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Journal of Natural Gas Chemistry 2011年第5期20卷 547-552页

作者： Tingting Zhao hongxia wang Key Laboratory of Design and Synthesis of Functional Materials and Green Catalysis Colleges of Heilongjiang Province Harbin Normal University Harbin 150025 Heilongjiang China

The effect of steam-treatment to HZSM-5 zeolite and Mo/HZSM-5 with a steaming time range of 0.5-1 h on the catalytic performance of methane dehydro-aromatization （MDA） over Mo/HZSM-5 catalyst prepared with impregnation has been studied in detail in combination with the characterization of 1H MAS NMR technique. Both the deactivation rate constant （kd） and the Brtnsted acid sites per unit cell were calculated to quantitatively evaluate the stability of Mo/HZSM-5 catalysts treated with steam at 813 K before and after impregnation of molybdenum species, and the corresponding variation of their Brtnsted acid sites. The results reveal that a V-shape relationship between kd and the number of B 1 acid sites per unit cell is presented on Mo/HZSM-5 catalyst under the tested steam-treatment and reaction conditions.

关键词： steam-treatment HZSM-5 zeolite Mo/HZSM-5 methane dehydro-aromatization in the absence of oxygen

Optimal Control and Stabilization for It?Systems with Input Delay

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Journal of Systems Science & Complexity 2021年第5期34卷 1895-1926页

作者： wang hongxia ZHANG Huanshui XIE Lihua School of Electrical and Automation Engineering Shandong University of Science and TechnologyQingdao 266590China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore

The paper considers the linear quadratic regulation(LQR)and stabilization problems for It?stochastic systems with two input channels of which one has input *** underlying problem actually falls into the field of asymmetric information control because of the nonidentical measurability induced by the input *** contrast with single-channel single-delay problems,the challenge of the problems under study lies in the interaction between the two channels which are measurable with respect to different *** key techniques conquering such difficulty are the stochastic maximum principle and the orthogonal decomposition and reorganization technique proposed in a companion *** authors provide a way to solve the delayed forward backward stochastic differential equation(D-FBSDE)arising from the maximum *** necessary and sufficient solvability condition and the optimal controller for the LQR problem are given in terms of a new Riccati differential equation established ***,the necessary and sufficient stabilization condition in the mean square sense is provided and the optimal controller is *** idea proposed in the paper can be extended to solve related control problems for stochastic systems with multiple input channels and multiple delays.

关键词： Input delay It?systems LQR optimal control stochastic systems

Preface:Innovative electrode materials for supercapacitors

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Science China Materials 2018年第2期61卷 131-132页

作者： Hengxing Ji hongxia wang Department of Materials Science and Engineering University of Science and Technology of China School of Chemistry Physics and Mechanical Engineering Science and Engineering Faculty Queensland University of Technology

Portable electrical power sources play increasingly vital roles in our daily lives due to the widespread use of mobile electronic devices and electrical *** capacitors,also referred as supercapacitors(SCs)or ultracapacitors,are an important type of energy storage system with superior advantages of rapid power delivery and recharging compared to other types of energy storage *** practice,SCs have played im-

关键词： SC Preface:Innovative electrode materials for supercapacitors flexible

Audio Perceptual Hashing Based on NMF and MDCT Coefficients

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Chinese Journal of Electronics 2015年第3期24卷 579-583页

作者： LI Jinfeng wang hongxia JING Yi School of Information and Science and Technology Southwest Jiaotong University College of Engineering Northeastern UniversityBoston

Audio perceptual hashing is a digest of audio contents, which is independent of content preserving manipulations, such as MP3 compression, amplitude scaling, noise addition, etc. It provides a fast and reliable tool for identification, retrieval, and authentication of audio signals. A new audio hashing scheme based on nonNegative matrix factorization(NMF) of Modified discrete cosine transform(MDCT) coefficients is proposed. MDCT coefficients, which have been widely used in audio coding,exhibit good discrimination for different audio contents and highly robustness against content preserving manipulations, especially MDCT based compression such as MP3,AAC, etc. Based on the extraction of MDCT coefficients of the audio frames firstly, NMF is used to construct hash bits. Experiment results demonstrate that, compared with methods mentioned in literature, the proposed scheme exhibits a high efficiency in terms of discrimination, perceptual robustness identification rate and time consumption.

关键词： Perceptual audio hashing Modified discrete cosine transform Non-negative matrix factorization Perceptual robustness

Nanodiamonds for energy

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Carbon Energy 2019年第1期1卷 13-18页

作者： hongxia wang Yi Cui Department of Materials Science and Engineering Stanford UniversityStanfordCalifornia Stanford Institute for Materials and Energy Sciences SLAC National Accelerator LaboratoryMenlo ParkCalifornia

Carbon materials have been playing important roles in advancing energyrelated technologies and offering great promise to addressing the rising global energy demands and environmental ***,an exciting class of carbon materials,with excellent mechanical,chemical,electronic,and optical properties,have great potentials in energy-related *** this contribution,we summarized some of the recent progress on nanodiamonds for energy storage,conversion,and other related applications in sustainable energy *** discussed the promising opportunities and outlooks for nanodiamonds in energy-related fields.

