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Journal of Systems Science and Systems Engineering 2023年第1期32卷 16-33页

作者： Tong YANG Yanzhong Dang Jiangning Wu Institute of Systems Engineering Dalian University of TechnologyDalian116024China

Perceived quality is consumers’subjective perceptions of a product’s attributes,which directly influences the overall evaluation of the product.Existing research has suggested that the perceived quality of attributes has an asymmetric effect on the overall evaluation,but limited research has been conducted on this asymmetric effect in the automobile industry and the moderating effect of sentiment.This paper investigates the asymmetric effect of perceived quality on overall evaluation using social media data from the automobile industry.First,the asymmetric effect of perceived quality on overall evaluation was identified for different attributes using penalty-reward contrast analysis(PRCA),and attribute classification was realized by calculating the IA index,i.e.,Appearance is an excitement attribute and the remaining attributes are basic attributes.Second,the differences in the asymmetric effects of each attribute category were analyzed,and the basic attributes were found to have a greater effect on the overall evaluation,with a positive moderating effect of sentiment on the effect.This study contributes to perceived quality research as well as consumer evaluation research and provides manufacturers with a prioritization method for attribute improvement.

关键词： Perceived quality overall evaluation asymmetric effects OLS automobile reviews

Real-time detection network for tiny traffic sign using multi-scale attention module

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Science China(Technological Sciences) 2022年第2期65卷 396-406页

作者： yang TingTing tong Chao School of Computer Science&Engineering Beihang UniversityBeijing 100191China

As one of the key technologies of intelligent vehicles, traffic sign detection is still a challenging task because of the tiny size of its target object. To address the challenge, we present a novel detection network improved from yolo-v3 for the tiny traffic sign with high precision in real-time. First, a visual multi-scale attention module(MSAM), a light-weight yet effective module, is devised to fuse the multi-scale feature maps with channel weights and spatial masks. It increases the representation power of the network by emphasizing useful features and suppressing unnecessary ones. Second, we exploit effectively fine-grained features about tiny objects from the shallower layers through modifying backbone Darknet-53 and adding one prediction head to yolo-v3. Finally, a receptive field block is added into the neck of the network to broaden the receptive field. Experiments prove the effectiveness of our network in both quantitative and qualitative aspects. The m AP@0.5 of our network reaches 0.965 and its detection speed is55.56 FPS for 512 × 512 images on the challenging Tsinghua-Tencent 100 k(TT100 k) dataset.

关键词： tiny object detection traffic sign detection multi-scale attention module real-time

Photocatalytic and Electrocatalytic Generation of Hydrogen Peroxide: Principles, Catalyst Design and Performance

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Nano-Micro Letters 2023年第6期15卷 24-72页

作者： Yan Guo Xili tong Nianjun yang State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China Institute of Materials Engineering University of Siegen57076 SiegenGermany Department of Chemistry Hasselt University3590 DiepenbeekBelgium IMO‑IMOMEC Hasselt University3590 DiepenbeekBelgium

Hydrogen peroxide(H_(2)O_(2)) is a high-demand organic chemical reagent and has been widely used in various modern industrial applications. Currently,the prominent method for the preparation of H_(2)O_(2) is the anthraquinone oxidation.Unfortunately, it is not conducive to economic and sustainable development since it is a complex process and involves unfriendly environment and potential hazards. In this context, numerous approaches have been developed to synthesize H_(2)O_(2). Among them, photo/electro-catalytic ones are considered as two of the most promising manners for on-site synthesis of H_(2)O_(2). These alternatives are sustainable in that only water or O_(2) is required. Namely, water oxidation(WOR) or oxygen reduction(ORR)reactions can be further coupled with clean and sustainable energy. For photo/electro-catalytic reactions for H_(2)O_(2) generation, the design of the catalysts is extremely important and has been extensively conducted with an aim to obtain ultimate catalytic performance. This article overviews the basic principles of WOR and ORR,followed by the summary of recent progresses and achievements on the design and performance of various photo/electro-catalysts for H_(2)O_(2) generation. The related mechanisms for these approaches are highlighted from theoretical and experimental aspects. Scientific challenges and opportunities of engineering photo/electro-catalysts for H_(2)O_(2) generation are also outlined and discussed.

关键词： H_(2)O_(2)generation Photocatalysts Electrocatalysts Reaction mechanisms

Heat Transfer Problem for the Boltzmann Equation in a Channel with Diffusive Boundary Condition

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Chinese Annals of Mathematics,Series B 2022年第6期43卷 1071-1100页

作者： Renjun DUAN Shuangqian LIU Tong YANG Zhu ZHANG Department of Mathematics The Chinese University of Hong KongShatinHong KongChina School of Mathematics and Statistics and Hubei Key Laboratory of Mathematical Sciences Central China Normal UniversityWuhan 430079China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong KongChina.

