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Two freedom linear parameter varying μ synthesis control for flight environment testbed

Chinese Journal of Aeronautics 2019年第5期32卷 1204-1214页

作者： Meiyin ZHU xi WANG Zhihong DAN song ZHANG xitong PEI School of Energy and Power Engineering Beihang University Collaborative Innovation Center for Advanced Aero-Engine Science and Technology on Altitude Simulation Laboratory

To solve the problem of robust servo performance of Flight Environment Testbed(FET)of Altitude Ground Test Facilities(AGTF) over the whole operational envelope, a two-degree-offreedom μ synthesis method based on Linear Parameter Varying(LPV) schematic is proposed, and meanwhile a new structure frame of μ synthesis control on two degrees of freedom with double integral and weighting functions is presented, which constitutes a core support part of the paper. Aimed at the problem of reference command's rapid change, one freedom feed forward is adopted, while another freedom output feedback is used to meet good servo tracking as well as disturbance and noise rejection; furthermore, to overcome the overshoot problem and acquire dynamic tuning,the integral is introduced in inner loop, and another integral controller is used in outer loop in order to guarantee steady errors; additionally, two performance weighting functions are designed to achieve robust specialty and control energy limit considering the uncertainties in system. As the schedule parameters change over large flight envelope, the stability of closed-loop LPV system is proved using Lyapunov inequalities. The simulation results show that the relative tracking errors of temperature and pressure are less than 0.5% with LPV μ synthesis controller. Meanwhile, compared with non-LPV μ synthesis controller in large uncertainty range, the proposed approach in this research can ensure robust servo performance of FET over the whole operational envelope.

关键词： Altitude ground test facilities Flight environment testbed Linear parameter varying Robust control Two-degree-of-freedom μ Synthesis

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多路径传输技术研究综述

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软件学报 2025年第1期36卷 289-320页

作者：苏金树宋丛溪计晓岚徐草韩彪国防科技大学计算机学院军事科学院

多路径传输技术是指通过设备上的多个网络接口,在通信双方建立多条传输路径,实现带宽聚合、负载均衡、路径冗余,增加传输的吞吐量,提高可靠性.多路径传输技术凭借其上述优势,已被广泛应用于服务器、终端和数据中心等场景,是网络体系结... 详细信息

多路径传输技术是指通过设备上的多个网络接口,在通信双方建立多条传输路径,实现带宽聚合、负载均衡、路径冗余,增加传输的吞吐量,提高可靠性.多路径传输技术凭借其上述优势,已被广泛应用于服务器、终端和数据中心等场景,是网络体系结构和传输技术研究的重要组成,具有重要研究价值和意义.为此,从概念、核心机制等方面,系统梳理了多路径传输技术.首先概述了多路径传输的基本概念、标准化进程以及应用价值.其次,阐述多路径传输技术的核心机制,包括拥塞控制、报文调度、路径管理、重传机制、安全机制,以及面向特定应用的机制设计.对每种机制的分类方法、主要研究成果给予了总结和评述,分析总结了不同机制的优缺点与发展方向.最后,探讨了多路径传输技术研究面临的挑战,展望了未来研究方向.

关键词：多路径传输 QUIC 拥塞控制报文调度智能网络

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An investigation on HOBEM in evaluating ship wave of high speed displacement ship

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Journal of Hydrodynamics 2019年第3期31卷 531-541页

作者： xi Chen Ren-chuan Zhu Ya-lan song Ju Fan Marine Design & Research Institute of China Shanghai 200011 China State Key L aboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

A practical numerical tool is developed to evaluate ship waves of high speed displacement ships on the basis of potential flow theory, in which high order boundary element method (HOBEM) based on biquadratic shape functions is applied to solve the boundary value problem. Since the sinkage and trim of ship at high speeds are notable, influences of ship attitude on wave drag are investigated and three kinds of models are used to evaluate them. To make the numerical approach highly efficient, an incomplete LU factorization preconditioner is adopted and incorporated with the restarted generalized minimal residual method GMRES (m) to solve the boundary integral equation. A corresponding Fortran code is developed and applied to evaluate ship waves of the Wigley hull and 4a model, a transom stem ship. Computations are performed for both monohulls and catamarans over a wide range of Froude numbers (Fr= 0.10-l.00). Numerical issues including mesh convergence and computational efficiency are investigated at first. Computed results of the wave drag, sinkage and trim show generally good agreement with experimental data. Reasonable wave patterns are obtained and physical phenomena that wake angle max, where the largest waves occur, would become narrow at high speeds is also captured by the present computations. Numerical results indicate the proposed method would be accurate and efficient to evaluate resistance for hull design of high speed displacement ship.

