摘要：A numerical procedure for hydrodynamic redesign of the conventional vaned diffuser into the low solidity vaned diffuser by means of a real-coded genetic algorithm with Boltzmann, Tournament and Roulette Wheel selection is presented. In the first part, an investigation on the relative efficiency of the different real-coded genetic algorithm is carried out on a typical mathematical test function. The real-coded genetic algorithm with Boltzmann selection shows the best optimization performance compared to the Tournament and Roulette Wheel selection. In the second part, an approach to redesign the vaned diffuser profile is introduced. Goal of the optimum design is to search the highest static pressure recovery coefficient and low solidity vaned diffuser. The result of the low solidity vaned diffuser optimum design confirms that the efficiency and optimization performance of the real-coded Boltzmann selection genetic algorithm outperforms the other selection methods. A comparison between the designed low solidity vaned diffuser and original vaned diffuser shows that the diffuser pump with the redesigned low solidity vaned diffuser has the higher static pressure recovery and improved total hydrodynamic performance. In addition, the smaller outlet diameter of designed vaned diffuser tends to a more compact size of diffuser pump compared to the original diffuser pump. The obtained results also demonstrate the real-coded Boltzmann selection genetic algorithm is a promising optimization algorithm for centrifugal pumps design.

摘要：Advanced energy storage technologies are widely needed to efficiently utilize renewable energies such as solar and wind energy and satisfy burgeoning clean energy needs while mitigating the environmental impact of fossil fuels[1–4].Aqueous organic redox flow batteries(AORFBs)have drawn substantial attention in this area because of their decoupled energy and power,excellent scalability,and use of highly structurally tunable organic redox active species[5].

摘要：Three-dimensional(3D)printing has attracted increasing research interest as an emerging manufacturing technology for devel-oping sophisticated and exquisite architecture through hierarchical *** has also been employed in various advanced industrial *** development of intelligent biomedical engineering has raised the requirements for 3D printing,such as flexible manufacturing processes and technologies,biocompatible constituents,and alternative ***,state-of-the-art 3D printing mainly involves inorganics or polymers and generally focuses on traditional industrial fields,thus severely limiting applications demanding biocompatibility and *** this regard,peptide architectonics,which are self-assembled by programmed amino acid sequences that can be flexibly functionalized,have shown promising potential as bioinspired inks for 3D ***,the combination of 3D printing and peptide self-assembly poten-tially opens up an alternative avenue of 3D bioprinting for diverse advanced ***,a small but innovative nation,has significantly contributed to 3D bioprinting in terms of scientific studies,marketization,and peptide architectonics,including modulations and applications,and ranks as a leading area in the 3D bioprinting *** review summarizes the recent progress in 3D bioprinting in Israel,focusing on scientific studies on printable components,soft devices,and tissue *** paper further delves into the manufacture of industrial products,such as artificial meats and bioinspired supramolecular architectures,and the mechanisms,physicochemical properties,and applications of peptide ***,Israel contributes significantly to the field of 3D bioprinting and should thus be appropriately recognized.

摘要：对高速边界层转捩与湍流的理解、建模与控制不但具有广泛的学术兴趣,而且对高速飞行器的设计与节能有至关重要的意义,因为转捩和湍流会急剧增加壁面摩阻和热流.根据Morkovin假设,高速流动具有一些与不可压缩流动本质上相似的特征,但另一方面,由于存在热力学过程、激波、高焓效应等多物理场耦合,与不可压缩流动也有显著区别.本文综述了高速边界层转捩与湍流的物理和建模方面的最新研究进展,其中较大部分内容为湍流研究.为了物理过程描述的完整性,我们首先简要综述了高速流动转捩,主要关注气动加热原理和推迟转捩的被动控制策略.随后,我们总结了近期在湍流平均流向速度和温度的标度率方面的一些令人鼓舞的发现,这些标度率能够用于构建一系列新颖的壁面模型以提高模式精度.此外,作为湍流建模的基础之一,我们还总结了湍流结构方面的研究,尤其关注边界层对数区含能运动的标度率与建模.另外,我们综述了各种用于预测壁湍流的线性模型.尽管湍流通常被认为是高度非线性的,这些线性模型在过去二十年的研究中取得了较大的成功.最后,我们对综述进行总结,并简要展望未来研究.

摘要：聚合物基固态电解质得益于其易加工性,最有希望应用于下一代固态锂金属电池.目前,聚合物基态电解质的离子电导率提升策略多为加入导锂陶瓷以构建离子传输通道,其提升程度有限.电场在锂离子输运过程中存在重要影响,目前研究中有关电场对锂离子传输的影响机制尚不明确.本文将兼具高离子电导率和高介电常数的铌酸锂嵌入聚偏氟乙烯基体中,设计了一种新型复合固态电解质.铌酸锂颗粒有效调节电解质内部电场结构,增强了离子输运方向电场强度,实现了离子电导率的大幅提升(7.39×10^(-4)S cm^(-1),25℃).该电解质匹配高镍正极和锂金属负极的固态电池可稳定循环1000次以上,容量保持率为72%.该研究为设计下一代固态锂电池用高离子电导复合固态电解质提供了新的策略.

