摘要：本文评估了拱形支撑结构周围的风流场特性,属于计算流体动力学的研究领域.通过与文献中风洞试验数据的对比,验证了数值模拟结果.本文不但给出了不同形状拱形支撑结构(尖顶、扁平和拱形结构)表面的平均、脉动、最大和最小风压系数,而且讨论了不同的风向和结构高径比对风压系数的影响.结果表明,与其他结构相比,尖顶结构表面的风压系数和湍流扰动在数值上较低.地形粗糙度指数越低,结构表面的平均风压系数越大.此外,对于尖顶结构,高径比的增加会导致结构表面风压的增加.与其他风向相比,来风角度为45°的情况下屋顶表面所受负风压最强.值得指出的是,本文对于不同风向和尖顶结构的详细研究结果可以对工程设计优化领域有一定的借鉴意义.

摘要：Synthetic polymer membranes are widely used in many applications,including,among others,water purification,protein separation,and ***,the use of existing polymer membranes faces major challenges,such as the trade-off between permeability and selectivity,membrane fouling,and poor mechanical *** address these problems the authors have focused their research on surface/interfacial tailoring and the structure-property relationship of polymer membranes used in liquid separation *** has been made as follows:(1)a methodology for membrane surface functionalization and nanofiltration(NF)membrane preparation based on mussel-inspired catecholic chemistry was proposed and established;(2)a class of mechanically robust and environmentally-responsive composite membranes with hydrogel pore-filled in rigid macroporous supports was designed and developed;(3)a methodology for surface tailoring and antifouling modification of polymer membranes based on amphiphilic copolymers was created and the scientific implications for amphiphilic polymer membranes elaborated;(4)an adsorption membrane with both filtration and adsorption functions was designed and developed to achieve rapid removal of trace micropollutants,including heavy metal ions,organic dyes,plasticizer,antibiotics,and *** mini-review briefly summarizes this work.

摘要：Vinblastine has been used clinically as one of the most potent therapeutics for the treatment of several types of ***,the traditional plant extraction method suffers from unreliable supply,low abundance,and extremely high ***,we use synthetic biology approach to engineer Saccharomyces cerevisiae for de novo biosynthesis of vindoline and catharanthine,which can be coupled chemically or biologically to *** the basis of a platform strain with sufficient supply of precursors and cofactors for biosynthesis,we reconstituted,debottlenecked,and optimized the biosynthetic pathways for the production of vindoline and *** vindoline biosynthetic pathway represents one of the most complicated pathways ever reconstituted in microbial cell *** shake flask fermentation,our engineered yeast strains were able to produce catharanthine and vindoline at a titer of 527.1 and 305.1μg·liter^(−1),respectively,without accumulating detectable amount of pathway *** study establishes a representative example for the production of valuable plant natural products in yeast.

摘要：The intrinsic drawbacks of electrolytes and the growth of lithium dendrites limit the development of commercial lithium *** address the aforementioned challenges,a novel biomimetic brain-like nanostructure(BBLN)solid polymer electrolyte was created by manipulating the shape of the incorporated *** designed BBLN solid polymer electrolyte was created by incorporating spherical core-shell(UIO-66@67)fillers into polymer electrolyte,which is significantly different from traditional polymer-based composite ***-66@67 spherical nanoparticles are highly favorable to eliminating polymer electrolyte stress and deformation during solidification,indicating a great potential for fabricating highly uniform BBLN solid polymer electrolytes with a substantial number of continuous ***,spherical nanoparticles can significantly reduce the crystalline structure of polymer electrolytes,improving polymer chain segmental movement and providing continuous pathways for rapid ion *** a result,BBLN solid polymer electrolyte shows excellent ionic conductivity(9.2×10^(−4)S cm^(−1)),a high lithium transference number(0.74),and outstanding cycle stability against lithium electrodes over 6500 h at room *** concept of biomimetic brain-like nanostructures in this work demonstrates a novel strategy to enhance ion transport in polymerbased electrolytes for solid-state batteries.

