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Hardware-in-loop adaptive neural control for a tiltable V-tail morphing aircraft

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Defence Technology（防务技术） 2023年第4期22卷 197-211页

作者： Fu-xiang Qiao jing-ping Shi Xiao-bo qu Yong-xi Lyu School of Automation Northwestern Polytechnical UniversityXi'an710129China Shaanxi Province Key Laboratory of Flight Control and Simulation Technology Xi'an710129China

This paper proposes an adaptive neural control(ANC)method for the coupled nonlinear model of a novel type of embedded surface morphing aircraft which has a tiltable V-tail.A nonlinear model with sixdegrees-of-freedom is *** first-order sliding mode differentiator(FSMD)is applied to the control scheme to avoid the problem of“differential explosion”.Radial basis function neural networks are introduced to estimate the uncertainty and external disturbance of the model,and an ANC controller is proposed based on this design *** stability of the proposed ANC controller is proved using Lyapunov theory,and the tracking error of the closed-loop system is semi-globally uniformly *** effectiveness and robustness of the proposed method are verified by numerical simulations and hardware-in-the-loop(HIL)simulations.

关键词： Morphing aircraft Back-stepping control Adaptive control Neural networks Radial basis function

Classification of Positive Solutions to a Divergent Equation on the Upper Half Space

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Acta Mathematica Sinica,English Series 2022年第3期38卷 499-509页

作者： jin Ge YAO jing bo DOU School of Mathematics and Statistics Shaanxi Normal UniversityXi’an710119P.R.China

In this paper we classify the positive solutions of the divergent equation with Neumann boundary on the upper half space{-div(t^(α)∇u)=t^(β)f(u),(y,t)∈R^(n+1)_(+),lim t→0^(+)t^(α)■u/■t=0 by the method of moving spheres and Kelvin transformations,where n≥1,α>0,β>−1,n−1/n+1β≤αquation arises from a weighed Sobolev inequality involving divergent operator div(t^(α)∇u)on the upper half space.

关键词： Divergent operator Liouville theorem Neumann boundary method of moving spheres Kelvin transformation

Forced Decadal Changes in Summer Precipitation Characteristics over China:The Roles of Greenhouse Gases and Anthropogenic Aerosols

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Journal of Meteorological Research 2020年第6期34卷 1226-1241页

作者： bo ZHANG Buwen DONG Ronghua jin National Meteorological Center China Meteorological AdministrationBeijing 100081China National Centre for Atmospheric Science-Climate Department of MeteorologyUniversity of ReadingReading RG66URUK

We investigated the decadal changes in the different types of summer mean precipitation over China across the mid-1990 s based on observational *** spatial variations in the observed decadal changes were estimated by comparing the present day(PD)time period of 1994–2011 with an earlier period of 1964–*** summer total precipitation increased in southern China and decreased in northern China from the early period to the *** increases of precipitation in southern China were due to increases in the frequency of heavy and moderate rainfall,whereas the decreases over northern China were mainly due to decreases in the frequency of moderate and light *** on a set of numerical experiments using an atmospheric general circulation model coupled with a multilevel mixed-layer ocean model,we found that the increase of precipitation frequency forced by greenhouse gases is the main reason of increasing precipitation over southern and northeastern China,while the decrease of frequency caused by anthropogenic aerosol(AA)induces the decreasing precipitation over northern *** water vapor flux convergence and water vapor flux strengthen in southern China and northeastern China by anthropogenic greenhouse *** distribution is also conducive to precipitation in most of southern China and northeastern *** the control of weakened southwesterly winds and 850-h Pa divergence,precipitation decreases over northern and southwestern China by AA.

关键词： decadal changes in precipitation frequency and intensity numerical experiments China

Stress injuries and autophagy in mouse hippocampus after chronic cold exposure

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Neural Regeneration Research 2017年第3期12卷 440-446页

作者： Ting-ting qu Jie-xin Deng Rui-ling Li Zhan-jun Cui Xiao-qing Wang Lai Wang jin-bo Deng Institute of Neurobiology College of Life ScienceHenan University Nursing College Henan Vocational College of Applied Technology

Cold exposure is an external stress factor that causes skin frostbite as well as a variety of *** might participate in neuroprotection after cold exposure,but its precise mechanism remains *** this study,mice were exposed to 10°C for 7 days and 0–4°C for 30 days to induce a model of chronic cold *** showed that oxidative stress-related c-fos and cyclooxygenase 2 expressions,MAP1LC3-labeled autophagic cells,Iba1-labeled activated microglia,and interleukin-1β-positive pyramidal cells were increased in the hippocampal CA1 *** cold exposure markedly elevated the levels of estrogen in the blood and the estrogen receptor,G protein-coupled receptor *** results indicate that neuroimmunoreactivity is involved in chronic cold exposure-induced pathological alterations,including oxidative stress,neuronal autophagy,and ***,estrogen exerts a neuroprotective effect on cold exposure.

