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Flow characteristics and bubble statistics during the fragmentation process of the ingested main cavity in plunging breaking waves

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Journal of Hydrodynamics 2024年第3期36卷 546-555页

作者： Wen-bin zhang Wei-wen Zhao de-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

Plunging breaking waves play an important role in the exchange of heat,momentum,and mass between the atmosphere and *** this paper,a series of direct numerical simulations is conducted to investigate the fragmentation process of the ingested main cavity in plunging breaking *** two-phase Navier-Stokes equations are solved using the finite-volume method based on adaptive refinement *** free surface is captured using a geometrical volume of fluid *** 2-D,3-D simulations are *** flow fields at different stages of wave breaking are presented and quantitative analysis for bubbles is *** 2-D instantaneous vorticity field and local velocity field are visualized to discuss the general flow characteristics during the fragmentation *** a 2-D parametric study is conducted to investigate the differences in the flow characteristics during the fragmentation process under different wave parameters including initial wave steepness(ε),Bond number(Bo),and Reynolds number(Re).3-D vortex structures are shown to further investigate the mechanisms behind the differences in the flow *** bubble size distributions under two different initial wave steepness are also discussed with their relationship to the fragmentation process of the ingested main *** research offers a significant understanding of the distinct procedures and fundamental dynamics involved in wave breaking,enhancing our comprehension of this intricate event.

关键词： Plunging breaking waves multiphase flow bubble statistics

Periodic Variation Studies of the Two Short Period W UMa-type Eclipsing binaries: LX Lyn and V0853 Aur

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Research in Astronomy and Astrophysics 2024年第1期24卷 273-284页

作者： Xu zhang bin zhang School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550025China

In this paper,new light curves(LCs) of contact eclipsing binary(CEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-devinney(W-D) *** order to explain their asymmetric LCs,cool starspots on the components were *** is suggested that their fill-out degrees are f=12.0%(LX Lyn) and f=26.3%(V0853 Aur).At the same time,we found that LX Lyn is a W-type eclipsing binary(EB) with an orbital inclination of i=84°.88 and a mass ratio of q=2.31.V0853 Aur is also a W-type CEB with a mass ratio of q=2.77 and an orbital inclination of i= 79°.*** on all available times of light minimum,their orbital period changes are studied by using the O-C *** O-C diagram of LX Lyn reveals a cyclic oscillation with a period of about 14.84 yr and an amplitude of 0.0019 days,which can be explained by the light-travel time effect(LTTE) due to the presence of a third body with a minimum mass of0.06M_⊙.For V0853 Aur,it is discovered that the O-C diagram of the system also shows a cyclic oscillation with a period of 9.64 yr and an amplitude of 0.03365 *** cyclic oscillation of V0853 Aur can be attributed to the LTTE by means of a third body with a mass no less than 3.77M_⊙.The third body may play an important role in the formation and evolution of these systems.

关键词： stars:activity (stars:)binaries(including multiple):close (stars:)binaries:eclipsing (stars:)brown dwarfs stars:evolution stars:formation

Response characteristics of PWR primary circuit under SBLOCAs considering steam bypass discharging

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Nuclear Science and Techniques 2024年第6期35卷 189-201页

作者： Shuai Yang Xiang-bin Li Yu-Sheng Liu Jia-Ning Xu de-Chen zhang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China Nuclear and Radiation Safety Center MEPBeijing 100084China

Small-break superposed station blackout(SBO)accidents are the basic design accidents of nuclear power *** the condition of a small break in the cold leg,SBO further increases the severity of the accident,and the steam bypass discharg-ing system(GCT)in the second circuit can play an important role in guaranteeing core *** explore the influence of the GCT on the thermal-hydraulic characteristics of the primary circuit,RELAP5 software was used to establish a numerical model based on a typical pressurized water reactor nuclear power *** different small breaks in the cold-leg super-posed SBO were selected,and the impact of the GCT operation on the transient response characteristics of the primary and secondary circuit systems was *** results show that the GCT plays an indispensable role in core heat removal during an accident;otherwise,core safety cannot be *** GCT was used in conjunction with the primary safety injection system during the placement *** the break diameter was greater than a certain critical value,the core cooling rate could not be guaranteed to be less than 100 K/h;however,the core remained in a safe state.

