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Further improvement of stability criterion and BRL for Markovian jump systems with interval time-varying delay

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控制理论与应用（英文版） 2012年第3期10卷 397-402页

作者： Jianchen LIU Jing zhang hongqiang zhang Min HE Faculty of Electrical and Control Engineering Liaoning Technical University Huludao Liaoning 125105 China College of Electrical and Information Engineering Hunan University Changsha Hunan 410082 China

This paper deals with delay-dependent stochastic stability and bounded real lemma （BRL） for Markovian jump linear systems with interval time-varying delays. By constructing some new Lyapunov functionals and using the Jensen＇s integral inequality method, the free weighting matrix method, the convex combination method and the delay decomposition approach integratedly, some less conservative delay-dependent stability criteria and BRL are established. Numerical examples are given to show the effectiveness of the proposed method.

关键词： Markovian jump systems Time-varying delay Delay-dependent Linear matrix inequality (LMI)

Guest ions pre-intercalation strategy of manganese-oxides for supercapacitor and battery applications

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Journal of Energy Chemistry 2021年第9期30卷 480-493页

作者： Lina Chen Chongyang Hao Yamin zhang Youri Wei Linna Dai Jun Cheng hongqiang zhang Lijie Ci State Key Lab of Advanced Welding and Joining School of Materials Science and EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055GuangdongChina Key Laboratory for Liquid-Solid Structural Evolution&Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061ShandongChina

Optimization of intrinsic structure of electrode materials plays decisive roles in promoting the development of energy storage systems to meet the fast-growing requirements in the *** engineering has been proved to be an effective way to obtain adequate active sites,preferable ion diffusion channels and stable structure,thus enhance the performance of *** in-depth understanding of the correlation among synthesis,structure and performance will significantly promote the development of excellent materials and energy storage ***,in this review,recent advances in regards to cation preintercalation engineering in Mn-based electrode materials for rechargeable metal ion batteries are systematically *** guest cations can expand interlayer space to promote ion diffusion kinetics,serve as pillars to stabilize structure,control composition and valence to switch electrochemical behavior,thus improve the overall performance of secondary ***,the existing challenges and perspectives are provided for the interlayer engineering and its promotion to battery industry.

关键词： Interlayer engineering Electrode materials Energy storage devices

Design and Analysis of Microstrip Multi-Channeled Filter Using Photonic Crystal Branchy Defect

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Journal of Rare Earths 2006年第z1期24卷 136-139页

作者： Li Yunhui Jiang Haitao He Li Li hongqiang zhang Yewen Chen Hong Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China Pohl Institute of Solid State Physics Tongji University Shanghai 200092 China

A multi-channeled filter based on branchy defect in a microstrip photonic crystal was proposed. By introducing a branchy structure across the defect region, multiple defect modes will appear inside the photonic gap, leading to the multi-channeled filtering phenomenon. In comparison with the conventional multi-channeled filters, the proposed structure is more compact and tunable as far as the device volume and fabrication are concerned. The microwave experiment results are found in agreement with simulation results.

关键词： photonic crystals defect mode multi-channeled filter

In-situ monitoring plume,spattering behavior and revealing their relationship with melt flow in laser powder bed fusion of nickel-based superalloy

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Journal of Materials Science & Technology 2024年第10期177卷 44-58页

作者： You Wang Wei Guo Yinkai Xie Huaixue Li Caiyou Zeng Ming Xu hongqiang zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Science and Technology on Power Beam Processes Laboratory AVIC Manufacturing Technology InstituteBeijing 100024China Key Laboratory of Aeronautical Technology on Additive Manufacturing AVIC Manufacturing Technology InstituteBeijing 100024China

Laser powder bed fusion(LPBF)is a highly dynamic and complex physical process,and single-track de-fects tend to accumulate into non-negligible internal defects of *** nickel-based superalloy single track was fabricated by LPBF,and its plume and spattering behavior were monitored in situ and recorded in real time based on image recognition and tracking in this *** relationship among laser energy density,melt flow,plume and spattering behavior during LPBF was *** energy density had limitations as a design parameter for ***,we found that plume and spattering behavior can be used as real-time design parameters for the processing of LPBF parts and implemented the initial velocity statistics for LPBF single-track spattering based on the centroid extraction *** influ-ence of melt flow evolution paths on the spattering and plume behavior in three different melting modes was revealed,and a shift in plume behavior was found in the overlap region of the additive *** study provides a new method for obtaining statistics of spattering-related physical quantities in the melting mode,which is beneficial for the development of processing methods to mitigate the instability of the LPBF process.

