non-uniform and the maximum tensile stress is located at a certain distance away from the center of *** aluminum profile is gradually attached to bending die,the distribution characteristic of cross-section distortion along the length direction of profile changes from V-shape to *** unloading the forming tools,cross-section distortion decreases obviously due to the stress relaxation,with a maximum distortion difference of 13%before and after *** pre-stretching and post-stretching forces increase,cross-section distortion increases gradually,while springback first decreases and then remains *** increasing friction between bending die and profile,cross-section distortion slightly decreases,while springback ***-section distortion decreases by 83%with adding PVC fillers into the cavities of profile,while springback increases by 192.2%.

摘要：Electrocatalysis is key to improving energy efficiency,reducing carbon emissions,and providing a sustainable way of meeting global energy ***,elucidating electrochemical reaction mechanisms at the electrolyte/electrode interfaces is essential for developing advanced renewable energy ***,the direct probing of real-time interfacial changes,i.e.,the surface intermediates,chemical environment,and electronic structure,under operating conditions is challenging and necessitates the use of in situ ***,we present a new lab-based instrument commissioned to perform in situ chemical analysis at liquid/solid interfaces using ambient pressure X-ray photoelectron spectroscopy(APXPS).This setup takes advantage of a chromium source of tender X-rays and is designed to study liquid/solid interfaces by the“dip and pull”*** of the main components was carefully described,and the results of performance tests are *** a three-electrode setup,the system can probe the intermediate species and potential shifts across the liquid electrolyte/solid electrode *** addition,we demonstrate how this system allows the study of interfacial changes at gas/solid interfaces using a case study:a sodium–oxygen model ***,the use of APXPS in electrochemical studies is still in the early stages,so we summarize the current challenges and some developmental *** the challenges,we expect that joint efforts to improve instruments and the electrochemical setup will enable us to obtain a better understanding of the composition–reactivity relationship at electrochemical interfaces under realistic reaction conditions.

摘要：从单体系统迁移到微服务系统是当前业界对遗留系统实施再工程化的主流选项之一,基于单体遗留系统的微服务体系架构重构则是实现该迁移的关键步骤.目前学界多集中在微服务识别方法的研究上;业界虽有许多面向微服务架构的遗留系统重构的实践,但缺乏系统性的方法及高效鲁棒的工具.鉴于此,在微服务识别与模型驱动开发方法前期研究的基础上,研发一种模型驱动的、可用于单体遗留系统微服务化重构的集成设计平台MSA-Lab.它通过分析单体遗留系统运行日志中的方法调用序列,对其中的类和数据表进行类型识别和聚类以构造抽象微服务,同时生成包括微服务图和微服务序列图在内的系统架构设计模型.它包括用于微服务自动识别与设计模型自动生成的核心部件MSA-Generator,以及用于微服务静态结构模型与动态行为模型可视化展现、交互式建模、模型语法约束检验的核心部件MSA-Modeller.在MSA-Lab平台上,通过对4个开源项目实施有效性、鲁棒性、功能转换完备性等实验以及对3个同类型工具实施性能对比实验,结果表明:所提平台拥有很好的有效性、鲁棒性及实现面向日志的功能转换完备性,且性能更加优越.

摘要：With the ever-pressing issues of global energy demand and environmental pollution,molecular hydrogen has been receiving increasing attention as a clean alternative energy *** hydrogen production,the design and development of high-performance catalysts remains rather *** the compositions and structures of catalyst interfaces have paramount influences on the catalytic performances,the central topic here has always been to design and engineer the interface structures via rational routes so as to boost the activities and stabilities of electrocatalysts on hydrogen evolution reaction(HER).Here in this review,we focus on the design and preparation of multi-scale catalysts specifically catering to HER *** start from the design and structure-activity relationship of catalytic nanostructures,summarize the research progresses related to HER nanocatalysts,and interpret their high activities from the atomistic perspective;then,we review the studies regarding the design,preparation,HER applications and structure-activity relationship of single-atom site catalysts(SASCs),and thereupon discuss the future directions in designing HER-oriented *** the end of this review,we present an outlook on the development trends and faced challenges of catalysts for electrochemical HER.

摘要：本文为揭示喷淋水膜对固体表面的红外辐射抑制机理并建立准确的红外辐射计算方法,开展了水膜对固体表面红外辐射影响规律的理论和实验研究,表明在8~12μm波段,水膜厚度大于100μm时,覆盖水膜固体表面的红外辐射特征主要取决于水膜的红外辐射。建立了覆盖水膜固体表面的红外辐射传输模型,对文献中常用计算方法的结果精度进行了分析。采用水膜自由表面温度计算红外辐射误差小于0.3%,而采用固体表面温度计算红外辐射最大误差达8.32%。