In this paper,the authors study the 1 D steady Boltzmann flow in a channel.The walls of the channel are assumed to have vanishing velocity and given temperaturesθ0andθ1.This problem was studied by Esposito-Lebowitz-Marra(1994,1995)where they showed that the solution tends to a local Maxwellian with parameters satisfying the compressible Navier-Stokes equation with no-slip boundary condition.However,a lot of numerical experiments reveal that the fluid layer does not entirely stick to the boundary.In the regime where the Knudsen number is reasonably small,the slip phenomenon is significant near the boundary.Thus,they revisit this problem by taking into account the slip boundary conditions.Following the lines of[Coron,F.,Derivation of slip boundary conditions for the Navier-Stokes system from the Boltzmann equation,J.Stat.Phys.,54(3-4),1989,829-857],the authors will first give a formal asymptotic analysis to see that the flow governed by the Boltzmann equation is accurately approximated by a superposition of a steady CNS equation with a temperature jump condition and two Knudsen layers located at end points.Then they will establish a uniform L∞estimate on the remainder and derive the slip boundary condition for compressible Navier-Stokes equations rigorously.

关键词： Boltzmann equation Compressible Navier-Stokes approximation Slip boundary conditions Chapman-Enskog expansion

High-Throughput Computational Discovery and Intelligent Design of Two-Dimensional Functional Materials for Various Applications

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Accounts of Materials Research 2022年第6期3卷 572-583页

作者： Lei Shen Jun Zhou Tong YANG Ming yang Yuan Ping Feng Department of Mechanical Engineering National University of SingaporeSingapore 117575Singapore Institute of Materials Research and Engineering Agency for ScienceTechnology and Research(A*STAR)138634Singapore Department of Physics National University of SingaporeSingapore 117551Singapore Department of Applied Physics The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong SARChina

Novel technologies and new materials are in high demand for future various applications to overcome the fundamental limitations of current techniques.For example,the nanomaterials are in high demand for the miniaturization of electric devices.Spintronics is one of the most viable solutions for green electric devices.The single-atom catalysts can provide a 100%utilization rate.Heterojunctions hold promise for applications in energy conversion and storage.Two-dimensional(2D)materials show promising applications in various applications because they can be tailored to the specific property on which a technology is based and may be compatible with other technologies.Although the number of experimentally discovered 2D materials is growing,the speed is very slow and only a few dozen 2D materials have been synthesized or exfoliated since the discovery of graphene.Recently,a novel computational technique,dubbed high-throughput computational materials design,has become a burgeoning area of materials science,which is a combination of quantum mechanical theory,materials information,and database construction with intelligent data mining.This new and powerful tool can greatly accelerate the discovery,design,and application of 2D materials by creating a database containing a large number of 2D materials with calculated fundamental properties and then intelligently mining(via high-throughput automation or machine learning)the database in the search for 2D materials with the desired properties for particular applications,such as energy conversion/storage,catalysis,water purification,electronics,and optoelectronics.In this Account,we summarize our recent progress in the emerging area of 2D materials discovery,database construction,2D functional materials design,and device development by quantum-mechanical modeling,high-throughput calculations,and machine learning inspired by the materials genome concept.We developed an open 2D materials database−2D materials encyclopedia(2DMatPedia;http://www.***.org/),which includes a vari

关键词： ferroelectric Outlook overcome

Swing Suppression and Accurate Positioning Control for Underactuated Offshore Crane Systems Suffering From Disturbances

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 892-900页

作者： Tong YANG Ning Sun He Chen Yongchun Fang Institute of Robotics and Automatic Information Systems(IRAIS) College of Artificial IntelligenceTianjin 300350China Tianjin Key Laboratory of Intelligent Robotics(tjKLIR) Nankai UniversityTianjin 300350China IEEE School of Artificial Intelligence Hebei University of TechnologyTianjin 300401China

Offshore cranes are widely applied to transfer largescale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate uniform boundedness or asymptotical stability results for the system's equilibrium point, and the state variables' convergence time cannot be theoretically guaranteed. To address these problems, a nonlinear sliding mode-based controller is suggested to accurately drive the boom/rope to their desired positions. Simultaneously, payload swing can be eliminated rapidly with sea waves. As we know, this paper firstly presents a controller by introducing error-related bounded functions into a sliding surface, which can realize boom/rope positioning within a finite time, and both controller design and analysis based on the nonlinear dynamics are implemented without any linearization manipulations. Moreover, the stability analysis is theoretically ensured with the Lyapunov method. Finally, we employ some experiments to validate the effectiveness of the proposed controller.