关键词： High speed ship ship waves HOBEM ILU-GMRES sinkage and trim

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Austenite Grain Growth in Heat Affected Zone of Zr-Ti Bearing Microalloyed Steel

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Journal of Iron and Steel Research International 2012年第2期19卷 73-78页

作者： ZHENG Lei YUAN Ze-xi song Shen-hua xi Tian-hui WANG Qian Department of Materials Science and Engineering Shenzhen Graduate School Harbin Institute of TechnologyShenzhen 518055 Guangdong China School of Materials and Metallurgy Wuhan University of Science andTechnology Wuhan 430081 Hubei China Research and Development Center Wuhan Iron and SteelCorporation Wuhan 430080 Hubei China

Austenite grain sizes in the heat affected zone （HAZ） of a high heat input welded Zr-Ti bearing microal- loyed steel are measured under different welding conditions simulated by a Gleeble-1500 thermal-mechanical simulator. The austenite grain growth is divided into two regimes in terms of temperature. When the temperature is lower than 1 250℃ where the pinning effect of precipitates is strong, the austenite grain size increases slowly with increas- ing peak temperature, but it increases drastically when the temperature is higher than 1 250 ~C where the pinning effect of precipitates is weak. Based on the experimental measurements, an analytical model for predicting the aus- tenite grain size in the heat affected zone is derived. model predictions indicate that the initial grain size has little effect on the final one, and the grain growth depends mainly on heat input and peak temperature as well as growth activation energy and exponent. With the use of the model, the width of coarse grained heat affected zone （CGHAZ） for a thick plate is predicted.

关键词： welding high heat input microstructure

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Multispectral ErBO_(3)@ATO porous composite microspheres with laser and electromagnetic wave compatible absorption

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Rare Metals 2023年第7期42卷 2406-2418页

作者： song-song Guo Jian-Ping Zhu Zhi song Qing-Guo Ren Tong Feng Qi-Tu Zhang Li-xi Wang College of Materials Science and Engineering Nanjing Tech UniversityNanjing211816China Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing211816China

The high-speed advances in electromagnetic(EM)wave and laser detection technology have accelerated the innovation of absorbing materials toward specific multi-band *** is difficult to achieve dual absorption of EM waves and near-infrared lasers by absorbing materials in a single frequency band;the design of high-performance laser-EM wave multi-band compatible absorbing materials is ***,ErBO_(3)@ATO(erbium borate/antimony-doped tin oxide)porous composite microspheres with an average size of 15-20μm are produced solvothermal method and self-assembly,which exhibit excellent laser-EM wave compatible *** porous structure on the surface of ErBO_(3)microspheres provides heterogeneous nucleation sites for ATO particle *** minimum reflectivity of the composite for1.06 and 1.54μm lasers is 9.59%and 4.79%,which is0.57%and 3.78%lower than those of pure ATO particles,*** composites containing 70 wt%porous ErBO_(3)@ATO reveal the minimum reflection loss(RL)value of-31.6 dB,and an effective absorption band width reaches 2.08 GHz at 2.5 mm *** mechanism of near-infrared laser and EM wave compatible absorption is the synergistic effect of the energy level transition of ErBO_(3)and the dielectric loss of ATO,coupled with the large surface area and porous structure of the micro ***,the designed porous ErBO_(3)@ATO composite microspheres can be an attractive choice for lasers and EM wave high-quality compatible absorption.

关键词： Core-shell ErBO_(3)@antinomy-doped tin oxide(ATO) Porous microsphere Laser reflection Electromagnetic(EM)wave loss

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Preparation and Performance of HGM/PPENK-based High Temperature-resistant Thermal Insulating Coatings

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Chinese Journal of Polymer Science 2021年第6期39卷 770-778,I0008页

作者： Lei song Li-Shuai Zong Jin-Yan Wang xi-Gao Jian State Key Laboratory of Fine Chemicals Department of Polymer Science and MaterialsSchool of Chemical EngineeringDalian University of TechnologyDalian 116024China

Novel high temperature-resistant coatings with high mechanical strength and thermal-insulating performance were prepared with poly(ether nitrile ketone)(PPENK)resin as matrix and hollow glass microspheres(HGMs)as thermal-insulating *** corresponding mechanical and thermal-insulating study indicated that the mechanical properties of the coatings decreased with the increase of HGM content,and were improved after surface modification of HGM by KH570 resulting in enhancement of interaction between HGM and PPENK *** thermal conductivity of HGM/PPENK thermal-insulating coating decreased with the increase of HGM content and coating thickness,along with the decrease of the true *** also showed slight increase trend due to HGMs surface *** HGM/PPENK coating filled with modified HGMs showed better thermal resistance than that of unmodified HGM/PPENK *** thermal decomposition temperature at 5%weight loss of the coating containing modified HGMs was 10°C lower than that of pure PPENK,and 40°C higher than that of neat HGM/PPENK *** coating exhibited commendable appearance after 400°C for 30 *** merits of HGM/PPENK-based thermal coatings obviously demonstrated promising prospect in thermal protection fields.

