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Analytical modeling on the vibration response of a beam-stiffened Mindlin thick plate with free boundary conditions

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International Journal of Mechanical System Dynamics 2023年第2期3卷 119-126页

作者： hui guo Kai Zhang School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdaoChina Department of Mechanical and Electrical Engineering Ocean University of ChinaQingdaoChina

This paper presents a new analytical solution for the vibration response of a beamstiffened Mindlin plate having a completely free boundary condition by utilizing a finite cosine integral *** the solution,the unknown coupling force and moments at the beam/plate interface and the unknown modal constants from the integral transform are determined by the continuity and compatibility conditions at the interface as well as the boundary *** provides an easily implemented tool for exploring complex edge value problems for a class of higher-order partial differential equations represented by fully free‐stiffened Mindlin thick *** validity of the model is evaluated by comparing the calculated free and forced vibration responses of the beam‐stiffened plate with those calculated using a beamstiffened thin plate and those from finite element analysis.

关键词： vibration beam-stiffened mindlin thick plate free boundary condition finite integral transform

The role of virus-derived small interfering RNAs in RNA silencing in plants

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Science China(Life Sciences) 2012年第2期55卷 119-125页

作者： ZHU hui guo huiShan State Key Laboratory of Plant Genomics and National Center for Plant Gene Research Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Antiviral defense is one of the important roles of RNA silencing in plants. Virus-derived small interfering RNAs (vsiRNAs) are found in the infected host cells, indicating that the host RNA silencing machinery can target viral RNAs for destruction. With the development of high-throughput sequencing of vsiRNAs, recent genetic studies have shed light on the origin and composition of vsiRNAs and their potential functions in the regulation of gene expression. Here, we briefly describe the origin and biogenesis of vsiRNAs, and review the recent discoveries regarding vsiRNA-mediated RNA silencing of viral genomes and host transcripts. This will better our understanding of virus pathogenicity and RNA silencing-related host-pathogen inter- actions in plants.

关键词： vsiRNA RNA silencing virus pathogenicity gene regulation

Faster-than-Nyquist signaling based on filter bank multicarrier modulation with joint optimization

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Journal of Systems Engineering and Electronics 2022年第6期33卷 1208-1223页

作者： CHE hui PENG Dingxiang guo Fachang BAI Yong School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Ruijie Networks Co. LtdFuzhou 350002China School of Information and Communication Engineering Hainan UniversityHaikou 570228China

Multi-carrier faster-than-Nyquist(MFTN)can improve the spectrum efficiency(SE).In this paper,we first analyze the benefit of time frequency packing MFTN(TFP-MFTN).Then,we propose an efficient digital implementation for TFP-MFTN based on filter bank multicarrier *** time frequency packing ratio pair in our proposed implementation scheme is optimized with the SE ***,the joint optimization for the coded modulation MFTN based on extrinsic information transfer(EXIT)chart is *** Monte-Carlo simulations are carried out to verify performance gain of the joint inner and outer code *** results demonstrate that the TFPMFTN has a 0.8 dB and 0.9 dB gain comparing to time packing MFTN(TP-MFTN)and higher order Nyquist at same SE,respectively;the TFP-MFTN with optimized low density parity check(LDPC)code has a 2.9 dB gain comparing to that with digital video broadcasting(DVB)*** with previous work on TFP-MFTN(SE=1.55 bit/s/Hz),the SE of our work is improved by 29%and our work has a 4.1 dB gain at BER=1×10^(-5).

关键词： faster-than-Nyquist filter bank multi-carrier time-frequency packing(TFP) spectrum efficiency(SE) joint optimization

Underwater acoustic signal denoising model based on secondary variational mode decomposition

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Defence Technology（防务技术） 2023年第10期28卷 87-110页

作者： Hong Yang Wen-shuai Shi guo-hui Li School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'anShaanxi710121China

