摘要：Ge2 Sb2 Te5 is the most widely utilized chalcogenide phase-change material for non-volatile photonic applications,which undergoes amorphous-cubic and cubic-hexagonal phase transition under external ***,the cubic-hexagonal optical contrast is negligible,only the amorphous-cubic phase transition of Ge_(2)Sb_(2)Te_(5) is *** limits the optical switching states of traditional active displays and absorbers to *** find that increasing structural disorder difference of cubic-hexagonal can increase optical contrast close to the level of ***,an amorphous-cubichexagonal phase transition with high optical contrast is *** this phase transition,we have developed display and absorber with three distinct switching states,improving the switching performance by 50%.Through the combination of first-principle calculations and experiments,we reveal that the key to increasing structural disorder difference of amorphous,cubic and hexagonal phases is to introduce small interstitial impurities(like N)in Ge2 Sb2 Te5,rather than large substitutional impurities(like Ag)previously *** is explained by the formation energy and lattice *** on the impurity atomic radius,interstitial site radius and formation energy,C and B are also potential suitable *** addition,introducing interstitial impurities into phase-change materials with van der Waals gaps in stable phase such as GeSb_(4) Te_(7),GeSb_(2) Te_(4),Ge_(3)Sb_(2) Te_(6),Sb_(2)Te_(3) will produce high optical contrast amorphous-metastable-stable phase *** research not only reveals the important role of interstitial impurities in increasing the optical contrast between metastable-stable phases,but also proposes varieties of candidate matrices and *** provides new phase-change materials and design methods for non-volatile optical devices with multi-switching states.

摘要：Scientific research is currently more *** have parsed the surface structure of virus,constructed the interaction model of virus-receptors,offering the clues for studying efficient targeted ***,catalysis is also highly relevant to modern human *** the surface structure and physicochemical properties of catalysts is of great significance for the design of efficient *** progresses have been made for endowing specific physicochemical properties of catalysts through controlling the size of materials and coordination chemistry of active sites,particularly at nanometer scale since Sir John Meurig Thomas and Tao Zhang’s early ground-breaking contribution,with casting on a very surface ***,functional regulation renders the emerging MXene quantum dots(MQDs)excel in contrast to the typical carbon-based quantum *** fact,similar to the interaction of virus-receptors model,the surface functional groups decorated MQDs provide a mini-lab to afford a variety of adjustments,involved with the type modification and electronic structure tuning of groups as well as their arrangement,together with the interaction between the groups and active materials/support,ultimately for packaging or designing high-activity catalysts.

摘要：Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel cell(PEMFC),already commercialized by automobile *** mass popularization,however,three major criteria must be balanced:performance,durability and *** electrocatalysts used in both the anode and cathode are the kernel of PEMFCs,being essential for efficient *** in the firing‐line is the oxygen reduction reaction(ORR)at the cathode,which is normally very sluggish:over six orders of magnitude slower than the anode hydrogen oxidation reaction(HOR)[1].Thus,considerable efforts have been made to improve the cathode *** the main active sites is key to the design of optimum materials for enhanced *** the complex balance of preparation,performance and cost,the active sites of metal‐nitrogen‐carbon(M‐N‐C)catalysts are particularly *** with the single metal atom(SMA)catalysts[2–5],two excellent M‐N‐C catalysts were recently reported[6,7].New insights were thereby gained into the delicate architecture of carbon‐based SMA catalysts for ORR.

摘要：Nanoporous metals show promising performances in electrochemical *** this paper,we report a self-supporting bimetallic porous heterogeneous indium/copper structure synthesized with a eutectic gallium-indium(EGaIn)material on a copper *** nanoporous copper-indium heterostructure catalyst exhibits excellent performance in the reduction of carbon dioxide to *** ratio of H_(2)/CO is tunable from 0.47 to 2.0 by changing working *** catalyst is highly stable,showing 96%maintenance of the current density after a 70-h continuous *** functional theory calculations reveal that the indium/copper interface induces charge redistribution within the copper surface,leading to the formation of two distinct active sites,namely,Cu^(δ)and Cu0,and enabling a high-performance generation of CO and H_(2).This work provides a new strategy for obtaining self-supporting nanoporous metal electrode catalysts.

