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H_(∞)/Passive Synchronization of Semi-Markov Jump Neural Networks subject to Hybrid Attacks via an Activation Function Division Approach

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Journal of Systems Science & Complexity 2024年第3期37卷 1023-1036页

作者： ZHANG Ziwei SHEN Hao su lei School of Electrical and Information Engineering Anhui University of TechnologyMa'anshan 243002China Anhui Province Key Laboratory of Special Heavy Load Robot and School of Electrical and Information Engineering Anhui University of TechnologyMa'anshan243002China

In this work,an H_(∞)/passive-based secure synchronization control problem is investigated for continuous-time semi-Markov neural networks subject to hybrid attacks,in which hybrid attacks are the combinations of denial-of-service attacks and deception attacks,and they are described by two groups of independent Bernoulli *** this foundation,via the Lyapunov stability theory and linear matrix inequality technology,the H_(∞)/passive-based performance criteria for semi-Markov jump neural networks are ***,an activation function division approach for neural networks is adopted to further reduce the conservatism of the ***,a simulation example is provided to verify the validity and feasibility of the proposed method.

关键词： Activation function division approach deception attacks denial-of-service attacks H_(∞)/passive synchronization semi-Markov jump neural networks

A review of geometry-confined perovskite morphologies:From synthesis to efficient optoelectronic applications

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Nano Research 2022年第8期15卷 7402-7431页

作者： Jinshuai Zhang Perry Ping Shum lei su School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUK College of Engineering Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen 518055China

With the continuous study of metal halide perovskite,geometry-confined technologies have been widely applied to reduce the material dimensionality and to produce pre-designed structures,which can tune optical reflectance,scattering,and absorption,thereby optimizing the performance of perovskite-based optoelectronic devices and improving their commercial *** morphologies of perovskite active layer play a pivotal role in optoelectronic properties and the resulting device *** this review,we systematically summarized recent progress in the preparation and manufacture of various perovskite geometry-confined morphologies,as well as their promising advances in different optoelectronic applications,including photodetectors,solar cells(SCs),lasers,and light-emitting diodes(LEDs).In addition,the remaining challenges and further improvements of preparation unique geometry-confined perovskite morphologies for next-generation high quality optoelectronic devices are discussed.

关键词： geometry confinement metal halide perovskite controllable morphology optoelectronics

Bifunctional SiC/Si_(3)N_(4) aerogel for highly efficient electromagnetic wave absorption and thermal insulation

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Journal of Advanced Ceramics 2023年第2期12卷 309-320页

作者： lei WANG Zhixin CAI lei su Min NIU Kang PENG lei ZHUANG Hongjie WANG State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

SiC ceramics are attractive electromagnetic(EM)absorption materials for the application in harsh environment because of their low density,good dielectric tunable performance,and chemical ***,the performance of current SiC-based materials to absorb EM wave is generally unsatisfactory due to poor impedance ***,we report ultralight SiC/Si3N4 composite aerogels(~15 mg·cm^(−3))consisting of numerous interweaving SiC nanowires and Si3N4 *** were prepared via siloxane pyrolysis and chemical vapor reaction through the template *** optimal aerogel exhibits excellent EM wave absorption properties with a strong reflection loss(RL,−48.6 dB)and a wide effective absorption band(EAB,7.4 GHz)at a thickness of 2 mm,attributed to good impedance matching and multi attenuation mechanisms of waves within the unique network *** addition,the aerogel exhibits high thermal stability in air until 1000℃and excellent thermal insulation performance(0.030 W·m^(−1)·K^(−1)).These superior performances make the SiC/Si_(3)N_(4) composite aerogel promising to become a new generation of absorption material served under extreme conditions.

