摘要：In clinical settings,tantalum(Ta)is extensively implemented as a bone implant *** is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone ***,since Ta is a refractory metal,its application as bone implant material is *** recently,additive manufacturing technology has introduced a novel approach to producing Ta *** present study compared the microstructure,surface and mechanical characteristics,and in vitro and in vivo biological characteristics of selective laser melted Ta(SLM Ta),selective laser melted titanium alloy Ti6Al4V with Ta coating(SLM Ti6Al4V with Ta coating),and selective laser melted Ti6Al4V(SLM Ti6Al4V).Results indicate that SLM Ta possesses superior mechanical characteristics contrasted with SLM Ti6Al4V and SLM Ti6Al4V with Ta ***,SLM Ta has anti-inflammatory activity,excellent osseointegration performance,and osteogenic *** fabricated an SLM porous Ta bone plate and employed it for internal fixation of ulnar and radius fractures,which has been known to promote fracture ***,the SLM porous Ta bone plate could form an integrated bone plate structure with the bone tissue at the implant ***,the porous structure of the plate minimizes its elastic modulus and eliminates stress shielding,leaving no need for further surgical *** conclusion,the SLM porous Ta bone plate meets the performance requirements(stimulating bone regeneration,non-stress shelter,and no need for second surgery)of an ideal bone plate and may revolutionize the field of internal fixation bone plates for fractures.

摘要：The interfacial perimeter of gold nanocatalysts is popularly viewed as the active sites for a number of chemical reactions,while the geometrical structure of the interface at atomic scale is less ***,TiO2-nanosheets and nanospindles were adapted to accommodate Au particles(~2.2 nm),forming Au-TiO2{001}and Au-TiO2{101}*** calcination at 623 K in air,HAADF-STEM images evidenced that the Au particles on TiO2{101}enlarged to 3.1 nm and these on TiO2{001}remained unchanged,suggesting the stronger metal-support interaction on TiO2{001}.Au/TiO2{001}was more active for CO oxidation than Au/TiO2{101}system.

摘要：Aqueous zinc-based batteries(ZBBs)have great potential as commercial energy storage ***,the poor cycling stability of zinc anode under high areal capacity limits their further ***,a coupled non-planar electrode design achieved by the tailored flat-top pyramid carbon felt(TCF)is proposed for ZBBs,which can effectively increase the zinc deposition sites,adjust the deposition morphology,optimize the current and electrolyte flow velocity distribution and provide necessary space for zinc ***,by utilizing "tip effect",the coupled TCFs enable precise control of the zinc dendrite growth position,effectively reducing the risk of short *** on such coupled TCFs,zinciodine flow batteries can deliver an ultra-high areal capacity of 240 m Ah cm^(-2) and a superb cycling stability over 300 cycles(areal capacity of 160 m Ah cm^(-2))at a high current density of 40 m A cm^(-2).Therefore,we provide an effective strategy for high areal capacity zinc anode design,which may promote the development of high energy density and long cycle life ZBBs.

摘要：共晶高熵合金因其所展现出的特殊物理/化学性能而受到材料界的广泛关注.然而,除了FCC+B2系外,其他大部分所报道的共晶高熵合金系均呈现为固有脆性,这使得它们逐渐失去了工业应用的竞争优势.本工作提出了一种新的协同改善脆性CoCrNi_(2)(V_(3)B_(2)Si)_(0.2)共晶高熵合金强韧性的球化+再结晶工艺.基于该工艺,CoCrNi_(2)(V_(3)B_(2)Si)_(0.2)共晶高熵合金获得了一种精心设计的球状M3B2镶嵌在细小FCC晶界处的微观结构,使其抗拉强度、屈服强度和延伸率从923 MPa/620 MPa/1.3%提高到1326-1530 MPa/990-1330 MPa/8.4%-13.9%,提高了43.7%-65.8%/59.7%-114.5%/546%-9.69%.强塑化机制主要归因于球化和再结晶微观结构提供了更多的界面阻碍位错移动和促进了更加均匀的应力分布.该工作为协同改善脆性共晶高熵合金强韧性以满足工程安全性需求提供了新的思路.

摘要：Photoredox catalysis has become an indispensable solution for the synthesis of small organic ***,the precise construction of single-atomic active sites not only determines the catalytic performance,but also avails the understanding of structure–activity ***,we develop a facile approach to immobilize single-atom Ni sites anchored porous covalent organic framework(COF)by use of 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline and 2,6-diformylpyridine(Ni SAS/TD-COF).Ni SAS/TDCOF catalyst achieves excellent catalytic performance in visible-light-driven catalytic carbon–nitrogen cross-coupling reaction between aryl bromides and amines under mild *** reaction provides amine products in excellent yields(71%–97%)with a wide range of substrates,including aryl and heteroaryl bromides with electron-deficient,electron-rich and neutral ***,Ni SAS/TD-COF could be recovered from the reaction mixture,corresponding to the negligible loss of photoredox performance after several *** work provides a promising opportunity upon rational design of single-atomic active sites on COFs and the fundamental insight of photoredox mechanism for sustainable organic transformation.