关键词： Steam bypass discharging Pressurized water reactor SBLOCA Numerical simulation

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基于元胞自动机间距识别的员工行为模拟方法

系统工程理论与实践 2006年第2期26卷 83-96页

作者：胡斌章德斌华中科技大学管理学院湖北武汉430074

为实现复杂管理系统的模拟,根据组织和员工行为的特点,通过改进传统的元胞自动机(CELLULARAUTOMATA,简称CA)方法,设计了一种基于CA间距识别的定性模拟方法,用于研究组织行为与员工行为的互动变化过程.由一定数量员工组成的企业被视作社... 详细信息

为实现复杂管理系统的模拟,根据组织和员工行为的特点,通过改进传统的元胞自动机(CELLULARAUTOMATA,简称CA)方法,设计了一种基于CA间距识别的定性模拟方法,用于研究组织行为与员工行为的互动变化过程.由一定数量员工组成的企业被视作社会场,元胞之间的距离用于描述社会场中的各种引力,这种间距也用于描述企业的管理措施、评价员工行为的表现.基于这种间距识别方法,设计了元胞的移动规则和模拟引擎.最后给出一个企业车间例子,将文中所提方法应用于企业管理措施的策略选择.确认和应用中的模拟结果说明,该方法可用于预测员工的两类行为(员工忠诚度和员工凝聚力)变化过程.

关键词：元胞自动机定性模拟员工行为元胞间距员工忠诚度

Visible-frequency nonvolatile reconfigurable Janus metasurfaces for dual-wavelength-switched and spin-asymmetric holograms

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Photonics Research 2024年第2期12卷 356-368页

作者： HUAN YUAN ZHEQIANG ZHONG bin zhang College of Electronics and Information Engineering Sichuan UniversityChengdu 610064China Big Data Analysis and Fusion Application Technology Engineering Laboratory of Sichuan Province Chengdu 610065China

Janus metasurface holography with asymmetric transmission characteristics provides new degrees of freedom for multiplexing ***,earlier metasurfaces with asymmetrical transmission faced limitations in terms of tunability and *** this study,we propose a metasurface color holographic encryption scheme with dynamic switching and asymmetric transmission at visible frequencies using a low-loss nonvolatile optical phase-change material,Sb_(2)S_(3).Using a modified holographic optimization strategy,we achieved highfidelity asymmetric holographic imaging of a nanostructured *** controlling the incident direction and wavelength of visible light,as well as the level of crystallization of Sb_(2)S_(3),this reconfigurable metasurface enables the precise manipulation of tunable color holographic image *** particular,in the semi-crystalline state of Sb_(2)S_(3),the encoded information can be securely encrypted using a two-channel color-holographic image,whereas only a preset camouflaged image is displayed in the crystalline or amorphous state of Sb_(2)S_(3).The proposed multiencrypted Janus metasurface provides a potential approach for dynamic holographic displays with ultrahigh capacity,holographic encryption,and information storage.

关键词： holographic asymmetric visible

Strategies to achieve effective nitrogen activation

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Carbon Energy 2024年第5期6卷 137-163页

作者： bin Chang Huabin zhang Shuhui Sun Gaixia zhang KAUST Catalysis Center(KCC) King Abdullah University of Science and Technology(KAUST)ThuwalKingdom of Saudi Arabia Institut National de la Recherche Scientifique(INRS) CentreÉnergie Matériaux TélécommunicationsVarennesQuébecCanada department of Electrical Engineering École de Technologie Supérieure(ÉTS)MontréalQuébecCanada

Ammonia serves as a crucial chemical raw material and hydrogen energy *** electrocatalytic nitrogen reduction reaction(NRR),powered by renewable energy,has attracted tremendous interest during the past few *** some achievements have been revealed in aqueous NRR,significant challenges have also been *** activity and selectivity are fundamentally limited by nitrogen activation and competitive hydrogen *** review focuses on the hurdles of nitrogen activation and delves into complementary strategies,including materials design and system optimization(reactor,electrolyte,and mediator).Then,it introduces advanced interdisciplinary technologies that have recently emerged for nitrogen activation using high-energy physics such as plasma and *** a better understanding of the corresponding reaction mechanisms in the coming years,these technologies have the potential to be extended in further *** review provides further insight into the reaction mechanisms of selectivity and stability of different reaction *** then recommend a rigorous and detailed protocol for investigating NRR performance and also highlight several potential research directions in this exciting field,coupling with advanced interdisciplinary applications,in situ/operando characterizations,and theoretical calculations.

关键词： activation via mediators catalyst optimization electrochemical nitrogen fixation high-energy activation of nitrogen nitrogen

Urea-induced interfacial engineering enabling highly reversible aqueous zinc-ion battery

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Rare Metals 2024年第4期43卷 1599-1609页

作者： bin-Rui Xu Quan-An Li Yong Liu Guang-bin Wang Zi-He zhang Feng-zhang Ren School of Material Science and Engineering Henan University of Science and TechnologyLuoyang471023China School of Information Engineering Henan University of Science and TechnologyLuoyang471023China Longmen Laboratory Luoyang471023China Provincial and Ministerial Co-Construction of Collaborative Innovation Center for Non-Ferrous Metal New Materials and Advanced Processing Technology Luoyang471023China