关键词： energy energy conversion energy storage nanodiamond

B-Spline Method for Spatio-Temporal Inverse Model

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Journal of Systems Science & Complexity 2022年第6期35卷 2336-2360页

作者： wang hongxia ZHAO Zihan WU Yuehua LUO Xuehong School of Statistics and Data Science Nanjing Audit UniversityNanjing 211815China Department of Mathematics and Statistics York UniversityTorontoOntarioCanada Department of Statistics and Data Science School of EconomicsXiamen UniversityXiamen 361005China

Inverse models can be used to estimate surface fluxes in terms of the observed atmospheric concentration measurement *** paper proposes a new nonparametric spatio-temporal inverse model and provides the global expressions for the estimates by employing the B-spline *** authors establish the asymptotic normality of the estimators under mild *** authors also conduct numerical studies to evaluate the finite sample performance of the proposed ***,the authors apply the method to anthropogenic carbon dioxide(CO_(2))emission data from different provinces of Canada to illustrate the validity of the proposed techniques.

关键词： Inverse model spatio-temporal heterogeneity spatio-temporal correlation

Evaluating the Vulnerability of Integrated Electricity-heat-gas Systems Based on the High-dimensional Random Matrix Theory

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CSEE Journal of Power and Energy Systems 2020年第4期6卷 878-889页

作者： Danlei Zhu Bo wang Hengrui Ma hongxia wang Department of Electrical Engineering Wuhan UniversityWuhan 430072China Department of Electrical Engineering Qinghai UniversityXining 810016China

Faced with the tight coupling of multi energy sources,the interaction between different energy supply systems makes it difficult for integrated energy systems(IES)to identify weak *** on the analysis of the data generated by the actual operation of IES,this paper proposes a weak node identification method based on random matrix theory(RMT).First,establish a unified power flow model for *** RMT and the characteristics of weak nodes,without considering the detailed physical model of the system,using historical data and real-time data to construct the random ***,the two limit spectrum distribution functions(Marchenko-Pastur law and ring law)are used to qualitatively analyze the system’s operating status,calculate linear eigenvalue statistics such as mean spectral radius(MSR),and establish the weak node identification model based on entropy ***,the simulation of IES verifies the effectiveness of the proposed method and provides a new approach for the identification of weak nodes in IES.

关键词： Integrated energy systems mean spectral radius random matrix theory ring law weakness identification

Study on Acoustic Performance for Diatom Frustule with Nanoporous Structure

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Journal of Bionic Engineering 2023年第4期20卷 1656-1669页

作者： Fanming Meng Yong Zheng hongxia wang Lin Chen College of Mechanical Engineering Hubei University of Automotive TechnologyShiyan442002China State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing400044China

The acoustic performance for the nanoporous frustule of the diatom is studied based on the computational fluid dynamics theory and acoustic theory *** Coscinodiscus *** is observed through the scanning electron microscope and modeled by the commercial software ***,the acoustic performance for the Coscinodiscus *** is studied at the varied depth,diameter or interval of the pore,as well as the film thickness of the fluid surrounding the Coscinodiscus *** numerical results show that,when the upper and lower pore diameters are separately 200 and 300 nm,the upper and lower pore depths are separately 200 and 250 nm,and both the pore interval and fluid film thickness are 500 nm,the elaborate nanoporous structure of Coscinodiscus *** can lower its acoustic power level by 17.49%,compared with that without porous ***,the double-layer pore of Coscinodiscus *** can decrease its acoustic power level by 12.69%,compared with its single-layer pore structures.

关键词： Acoustic performance Nanoporous structure Diatom Computational fluid dynamics

Stochastic LQ Control with Extra Measurability Restriction

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Journal of Systems Science & Complexity 2024年第3期37卷 1003-1022页

作者： wang hongxia HU Yuxi LI Zixing SONG Lianfeng College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

Different from the standard linear quadratic(LQ)problem for stochastic systems,the LQ problem considered in the paper has extra measurability *** problem also appears in the LQ control problem for stochastic systems with delays,rational expectations problems,asymmetric information control,and so *** essential difficulty lies in that one has to optimize the input and its conditional expectations *** stochastic maximum principle(SMP)and orthogonal decomposition technique are the key ***,the authors establish the SMP and convert the original problem into forward and backward stochastic difference equations(FBSDEs)with extra measurability ***,the authors resolve the FBSDEs by using the orthogonal decomposition technique and obtain the analytical solution to the underlying ***,the authors explore the essential distinction between the problem and the standard stochastic LQ control ***,numerical examples are given to illustrate the obtained results.

关键词： Multiplicative noise systems optimal control stochastic maximum principle stochastic systems

Reversible Data Hiding Based on Run-Level Coding in H.264/AVC Video Streams

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Computers, Materials & Continua 2020年第5期63卷 911-922页

作者： Yi Chen hongxia wang Xuyun Zhang School of Information Science and Technology Southwest Jiaotong UniversityChengdu611756China College of Cybersecurity Sichuan UniversityChengdu610064China Department of Electrical Computer and Software EngineeringUniversity of AucklandAuckland1023New Zealand

This paper presents a reversible data hiding(RDH)method,which is designed by combining histogram modification(HM)with run-level coding in H.264/advanced video coding(AVC).In this scheme,the run-level is changed for embedding data into H.264/AVC video *** order to guarantee the reversibility of the proposed scheme,the last nonzero quantized discrete cosine transform(DCT)coefficients in embeddable 4×4 blocks are shifted by the technology of histogram *** proposed scheme is realized after quantization and before entropy coding of H.264/AVC compression ***,the embedded information can be correctly extracted at the decoding ***-signal-noise-to-ratio(PSNR)and Structure similarity index(SSIM),embedding payload and bit-rate variation are exploited to measure the performance of the proposed *** results have shown that the proposed scheme leads to less SSIM variation and bit-rate increase.

关键词： Reversible data hiding run-level coding visual quality bit-rate increase H.264/AVC video streams