摘要：Solid oxide fuel cell–proton exchange membrane(SOFC–PEM) hybrid system is being foreseen as a valuable alternative for power generation. As this hybrid system is a conceptual design, many uncertainties involving input values should be considered at the early stage of process optimization. We present in this paper a generalized framework of multi-objective optimization under uncertainty for the synthesis/design optimization of the SOFC–PEM hybrid system. The framework is based on geometric, economic and electrochemical models and focuses on evaluating the effect of uncertainty in operating parameters on three conflicting objectives: electricity efficiency, SOFC current density and capital cost of system. The multi-objective optimization provides solutions in the form of a Pareto surface, with a range of possible synthesis/design solutions and a logical procedure for searching the global optimum solution for decision maker. Comparing the stochastic and deterministic Pareto surfaces of different objectives, we conclude that the objectives are considerably influenced by uncertainties because the two trade-off surfaces are different.

摘要：Combining named data networking（NDN） and software-defined networking（SDN） has been considered as an important trend and attracted a lot of attention in recent years. Although much work has been carried out on the integration of NDN and SDN, the forwarding mechanism to solve the inherent problems caused by the flooding scheme and discard of interest packets in traditional NDN is not well considered. To fill this gap, by taking advantage of SDN, we design a novel forwarding mechanism in NDN architecture with distributed controllers, where routing decisions are made globally. Then we show how the forwarding mechanism is operated for interest and data packets. In addition, we propose a novel routing algorithm considering quality of service（QoS） applied in the proposed forwarding mechanism and carried out in controllers. We take both resource consumption and network load balancing into consideration and introduce a genetic algorithm（GA） to solve the QoS constrained routing problem using global network information. Simulation results are presented to demonstrate the performance of the proposed routing scheme.

摘要：As feature size scales down, reliability issues like single event upset(SEU) have become serious for circuit and system designers, especially for those who work on memory and latch designs. In this paper, an improved SEU tolerant data cell design based on the Quatro-10 T cell is proposed. The introduced cell enhances the capability of SEU tolerance by weakening the key transistors in the feedback loop to block the effects of transient fault. Simulation results show that our proposed design achieves obvious higher resilience to SEU and better performance on speed and power dissipation at the expense of an increased area. The proposed cell is a fully SEU immune design with an amount of critical charge at least 7 times more than the Quatro-10 T cell and has the lowest Power Delay Product. It shows that our design is very suitable in high-performance circuit and system design.

摘要：Two-dimensional Fourier transform(2D FT) spectroscopy is an important technology that developed in recent decades and has many advantages over other ultrafast spectroscopy methods. Although 2D FT spectroscopy provides great opportunities for studying various complex systems, the experimental implementation and theoretical description of 2D FT spectroscopy measurement still face many challenges, which limits their wide ***, the 2D FT spectroscopy reaches maturity due to many new developments which greatly reduces the technical barrier in the experimental implementation of the 2D FT spectrometer. There have been several different approaches developed for the optical design of the 2D FT spectrometer, each with its own advantages and limitations. Thus, a procedure to help an experimentalist to build a 2D FT spectroscopy experimental apparatus is *** tutorial review is intending to provide an accessible introduction for a beginner to build a 2D FT spectrometer.

摘要：Water oxidation is significant in both natural and artificial *** nature,water oxidation occurs at the oxygen‐evolving center of photosystem II,and leads to the generation of oxygen,protons,and *** last two are used for fixation of carbon dioxide to give *** artificial processes,the coupling of water oxidation to evolve O2and water reduction to evolve H2is known as water splitting,which is an attractive method for solar energy conversion and *** water oxidation is a thermodynamically uphill reaction and is kinetically slow,this reaction causes a bottleneck in large‐scale water *** a consequence,the development of new and efficient water oxidation catalysts(WOCs)has attracted extensive *** efforts have identified a variety of mononuclear earth‐abundant transition‐metal complexes as active and stable molecular *** review article summarizes recent progress in research on mononuclear catalysts that are based on first‐row transition‐metal elements,namely manganese,iron,cobalt,nickel,and *** attention is paid to catalytic mechanisms and the key O?O bond formation *** information is critical for designing new catalysts that are highly efficient and stable.

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.