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Efficient Monolithic Perovskite/Silicon Tandem Photovoltaics

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Energy & Environmental Materials 2024年第3期7卷 268-281页

作者： Yong wang Yu wang Feng Gao Deren Yang State Key Laboratory of Silicon Materials and School of Materials Science and engineering Zhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 310014China Department of Physics Chemistry and Biology(IFM)Linköping UniversityLinköping 58183Sweden

Tunable bandgaps make halide perovskites promising candidates for developing tandem solar cells(TSCs),a strategy to break the radiative limit of 33.7%for single-junction solar *** perovskites with market-dominant crystalline silicon(c-Si)is particularly attractive;simple estimates based on the bandgap matching indicate that the efficiency limit in such tandem device is as high as 46%.However,state-of-the-art perovskite/c-Si TSCs only achieve an efficiency of~32.5%,implying significant challenges and also rich *** this review,we start with the operating mechanism and efficiency limit of TSCs,followed by systematical discussions on wide-bandgap perovskite front cells,interface selective contacts,and electrical interconnection layer,as well as photon management for highly efficient perovskite/c-Si *** highlight the challenges in this field and provide our understanding of future research directions toward highly efficient and stable large-scale wide-bandgap perovskite front cells for the commercialization of perovskite/c-Si TSCs.

关键词： 2-terminal electrical interconnection perovskite/silicon tandem photovoltaics photon management wide-bandgap perovskites

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

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Nano Research 2024年第1期17卷 5-17页

作者： Tian wang Yating wang Yuhang Li Chunzhong Li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of Chemical engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(CH_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of CH_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-CH_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface

Quaternion-Based Adaptive Trajectory Tracking Control of a Rotor-Missile with Unknown Parameters Identification

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Defence Technology（防务技术） 2024年第1期31卷 375-386页

作者： Jie Zhao Zhongjiao Shi Yuchen wang Wei wang Beijing Institute of Technology Beijing 100081China

This paper investigates the adaptive trajectory tracking control problem and the unknown parameter identification problem of a class of rotor-missiles with parametric system ***,considering the uncertainty of structural and aerodynamic parameters,the six-degree-of-freedom(6Do F) nonlinear equations describing the position and attitude dynamics of the rotor-missile are established,respectively,in the inertial and body-fixed reference ***,a hierarchical adaptive trajectory tracking controller that can guarantee closed-loop stability is proposed according to the cascade characteristics of the 6Do F ***,a memory-augmented update rule of unknown parameters is proposed by integrating all historical data of the regression *** long as the finitely excited condition is satisfied,the precise identification of unknown parameters can be ***,the validity of the proposed trajectory tracking controller and the parameter identification method is proved through Lyapunov stability theory and numerical simulations.

关键词： Rotor-missile Adaptive control Parameter identification Quaternion control

A Mode-switching Strategy of Droop Control for VSC-MTDC Systems Considering Maximum DC Voltage Regulation Capability

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 903-912页

作者： Yizhen wang Fengliang Qiu Zhongguan wang Yirun Ji Zhengguang Chen Chengshan wang Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China Electric Power Research Institute of State Grid JiBei Electric Power Co.Ltd. Beijing 100045China State Grid Corporation of China Beijing 100031China IEEE

To achieve the goal of carbon neutrality,renewable energy integration through a voltage source converter based multi-terminal direct current(VSC-MTDC)system has been identified as a promising *** tackle the significant DC voltage over-limit problem in a VSC-MTDC system during disturbances,this paper proposes a mode-switching strategy of droop control considering maximum DC voltage regulation *** close relationship between node injection powers and node DC voltages in the MTDC system is elaborated,and the most effective regulation approach of local injection power for limiting DC voltage deviation is *** operating point trajectories of different droop control explains that the DC voltage deviation can be minimized by fully utilizing the capacity of ***,the mode-switching strategy with the maximum DC voltage regulation capability is realized by the switching between the voltage droop control and the constant maximum power *** addition,a mode recovery process and a smooth switching method are developed to make converters regain the capability of maintaining DC voltage and reduce power fluctuation during mode switching,***,three cases are investigated to verify the effectiveness of the proposed mode-switching *** with simulation results of the conventional droop control and the DC voltage deviation-dependent droop control,better performance of transient and steady-state DC voltage deviation is achieved through the proposed strategy.