关键词： Laser powder bed fusion Plume behavior Spattering behavior In-situ monitoring Ickel-based superalloy

HAZ Characterization and Mechanical Properties of QP980-DP980 Laser Welded Joints

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Chinese Journal of Mechanical Engineering 2021年第4期34卷 262-275页

作者： Junliang Xue Peng Peng Wei Guo Mingsheng Xia Caiwang Tan Zhandong Wan hongqiang zhang Yongqiang Li School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China R&D Center TANGSTEEL CompanyHBIS GroupTangshan 063016China Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Electrical Engineering Department Changchun Automobile Industry InstituteChangchun 130013China

The QP980-DP980 dissimilar steel joints were fabricated by fiber laser *** weld zone(WZ)was fully martensitic structure,and heat-affected zone(HAZ)contained newly-formed martensite and partially tempered martensite(TM)in both *** supercritical HAZ of the QP980 side had higher microhardness(~549.5 Hv)than that of the WZ due to the finer martensite.A softened zone was present in HAZ of QP980 and DP980,the dropped microhardness of softened zone of the QP980 and DP980 wasΔ21.8 Hv andΔ40.9 Hv,*** walls and slip bands were likely formed at the grain boundaries with the increase of strain,leading to the formation of low angle grain boundaries(LAGBs).Dislocation accumulation more easily occurred in the LAGBs than that of the HAGBs,which led to significant dislocation interaction and formation of *** electron back-scattered diffraction(EBSD)results showed the fraction of LAGBs in sub-critical HAZ of DP980 side was the highest under different deformation conditions during tensile testing,resulting in the failure of joints located at the sub-critical HAZ of DP980 *** QP980-DP980 dissimilar steel joints presented higher elongation(~11.21%)and ultimate tensile strength(~1011.53 MPa)than that of DP980-DP980 similar steel joints,because during the tensile process of the QP980-DP980 dissimilar steel joint(~8.2%and 991.38 MPa),the strain concentration firstly occurred on the excellent QP980 ***,Erichsen cupping tests showed that the dissimilar welded joints had the lowest Erichsen value(~5.92 mm)and the peak punch force(~28.4 kN)due to the presence of large amount of brittle martensite in WZ and inhomogeneous deformation.

关键词： QP980 steel DP980 steel Fiber laser welding Microstructure evolution Tensile properties Formability

In-situ observation of microcrack initiation and damage nucleation modes on the HAZ of laser-welded DP1180 joint

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Journal of Materials Science & Technology 2023年第17期148卷 138-149页

作者： Junliang Xue Wei Guo Jin Yang Mingsheng Xia Guang Zhao Caiwang Tan Zhandong Wan Jiaxuan Chi hongqiang zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing100191China School of Materials Engineering Shanghai University of Engineering ScienceShanghai201620China R&D Center TANGSTEEL CompanyHBIS GroupTangshan063016China Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai264209China Department of Mechanical Engineering Tsinghua UniversityBeijing100084China School of Materials Science and Engineering Beihang UniversityBeijing100191China

In-situ SEM can intuitively observe the changes in microstructure and microcrack initiation during the deformation process of the *** this paper,the microstructural evolution,mechanical properties,and damage nucleation modes of DP1180 laser welded joints were systematically discussed by the trans-mission electron microscope(TEM),focused ion beam(FIB),and in-situ tensile *** precipitation of carbides and disappearance of dislocations tangles deteriorated the mechanical properties of tempered martensite in the sub-critical heat affected zone(SCHAZ),which caused its microhardness slightly de-creased(∼27 HV)and also called the softened *** joints fractured in the SCHAZ during the tensile and Erichsen cupping tests and microcracks initiated from the tempered martensite,while the microc-rack initiation of base material(BM)occurred at the ferrite/martensite *** dominant damage nucleation mode of the joint was tempered martensite cracking,and that of BM was ferrite/martensite interface decohesion during tests.