摘要：The high cost and low efficiency of fatigue tests are bottleneck problem for the anti-fatigue design of metallic *** this problem,a theoretical fatigue model is proposed in this study,the possible applications have also been *** results would be introduced in two serial papers,in which the first paper focuses on the model building and the applications on fatigue strength prediction;the second paper put emphasis on the influencing factors of the model parameters and the applications on fatigue strength *** this first paper,a theoretical model is proposed considering both the strength and plastic restrictions of fatigue *** the model builds up a brief relationship among yield strength(Y),tensile strength(T)and fatigue strength(F),it is named as the Y-T-F *** the verification with fatigue strength data covering various kinds of metallic materials and loading conditions,this Y-T-F model exhibits both generality and *** the Y-T-F model,the efficient fatigue strength prediction could be conducted by brief linear fitting and calculation,just through yield strength,tensile strength and several known fatigue strength ***,through its deduced Y-F model,the analytical formula of fatigue strength continuously changing with materials strengthening can be obtained,as well as the maximum value of fatigue strength and corresponding critical yield *** summary,the Y-T-F model would be useful for reducing the fatigue tests,thus providing new possibilities on the efficient anti-fatigue design and selection of metallic materials.

摘要：A novel extrusion-shearing(ES) composite process was designed to fabricate fine-grained, high strength and tough magnesium alloy. The structural parameters of an ES die were optimized by conducting an orthogonal simulation experiment using finite element software Deform-3D, and Mg-3 Zn-0.6 Ca-0.6 Zr(ZXK310) alloy was processed using the ES die. The results show that the optimized structural parameters of ES die are extrusion angle(α) of 90°, extrusion section height(h) of 15 mm and inner fillet radius(r) of 10 mm. After ES at an extrusion temperature and a die temperature of 350 °C, ZXK310 alloy exhibited good ES forming ability, and obvious dynamic recrystallization occurred in the forming area. The grain size decreased from 1.42 μm of extrusion area to 0.85 μm of the forming area. Owing to the pinning of second phase and formation of ultrafine grains, the tensile strength, yield strength and elongation of alloy reached 362 MPa, 289 MPa and 21.7%, respectively.

摘要：Objective:Swertia pseudochinensis,an annual herb of the genus Swertia in the family *** constituents and extracts from the Swertia genus have been recently reported to possess neuroprotective effects,suggesting their potential utility in the prevention and treatment of Parkinson disease(PD).The aim of this work is to identify the chemical constituents and evaluate the potential biological activists of Swertia ***:The phytochemicals from the aerial parts of *** were isolated and purified by silica gel,Sephadex LH-20 gel,semi-preparative high-performance liquid chromatography,and identified by the spectroscopic *** compounds were evaluated for their potential neuroprotective effects against 1-methyl-4-phenylpyridinium-induced apoptosis in the SH-SY5Y human neuroblastoma cell line using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide ***,we performed an enrichment analysis using the Database for Annotation,Visualization,and Integrated Discovery and investigated the mechanisms by which bellidifolin regulates neurodegenerative ***:Two new anthraquinone,1,5,6-trimethoxy-2-hydroxy-3-methy-anthraquinone(1)and 1,5,6,8-tetramethoxy-2-hydroxy-3-methyanthraquinone(2),together with nine known including 7-O-b-d-glucopyranosyl-1,8-dihydroxy-3-methoxyxanthone(3),gentisin(4),swertianolin(5),bellidifolin(6),gentiacaulein(7),norswertianolin(8),5-O-b-d-glucopyranosyl-1,3,8-trihydroxyapatone(9),1-hydroxy-3,5,8-trimethoxyxanthone(10),and aurantio-obtusin(11),were isolated and compounds 6–8 and 10 exhibited neuroprotective effects at a concentration of 50mmol/*** them,bellidifolin showed significant protective activity,and might have potential as a neuroprotective agent for the treatment of PD,possibly by acting on oxidative damage and reactive oxygen ***:These findings indicate that further research on the genus Swertia and its bioactive constituents toward neurodegenerative d

摘要：研究温度对新型体心立方(BCC)基Fe_(3.5)Cr_(1.5)NiAl_(0.8)多组元合金(MCA)中有序椭圆状B2-NiAl纳米析出相的显微组织稳定性和力学性能的影响。采用XRD、EBSD、EPMA和TEM等检测方法对该多组元合金的显微组织和物相组成进行表征。结果表明,所设计的高含量椭圆状B2纳米析出相与BCC基体完全共格且能在1073 K高温下保持稳定,平均粒径为245.509~251.328 nm。铸态和热处理态(873 K≤T≤1073 K)合金具有独特的共格结构,这是由于低错配度的共格析出强化机制可使合金具有较高的屈服强度(809.2~1164.1 MPa)。随着热处理温度的进一步提高(1173 K≤T≤1273 K),B2纳米析出相的平均粒径逐渐粗化,载荷传递强化机制对其屈服强度提高起主要作用。

摘要：程序升温脱附谱技术能定量识别表面物种和测量脱附动力学,因此被广泛应用于多相催化和表面科学研究.对于高效率和高质量的程序升温脱附谱实验而言,减小吸附过程中的气载并在不破坏超高真空条件下完成样品更换以及实现对样品全方位的温度控制是至关重要的.然而,现有的表面科学程序升温脱附谱装置通常无法同时满足这些条件。鉴于此,本文搭建了一台可实现小气载进样、快速换样以及全面温控的程序升温脱附谱装置。使用自动控制的基于微毛细管阵列的溢流分子束给样器,制备分子吸附的表面,让气体的进样更加精准并大幅减小了气载。借助液氮传输线并优化样品台处的热接触和热偶连接方式,使得这台程序升温脱附谱装置同时具备了快速换样、精准测温、快速降温以及稳定线性升温等功能。通过测量水从高定向热解石墨和TiO_(2)(110)表面的脱附特征以及甲氧基阴离子在TiO_(2)(110)表面的光催化氧化反应,证实了该程序升温脱附谱装置在测量脱附动力学参数、定量识别表面吸附物种和吸附位点以及分析表面光化学反应等方面的性能,本工作将为研究人员设计高效率和高质量的程序升温脱附谱装置提供宝贵的经验和思路。