关键词： Boom/rope positioning offshore cranes swing elimination underactuated systems

Numerical simulation study of sympathetic detonation in stages

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Defence Technology（防务技术） 2022年第8期18卷 1382-1393页

作者： tong-hui yang Cheng Wang Tao Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

A Direct Numerical Simulation (DNS) scheme for solving the temporal-spatial multiscale problem of sympathetic detonation is proposed. According to the physical and chemical properties, the SD process is divided into two stages in the numerical simulation. Two different grid sizes are used in the two stages to improve calculation accuracy and efficiency. The local Level Set Method is used to accurately track the multi-material interface, and the Harten Lax and van Leer Contact (HLLC) method is used to solve local Riemann problem. Based on the computing method mentioned above, choosing the high evolution Weighted Essentially Non-Oscillatory (WENO) scheme for the spatial discretization of governing equations in alliance with Total Variation Diminishing (TVD) Runge-Kutta for time discretization, the Eulerian code of SD is developed. It solves the data interaction between the two solvers with variable grid size and time step, and realizes the three-dimensional parallel computing of SD. Composition B is taken as the research object. The processes of SD in different stand-off distances are analyzed. The transmission and safety distances of Composition B are given. The test under the same conditions is designed to verify the numerical simulation. The numerical simulation results are in good agreement with the experiment, which proves the accuracy and feasibility of the numerical method.

关键词： Sympathetic detonation Explosives Numerical simulation

Spectrum structure and decay rate estimates on the Landau equation with Coulomb potential

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Science China Mathematics 2023年第1期66卷 37-78页

作者： Tong YANG Hongjun Yu Department of Mathematics City University of Hong KongHong KongChina School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper we first deduce the estimates on the linearized Landau operator with Coulomb potential and then analyze its spectrum structure by using semigroup theory and linear operator perturbation theory.Based on these estimates,we give the precise time decay rate estimates on the semigroup generated by the linearized Landau operator so that the optimal time decay rates of the nonlinear Landau equation follow.In addition,we present a similar result for the non-angular cutoff Boltzmann equation with soft potentials.

关键词： spectrum structure time decay rate Landau equation Boltzmann equation

Partial Differential Equations and Continuum Mechanics:a Collection of Papers Dedicated to Professor Philippe G. Ciarlet on the Occasion of His 80th Birthday

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Acta Mathematicae Applicatae Sinica 2019年第1期35卷 1-2页

作者： Cristinel MARDARE Tong YANG 不详

Preface This Special Issue in'Acta Mathematicae Applicatae Sinica(English Series)'gathers peer reviewed papers dedicated to Professor Philippe G.Ciarlet on the occasion of his eightieth birthday.Written by friends and colleagues from France and Hong Kong/China,they stand as a testimony of their admiration for an exceptional human being and mathematician.

关键词： Partial Differential Equations Continuum Mechanics

Decomposition analysis of CO_(2) emissions of electricity and carbon-reduction policy implication: a study of a province in China based on the logarithmic mean Divisia index method

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Clean Energy 2023年第2期7卷 340-349页

作者： Fuyuan yang Xiaobin yang Xueqin Tian Xinlei Wang tong Xu State Grid Economic and Technological Research Institute Co. LtdBeijing102209China State Grid Jiangxi Electric Power Research Institute State Grid Jiangxi Electric Power Co.LtdNanchangChina

As the proportion of electricity in final energy consumption gradually increases,CO_(2) emissions reduction actions in the power system will become the key to achieving China’s carbon-peak and carbon-neutrality goals.It is essential to analyse and quantify the driving forces of CO_(2) emissions from electricity generation in the fossil-rich area in China.This paper aims to identify the characteristics of CO_(2) emissions generated by electricity and provide a basis for formulating CO_(2)-reduction policies in power systems.First,we analyse the current state of CO_(2) emissions from electricity generation in Anhui Province that was dominated by fossil energy during the period 2010-19.Then,we apply the logarithmic mean Divisia index method to find the nature of the factors influencing the changes in CO_(2) emissions.Finally,we analyse the CO_(2)-reduction measures of each side of the source-network-load-storage of the power system in Anhui through a power-system carbon-reduction path analysis model proposed in this study and provide policy suggestions.The results showed the following.(i)CO_(2) emissions in Anhui Province continued to increase from 2010 to 2019 and the trend in the growth rate of CO_(2) emissions presented approximately a u-shaped curve.(ii)Economic activity has always been the dominant factor driving the growth of electricity CO_(2) emis-sions.The increase in the proportion of renewable energy in power generation,the improvement in thermal power-conversion efficiency and the decrease in the intensity of power consumption are the three major driving factors for the reduction in CO_(2) emissions from power generation in Anhui.(iii)The CO_(2)-reduction measures of the power system are provided in each link of the source-network-load-storage,such as developing the photovoltaic industry and building energy storage,upgrading and transforming coal-fired power stations,redu-cing the loss rate of transmission lines on the grid side and improving the efficiency of the utilization of electricity on the user s

关键词： CO_(2)emissions LMDI electricity generation carbon-reduction measures