关键词： Coatings Temperature-resistant HGM/PPENK Thermal conductivity Mechanical properties

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A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing

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Digital Communications and Networks 2024年第2期10卷 282-291页

作者： Jiachen Yang Meng xi Jiabao Wen Yang Li Houbing Herbert song School of Electrical and Information Engineering Tianjin UniversityTianjin300072China Security and Optimization for Networked Globe Laboratory(song Lab) Embry-Riddle Aeronautical UniversityDaytona BeachFL32114USA

The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential *** to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal *** traditional models mainly utilize mathematical functions,which are not complete and *** existing path planning algorithms depend on the environment and lack *** overcome these challenges,we propose a path planning system for underwater intelligent internet *** applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path *** design a value-based reinforcement learning path planning algorithm and explore the optimal network structure *** path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge *** integration of state input enriches the learning of neural networks and helps to improve generalization and *** task-related reward function promotes the rapid convergence of the *** experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions.

关键词： Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning

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Metabolomics of Fuzi-Gancao in CCl4 induced acute liver injury and its regulatory effect on bile acid profile in rats

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World Journal of Gastroenterology 2021年第40期27卷 6888-6907页

作者： mo-Fei Wang song-song Zhao Dil momin Thapa Yu-Ling song Zheng xiang The Second Department of General Surgery The Affiliated Hospital of Inner Mongolia University for the NationalitiesTongliao 028000Inner Mongolia Autonomous RegionChina Department of Educational Administration The First Affiliated Hospital of Liaoning Medical UniversityJinzhou 121000Liaoning ProvinceChina School of Pharmaceutical Science Liaoning UniversityShenyang 110032Liaoning ProvinceChina

BACKGROUND Fuzi(Radix aconiti lateralis)-Gancao(Radix glycyrrhizae)is one of the most classical drug pairs of traditional Chinese *** clinical practice,decoctions containing Fuzi-Gancao(F-G)are often used in the treatment of liver diseases such as hepatitis and liver *** To investigate the metabolomics of F-G in CCl4 induced acute liver injury in rats and its regulatory effect on the bile acid *** The pharmacodynamic effect of F-G on CCl4 induced acute liver injury in rats was evaluated,and an ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for the simultaneous determination of 92 metabolites from multiple pathways was established to explore the protective metabolic mechanism of F-G in serum on the *** Twenty-four differential metabolites were identified in serum *** primary bile acid biosynthetic metabolic pathway was the major common pathway in the model group and F-G ***,a UPLC-MS/MS method for simultaneous determination of 11 bile acids,including cholic acid,ursodeoxycholic acid,glycochenodeoxycholic acid,glycochenodeoxycholic acid,taurocholic acid,glycocholic acid,chenodeoxycholic acid,deoxycholic acid,taurochenodeoxycholic acid,taurocholic acid,and glycinic acid,was established to analyze the regulatory mechanism of F-G in serum.F-G decreased the contents of these 11 bile acids in serum in a dose-dependent manner compared with those in the model control *** F-G could protect hepatocytes by promoting the binding of free bile acids to glycine and taurine,and reducing the accumulation of free bile acids in the liver.F-G could also regulate the compensatory degree of taurine,decreasing the content of taurine-conjugated bile acids to protect hepatocytes.

关键词： Radix aconiti lateralis Radix glycyrrhizae Liver injury Metabolites Bile acid Fuzi-Gancao

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modeling and simulation of percussive impact for robotic riveting system

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Advances in Manufacturing 2014年第4期2卷 344-352页

作者： Shuai Guo song-Liang Nie Feng-Feng xi Tao song Shanghai Key Laboratory of Intelligent Manufacturing and Robotics Shanghai University Department of Aerospace Engineering Ryerson University

Riveting is one of the major joining methods used in assembly, and the robotic riveting has been grad- ually introduced into aircraft industry. In this paper, a method is presented for modeling and simulation of per- cussive robotic riveting. In percussive riveting, vibration always exists. When an impact force is employed, a forced vibration will be induced. If it resonates with a robot nat- ural frequency, the vibration will cause damage to the robot. The main content of this paper is divided into three parts. Firstly, a robot dynamic model is established to compute the driving torque for each joint. Secondly, vibration responses under impact are analyzed for the percussive riveting process. Thirdly, the effect of riveting on robot vibration is studied over the robot workspace. The purpose of this paper is to discuss the suitable regions for riveting where the robot vibration is very minimal. It is shown that based on the presented method an appropriate trajectory can be planned for robotic riveting.

关键词： Robotic dynamics Analysis Vibrationresponse Impact force Riveting

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An Inherent Chiral Calix[4]arene Bearing Chiral Groups without Forming Sub-ring

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Chinese Chemical Letters 2006年第9期17卷 1169-1172页

作者： xian xian LIU Yan song ZHENG Wan Ling mo Departmentof Chemistry Huazhong University of Science and Technology Wuhan 430074 Department of Chemistry Guilin Normal College Guilin 541001 不详

The NMR spectra revealed that the calixarene frame of 1, 3-disubstituted calix[4]arenes beating optically active groups is asymmetric, even without the formation of a sub-ring. This inherent chirality arises from the interaction of the two chiral groups, which hinder the substituents＇ free rotation. Thus, these chiral calix[4]arenes display good chiral recognition ability.

关键词： Calixarene inherent chirality chiral recognition.

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