摘要：In this article, the UDF technology in Fluent software is used to simulate three-dimensional flow fields and to obtain various flow parameters. The standard k -ε model and the RNG k -ε model are both used to calculate the inner flow field of the basal meter, and a comparison of the calculated results between two models shows that RNG k - ε model is more effective for calculations of the inner flow of rotary wing mechanism. The influence of tip clearance on the characteristics of the basal meter is studied. The influence of the bottom ribs on the heat meter is evaluated by the numerical simulation method. This article also simulates the flow of disturbance located at the inlet of the basal meter, and shows that a swirl located at the front of the basal meter can affect the stability of the heat meter.

摘要：This paper presents an aerodynamic optimum design method for transonic turbine cascades based on the Genetic Algorithms coupled to the inviscid flow Euler solver and the boundary-layer *** Genetic Algorithms control the evolution of a population of cascades towards an optimum *** fitness value of each string is evaluated using the flow solver. The design procedur6 has been developed and the behavior of the genetic algorithms has been tested. The objective functions of the design examples are the minimum mean-square deviation between the aimed pressure and computed pressure and the minimum amount of user expertise.

摘要：目的:研究余热回收中的新型烧结矿立式冷却装置填充床的阻力特性,揭示烧结矿填充床宏观特性参数和空隙流动状态,提出适用于烧结矿的阻力特性公式。创新点:1.采用实验方法,获取全面的复杂异形烧结矿颗粒宏观特性数据;2.通过实验测量,提出适用于烧结矿填充床的修正型Ergun阻力方程。方法:1.采用多种实验方法,测量烧结矿的颗粒粒度、球形度和堆积空隙率等宏观特性参数;2.通过阻力实验数据分析,得到烧结矿填充床的宏观特性参数和堆积空隙流动状态;3.通过实验数据拟合,提出适用于烧结矿的阻力特性公式。结论:1.表观流速为0.4?2.4 m/s时烧结矿填充床堆积空隙流动状态由层流过渡到湍流;***方程的不规则异形颗粒的阻力预测值比实验值偏低约40%;3.提出的修正型Ergun预测公式能够预测颗粒雷诺数500至12 000的烧结矿填充床阻力,预测误差在10%以内。

摘要：Homogeneous redox mediation is efficient in alleviating the shuttling effect and slow redox kinetics of lithium polysulfides in lithium-sulfur ***,their perfect performance is not fulfilled owning to the fact that the multi-step transformation of lithium polysulfides requests the multifunctional active positions for the tandem *** on the redox comediation principles,a promoter of mixing organodiselenide and organoditelluride(mixed-Se/Te)was raised to induce tandem catalysis and boost the effective electrochemical conversion of lithium *** specifically,diphenyl diselenide facilitated the liquid-liquid and solid-liquid transformation between lithium polysulfides and sulfur,while diphenyl ditelluride improved the solid-liquid transformation concerning lithium sulfide ***,even under high sulfur loading of 6.5 mg cm^(−2) and low electrolyte/sulfur ratio of 5.88μL mg^(−1),the 10 mM low concentration mixed-Se/Te promoter offered a high discharge capacity of 6.6 mAh cm^(−2) and high rate performance of 4.1 mAh cm^(−2) at 0.5 ***,the assembled 1.5 Ah-level lithium-sulfur pouch cells provide an energy density of 332 Wh kg^(−1) at 0.05 C and good cycling *** research demonstrates the applicability of propelling continuous sulfur conversion reactions with detached active positions and is anticipated to stimulate deep molecular design of kinetic promoter to targeted energy-associated redox reactions.