Aqueous zinc-ion batteries(AZIBs)have been regarded as prospective rechargeable energy storage devices because of the high theoretical capacity and low redox potential of Zn ***,the uncontrollable formation of dendrites and the water-induced side reactions at the Zn/electrolyte interface,and the poor reversibility under a high current density(>2 mA·cm^(-2))and large area capacity(>2 mAh·cm^(-2))still limit the practical applications of ***,a strategy that can overcome these difficulties is urgently ***,we introduce an environmentally friendly and low-cost additive,namely urea,to the electrolyte of AZIBs to induce uniform Zn deposition and suppress the side *** of the adsorption behavior,electrochemical characterization,and observations of the morphology revealed the interfacial modification induced by urea on the Zn/electrolyte interface,demonstrating its huge potential in ***,the long-term cycling stability(over2100 h)of a Zn/Zn symmetric cell under a high current density of 5 mA·cm^(-2)and a capacity of 5 mAh·cm^(-2)was achieved with a 1 mol·L^(-1)ZnSO_(4)electrolyte with the urea ***,the assembled Zn/NH_4V_4O_(10)full cell with urea exhibited excellent cycling performance and an outstanding average Coulombic efficiency of 99.98%.These results indicate that this is a low-cost and effective additive strategy for realizing highly reversible AZIBs.

关键词： Zn anode Urea additive Interface engineering dendrite growth Side reaction

Churning loss characteristics of a wet three-phase high-speed reluctance motor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 251-267页

作者： Zhenzhou zhang Mingzhu DAI Chenchen zhang Yi CHEN bin MENG College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China

With the increasing requirements of electro-hydrostatic actuators(EHAs)for power,volume,and pressure,there is a growing tendency in the industry to combine the motor and pump to form a so-called'motor pump'to improve the *** this paper,a novel structure for a wet three-phase high-speed reluctance motor pump is proposed,which can further improve integration by removing the dynamic seal on the pump shaft,thereby avoiding the problems of dynamic seal wear and oil leakage and improving heat dissipation under high-speed working ***,after the motor is wetted,the churning loss caused by immersion of the rotor in the oil causes additional fluid resistance *** on fundamental fluid mechanics,an analytical model of the churning torque of a wet motor was *** verify the accuracy of the analytical model,a simulation model of churning loss was established based on computational fluid dynamics(CFD),and the churning torque and flow field state were ***,an experimental prototype was designed and manufactured,and a test bench for churning loss was *** oil churning torque was measured at different speeds and *** results from the analytical,simulation,and experimental models agreed *** experimental results validated the analytical model and CFD *** research provides a practical method for calculating the churning loss and serves as guidance for future optimization of churning loss reduction.

关键词： Motor pump Wet motor Churning loss Analytical model Computational fluid dynamics(CFD)

Multi-scenario Simulation of the Impact of Land Use Change on the Ecosystem Service Value in the Suzhou-Wuxi-Changzhou Metropolitan Area,China

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Chinese Geographical Science 2024年第1期34卷 79-92页

作者： WANG bin HU Chunguang zhang Yushuo department of Tourism Management Soochow UniversitySuzhou215123China Academy of Culture and Tourism Research Soochow UniversitySuzhou215123China School of Architecture and Urban Planning Huazhong University of Science and TechnologyWuhan430074China Hubei Engineering and Technology Research Center of Urbanization Wuhan430074China Faculty of Culture Tourism Shanxi University of Finance and EconomicsTaiyuan030006China

As the most economically developed metropolitan area in China’s Yangtze River delta,the rapid changing land use patterns of Suzhou-Wuxi-Changzhou(Su-Xi-Chang) metropolitan area have profound impacts on the ecosystem service value(ESV).Based on the patterns of land use change and the ESV change in Su-Xi-Chang metropolitan area from 2000 to 2020,we set up four scenarios:natural development scenario,urban development scenario,arable land protection scenario and ecological protection scenario,and simulated the impact of land use changes on the ESV in these *** results showed that:1) the area of built-up land in the Su-XiChang metropolitan area increased significantly from 2000 to 2020,and the area of other types of land *** land underwent the highest transfer-out area,and was primarily converted into built-up *** total ESV of Su-Xi-Chang metropolitan area increased initially then declined from 2000–2020,and the value of almost all individual ecosystem services decreased.2) Population density,GDP per area,night lighting intensity,and road network density can negatively impact the ESV.3) The total ESV loss under the natural development and urban development scenarios was high,and the expansion of the built-up land and the drastic shrinkage of the arable land contributed to the ESV decline under both *** total ESV under arable land protection and ecological protection scenarios increases,and therefore these scenarios are suitable for future land use optimization in *** study could provide a certain reference for land use planning and allocation,and offer guidance for the rational allocation of land resources.

关键词： multiple scenarios land use simulation ecosystem service value(ESV) Patch-Generating Land Use Simulation(PLUS)model Suzhou-Wuxi-Changzhou(Su-Xi-Chang)metropolitan area