关键词： nerve regeneration chronic cold exposure oxidative stress autophagy microglial cells neuroimmunoreactivity hippocampal CA1 area estrogen neural regeneration

Stability of Entropy Solution of Conservation Law Systems on Flow Function and Relaxation Function

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Acta Mathematicae Applicatae Sinica 2021年第4期37卷 747-757页

作者： jin-bo GENG Xu-dong WANG College of Mathematics and Computer Science Zhejiang Normal UniversityJinhua321004China School of Mathematical Sciences Fudan UniversityShanghai200433China

In this paper,using the fractional step Lax-Friedrichs difference scheme,we establish the stability of the entropy solution on flow function and relaxation function for a class of conservation law systems with a sourc... 详细信息

关键词： stability Lax-Friedrichs difference scheme conservation law entropy solution

quantitative Assessment of Hepatic Fibrosis by Contrast-enhanced Ultrasonography

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Chinese Medical Sciences Journal 2011年第4期26卷 208-215页

作者： Ming-bo Zhang En-ze qux En-ze qu Ji-Bin Liu jin-rui Wang Department of Ultrasound Peking University Third Hospital Beijing 100191 China Inner Mongolia Institute of Ultrasound Erdos 017000 China

Objective To explore the contrast-enhanced ultrasonographic features for quantitative assessment of hepatic fibrosis. Methods 86 patients with chronic viral hepatitis B were enrolled in this study from March 2007 to August 2009. The patients were classified into 5 groups (S0-S4) according to fibrosis stage evaluated with ultrasound guided liver biopsy. New contrast-enhanced ultrasonography (CEUS) features including area under the time-intensity curve (TIC) of portal venous phase/hepatic arterial phase (Qp/Qa) and intensity of portal venous phase/hepatic arterial phase (Ip/Ia) were used to detect the blood supply ratio (portal vein/hepatic artery) in each group. Arrival time of portal vein trunk (Tp) and decreasing rate of TIC (β ) were also analyzed. Results Qp/Qa and Ip/Ia decreased from S0 to S4, while Tp and β increased. These 4 features were significantly correlated with the degree of fibrosis (Pquantitative assessment of hepatic fibrosis.

关键词： hepatic fibrosis contrast-enhanced ultrasonography quantitative non- invasive

Experimental investigation of the effect of Reynolds number on flow structures in the wake of a circular parachute canopy

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Acta Mechanica Sinica 2014年第3期30卷 361-369页

作者： Zhe-Yan jin Sylvio Pasqualini bo Qin School of Aerospace Engineering and Applied Mechanics Tongji University Institute of Unmanned Aircraft System Beihang University

In the present study, an experimental study was conducted to characterize the effect of Reynolds number on flow structures in the turbulent wake of a circular parachute canopy by utilizing stereoscopic particle image velocime- try （Stereo-PIV） technique. The parachute model tested in the present study was attached by 28 nylon suspension lines and placed horizontally at the test section center of the wind tunnel. The obtained results showed that with the in- crease of Reynolds number, the intensities of the vortices near the downstream region of the canopy skirt were found to increase accordingly. However, the increase of Reynolds number did not result in a significant change in ensemble- averaged normalized x-component of the velocity, ensembleaveraged normalized vorticity, normalized Reynolds stress, and normalized turbulent kinetic energy distributions in the turbulent wake of the circular parachute canopy. The obtained results are very useful to further our understanding about the unsteady aerodynamics in the wake of flexible circular parachute canopies and to constitute a reference for CFD computation.

关键词： Stereo-PIV Circular parachute - Canopy Flexible Turbulent wake

Maximal Dimension of Invariant Subspaces to Systems of Nonlinear Evolution Equations

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Chinese Annals of Mathematics,Series B 2012年第2期33卷 161-178页

作者： Shoufeng SHEN Changzheng qu Yongyang jin Lina JI Department of Applied Mathematics Zhejiang University of TechnologyHangzhou 310023China Department of Mathematics Ningbo UniversityNingbo 315211ZhejiangChina Department of Information and Computational Science Henan Agricultural UniversityZhengzhou 450002China

In this paper, the dimension of invariant subspaces admitted by nonlinear sys- tems is estimated under certain conditions. It is shown that if the two-component nonlinear vector differential operator F = （F1, F2） with orders {k1, k2} （k1≥ k2） preserves the invariant subspace Wn1^1× Wn2^2 （n1 ≥ n2）, then n1 - n2 ≤ k2, n1 ≤2（k1 ＋ k2）＋ 1, where Wnq^q is the space generated by solutions of a linear ordinary differential equation of order nq （q = 1, 2）. Several examples including the （1＋1）-dimensional diffusion system and Ito＇s type, Drinfel＇d-Sokolov-Wilson＇s type and Whitham-Broer-Kaup＇s type equations are presented to illustrate the result. Furthermore, the estimate of dimension for m-component nonlinear systems is also given.

关键词： Invariant subspace Nonlinear PDEs Exact solution Symmetry Dynamical system

Settled fast measurement of topological charge by direct extraction of plane wave from vortex beam

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Chinese Physics B 2021年第10期30卷 306-317页

作者： Xiao-bo Yang jin Hu School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China Institute of Information Engineering Chinese Academy of SciencesBeijing 100195China China Beijing Key Laboratory of Fractional Signals and Systems Beijing 100081China

A method of measuring the vortex beam topological charge(TC)is proposed based on a device that can directly extract the plane wave form from the vortex beam in which the different propagation angles of the plane waves are uniquely related to the different *** the TC can be obtained by simply comparing the energy values perceived by two fixed sensors in the detection location with the help of twin omnidirectional energy absorbers(OEAs).Because the settled detection relies only on the simple quantitative value at two fixed positions,neither pattern recognition nor field analysis procedure is applied,thus allowing faster *** features of the methodology are investigated,and the numerical simulations verify the feasibility and robustness of the system.

关键词： vortex beam topological charge settled measurement