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Journal of Thermal Science 2021年第4期30卷 1160-1173页

作者： tao Chengfei ZHOU Hao Institute for Thermal Power Engineering Zhejiang UniversityState Key Laboratory of Clean Energy UtilizationHangzhou 310027China

The effects of tabular stratified CO_(2)/O_(2)jet in cross flow on thermoacoustic instability and NO_(x)emission were experimentally *** explore the dependence of injection positions on flame stability,two factors were taken:the injection height and the injection direction of CO_(2)/O_(2)*** show that the injection positions seriously affect the control *** optimum acoustic amplitude-damped ratio of thermoacoustic instability can reach 76.61%with the first layer of horizontal *** sound pressure amplitude declined from 56 Pa to 13.1 *** concentration-damped ratio of NO_(x)emission can achieve 66.67%with the first layer of vertical *** concentration of NO_(x)emission declined from 50.4 mg/m^(3)to 16.8mg/m^(3)as the jet in cross flow rate *** oxygen ratio of stratified CO_(2)/O_(2)jets can produce lower NO_(x)emission but higher combustion *** descending gradient of NO_(x)emissions is different among different injection *** shifting of the sound pressure and flame CH*chemiluminescence *** oscillation frequency declined as the flow rate of CO_(2)/O_(2)jets *** unsteady long and compact flame was dispersed after CO_(2)/O_(2)*** macrostructure of flame was characterized as flatter and short under jet in cross *** variation curves of the flame length and top view area are similar to the shape of half saddle *** research proved the optimal control of thermoacoustic instability and NO_(x)emissions with a passive method,which could be conducive to the realization of clean and secure combustion in industrial lean premixed combustors.

关键词： CO_(2)/O_(2) combustion instability jet in cross flow NO_(x)emission tabular injector

Quantum-Behaved Particle Swarm Optimization Algorithm Based on the Two-Body Problem

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Chinese Journal of Electronics 2019年第3期28卷 569-576页

作者： YAN tao LIU Fengxian Institute of Big Data Science and Industry Shanxi University School of Computer and Information Technology Shanxi University Key Laboratory of Computational Intelligence and Chinese Information Processing of Ministry of Education Guangzhou Institute of Electronic Technology Chinese Academy of Sciences University of Chinese Academy of Sciences

The present study proposes an improved Quantum-behaved particle swarm optimization algorithm based on the two-body problem model(QTPSO) for solving the problem that other quantum-behaved particle swarm optimization algorithms easily converge on local optimal solutions when solving complex nonlinear problems. In the proposed QTPSO algorithm, particles are categorised as core particles and edge particles. Once the position of the core particle is determined, the edge particle appears in the vicinity of the attractor exhibiting a high probability, and the attractor is obtained through the random weighted sum of the core particle and the optimal mean position. Through simulation of the motion of these two particles by applying the interaction of the particles in the two-body problem, this mechanism not only improves the diversity of the population, but also enhances the local search capacity. To validate the proposed algorithm, three groups of experimental results were obtained to compare the proposed algorithm with other swarm intelligence algorithms. The experimental results indicate the superiority of the QTPSO algorithm.

关键词： Quantum-behaved particle swarm optimization Two-body problem Quantum potential well Wave function Nonlinear optimization problems

Track-before-detect for bistatic radar based on pseudo-spectrum

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Chinese Journal of Aeronautics 2024年第1期37卷 236-246页

作者： tao HAN Gongjian ZHOU School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Marine Environmental Monitoring and Information Processing Ministry of Industry and Information TechnologyHarbin 150001China

Track-Before-Detect(TBD) is an efficient method to detect dim targets for radars. Conventional TBD usually follows an approximate motion model of the target, which may cause an inaccurate integration of the target energy. A TBD technique on basis of pseudo-spectrum in mixed coordinates adopting an accurate motion model for bistatic radar system is developed in this *** predicted position in bistatic polar plane is derived according to a nonlinear function that exactly describes the constant Cartesian velocity motion. Then around the predicted position, a pseudo-spectrum is formulated and its samples are accumulated to the integration frame for energy integration. The evolution of the state and the procedure of accumulation of the target energy are derived elaborately. The superior performance of the proposed method is demonstrated by some simulations.