摘要：Introduction The climax of the industrial revolution was marked by the rapid growth of industry,and advancement in technologies have further fueled this industrial expansion,leading to a surge in economic *** technologies have also increased the degree of destructive human inter-ference with the biosphere.

摘要：Commercially pure titanium and titanium alloys have been among the most commonly used materials for biomedical applications since the 1950 *** to the excellent mechanical tribological properties,corrosion resistance,biocompatibility,and antibacterial properties of titanium,it is getting much attention as a biomaterial for ***,titanium promotes osseointegration without any additional adhesives by physically bonding with the living bone at the implant *** properties are crucial for producing high-strength metallic alloys for biomedical *** alloys are manufactured into the three types ofα,β,andα+β.The scientific and clinical understanding of titanium and its potential applications,especially in the biomedical field,are still in the early *** review aims to establish a credible platform for the current and future roles of titanium in *** first explore the developmental history of ***,we review the recent advancement of the utility of titanium in diverse biomedical areas,its functional properties,mechanisms of biocompatibility,host tissue responses,and various relevant antimicrobial *** research will be directed toward advanced manufacturing technologies,such as powder-based additive manufacturing,electron beam melting and laser melting deposition,as well as analyzing the effects of alloying elements on the biocompatibility,corrosion resistance,and mechanical properties of ***,the role of titania nanotubes in regenerative medicine and nanomedicine applications,such as localized drug delivery system,immunomodulatory agents,antibacterial agents,and hemocompatibility,is investigated,and the paper concludes with the future outlook of titanium alloys as biomaterials.

摘要：探讨使用低功率等离子体炬生产钛合金金属粉末的可能性。设计一种氩气直流非转移电弧等离子体炬,并对其等离子体射流特性和导线温度进行数值分析。喷嘴附件内的最高射流速度为838~1178 m/s,不同气体流速下顶点处的射流速度为494~645 m/s。等离子体气体流速对有效等离子体射流长度无显著影响。利用等离子体射流的温度和速度随距离的变化,可通过数值分析预测等离子体射流的长度。所制备的粉末为球形,无卫星粉。总之,本研究开发并使用低功率等离子体炬成功生产了钛合金粉末。

摘要：本文对选择性激光熔化的17-4 PH不锈钢进行了参数化研究和表征。通过改变工艺参数包括激光功率和扫描速度以及扫描方式(设计参数)来研究试样的相对密度和显微硬度的变化。当使用中等能量密度和内外六角扫描方式时,试样的相对密和显微硬度最大;当使用低能量密度和交替带状扫描方式时,试样的相对密和显微硬度最小。在光学和扫描电子显微组织中,试样侧面有奥氏体、铁素体和小熔池。能量色散光谱分析表明,试样的化学成分变化导致相对密度和显微硬度发生变化。X射线衍射结果表明,中等能量密度试样的奥氏体相和铁素体峰强度最高。背散射电子衍射结果表明,随着能量密度的增加,奥氏体相增加,导致试样的显微硬度变化。相比于中等能密度试样,低能量密度试样易诱发更多的残余应力。采用不同能量密度得到的样品都具有较强的耐蚀性(0.05 mm/a),未出现明显的腐蚀裂纹。

摘要：折纸作为一种折纸艺术,几个世纪以来一直被艺术家们广泛探索.直到最近几十年,它才因其复杂的几何形状和丰富的力学性能而受到数学家和工程师的关注.以折纸为灵感的超材料的激增为材料和结构的设计打开了一扇新的窗口.通常,会根据标有合规机制的折痕线折叠一张材料来构建折纸结构.尽管它们在折纸制造中很重要,但在折纸超材料的设置中,这种合规机制尚未得到探索.本研究探讨了合规机制设计参数与折纸力学性能之间的关系.尤其我们采用的是单铰链折痕和Kresling折纸,这是刚性和非刚性折纸单元的代表性示例,采用双针穿孔兼容机构设计制造.我们使用不同的折痕参数进行轴向压缩测试,并将结果拟合到由轴向和扭转弹簧组成的棒铰折纸模型中.使用高斯回归过程提取弹簧系数和折痕参数之间的关系.结果表明,折痕参数的变化以非常不同的方式对每个弹簧元件有显著贡献,这表明合规机制根据变形模式的微调性.特别是,刚性和非刚性折纸的弹簧刚度随折痕参数而变化不同,即使调整了相同的折痕参数也是如此.此外,我们报道了Kresling折纸的定性静态响应只需改变折痕参数,就可以在单稳态和双稳态之间,或者线性和非线性之间调节,同时可以保持相同的折叠图案几何形状.我们相信,我们的结果为折纸机械超材料的褶皱选择合规机制提供了一个库和指南.