关键词： Droop control maximum DC voltage regulation capability mode-switching VSC-MTDC

Dynamics modeling and optimal control for multi-information diffusion in Social Internet of Things

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Digital Communications and Networks 2024年第3期10卷 655-665页

作者： Yaguang Lin Xiaoming wang Liang wang Pengfei Wan School of Computer Science Shaanxi Normal UniversityXi'an710119China

As an ingenious convergence between the Internet of Things and social networks,the Social Internet of Things(SIoT)can provide effective and intelligent information services and has become one of the main platforms for people to spread and share ***,SIoT is characterized by high openness and autonomy,multiple kinds of information can spread rapidly,freely and cooperatively in SIoT,which makes it challenging to accurately reveal the characteristics of the information diffusion process and effectively control its *** this end,with the aim of exploring multi-information cooperative diffusion processes in SIoT,we first develop a dynamics model for multi-information cooperative diffusion based on the system dynamics theory in this ***,the characteristics and laws of the dynamical evolution process of multi-information cooperative diffusion are theoretically investigated,and the diffusion trend is *** this basis,to further control the multi-information cooperative diffusion process efficiently,we propose two control strategies for information diffusion with control objectives,develop an optimal control system for the multi-information cooperative diffusion process,and propose the corresponding optimal control *** optimal solution distribution of the control strategy satisfying the control system constraints and the control budget constraints is solved using the optimal control ***,extensive simulation experiments based on real dataset from Twitter validate the correctness and effectiveness of the proposed model,strategy and method.

关键词： Social Internet of Things Information diffusion Dynamics modeling Trend prediction Optimal control

Underwater Directional Acoustic Source Based on Pentamode Material

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Acta Mechanica Solida Sinica 2024年第1期37卷 1-9页

作者： Binghao Zhao Peng wang Dongwei wang Gengkai Hu School of Aerospace engineering Beijing Institute of TechnologyBeijing 100081China Wuhan Second Ship Design and Research Institute Wuhan 430205China

An underwater directional acoustic emitter is conceived with a highly anisotropic lattice material,whose acoustic characteristics manifest strong dependence on the orientation of the lattice material’s principal *** these features,a cylindrical structure made of such anisotropic lattice material is engineered to possess distinct impedance values in different directions,thereby facilitating wave emission along the principal axis while inducing reflection in other ***,through numerical simulations,it is demonstrated that the emission direction can be effectively manipulated by adjusting the principal axis orientation,concurrently enhancing the emitted *** contrast to previous directional acoustic structures,the compact emitter presented in this study can get rid of the size-wavelength constraint,enabling effective control of low-frequency waves.

关键词： Underwater Directional emission Pentamode material Broadband frequency

Numerical study on ignition start-up process of an underwater solid rocket motor across a wide depth range

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Chinese Journal of Aeronautics 2024年第10期37卷 136-157页

作者： Deyou wang Shipeng LI Ge JIN Ruyao wang Dian GUAN Ningfei wang School of Aerospace engineering Beijing Institute of TechnologyBeijing 100081China Beijing System Design Institute of Electro-mechanic engineering Beijing 100854China

Solid rocket motors have important applications in the propulsion of trans-media vehicles and underwater launched *** this paper,the ignition start-up process of an underwater solid rocket motor across a wide depth range has been numerically studied.A novel multi-domain integrated model has been developed by combining the solid propellant ignition and combustion model with the volume of fluid multiphase *** integrated model enables the coupled simulation of the propellant combustion and gas flow inside the motor,along with the gas jet evolution in the external water *** detailed flow field developments in the combustion chamber,nozzle,and wake field are carefully *** variation rules of the internal ballistics and thrust performance are also *** effects of environmental medium and operating depth on the ignition start-up process are systematically *** results show that the influence of the operating environment on the internal ballistic characteristics is primarily reflected in the initial period after the nozzle closure *** development of the gas jet in water lags significantly compared with that in *** the water depth increases,the ignition delay time of the motor is shortened,and the morphology evolution of the gas jet is significantly compressed and ***,the necking and bulging of the jet boundary near the nozzle outlet and the consequent shock oscillations are intensified,resulting in stronger fluctuations in the wake pressure field and motor thrust.

