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Stability analysis of a hypersonic vehicle controlled by the characteristic model based adaptive controller

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Science china(Information Sciences) 2012年第10期55卷 2243-2256页

作者： ZHANG Zhao 1,2.& hu jun 1 1 beijing institute of control engineering,beijing 100190,china 2 Science and Technology on Space Intelligent control Laboratory,beijing 100190,china 1. beijing institute of control engineering Beijing 100190 China2. Science and Technology on Space Intelligent Control Laboratory Beijing 100190 China

The closed loop attitude stability of a hypersonic vehicle controlled by the characteristic model-based all-coefficient adaptive controller is studied in this paper,and an algorithm based on the computation of induced matrix 1-norm or ∞-norm is *** of all,the Taylor series expansion is applied to discretize the inputoutput description of the attitude dynamics of the *** obtained difference equations have the same structure as characteristic model;thus the intervals which contain all possible values of certain characteristic model parameters are *** the linear feedback controller is used in the feedback loop,with some conservation,the closed loop system is viewed as a class of interval time-varying systems defined by a number of free time-varying *** free parameters take values from predefined *** sufficient and necessary condition for the stability of this class of system is ***,a sufficient condition for the stability of hypersonic vehicle attitude control loop is proposed and demonstration example is *** method proposed checks up the stability of the closed loop system by evaluating a finite number of matrix norms,and overcomes the difficulties brought by the time-varying nature of the characteristic model and parameter estimation.

关键词： characteristic model hypersonic vehicle interval time-varying system stability test attitude control

Prediction-based guidance algorithm for high-lift reentry vehicles

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Science china(Information Sciences) 2011年第3期54卷 498-510页

作者： ZHANG Zhao 1,2.& hu jun 1 1 beijing institute of control engineering, beijing 100190, china 2 Science and Technology on Space Intelligent control Laboratory, beijing 100190, china 1. beijing institute of control engineering Beijing 100190 China2. Science and Technology on Space Intelligent Control Laboratory Beijing 100190 China

In this work, we propose a pseudo four-degrees-of-freedom (DOF) prediction based guidance algo- rithm specifically for high-lift reentry vehicles. The algorithm is composed mainly of three parts. First, at the beginning of each guidance cycle, the 4-DOF predictor is called upon to predict the final downrange, crossrange, and heading errors. Then, the magnitude of the bank angle is determined from the downrange error, using the proportional-integral (PI) control method. Finally, two bank angle reversal time points are determined to minimize the crossrange and heading errors. Compared with traditional predictor-corrector guidance, the algorithm proposed does not require iterative procedures which significantly decreases the computational burden for the on-board computer and makes the implementation practical. Simulation results for dispersion tests demonstrated that our algorithm is computationally efficient and robust against uncertainties and disturbances.

关键词： pseudo 4-DOF prediction-based guidance high-lift reentry vehicle

Real-Time Co-optimization of Gear Shifting and Engine Torque for Predictive Cruise control of Heavy-Duty Trucks

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Chinese Journal of Mechanical engineering 2024年第2期37卷 294-317页

作者： Hongqing Chu xiaoxiang Na huan liu Yuhai Wang Zhuo Yang Lin Zhang Hong Chen School of Automotive Studies Tongji UniversityShanghaiChina Department of engineering University of CambridgeCambridgeUK State Key Laboratory of Automotive Simulation and control Jilin UniversityChangchunChina Qingdao Automotive Research institute Jilin UniversityQingdaoChina Dongfeng Commercial Vehicle Technology Center Dongfeng Motor CorporationWuhanChina

Fuel consumption is one of the main concerns for heavy-duty *** cruise control(PCC)provides an intriguing opportunity to reduce fuel consumption by using the upcoming road *** this study,a real-time implementable PCC,which simultaneously optimizes engine torque and gear shifting,is proposed for heavy-duty *** minimize fuel consumption,the problem of the PCC is formulated as a nonlinear model predictive control(MPC),in which the upcoming road elevation information is *** the solution of the nonlinear MPC is time consuming;thus,a real-time implementable solver is developed based on Pontryagin’s maximum principle and indirect shooting *** programming(DP)algorithm,as a global optimization algorithm,is used as a performance benchmark for the proposed ***,hardware-in-the-loop and real-truck experiments are conducted to verify the performance of the proposed *** results demonstrate that the MPC-based solution performs nearly as well as the DP-based solution,with less than 1%deviation for testing ***,the proposed co-optimization controller is implementable in a real-truck,and the proposed MPC-based PCC algorithm achieves a fuel-saving rate of 7.9%without compromising the truck’s travel time.