关键词： In-situ tensile test DP steel Laser welded Damage nucleation modes

Influence of ocean tidal loading on InSAR offshore areas deformation monitoring

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Geodesy and Geodynamics 2017年第1期8卷 70-76页

作者： Mengfei Lei Qijie Wang Xiaoli Liu Bing Xu hongqiang zhang School of Geoscienees and lnfo-Physics Central South University Changsha 410083 China

The ocean tide can cause the redistribution of the seawater mass, resulting in earth＇s surface deforma- tion, namely ocean tidal loading （OTL）. OTL vertical displacement may reach several centimeters, especially in coastal areas, so its effect in the field of high precision geodesy must be considered. This study concentrates on the influences of OTL on InSAR deformation measurements. We improve the ***.2010 regional model and then compare the improved regional model with other regional models. It turns out that the improved regional model can achieve higher precision. Then we use it to replace the offshore part of the global model to generate the present model. We find that the displacement observed by the present model is 2-3 mm larger than that of other models on some sites. Finally, the present model is used to correct the deformation observed by InSAR of Shanghai and Los Angeles. A comparison between the displacements of IGS station with the corrected data shows that the OTL correction can improve the accuracy of InSAR deformation results by about 20%.

关键词： Ocean tidal loadingInSARImproved regional modelPresent modelIGS station

Hybrid Deep Learning Model for Short-Term Wind Speed Forecasting Based on Time Series Decomposition and Gated Recurrent Unit

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Complex System Modeling and Simulation 2021年第4期1卷 308-321页

作者： Changtong Wang Zhaohua Liu Hualiang Wei Lei Chen hongqiang zhang School of Information and Electrical Engineering Hunan University of Science and TechnologyXiangtan 411201China Department of Automatic Control and Systems Engineering the University of SheffieldSheffieldS13JDUK.

Accurate wind speed prediction has been becoming an indispensable technology in system security,wind energy utilization,and power grid dispatching in recent ***,it is an arduous task to predict wind speed due to its variable and random *** the objective to enhance the performance of forecasting short-term wind speed,this work puts forward a hybrid deep learning model mixing time series decomposition algorithm and gated recurrent unit(GRU).The time series decomposition algorithm combines the following two parts:(1)the complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN),and(2)wavelet packet decomposition(WPD).Firstly,the normalized wind speed time series(WSTS)are handled by CEEMDAN to gain pure fixed-frequency components and a residual *** WPD algorithm conducts the second-order decomposition to the first component that contains complex and high frequency signal of raw ***,GRU networks are established for all the relevant components of the signals,and the predicted wind speeds are obtained by superimposing the prediction of each *** from two case studies,adopting wind data from laboratory and wind farm,respectively,suggest that the related trend of the WSTS can be separated effectively by the proposed time series decomposition algorithm,and the accuracy of short-time wind speed prediction can be heightened significantly mixing the time series decomposition algorithm and GRU networks.

关键词： deep learning complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN) gated recurrent unit(GRU) short term wavelet packet decomposition wind speed prediction

Stable operation of polymer electrolyte-solid-state batteries via lonepair electron fillers

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Nano Research 2023年第11期16卷 12727-12737页

作者： Hongbin Liu Qing Sun Jun Cheng hongqiang zhang Xiao Xu Yuanyuan Li Zhen Zeng Yue Zhao Deping Li Jingyu Lu Lijie Ci State Key Laboratory of Advanced Welding and Joining School of Materials Science and EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Science Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Research Center for Carbon Nanomaterials Key Laboratory for Liquid–Solid Structural Evolution&Processing of Materials(Ministry of Education)School of Materials Science and EngineeringShandong UniversityJinan 250061China College of Materials and Chemistry China Jiliang UniversityHangzhou 310018China

Due to the increasing demand and wide applications of lithium-ion batteries,higher requirements have been placed on the energy density and *** solid-state electrolytes have gained significant popularity due to their excellent interface compatibility and ***,their applications have been greatly restricted by the high crystallinity at room temperature,which hinders the transport of lithium ***,we utilize inorganic tubular fillers with abundant lone-pair atoms to reduce the crystallinity of the polyethylene oxide(PEO)solid-state electrolyte membrane and improve its ionic conductivity at room temperature,enabling stable operation of the *** tubular lone-pair-rich inorganic fillers play a key role in providing avenues for both internal and external charge *** surface lone-pair electrons facilitate the dissociation and transport of lithium ions,while the internally tubular electron-rich layer attracts ions into the cavities,further enhancing the ion *** 100 cycles at room temperature,the lithium battery loaded with this solid-state electrolyte membrane delivers a specific capacity of 141.6 mAh·g−1,which is 51.3%higher compared to the membrane without the fillers.

关键词： nanotube filler polymer electrolyte ion transport room temperature(RT)operation