摘要：Lithium-sulfur batteries have been regarded as the next-generation rechargeable batteries due to their high theoretical energy density and specific ***,the shuttle effect of lithium polysulfides has hindered the development of lithium-sulfur ***,a novel zirconium-based metal-organic framework-801 film on carbon cloth was developed as a versatile interlayer for lithium-sulfur *** interlayer has a hierarchical porous structure,suitable for the immobilization of lithium polysulfides and accommodating volume expansion on ***,the MOF-801 material is capable of strongly adsorbing lithium polysulfides and promoting their catalytic conversion,which can be enhanced by the abundant active sites provided by the continuous structure of the MOF-801 *** on the above advantages,the lithium-sulfur battery,with the proposed interlayer,delivers an initial discharge capacity of 927 mAh·g^(-1) at 1 C with an extremely low decay rate of 0.04%over 500 ***,a high area capacity of 4.3 mAh·cm^(-2) can be achieved under increased S loading.

摘要：Alkali-water electrolyzers and hydroxide exchange membrane fuel cells are emerging as promising technologies to realize hydrogen *** cost-effective electrode materials with high activities towards corresponding hydrogen evolution(HER)and oxidation(HOR)reactions plays a crucial role in commercial hydrogen production and ***,we fabricated a V-doped Ni_(3)N/Ni heterostructure(V-Ni_(3)N/Ni)through a controlled nitridation treatment on a V-incorporated nickel hydroxide *** resultant catalyst exhibits comparable catalytic activity and durability to commercial Pt/C in terms of both HER(a low overpotential of 44 mV at the current density of 10 mA·cm^(-2))and HOR(a high current density of 1.54 mA·cm^(-2)at 0.1 V versus reversible hydrogen electrode)under alkaline *** superior activity of V-Ni_(3)N/Ni grown on different substrates further implies its intrinsic *** functional theory(DFT)calculations reveal that the coupled metallic Ni and doped V can promote the water adsorption,accelerate the Volmer step of alkaline HER,as well as optimize the adsorption and desorption of hydrogen intermediate(H^(*))to reach a balancedΔGH*value.

摘要：LHAASO-WCDA is a large ground-based water Cherenkov detector array planned to be built at ShangriLa, Yunnan Province, China. As a major component of the LHAASO project, the main purpose of LHAASO-WCDA is to survey the northern sky for very-high-energy（above 100 GeV） gamma ray sources and measure the spectrum. To gain full knowledge of the water Cherenkov technique and to investigate the engineering issues, a 9-cell detector array has been built at the Yang-Ba-Jing site, neighboring the ARGO-YBJ experiment. With the array, charge calibration methods for both low and high ranges of the PMT readout are studied, whose result shows that a precision at several percentages can be reached, which can satisfy the requirement of the detector array. During the long term operation, the charge calibration stability and environmental afection are studied; in this paper, the results are discussed. These calibration methods are proposed to be applied in the future LHAASO-WCDA project.

摘要：Exploring the production and application of clean energy has always been the core of sustainable *** a clean and sustainable technology,electrocatalysis has been receiving widespread *** is crucial to achieve efficient,stable and cheap ***,the traditional“trial and error”method is time-consuming,laborious and *** recent years,with the significant increase in computing power,computations have played an important role in electrocatalyst ***,it is still difficult to search for advanced electrocatalysts in the vast chemical space through traditional density functional theory(DFT)***,the development of machine learning and interdisciplinary integration will inject new impetus into targeted design of *** learning is able to predict electrochemical performances with an accuracy close to *** we provide an overview of the application of machine learning in electrocatalyst design,including the prediction of structure,thermodynamic properties and kinetic *** also discuss the potential of explicit solvent model combined with machine learning molecular dynamics in this ***,the favorable circumstances and challenges are outlined for the future development of machine learning in *** studies on electrochemical processes by machine learning will further realize targeted design of high-efficiency electrocatalysts.

摘要：The sharp rise of CO2 in the atmosphere has become a potential threat to global climate, which results from the massive utilization of fossil fuel since the industry revolution. CO2 electroreduction provides us a new possibility of utilizing CO2 as a carbon feedstock for fuel and commercial chemicals generation. In this article, a new method is developed for synthesizing CuInS2 hollow nanostructures through the Kirkendall effect. The CuInS2 hollow nanostructures exhibit excellent catalytic activity for electrochemical reduction of CO2 with particular high selectivity, achieving high faradaic efficiency for HCOOH of 72.8% at -0.7 V. To elucidate the mechanisms, operando electrochemical Raman spectroscopy is employed to examine the CO2 reduction process. This work provides new insights into the design of hollow nanostructures toward electrocatalytic CO2 conversion and offers us an effective and reliable way for real-time investigation of electrochemical CO2 reduction reaction processes.