摘要：针对传统郁闭果园内部空间狭窄密闭,现有割草机难以进入作业,面临无机可用的生产难题,设计了一种适用于郁闭果园环境、割茬高度可调且株间避障灵活便捷的小型图传遥控式割草机。在分析郁闭果园种植模式和割草农艺要求的基础上,确定了割草机的总体设计方案,然后对割草机关键部件(刀盘高度调节机构、株间避障切割机构、遥控及图传系统等)进行了设计与匹配选型,最后完成了整机集成与性能试验。基本性能试验结果表明:割草机整机尺寸(长×宽×高)为1.9 m×1.7 m×0.7 m,割茬高度调节范围为30~110 mm,株间避障通过率为100%,遥控和图传距离均大于110 m。同时以前进速度、刀盘转速和割茬高度为试验因素,割茬稳定系数、割幅利用率和漏割率为试验性能指标开展正交试验,并对试验结果进行显著性分析。结果表明,各因素对割茬稳定系数、割幅利用率和漏割率性能指标影响的主次顺序均为前进速度、刀盘转速和割茬高度;确定的较优方案为前进速度0.6 m/s、刀盘转速3000 r/min、割茬高度70 mm,并对该较优方案进行了验证试验,结果表明:设计的新型割草机在该方案下割茬稳定系数为93.2%,割幅利用率为99.3%,漏割率为0.5%,能满足郁闭果园实际作业要求。

摘要：跨学科作业设计对减轻学生过重作业负担、丰富作业设计类型、走出学科藩篱以及打破学科界限具有重要的意义。然而,关于如何开展小学跨学科作业设计的研究仍相对缺乏。基于相关政策、理论与实践,从目标、内容、实施、评价四个维度阐释小学跨学科作业设计:目标聚焦核心主题,彰显情境化;内容突出作业本质,实现串联化;实施基于学生生活,体现实践化;评价立足素养导向,力求多样化。由此构建小学跨学科作业设计体系,提炼出四个阶段:作业目标设定阶段、学科内容整合阶段、作业实施设计阶段、作业评价审视阶段。

摘要：多光谱辐射测温技术具有不干扰被测场、测量无上限以及响应速度快等优点,是高温测量领域的最有力工具之一。目前,多光谱高温计以点温测量为主,光路通过物镜、光阑、棱镜等光路通道将待测点辐射分光后进入探测器阵列,实现单点的多光谱信息采集。随着工业智能化程度的不断提高,更加需要实时获得大量的温度分布信息,如特种金属材料的冶炼过程、高温合金激光自动焊接过程、半导体晶体生长过程、火箭发动机尾喷焰温度诊断等领域都需要实时获得某条线乃至整个二维表面的温度,从而提高产品性能和质量,因此通过多光谱辐射测温技术测量待测表面某条线的温度分布十分重要。但是,简单将光阑变为狭缝,实现待测线表面的辐射经透镜、棱镜等传统光路分光后,由于光学系统球差的作用,会使得分光后的狭缝光谱由于离轴传输而呈现严重的弯曲现象,不利于矩形光电探测器阵列的完全接收。为此,提出基于正交柱状透镜组的多光谱线温光路系统,利用正交柱状透镜在不同位置成像可以实现由圆到椭圆再到直线的特殊作用,较好地解决了传统多光谱辐射高温计光路所存在的球差问题。利用ZEMAX光学设计软件,基于S4111-16Q的光电探测器阵列实际大小进行反向光学系统设计,确定了狭缝、物镜、棱镜、正交柱状透镜等光学器件关键的参数,基于这些参数所实际加工的光学器件,搭建了多光谱线温高温计光学系统,并进行了无正交柱状透镜和有正交柱状透镜成像情况下的对比实验,结果表明,在没有柱状透镜的情况下,狭缝成像明显弯曲,在加入正交柱状透镜的情况下,狭缝成像弯曲现象消失,经狭缝分光后的线光谱明显呈直线状态,这为整条线的光谱辐射信息完整进入各探测器阵列提供了技术支撑,从而为后续线温测量提供了有力的光谱辐射数据信息。

摘要：为了给航空动平台激光通信的附面层效应校正系统提供验证条件,设计了一种基于液晶空间光调制器来模拟附面层效应的模拟器。首先,从几何光学的角度分析附面层效应,将其等效为负透镜。然后,利用计算机对不同飞行条件下附面层效应与等效负透镜焦距之间的关系进行数值分析仿真。之后在液晶空间光调制器上导入不同焦距透镜的相位灰度图以实现变焦透镜的功能,通过改变变焦透镜的焦距来模拟航空平台不同飞行条件下的附面层效应。最后通过实验验证模拟的准确性,在环境温度下,模拟附面层效应的液晶空间光调制器得到的光斑图像由红外相机拍摄,之后进行图像处理分析实际光斑大小,并与理论计算光斑大小比较,得出误差曲线图。研究结果显示,基于液晶空间光调制器模拟附面层效应引起散斑效应的理论光斑大小与实际光斑大小的均方根误差为0.04375,验证了所提出的方法的可行性和有效性。

摘要：海底钻机是一种钻探系统完全工作于海底的钻探设备,与搭载船只需要一条具有承载能力的脐带缆即可实现远程的能量供应和通讯控制。受脐带缆承载能力的限制,有限空间、重量内存储更多钻管及可靠、快速的接卸是大钻深海底钻机设计的难点。以60 m海底钻机移摆管系统为研究对象,介绍了移摆管系统的构成、技术指标和特点,对移摆管系统中机械手回转机构进行了受力分析,推导出了海水阻力矩的方程。利用AMESim建立了机械手回转控制系统仿真模型,分析了输入的线性控制信号的斜率、海水阻力矩等因素对机械手回转机构控制性能的影响。仿真结果表明:海水阻力矩对械手回转机构动作的瞬间影响较大,输入的线性控制信号的斜率较大时,会引起机械手回转角度振荡。通过对60 m海底钻机移摆管系统开展室内及海上试验,验证了该系统能够满足60 m海底钻机钻杆接卸及存储的要求。