关键词： Weak target detection Bistatic radar Track-before-detect Pseudo-spectrum Multiframe integration

Exploration of Multiple Access Interference Suppression Based on Multi-user Detection

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Chinese Journal of Electronics 2019年第4期28卷 835-840页

作者： WU tao JING Xiaojun Beijing University of Posts and Telecommunications

A multi-user detection algorithm for multiple access interference suppression combined with the minimum mean squared error and an artificial fish swarm algorithm is proposed. By taking advantage of the artificial fish swarm algorithm, the proposed algorithm can quickly converge to the optimal solution. The variation in the minimum mean squared error based test results is assigned to the artificial fish swarm algorithm, which is regarded as the initial state of artificial fish. The simulation results show that the proposed algorithm has a better multi-user capacity performance and lower bit-error rate than the minimum mean squared error detector.

关键词： Multiple access interference suppression Minimum mean squared error Artificial fish swarm algorithm Multi-user detection algorithm Code division multiple access

Radar emitter signal recognition method based on improved collaborative semi-supervised learning

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Journal of Systems Engineering and Electronics 2023年第5期34卷 1182-1190页

作者： JIN tao ZHANG Xindong College of Electronic Science and Engineering Jilin UniversityChangchun 130012China

Rare labeled data are difficult to recognize by using conventional methods in the process of radar emitter *** solve this problem,an optimized cooperative semi-supervised learning radar emitter recognition method based on a small amount of labeled data is ***,a small amount of labeled data are randomly sampled by using the bootstrap method,loss functions for three common deep learning net-works are improved,the uniform distribution and cross-entropy function are combined to reduce the overconfidence of softmax ***,the dataset obtained after sam-pling is adopted to train three improved networks so as to build the initial *** addition,the unlabeled data are preliminarily screened through dynamic time warping(DTW)and then input into the initial model trained previously for *** the judg-ment results of two or more networks are consistent,the unla-beled data are labeled and put into the labeled data ***,the three network models are input into the labeled dataset for training,and the final model is *** revealed by the simula-tion results,the semi-supervised learning method adopted in this paper is capable of exploiting a small amount of labeled data and basically achieving the accuracy of labeled data recognition.

关键词： emitter signal identification time series bootstrap semi supervised learning cross entropy function homogeniza-tion dynamic time warping(DTW)

Deep Reinforcement Learning Based Mobile Robot Navigation:A Review

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Tsinghua Science and Technology 2021年第5期26卷 674-691页

作者： Kai Zhu tao Zhang the Department of Automation Tsinghua UniversityBeijing 100084China the Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Navigation is a fundamental problem of mobile robots,for which Deep Reinforcement Learning(DRL)has received significant attention because of its strong representation and experience learning *** is a growing trend of applying DRL to mobile robot *** this paper,we review DRL methods and DRL-based navigation *** we systematically compare and analyze the relationship and differences between four typical application scenarios:local obstacle avoidance,indoor navigation,multi-robot navigation,and social ***,we describe the development of DRL-based ***,we discuss the challenges and some possible solutions regarding DRL-based navigation.