摘要：Silicon suboxide(SiOx)is considered to be one of the most promising materials for next-generation anode due to its high energy *** its preparation,the wet-chemistry method is a cost-effective and readily scalable route,while the so-derived SiOx usually shows lower capacity compared with that prepared by high temperature-vacuum evaporation ***,we present an elaborate particle structure design to realize the wet-chemistry preparation of a high-performance SiOx/C ***-like highly porous SiOx particle coated with conformal carbon layer is designed and *** highly-porous SiOx skeleton provides plenty specific surface for intimate contact with carbon layer to allow a deep reduction of SiOx to a low O/Si ratio at relatively low temperature(700℃),enabling a high specific *** abundant mesoscale voids effectively accommodate the volume variation of SiOx skeleton,ensuring the high structural stability of SiOx@C during lithiation/delithiation ***,the three-dimensional(3D)conformal carbon layer provides a fast electron/ion transportation,allowing an enhanced electrodereaction *** to the optimized O/Si ratio and well-engineered structure,the prepared SiOx@C electrode delivers an ultra-high capacity(1,115.8 mAh·g^-1 at 0.1 A·g^-1 after 200 cycles)and ultra-long lifespan(635 mAh·g^-1 at 2 A·g^-l after 1,000 cycles).To the best of our knowledge,the achieved combination of ultra-high specific capacity and ultra-long cycling life is unprecedented.

摘要：Silicon nanowires（SiNWs） encapsulated with graphene-like carbon sheath（GS） having a void space in between（SiNW@V@GS） are demonstrated for the improved electrochemical performance of Si anode in lithium ion battery. The Si NW@V@GS structure was synthesized by a scalable fabrication method including four successive reactions： metal-catalyzed CVD growth of Si NWs, controlled thermal oxidation, and deposition of the graphitic layer, to form Si NW@SiO2@GS and additional chemical etching of sacrificial SiO2 layer between Si NWs and carbon sheath. During the synthetic process, the thickness of the void spacing was controlled by adjusting the oxidation-dependent process. The well-controlled void space and crystalline graphitic carbon sheath of the SiNW@V@GS structure enable good reversible capacity of1444 m Ahg^（-1） and cycling stability of 85% over 150 cycles.

摘要：The paper presented topology optimization of 2 D and 3 D Nanofluid-Cooled Heat Sink(NCHS). The flow and heat transfer problem in the NCHS was treated as a single-phase nanofluid based convective heat transfer model. The temperature-dependent fluid properties were taken into account in the model due to the strong temperature-dependent features of nanofluids. An average temperature minimum problem was studied subject to the fluid area and energy dissipation constraints by using the density method. In the method, the design variable is updated according to the gradient information obtained by an adjoint based sensitivity analysis process. The effects of the energy dissipation constraint, temperature-dependent fluid properties and nanofluid characteristics on optimal configurations of NCHS were numerically investigated with following ***, branched flow channels in the optimal configuration increased with the rise of the allowed energy dissipation. Secondly, temperature-dependent fluid properties were significant for obtaining the appropriate optimal results with best cooling performance. Thirdly, heat transfer performances of optimal configurations were enhanced by reducing the nanoparticle diameter or increasing the nanoparticle volume fraction. Fourthly, the optimal configuration for nanofluid had better cooling performance than that for its base fluid.

摘要：Methods for the analysis of heat exchangers with various flow arrangements modeling,design,and performance are essential for heat transfer system modeling and its integration with other energy system *** paper proposes the use of the linear-transfer law for the heat exchanger design and performance analysis as a function of the thermal resistance related to the ratio of a linear temperature difference to the total heat transfer ***,we derived a correction factor that represents the influence of the flow arrangement on the heat transfer performance by the effective thermal conductance,as a function of correction factor,heat transfer coefficient,and surface *** on the effective thermal conductance,we propose the hot-end NTU and cold-end NTU for deriving a standardized and general thermal resistance formula for different types of heat exchangers by the combination of the correction factor with linear-transfer ***,for parallel-flow,cross-flow,and 1-2 Tubular Exchanger Manufacturers Association(TEMA)E shell-and-tube heat exchangers,we derived and obtained alternative correction factor expressions without introducing any *** cases about heat exchanger design and performance analysis show that the calculation processes using the correction factor-based general thermal resistance are straightforward without any iteration and the calculation results are ***,the experimental validation shows that the general thermal resistance formula is appropriate for analyzing the heat transfer *** is,the correction factor-based general thermal resistance formula provides a standardized model for heat exchanger analysis and heat transfer/integrated energy system modeling using the heat current method.

摘要：Performance-based design is more holistic and flexible than prescriptive design for providing safety in large complex buildings. Here, a multi-agent method to model the egress patterns of evacuees is combined with a microscopic pedestrian simulation model used to analyze the forces between individuals in a densely populated enclosed space in a crowd crushing and trampling analysis （CroC＆Ts）. The system is used to model egress patterns in a typical crowd evacuation simulation. The simulations indicate that some individuals will die from crushing in 2 m and 4 m wide exits in emergencies. The simulations also show that the fatality probability increases when barriers obstacled the path and when the egress distances were lar- ger. The simulations validate the conclusions of the stranded crowd model （SCM） and provide quantitative predictions of the crowd crushing and trampling risk. Therefore, the CroC＆Ts can provide performancebased egress designs for large pubic buildings and improve crowd safety management and emergency planning.