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Extension of continuous scanning laser Doppler vibrometry measurement for complex structures with curved surfaces

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Chinese Journal of Aeronautics 2020年第12期33卷 3220-3227页

作者： cuihong LIU Chaoping ZANG Biao ZHOU Aero-engine Thermal Environment and Structure Key Laboratory of Ministry of Industry and Information Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The continuous Scanning Laser Doppler Vibrometry(SLDV)developed on the base of the galvanometer scanner system has made it possible to quickly obtain the full field vibration responses within a rectangular area of the *** this paper,an arbitrary continuous scanning path generating method for Continuous Scanning Laser Doppler Vibometry(CSLDV)is further put forward in order to allow the CSLDV suitable for testing structures featured by complex shapes not just for regular *** the first step,the relationship between position of laser spot and the driving voltages of galvanometer scanner system has been described by a mathematical ***,a novel arbitrary scanning path generating strategy based on CSLDV is presented by deforming a normalization rectangular scanning path to an arbitrary continuous scanning *** mapping relation between the normalization rectangular scanning path and arbitrary continuous scanning path is established using the reference *** the second step,a compressor blade with curved surface was taken as an example for modal test using the proposed *** the same time,a validated experiment was performed in *** results show the mode shapes derived from the extended CSLDV are in agreement with those from SLDV and the Modal Assurance Criterion(MAC)between the two are all greater than *** also demonstrate the feasibility and effectiveness of the proposed method for CSLDV test and show strong potential on further practical engineering applications.

关键词： Arbitrary scanning path Continuous Scanning Laser Doppler Vibometry(CSLDV) Fitted polynomial Galvanometer scanner system Rectangular scanning path

The Controllability, Observability, and Stability Analysis of a Class of Composite Systems with Fractional Degree Generalized Frequency Variables

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IEEE/CAA Journal of Automatica Sinica 2019年第3期6卷 859-864页

作者： cuihong Wang Yafei Zhao YangQuan Chen IEEE the Department of Mathematics and Computer Science Shanxi Normal University the Mechatronics Embedded Systems and Automation(MESA) Lab

This paper is concerned with fundamental properties of a class of composite systems with fractional degree generalized frequency variables, including controllability, observability and stability. Firstly, some necessary and sufficient conditions are given to guarantee controllability and observability of such composite systems. Then we prove that the stability problem of such composite systems can be reduced to judging whether a fractional degree polynomial is stable. Finally, the stability analysis result is applied in the supervisory control of fractional-order multi-agent systems, and an example is provided to illustrate the effectiveness of the proposed methods.

关键词： Composite system controllability fractionalorder system observability stability

STRUCTURAL DECOMPOSITION ANALYSIS ON CHINA'S ENERGY INTENSITY CHANGE FOR 1987-2005

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Journal of Systems Science & Complexity 2012年第1期25卷 156-166页

作者： Yan XIA cuihong YANG Xikang CHEN Institute of Systems Science Academy of Mathematics and Systems ScienceChinese Academy of Sciences Graduate School of the Chinese Academy of Sciences

There has been considerable debate about the major factors responsible for the dramatic decline of China＇s energy intensity in the 1980s and 1990s. However, few detailed analysis has been done to explain the fluctuation in energy intensity during 2002-005. In this paper, we use the structural decomposition analysis （SDA） to decompose energy intensity into five determining factors： Energy input coefficient, technology coefficient （Leontief inverse coefficient）, final demands structure by product, final demands by category and final energy consumption coefficient. We then further decompose two coefficients, energy input coefficient and technology coefficient, into structure and real coefficient. Empirical study is carried out based on the energy-input-output tables from 1987 to 2005 in 2000 constant price. The results show that between 1987 and 2002, energy input structure accounts for most of the decline in energy intensity. However, the input structure and final demands structure by product explain the increase of the energy intensity between 2002 and 2005.

关键词： Energy intensity input-output technology RAS method structural decomposition anal ysis

Experimental continuous sludge microwave system to enhance dehydration ability and hydrogen production from anaerobic digestion of sludge

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Journal of Environmental Sciences 2018年第5期30卷 145-153页

作者： cuihong Zhou Xintong Huang Meng Zeng Department of Environmental Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China