关键词： Heavy-duty truck Predictive cruise control Model predictive control Pontryagin’s maximum principle Real-truck implementation

Effect of solar radiation on human thermal sensation and physiological parameters in a convection–radiation air conditioning environment

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Building Simulation 2024年第8期17卷 1359-1377页

作者： Guanyu Li Dong liu Anjie hu Qidong Yan Lina Ma liu Tang Xiaozhou Wu jun Wang Zhenyu Wang School of Civil engineering and Architecture Southwest University of Science and TechnologyMianyang 621010China Sichuan Province engineering Technology Research Center of Healthy human Settlement Chengdu 610065China Sichuan University engineering Design&Research institute Co.Ltd Chengdu 610065China School of Civil engineering Dalian University of TechnologyDalian 116081China College of Architecture and Environment Sichuan UniversityChengdu 610065China School of Environment and Resources Southwest University of Science and TechnologyMianyang 621010China

This study focused on the effect of glass structures of modern architecture on the indoor thermal environment during *** particular,this study examined how solar radiation significantly altered people’s thermal *** tests on convection–radiation air conditioning systems were conducted,encompassing 12 different scenarios,including diverse indoor open areas,terminal forms,and levels of solar *** tests aimed to explore the physiological and psychological responses of the human body to solar radiation penetrating through windows into the inner *** the experiments,the participants’subjective thermal sensations and thermal comfort were recorded,along with continuous monitoring of their physiological and environmental *** showed that solar radiation significantly increased local skin temperature,with a maximum rise of 2.15℃.Operative temperature is a reliable indicator of human skin temperature and thermal sensation vote(TSV).This study established two models that could predict the skin temperature of individuals indoors through operative temperature under conditions without or with solar radiation,and identified sensitive ranges of operative temperature for both models,to be specific,26.32℃to 28.43℃and 28.51℃to 34.11℃,***,this study established the relationship between skin temperature and TSV under conditions with and without solar *** results indicate that solar radiation enhances the human body’s adaptability to indoor environmental parameters;a convection–radiation system(FC+RF)could be used to optimize indoor thermal control under solar radiation,achieving more stable environmental temperatures and improved indoor comfort.

关键词： system modeling solar radiation mean skin temperature thermal comfort terminal form irradiation area

Photoinduced transposed Paternò-Büchi reaction for effective synthesis of high-performance jet fuel

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Chinese Journal of Chemical engineering 2024年第3期67卷 39-48页

作者： Jinxiu hu Xianlong liu Yi liu Kang Xue Chengxiang Shi Xiangwen Zhang Li Wang Ji-jun Zou Lun Pan Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Zhejiang institute of Tianjin University Ningbo 315201China Collaborative Innovative Center of Chemical Science and engineering(Tianjin) Tianjin 300072China

High-energy-density fuels are important for volume-limited aerospace vehicles,but the increase in fuel energy density always leads to poor cryogenic ***,we investigated the transposed Paternò-Büchi reaction of biomass cyclic ketone and cyclic alkene to synthesize a new kind of alkyl-substituted polycyclic hydrocarbon fuel with high energy density and good cryogenic *** triplet-energy-quenching results and phosphorescent emission spectra reveal the sensitization mechanism of the reaction,including photosensitizer excitation,triplettriplet energy transfer,cyclization,and relaxation,and the possible reaction path was revealed by the density functional theory(DFT)*** reaction conditions of photosensitizer type and addition,molar ratio of substrates,reaction temperature,and incident light intensity were optimized,with the target product yield achieving 65.5%.Moreover,the reaction dynamics of the reaction rate versus the light intensity are *** the hydrogenation-deoxygenation reaction,three fuels with a high density of 0.864-0.938 g·ml^(-1) and a low freezing point of<-55℃ are *** work provides a benign and effective approach to synthesize high-performance fuels.