关键词： bicontinuous network SiC nanowires impedance matching electromagnetic(EM)wave absorption extreme conditions

Studies on the PEO-PPO-PEO Block Copolymer Release from Alginate Hydrogel

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Chemical Research in Chinese Universities 2001年第3期17卷 341-346页

作者： su Yan-lei GUO Chen LIU Hui-zhou Young Scientist Laboratory of Separation Science and Engineering State Key Laboratory of Biochemical EngineeringInstitute of Chemical MatellurgyChinese Academy of SciencesBeijing 100080P.R.China

Alginate hydrogel is one of the most widely used carriers for the immobilization of microbial cells. If surfactants are encapsulated with alginate hydrogel, increasing temperature or concentration can make the encapsu... 详细信息

关键词： Sodium alginate hydrogel PEO-PPO-PEO block copolymer Release mechanism

Numerical simulations of shake-table experiment for dynamic soil-pile-structure interaction in liquefi able soils

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 171-180页

作者： Tang Liang Baydaa Hussain Maula Ling Xianzhang su lei Key Lab of Structures Dynamic Behavior and Control(Harbin Institute of Technology) Ministry of Education School of Civil Engineering Harbin Institute of Technology

A shake-table experiment on pile foundations in liquefi able soils composed of liquefi able sand and overlying soft clay is studied. A three-dimensional(3D) effective stress fi nite element(FE) analysis is employed to simulate the experiment. A recently developed multi-surface elasto-plastic constitutive model and a fully coupled dynamic inelastic FE formulation(u-p) are used to model the liquefaction behavior of the sand. The soil domains are discretized using a solid-fl uid fully coupled(u-p) 20-8 noded brick element. The pile is simulated using beam-column elements. Upon careful calibration, very good agreement is obtained between the computed and the measured dynamic behavior of the ground and the pile. A parametric analysis is also conducted on the model to investigate the effect of pile-pinning, pile diameter, pile stiffness, ground inclination angle, superstructure mass and pile head restraints on the ground improvement. It is found that the pile foundation has a noticeable pinning effect that reduces the lateral soil displacement. It is observed that a larger pile diameter and fi xed pile head restraints contribute to decreasing the lateral pile deformation; however, a higher ground inclination angle tends to increase the lateral pile head displacements and pile stiffness, and superstructure mass seems to effectively infl uence the lateral pile displacements.

关键词： liquefaction pile pinning soil improvement pile deformation earthquake nonlinear fi nite element method shake-table experiment

Seismic response and correlation analysis of a pile-supported wharf to near-fault pulse-like ground motions

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 883-897页

作者： Wang Jianfeng su lei Xie Libo Ling Xianzhang Ju Peng School of Civil Engineering Qingdao University of TechnologyQingdao 266500China School of Civil Engineering Harbin Institute of TechnologyHarbin 150006China No.2 Engineering Company Ltd.of CCCC First Harbor Engineering Company Ltd Qingdao 266071China

Earthquake investigations have shown that near-fault pulse-like(NF-P)ground motions have unique characteristics compared to near-fault non-pulse-like(NF-NP)and far-field(FF)ground *** is necessary to study the seismic response of pile-supported wharf(PSW)structures under NF-P ground *** this study,a three-dimensional finite element numerical model is created to simulate a *** imparting three types of ground motion,the engineering demand parameters(EDPs)of PSW under NF-P ground motions were analyzed and compared,in which EDPs are the maximum displacement and bending moment of the *** intensity measures(IMs)were selected to characterize the properties of ground *** correlation between IMs and EDPs was *** results show that the piles present larger displacement and bending moment under NF-P ground motions compared to NF-NP and FF ground *** of the IMs have a high correlation with EDPs under NF-P ground motions,and these IMs are more applicable to FF ground *** correlation coefficients between EDPs and IMs under three types of ground motion were obtained,which will provide a valuable reference for the seismic design of PSWs.