关键词： Underwater propulsion Solid rocket motor Ignition start-up process Underwater gas jet Thrust oscillation

Polyelectrolytes of Inorganic Polyoxometalates:Prospecting New Charged Polymers for Advanced Applications

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Chinese Journal of Polymer Science 2024年第9期42卷 1254-1269,I0005页

作者： De-Yin wang Zhuo-Qun Lu Wei wang College of Medical Linyi UniversityLinyi276000China Center for Synthetic Soft Materials Key Laboratory of Functional Polymer Materials of the Ministry of EducationInstitute of Polymer ChemistryNankai UniversityTianjin300071China

Polyelectrolytes are charged polymers comprising macromolecules in which substantial portions of the constituent units contain cationic(e.g.,pyridinium,ammonium)or anionic(e.g.,sulfonate,carboxylate)groups,which possess special functions from the features of counterions,such as dissociation to charged species,mechanical stability,phase behavior,***,functional polyelectrolytes have been widely applied in many *** this perspective,we present some progresses in the studies of poly(polyoxometalate)s,denoted as poly(POM)s,as a kind of new charged polymers/polyelectrolytes,by covalent bonding between the inorganic polyoxometalate(POM)clusters and the organic polymer *** to the distinct positions of POMs in polymer chain and functions of poly(POM)s,they are divided into the following four categories:crosslinked poly(POM);side-chain poly(POM);backbone poly(POM),including poly(POM)-conjugated polymer hybrid and block poly(POM)-polymer;and POM-based covalent organic framework(PCOF).This perspective introduces the synthesis methods of poly(POM)polyelectrolytes and their macromolecular and aggregate structural characteristics,while also focusing on their properties and *** application areas include catalysis,thermal resistance,optical functions,fuel cells and batteries,etc.

关键词： Charged polymer Polyelectrolyte Polyoxometalate Poly(polyoxometalate) Covalent organic framework

Influence of bolt dynamic installation on topography characteristics and mechanical behaviors of CFRP interference-fit bolted joints

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Chinese Journal of Aeronautics 2024年第2期37卷 482-500页

作者： Xiaohe wang Zengqiang CAO Yuehaoxuan wang Yingjiang GUO School of Mechanical engineering Northwestern Polytechnical UniversityXi’an 710072China NPU Xuhang Electromagnetic Technology Co. Ltd.Xi’an 710100China

As the controlled research of Dynamic Installation(DI)and Static Installation(SI),a new interference installation method was developed based on electromagnetic loading to enhance the mechanical properties of composite *** different interference-fit sizes were considered,ranging from a net fit to 2.0%.The experiments were conducted to evaluate the installation resistance and the mechanical behavior of the joint under external ***,an FFA model to model the stress distribution and damage behavior of the bolt-hole contact interface was *** load-displacement curve and damage modes of experiments were used to verify the FEA *** results show that the installation resistance during DI process was remarkably lower than that of SI process corresponding to all interference-fit sizes,and the stress amplitudes induced by interference were larger and widely *** damage of the hole wall was positively correlated with interference fit size,but DI can significantly reduce the damage compared to *** performance tests,DI enhanced the static bearing capacity and extended longer fatigue life of the joints than *** methods can be an effective way to achieve highly reliable interference joints in composite structures.

关键词： Carbon Fiber-Reinforced Polymer(CFRP) Bolted joints Interference-fit Electromagnetic installation Finite Element Analysis(FEA) Damage mechanics Bearing behavior