关键词： High-energy-density fuel Transposed Patern-oeBüchi reaction Kinetics Bioenergy Photochemistry

Association between Gene Polymorphisms and SNP-SNP Interactions of the Matrix Metalloproteinase 2 Signaling Pathway and the Risk of Vascular Senescence

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Biomedical and Environmental Sciences 2024年第2期37卷 146-156页

作者： LIAO Zhen Yu YANG Shuo hu Song liu Jia MAO Yong jun SUN Shu Qin Department of Geriatrics the Affiliated Hospital of Qingdao UniversityQingdao 266000ShandongChina Department of Critical Care Medicine the Affiliated Hospital of Qingdao UniversityQingdao 266000ShandongChina

Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sectional study,between May and November 2022,peripheral venous blood of151 VS patients(case group)and 233 volunteers(control group)were *** SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway,assessed through carotid-femoral pulse wave velocity(cf PWV),and analyzed using multivariate logistic *** multigene influence on the risk of VS was assessed using multifactor dimensionality reduction(MDR)and generalized multifactor dimensionality regression(GMDR)*** Within the multivariate logistic regression models,four SNPs were screened to have significant associations with VS:chemokine(C-C motif)ligand 2(CCL2)rs4586,MMP2 rs14070,MMP2rs72.1,and MMP2 *** of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype,and those of the T/T genotype had a19.375-fold increased ***2 rs4586 and MMP-2 rs14070 exhibited the most significant *** CCL2 rs4586,MMP-2 rs14070,MMP-2 rs72.1,and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS.

关键词： Vascular senescence Pulse wave velocity(PWV) Single nucleotide polymorphism(SNP) Matrix metalloproteinase 2(MMP-2) Extracellular matrix(ECM) Structural degradation Multifactor dimensionality reduction(MDR)

Outlier-resistant distributed fusion filtering for nonlinear discrete-time singular systems under a dynamic event-triggered scheme

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Frontiers of Information Technology & Electronic engineering 2024年第2期25卷 237-249页

作者： Zhibin hu jun hu Cai CHEN Hongjian liu Xiaojian YI Department of Applied Mathematics Harbin University of Science and TechnologyHarbin150080China Heilongjiang Provincial Key Laboratory of Optimization control and Intelligent Analysis for Complex Systems Harbin University of Science and TechnologyHarbin150080China School of Automation Harbin University of Science and TechnologyHarbin150080China School of Mathematics and Physics Anhui Polytechnic UniversityWuhu241000China School of Mechatronical engineering Beijing Institute of TechnologyBeijing100081China Yangtze Delta Region Academy of beijing institute of Technology Jiaxing314003China Tangshan Research institute Beijing Institute of TechnologyTangshan063099China

This paper investigates the problem of outlier-resistant distributed fusion filtering(DFF)for a class of multi-sensor nonlinear singular systems(MSNSSs)under a dynamic event-triggered scheme(DETS).To relieve the effect of measurement outliers in data transmission,a self-adaptive saturation function is ***,to further reduce the energy consumption of each sensor node and improve the efficiency of resource utilization,a DETS is adopted to regulate the frequency of data *** the addressed MSNSSs,our purpose is to construct the local outlier-resistant filter under the effects of the measurement outliers and the DETS;the local upper bound(UB)on the filtering error covariance(FEC)is derived by solving the difference equations and minimized by designing proper filter ***,according to the local filters and their UBs,a DFF algorithm is presented in terms of the inverse covariance intersection fusion *** such,the proposed DFF algorithm has the advantages of reducing the frequency of data transmission and the impact of measurement outliers,thereby improving the estimation ***,the uniform boundedness of the filtering error is discussed and a corresponding sufficient condition is ***,the validity of the developed algorithm is checked using a simulation example.

关键词： Distributed fusion filtering Multi-sensor nonlinear singular systems Dynamic event-triggered scheme Outlier-resistant filter Uniform boundedness

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang liu Chang-jun Wang Chang liu School of Material Science and engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Using vitamin C to improve both performance and stability of n-type organic semiconductors

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Science china Materials 2024年第11期67卷 3755-3756页

作者： Sizhe liu Xingxin Shao jun liu Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied Chemistry and engineering University of Science and Technology of China

Organic semiconductors(OSCs) have the great advantages of flexibility, light weight, low-cost and large-area processing [1].After intensively studied for several decades, OSCs are now considered to be the most promising candidate materials for next-generation electronic circuits. N-type OSCs are the vital component for the basic electronic element, such as p-n junctions, light-emitting diodes and complementary circuits [2].

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