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：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：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：随着计算机技术的迅速发展,数值模拟已成为帆船帆翼空气动力性能研究的重要工具。利用数值模拟,可实现在较短的时间以内完成多种设计方案的模拟计算,得到帆翼升力、阻力系数等空气动力学特性,为帆船比赛过程中运动员调帆提供技术指导。通过讨论5种湍流模型(S-A模型、standard模型、RNG模型、Realizable模型、SST模型)对于帆翼空气动力性能计算结果的影响,根据与试验结果比较分析,确定了帆翼数值模拟采用Realizable模型。研究结果为下一步数值模拟帆船帆翼空气动力性能打下了基础。

摘要：通过对国内有关水上运动项目器材流体动力性能研究方法、现状和取得成果的综述,为我国的体育流体动力性能研究的发展提供借鉴。水上运动项目器材流体动力性能研究主要方法是试验研究和数值模拟。我国的水上运动器材的流体动力性能研究起步较早,主要涉及到帆船、帆板、风帆的空气动力特性和船体水动力性能,赛艇、皮划艇桨叶推进特性,蹼泳板的推进性能等等。这些研究为设计高性能体育器材奠定了理论基础,其研究结果为运动训练的科学化水平的提高提供了依据。

摘要：应用计算流体力学方法优化F1赛车外形设计以改善其空气动力学特性。结果表明,应用计算流体力学方法可实现在很短的时间内完成多种设计方案的模拟计算,得到赛车外形与气动阻力系数等空气动力学特性的定量关系,还可以进行F1赛车的操纵稳定性,空气噪声,排、进气道等研究。

摘要：Diamond, as the hardest known material, has been widely used in industrial applications as abrasives, coatings, and cutting and polishing tools, but it is restricted by several shortcomings, e.g., its low thermal and chemical stability. Considerable efforts have been devoted to designing or synthesizing the diamond-like B-C-N-O compounds, which exhibit excellent mechanical property. In this paper, we review the recent theoretical design of diamond-like superhard structures at high pressure. In particular, the recently designed high symmetric phase of low-energy cubic BC3 meets the experimental observation, and clarifies the actual existence of cubic symmetric phase for the compounds formed by B-C-N-O system,besides the classical example of cubic boron nitride.

摘要：自行车除了载人还能做什么？代旭彪认为它可以作为分众传媒而具有广告价值。那么自行车与互联网结合在一起又能做什么？

摘要：利用磁控溅射法制备了TiC/α-C∶H纳米复合涂层尺寸效应,并对涂层择优取向的影响进行了研究。通过改变涂层中的C含量来调节晶粒尺寸,发现晶粒尺寸对晶粒的择优取向有着重要影响。随着晶粒尺寸减小,TiC的择优取向从面心立方(111)向(200)转变。这种择优取向的尺寸依赖效应可以用热力学来解释。通过计算与尺寸相关的吉布斯自由能解释了尺寸效应与涂层择优取向的关系。

摘要：自去年天下互联CEO张向宁宣称“‘窄告’启动互联网广告新纪元”后,随着窄告联盟的成立及众多合作者的加入,窄告顿时风生水起,成为2004年最亮的明星。一年后,时至今日,虽然业内人士对窄告极为推崇,但基于种种原因,更多的网民对窄告似乎还没有一个清晰的认识,一些人对其目前发展的情况仍存在质疑,基于此,我们不妨对窄告做一次细细的解读。