Due to the complexity of marine environment,underwater acoustic signal will be affected by complex background noise during *** acoustic signal denoising is always a difficult problem in underwater acoustic signal *** obtain a better denoising effect,a new denoising method of underwater acoustic signal based on optimized variational mode decomposition by black widow optimization algorithm(BVMD),fluctuation-based dispersion entropy threshold improved by Otsu method(OFDE),cosine similarity stationary threshold(CSST),BVMD,fluctuation-based dispersion entropy(FDE),named BVMD-OFDE-CSST-BVMD-FDE,is *** the first place,decompose the original signal into a series of intrinsic mode functions(IMFs)by ***,distinguish pure IMFs,mixed IMFs and noise IMFs by OFDE and CSST,and reconstruct pure IMFs and mixed IMFs to obtain primary denoised *** the end,decompose primary denoising signal into IMFs by BVMD again,use the FDE value to distinguish noise IMFs and pure IMFs,and reconstruct pure IMFs to obtain the final denoised *** proposed mothod has three advantages:(i)BVMD can adaptively select the decomposition layer and penalty factor of VMD.(ii)FDE and CS are used as double criteria to distinguish noise IMFs from useful IMFs,and Otsu algorithm and CSST algorithm can effectively avoid the error caused by manually selecting thresholds.(iii)Secondary decomposition can make up for the deficiency of primary decomposition and further remove a small amount of *** chaotic signal and real ship signal are *** experiment result shows that the proposed method can effectively *** improves the denoising effect after primary decomposition,and has good practical value.

关键词： Underwater acoustic signal Denoising Variational mode decomposition Secondary decomposition Fluctuation-based dispersion entropy Cosine similarity

A Possible 456-Day Optical Period of OQ 530

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Chinese Journal of Astronomy and Astrophysics 2007年第3期7卷 380-388页

作者： Yi Liu juan Li Jun-hui Fan Center for Astrophysics Guangzhou University Guangzhou 510006

The post-1994 observations of the blazar OQ 530 in optical BVRI bands, and radio observations at 22 GHz and 37 GHz were collected. The date compensated discrete Fourier transform （DCDFr） and CLEANest methods were used to search for possible periodicities. Two possible periods of 456±100 days and 258±29 days were found in the optical bands. The existence of possible correlations between the optical and radio emissions was investigated by means of discrete correlation function （DCF） analysis, and no significant correlation was found. Some possible mechanisms for the periodic variability are discussed.

关键词： galaxies active - BL Lacertae objects general - BL Lacertae objects indi-vidual OQ 530

A Type-2 Fuzzy Approach to Driver-Automation Shared Driving Lane Keeping Control of Semi-Autonomous Vehicles Under Imprecise Premise Variable

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Chinese Journal of Mechanical Engineering 2022年第2期35卷 210-227页

作者： Yue Liu Qing Xu Hongyan guo hui Zhang School of Transportation Science and Engineering Beihang UniversityBeijing 100091China School of Vehicle and Mobility Tsinghua UniversityBeijing 100000China College of Automotive Engineering Jilin UniversityChangchun 130000China

The driver-automation shared driving is a transition to fully-autonomous driving,in which human driver and vehicular controller cooperatively share the control *** paper investigates the shared steering control of semi-autonomous vehicles with uncertainty from imprecise *** considering driver’s lane-keeping behavior on the vehicle system,a driver-automation shared driving model is introduced for control *** on the interval type-2(IT2)fuzzy theory,moreover,the driver-automation shared driving model with uncertainty from imprecise parameter is described using an IT2 fuzzy *** that,the corresponding IT2 fuzzy controller is designed and a direct Lyapunov method is applied to analyze the system *** this work,sufficient design conditions in terms of linear matrix inequalities are derived,to guarantee the closed-loop stability of the driver-automation shared control *** addition,an H∞performance is studied to ensure the robustness of control ***,simulation-based results are provided to demonstrate the performance of proposed control ***,an existing type-1 fuzzy controller is introduced as comparison to verify the superiority of the proposed IT2 fuzzy controller.