摘要：The nitrogen-coordinated metal single-atom catalysts(M−N−C SACs)with an ultra-high metal loading synthetized by direct high-temperature pyrolysis have been widely ***,most of metal single atoms in these catalysts were buried in the carbon matrix,resulting in a low metal utilization and inaccessibility for adsorption of reactants during the catalytic ***,we reported a facile synthesis based on the hard-soft acid-base(HSAB)theory to fabricate Co single-atom catalysts with highly exposed metal atoms ligated to the external pyridinic-N sites of a nitrogen-doped carbon *** from the highly accessible Co active sites,the prepared Co−N−C SAC exhibited a superior oxygen reduction reactivity comparable to that of the commercial Pt/C catalyst,showing a high turnover frequency(TOF)of 0.93 e^(−)·s^(-1)·site^(-1)at 0.85 V ***,far exceeding those of some representative SACs with a ultra-high metal *** work provides a rational strategy to design and prepare M−N−C single-atom catalysts featured with high site-accessibility and site-density.

摘要：The development of low-cost,highly active platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)is crucial for widespread applications of fuel *** effective approach lies in alloying Pt with non-noble transition metals to modulate the physicochemical state of the Pt ***,fundamental challenges remain in understanding the structure-performance relationship due to the complexity of composition,crystal type,and surface structure during the alloying *** this study,we synthesized a series of PtCo bimetallic solid solutions with varying ratios using a liquid-phase synthesis *** exploiting the characteristics of solid solutions,the resulting PtCo bimetallic alloy maintains the face-centered cubic crystal structure of pure platinum,minimizing the complexities introduced during alloying and facilitating mechanism ***,under controlled alloy composition and crystal structure,we investigated the dependence of the electrocatalytic activity for the oxygen reduction reaction on the surface strain of the platinum *** S-PtCo-SNPs cathode designed accordingly endows both proton exchange membrane fuel cell(PEMFC)(2.08 W cm^(−2) at 4 A cm^(−2))and Zn-air battery(ZAB)(143.1 mW cm^(−2) at 214.5 mA cm^(−2))with outstanding performance.

摘要：Inorganic-organic composite electrolyte is proved an effective way to enhance the overall performance of the ***,simply combining powder fillers with polymers is not sufficient for the application of composite *** this work,we designed an ultrathin organic-inorganic composite solid electrolyte with high mechanical strength and ionic conductivity,in which the inorganic Li1.5Al0.5Ge1.5(PO_(4))3(LAGP)solid electrolyte is prefiberized into a three-dimensional nanofiber network to serve as a self-supporting skeleton for the polyethylene oxide(PEO)*** continuous skeleton structure not only significantly improves the mechanical strength of the PEO-based electrolyte,but also forms a continuous lithium-ion conduction path,promoting the rapid migration of lithium *** fiber-reinforced composite electrolyte has an ionic conductivity of 8.27×10^(−4) S cm^(-1) at 60°C and a tensile strength of up to 4.29 ***,it exhibits a reduced overpotential and stable long-term cycling performance over 1700 h when used in Li/Li symmetric *** LiFePO_(4)(LFP)|Li cell assembled with the fiber-reinforced composite electrolyte also delivers a specific capacity of about 142 mAh g^(−1) over 300 cycles at 0.5 C and maintains good cycling *** work provides a novel idea for designing the next generation of safe and reliable organic-inorganic composite solid-state electrolyte membranes.

摘要：Solid oxide cells(SOCs)are emerging devices for efficient energy storage and ***,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of *** mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis ***,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.

摘要：The A–D–A′–D–A-type non-fused ring electron acceptors(NFREAs),consisting of electron-donating unit(D)as the bridge to link electron-accepting units(A and A′),have emerged as promising electron acceptors for organic solar cells(OSCs)and organic photodetectors(OPDs).As the units are linked by the carbon–carbon single bonds,these electron acceptors generally possess feasible synthesis and tunable optoelectronic ***,the recent progress of A–D–A′–D–A-type NFREAs is reviewed,including molecular design,device performance,structure–property relationships,and their applications in OSCs and ***,we discuss the challenges and propose the perspectives for the further development of A–D–A′–D–A-type NFREAs.

摘要：Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried *** this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel *** numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily *** is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~*** is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel *** the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are *** the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural ***,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.