摘要：Splitting water under large current density is essential for efficient large-scale production and commercial utilization of ***,the performance of the available electrocatalysts for hydrogen evolution reaction(HER)is far from satisfactory under large current density in alkaline *** we report a remarkably active and durable electrocatalyst,long and dense MoS2/Ni3S2 co-axial heterostructure nanowires on nickel foam(NF).Notably,it requires only 182 and 200 mV overpotential to achieve large current density of 500 and 1000 mA cm^-2,respectively,in alkaline solution,which are far superior to those of Pt/C-NF(281 and 444 mV)and the reported best non-noble metal catalysts(191 and 220 mV).The physical origin for this extraordinary HER performance is analyzed,which provides a useful guide for structure design of electrocatalysts to further improve their performance.

摘要：Metal–organic framework(MOF)membranes hold great promise in energy-efficient chemical *** outstanding challenges of the microstructural design stem from(1)thinning of membranes to immensely reduce the mass-transfer resistance(for high permeances);(2)tuning of orientation to optimize the selective transport of gas molecules,and(3)reinforcement of intercrystalline structure to subside leakage through defective gaps(for high selectivity).Here,we propose the ZIF-L membrane that is completely confined into the voids of the alumina support through an interfacial assembly process,producing an appealing membrane-interlocked-support(MIS)composite architecture that meets the requirements of the microstructural design of MOF ***,the membranes show average H2 permeances of above 4000 GPU and H_(2)/CO_(2) separation factor(SF)of above 200,representing record-high separation performances of ZIF-L membranes and falling into the industrial target zone(H_(2) permeance>1000 GPU and H_(2)/CO_(2) SF>60).Furthermore,the ZIF-L membrane possessing the MIS composite architecture that is established with alumina particles as scaffolds shows mechanical stability,scraped repeatedly by a piece of silicon rubber causing no selectivity loss.

摘要：本文提出了一种考虑几何非线性的三维连续体结构显式拓扑优化方法.采用移动可变形孔洞(MMV)方法描述结构,具有设计变量少、可与CAD系统无缝集成的优点.此外,由于结构拓扑描述模型与有限元分析模型之间解耦,在有限元分析中可以直接删除孔洞区域的冗余自由度,从根本上解决有限变形拓扑优化因弱单元引起的收敛性问题,同时显著提高了有限元分析的计算效率.数值算例验证了该方法的有效性,结果表明:(1)无论单工况还是多工况载荷作用下,几何非线性对三维结构的最优拓扑构型均具有显著影响;(2)优化后的几何非线性结构可以充分利用大位移和小应变来降低结构柔顺度;(3)几何非线性拓扑优化应评估优化设计的临界失稳荷载,以保证结构服役的安全性.

摘要：Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at ***, we synthesized Bi_(2)O_(3)-polyoxometalate heterostructure SNWs(PMB SNWs), and fabricated super-aligned PMB SNWs films(S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide(LPS)shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur(Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.