关键词： Driver-automation shared control Fuzzy control Interval type-2 fuzzy system Autonomous vehicles

In situ TiN-reinforced CoCr2FeNiTi(0.5) high-entropy alloy composite coating fabricated by laser cladding

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Rare Metals 2020年第10期39卷 1190-1195页

作者： Ya-Xiong guo Qi-Bin Liu Xiao-juan Shang College of Materials and Metallurgy Guizhou UniversityGuiyang 550025China Guizhou Province Key Laboratory of Materials Structure and Strength Guiyang 550025China

The fcc structural CoCr2 FeNiTi(0.5) high-entropy alloy(HEA) composite coating with TiN particles reinforced was acquired by laser cladding on the commercial904 L stainless *** results show that phase structure is mainly composed of fcc solid solution and TiN *** coating exhibits excellent structural stability below850℃.The microstructure consists of irregular dendrite and TiN *** electron microscopy(TEM) results reveal that the close-packed plane of fcc phase is(111) with interplanar spacing of ~ 0.208 *** interface between TiN and fcc matrix is *** the angle of boundary between dendrite and matrix is ~ 65°.The hardness and corrosion resistance of coating have much improvement compared with those of substrate.

关键词： TiN particle reinforced High-entropy alloy Semi-coherent interface Laser cladding

Improved frequency modeling and solution for parallel liquid-filled pipes considering both fluid-structure interaction and structural coupling

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Applied Mathematics and Mechanics(English Edition) 2022年第8期43卷 1269-1288页

作者： Xumin guo Chunliang XIAO hui MA hui LI Xufang ZHANG Bangchun WEN School of Mechanical Engineering and Automation Northeastern UniversityShenyang110819China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern UniversityShenyang110819China

The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous *** parallel liquid-filled pipe(PLFP)system is also widely used in engineering,and its structure is more complex than that of a single ***,there are few reports about the dynamic characteristics of the ***,this paper proposes improved frequency modeling and solution for the PLFPs,involving the logical alignment principle and coupled matrix *** established model incorporates both the fluid-structure interaction(FSI)and the structural coupling of the *** validity of the established model is verified by modal *** effects of some unique parameters on the dynamic characteristics of the PLFPs are *** work provides a feasible method for solving the FSI of multiple pipes in parallel and potential theoretical guidance for the dynamic analysis of the PLFPs in engineering.

关键词： parallel liquid-filled pipe(PLFP) dynamic analysis improved frequency modeling and solution fluid-structure interaction(FSI) structure coupling

Deposition of TiN/TiAlN multilayers by plasma-activated EB-PVD:tailored microstructure by jumping beam technology

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Rare Metals 2017年第8期36卷 651-658页

作者： guo-Yuan Yang hui Peng Hong-Bo guo Sheng-Kai Gong School of Materials Science and Engineering Beihang UniversityBeijing 100191China Beijing Key Laboratory for Advanced Functional Material and Thin Film Technology Beihang UniversityBeijing 100191China Key Laboratory of Aerospace Materials and Performance(Ministry of Education) Beihang UniversityBeijing 100191China

Plasma-activated electron beam-physical vapor deposition（EB-PVD）was used for depositing nitride multilayer coatings in this *** from the conventional coating methods,the multilayers were obtained by manipulating electron beam（EB）to jump between two different evaporation sources alternately with variable frequencies（jumping beam technology）.The plasma activation was generated by a hollow cathode plasma *** deposition process was demonstrated by means of tailoring TiN/TiAlN multilayers with different modulation periods（M1：26.5 nm,M2：80.0 nm,M3：6.0 nm,M4：4.0 nm）.The microstructure and hardness of the multilayer coatings were comparatively studied with TiN and TiAlN singlelayer *** columnar structure of the coatings（TiN,TiAlN,M1,M2）is replaced by a glassy-like microstructure when the modulation period decreases to less than 10 nm（M3,M4）.Simultaneously,superlattice growth *** the decrease of modulation period,both the hardness and the plastic deformation resistance（H^3/E^2,H-hardness and E-elastic modulus）increase.M4coating exhibits the maximum hardness of（49.6±2.7）GPa and the maximum plastic deformation resistance of^0.74 GPa.

关键词： Nano-multilayer coatings Superlattice Plasmaactivation TiN/TiAlN EB-PVD Hardness