关键词： pile-supported wharf correlation analysis near-fault pulse-like ground motion intensity measure seismic response

Early Stage Hydration Mechanism of Cellulose Ether Modified Thin Layer Cement Pastes

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Journal of Wuhan University of Technology(Materials Science) 2012年第6期27卷 1172-1176页

作者：马保国 su lei JIAN Shouwei SONG Xuefeng State Key Laboratory of Silicate Building Materials Wuhan University of Technology

The early stage hydration mechanism of cellulose ether modified thin layer cement pastes was studied, using brick as the matrix. Samples of 6 h, 24 h, and 3 d and 7 d hydration time were analyzed to study the hydration law on the surface of high water-absorbing matrix. Hydration products were qualitatively and semi-quantitatively analyzed using XRD, TG-DSC-DTG, FTIR and SEM. The experimental results show that there is no enough water for 2 mm thick cement pastes to hydrate, because of rapid water absorption of matrix. Trace amounts of Ca （OH）2 was detected after three days hydration. With the prolongation of hydration time, the category and concentration of hydration products do not change. Compared with 2 mm thick cement pastes, 6 mm thick cement pastes and 10 mm thick cement pastes have lower dehydration rate and water loss. The humidity field of the cement paste show different changes within the same time. 6 mm thick cement paste and 10 mm thick cement pastes have longer time and more water to hydrate. Ca（OH）2 and ettringite were detected after 6 hours hydration and the concentrations of hydration products increased from 24 hours to 7 days.

关键词： cellulose ether thin layer cement pastes high water-absorbing matrix hydration products

Response of a pile group behind quay wall to liquefaction-induced lateral spreading:a shake-table investigation

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Earthquake Engineering and Engineering Vibration 2014年第4期13卷 741-749页

作者： Tang Liang Zhang Xiaoyu Ling Xianzhang su lei Liu Chunhui School of Civil Engineering Harbin Institute of Technology Key lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology

The response of pile foundations near a quay wall under liquefaction-induced lateral spreading remains a complex problem. This study presents the results of a shake-table test on a 2×2 pile group behind a sheet-pile quay wall that was subjected to lateral spreading. The quay wall was employed to trigger liquefaction-induced large lateral ground deformation. The discussions focus on the behavior of the pile and the soil and on the bending moment distributions within the group pile and the restoring force characteristics at the superstructure. Overall, the piles exhibited apparent pinning effects that reduced soil deformation. In addition, the rear-row piles near the quay wall experienced larger bending moments than did the front-row piles, indicating significant pile group effects. The tests showed that lateral spreading could be a primary cause of larger monotonic deformations and bending moments. It can also be concluded that the monotonic bending moments were significantly decreased due to the presence of slow soil flow. The stiffness at the superstructure was reduced because of accumulated excess pore pressure before liquefaction, and it was recovered during lateral spreading. The present study further enhances current understanding of the behavior of low-cap pile foundations under lateral spreading.

关键词： lateral spreading liquefaction pile group behavior shake-table experiment

An improved empirical wavelet transform method for rolling bearing fault diagnosis

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Science China(Technological Sciences) 2020年第11期63卷 2231-2240页

作者： HUANG HaiRun LI Ke su WenSheng BAI JianYi XUE ZhiGang ZHOU Lang su lei PECHT Michael Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology School of Mechanical EngineeringJiangnan UniversityWuxi 214122China Jiangsu Province Special Equipment Safety supervision Inspection Institute Wuxi 214071China HUST-Wuxi Research Institute Wuxi 214071China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Center for Advanced Life Cycle Engineering University of MarylandCollege Park MD 20742USA

Empirical wavelet transform(EWT)based on the scale space method has been widely used in rolling bearing fault ***,using the scale space method to divide the frequency band,the redundant components can easily be separated,causing the band to rupture and making it difficult to extract rolling bearing fault characteristic frequency *** paper develops a method for optimizing the frequency band region based on the frequency domain feature parameter *** frequency domain feature parameter set includes two characteristic parameters:mean and *** adaptively dividing the frequency band by the scale space method,the mean and variance of each band are ***-bands with mean and variance less than the main frequency band are combined with surrounding bands for subsequent *** adaptive empirical wavelet filter on each frequency band is established to obtain the corresponding empirical *** margin factor sensitive to the shock pulse signal is introduced into the screening of empirical *** empirical mode with the largest margin factor is selected to envelope spectrum *** and experiment data show this method avoids over-segmentation and redundancy and can extract the fault characteristic frequency easier compared with only scale space methods.

关键词： fault diagnosis empirical wavelet transform scale space method feature parameter margin factor