摘要：随着全球农业现代化进程的加快,以及物联网、人工智能等先进技术的发展,智慧农业已经成为现代农业发展的新趋势。基于精准感知、智能控制和远程管理的智慧农业系统能够显著提高农作物生产效率,降低资源消耗,促进农业绿色化发展。基于此,设计一个果园生产环境在线监测系统,借助STM32F407单片机、DHT11温湿度传感器模块、BH1750光强度传感器等实现数据监测功能,借助ESP-12F Wi-Fi模块实现通信功能,将数据传输到上位机,实现果园生产和环境数据的实时监测。

摘要：提出一种可产生无衍射贝塞尔光束的非球面透镜-贝塞尔透镜,该透镜由球面和非球面组成,呈旋转对称结构。利用光学设计软件ZEMAX通过光线追迹法对贝塞尔透镜进行设计,在设计和优化过程中,将出射光线与光轴的夹角作为边界条件,二次曲线参量和高次项系数作为变量。结果表明:利用标准二次曲线加上第一个高次项就可以得到比较理想的优化结果,设计的非球面贝塞尔透镜可以产生具有贝塞尔光束特性的无衍射光束。

摘要：首先通过论述"核心"的相关概念,并结合帆板项目特点以及讨论传统帆板力量训练方法的重点和弊端,阐明核心训练对于帆板项目的重要作用及意义。其次,根据帆板运动训练相关的理论知识,讨论了帆板运动员核心训练的相关器械,绘制了训练计划设计的流程图。最后,总结了帆板运动员核心训练的具体方案和注意事项,归纳了基本的训练思路,以期为当前该项运动员的力量训练和体能训练提供参考性建议。

摘要：从体育学、语言学、计算机科学等多学科维度,利用ABBYYreader、Edit Pad、ABBYYaligner、Winaline、Para Conc、Elan、Treetag以及Mysql等软件,通过设计规划、语料文本抽取、加工与检索等众多步骤实现多模态体育语料库的创建;基于此语料库,利用Mysql、Redis、Elastic Search、jquery、Mysql+Redis等软件实现结构化数据管理,数据缓存、数据查询、用户基本交互与数据展现以及数据缓存等功能,进而探讨了"翻译工作坊"教学与实训平台的设计构架,阐释了平台的语料制作、教学以及实训等多重功能以及实现流程,以期提升体育类文本的翻译技能和个人责任意识,改进新的教学方法和理念,寻求新的体育系统国际化人才培养模式,重构体育类语言服务专业人才培养方案,从而实现专业人才的职业化,为体育院校英语专业课程建设提供新思路.

摘要：目的:探明迎风阶段摇帆频率和幅度组合方案对帆翼推进性能的影响,为运动员在迎风起航、紧急避让及迎风航行等过程提供个性和科学的摇帆调控建议,助力运动员对帆翼的科学操控。方法:确定运动员摇帆特征并建立帆翼运动模型,采用URANS方法,调用SST k-ω湍流模型,求解迎风摇帆时帆翼空气流场气动力变化规律。基于力学分析建立帆翼推进性能评价方法,并研究攻角20°的帆翼在风速3 m/s迎风、频率0.67~2.00 Hz和幅度2°~10°组合工况下的帆翼推力系数和能耗系数。结果:摇帆频率为0.67~1.00 Hz时,推力系数和偏航力系数平均值随幅度增加而增大;摇帆频率为1.30~2.00 Hz时,推力系数和偏航力系数平均值均随幅度增加呈现先增大后减小的趋势,配合幅度8°摇帆可使推进性能最优;摇帆能耗系数随幅度和频率增加而增大,高频大幅摇帆能耗是低频大幅的25倍,是高频小幅的10倍。结论:为促进运动员帆翼推进性能的最优,低频摇帆应配合较大的幅度,而高频摇帆则需配合适宜幅度。

摘要：为探究静水压力对舰用BE40型橡胶隔振器的静刚度的影响,开展了常压空气和浅水条件下的静刚度试验并建立了橡胶隔振器在不同静水压下的静刚度预测模型。通过商用有限元软件建立橡胶隔振器有限元模型以及与试验对应的流体域,然后拟合橡胶材料静态拉伸试验数据,并选择最优橡胶材料超弹性模型,分别计算了常压空气和浅水条件下的静刚度,将计算结果和试验结果进行对比,吻合较好。最后研究了不同静水压对橡胶隔振器的静刚度的影响,结果表明:静水压力增大至0.5MPa时,橡胶隔振器的静刚度增加约24%,说明静水压力对橡胶隔振器的静刚度产生明显影响。该结果可为水下隔振装置的优化设计提供技术支撑。