关键词： mobile robot navigation obstacle avoidance deep reinforcement learning

Heat Transfer and Friction Characteristics of Printed Circuit Heat Exchangers with Different Channel Structures for S-CO_(2) Power System

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Journal of Thermal Science 2024年第3期33卷 1132-1147页

作者： JIANG tao LI Mingjia Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

Printed circuit heat exchanger(PCHE)has been widely used in supercritical carbon dioxide(S-CO_(2))power systems because of its high heat transfer efficiency and good ***,due to the large variety of PCHE configurations,channel selection in practical applications lacks a ***,this paper discussed the heat transfer and friction characteristics and the synergy of three fields in the channel under the guidance of the field synergy principle for four typical PCHE ***,the comprehensive performance of four channels was ***,the heat transfer and friction factor correlations for S-CO_(2)in four channels were *** findings demonstrate that the synergy of velocity and pressure fields of the straight channel PCHE is better(β≈180°),so its resistance loss is relatively *** zigzag and sinusoidal wavy channels and the airfoil fins can reduce the angle a between the temperature gradient and velocity,thus enhancing the heat *** sinusoidal wavy channel can reduce flow resistance compared to the zigzag channel due to the rounded *** streamlined airfoil structure can guide the flow and reduce backflow,thus reducing resistance *** the range of Re studied in this paper,the maximum error of the proposed heat transfer and friction factor correlations of PCHE is 7.0%,which shows good fitting *** research in this paper can provide a reference for the selection and design of PCHE with different channel configurations.

关键词： printed circuit heat exchanger supercritical carbon dioxide typical channel structure field synergy analysis

C–H bond activation in the total syntheses of natural products

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Science China Chemistry 2016年第9期59卷 1109-1125页

作者： Pengyu tao Yanxing Jia State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical Sciences Peking University

The transition metal-mediated C–H bond activation has emerged as a powerful and ideal method for the total syntheses of natural products and pharmaceuticals, and has had a significant impact on synthetic planning and strategy in complex natural *** this review, we describe selected recent examples of the transition metal-mediated C–H bond activation strategies for the rapid syntheses of natural products.

关键词： C-H activation transition metal natural product total synthesis

On m-ovoids of finite classical polar spaces with an irreducible transitive automorphism group

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Science China Mathematics 2024年第3期67卷 683-712页

作者： tao Feng Weicong Li Ran tao School of Mathematical Sciences Zhejiang UniversityHangzhou 310027China Department of Mathematics and National Center for Applied Mathematics Shenzhen Southern University of Science and TechnologyShenzhen 518055China Key Laboratory of Cryptologic Technology and Information Security Ministry of EducationShandong UniversityQingdao 266237China School of Cyber Science and Technology Shandong UniversityQingdao 266237China

In this paper, we classify the m-ovoids of finite classical polar spaces that admit a transitive automorphism group acting irreducibly on the ambient vector space. In particular, we obtain several new infinite familie... 详细信息

关键词： transitive m-ovoids irreducible action finite classical polar spaces primitive divisor

Gas-surface interaction features under effects of gas-gas molecules interaction in high-speed flows

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Chinese Journal of Aeronautics 2024年第5期37卷 228-242页

作者： Ruiling tao Zhihui WANG School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Understanding interactions between gas molecules and solid surface is key to the aerodynamic design of high-speed,high-altitude aerospace vehicles,but there is a large dispersion of gas-surface interaction parameters or namely accommodation *** uncertainty results partly from different considerations of the interaction between gas molecules in various experimental and numerical *** this study,effects of gas-gas molecules interaction are systematically discussed by comparing two different approaches of molecular dynamics simulation of high-speed argon molecules scattering on a graphite *** popularly-used“single scattering”approach repeats the scattering process of a single gas molecule without considering the gas-gas molecules *** newly-developed“continual scattering”approach continually shoots gas molecules at the surface,considering collisions between gas molecules in addition to gas molecules’collisions with ***-surface interaction features in the two approaches are compared and discussed under various affecting factors including rarefaction degree,gas-surface interaction strength,surface temperature and incident *** is shown that these two approaches usually produce different accommodation coefficients,and the corresponding mechanisms are *** study could help clarify some doubts about the selection of accommodation coefficients in engineering practice,and also provide an instruction on design of an appropriate molecular dynamics simulation approach.

关键词： Gas-surface interaction Molecular dynamics Accommodation coefficient Aerospace vehicles High-speed flow