Dehydrating large amounts of sludge produced by sewage treatment plants is *** pretreatment can effectively and significantly improve the dewaterability and hydrogen production of sludge subjected to anaerobic digestion. The aim of this study was to investigate the effects of different microwave conditions on hydrogen production from anaerobic digestion and dewaterability of sludge. Based on an analysis of the electric field distribution, a spiral reactor was designed and a continuous microwave system was built to conduct intermittent and continuous experiments under different conditions. Settling Volume, Capillary Suction Time, particle size, and moisture content of the sludge were measured. The results show that sludge pretreatment in continuous experiments has equally remarkable dehydration performance as in intermittent experiments; the minimum moisture content was 77.29% in the intermittent experiment under a microwave power of 300 W and an exposure time of 60 sec, and that in the continuous experiment was 77.56% under a microwave power of 400 W and an exposure time of 60 *** peak measured by Differential Scanning Calorimeter appeared earliest under a microwave power of 600 W and an exposure time of 180 sec. The heat flux at the peak was 4.343 W/g, which is relatively small. This indicates that microwave pretreatment induced desirable effects. The maximum yield of hydrogen production was 7.967% under the conditions of microwave power of 500 W, exposure time of 120 sec, and water bath at 55℃. This research provides a theoretical and experimental basis for the development of a continuous microwave sludge-conditioning system.

关键词： Sludge Microwave Dehydration performance Conditioning Continuous Anaerobic digestion

Government Investment and High-Quality Economic Development——Measurement and Analysis Based on Input-Output Method

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Journal of Systems Science & Complexity 2022年第3期35卷 993-1008页

作者： YANG Xuelian TIAN Kailan ZHU Lingxiu YANG cuihong School of Economics and Management University of Chinese Academy of SciencesBeijing 100190China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

Analysis of how government investment promotes economic development and employment is important for improving government’s decision-making and promoting high-quality economic development in western *** this paper,the authors take Xinjiang as an example to conduct such an ***,based on the competitive input-output table of Xinjiang,the non-competitive input-output tables of 2007,2012 and 2015 are compiled in this ***,the contribution of Xinjiang government investment,especially the major government investment projects,to the valueadded of Xinjiang,other provinces and cities in China and abroad are ***,this paper uses the non-competitive input-output table to compile the sectoral employment vector,and uses the input-occupancy-output technique to measure how government investment promotes *** results show that Xinjiang government investment contributes the most to the value-added of Xinjiang and other provinces and cities,but less to foreign countries;the government investment create the most job opportunities in projects including transportation projects and livelihood projects etc.

关键词： Economic growth employment government investment high-quality economic development input-output model

Trade Destruction and Trade Deflection:A Quasi-Natural Experiment Based on the US Additional Tariffs

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Journal of Systems Science & Complexity 2023年第6期36卷 2467-2496页

作者： ZHANG Yu GAO Xiang XU Ran YANG cuihong Yangtze Industrial Economic Institute Nanjing UniversityNanjing210093China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China School of Management Engineering Qingdao University of TechnologyQingdao266520China

This paper adopts the DID approach to investigate the trade destruction effects and trade deflection effects of the US additional *** authors find that the US additional tariffs significantly reduce China's exports of tariffed products to the US(i.e.,trade destruction effect),especially intermediate and labor-intensive *** the other hand,they significantly increase China's exports of tariffed products to the third market(i.e.,trade deflection effect).For the$50 billion list,both the trade destruction effect and trade deflection effect are concentrated on processing exports,and the US additional tariffs significantly increase China's exports of tariffed products to ASEAN,Japan and *** the$200 billion list,the US additional tariffs boost China's exports of chemicals,textiles,wood,metal products,furniture and other products to the EU,Australia,Japan,South Africa and Hong Kong,***,most trade deflections are not realized by lowering export prices,indicating that the trade deflections could compensate for the profit losses caused by the US additional tariffs to a certain *** proposed results suggest that searching for substitutions of export markets and a more open trade policy is an important way to avoid profit losses and reduce risks for enterprises and economies suffering from trade frictions.

关键词： DID approach trade deflection trade destruction US additional tariffs

Quantum properties of fermionic fields in multi-event horizon spacetime

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 56-62页

作者： Qianqian Liu Shu-Min Wu cuihong Wen Jieci Wang Department of Physics Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationHunan Normal UniversityChangsha 410081China Department of Physics Liaoning Normal UniversityDalian 116029China

We investigated the properties of quantum entanglement and mutual information in the multi-event horizon Schwarzschild-de Sitter(Sd S)spacetime for massless Dirac *** the first time,we obtained the expression for the evolutions of the quantum state near the black hole event horizon(BEH)and cosmological event horizon(CEH)in the Sd S *** the Nariai limit,the physically accessible entanglement and mutual information are maximized,and the physically inaccessible correlations are *** the increase in temperature of either horizon,the physically accessible correlations experience ***,the initial state remains entangled and can be utilized in entanglement-based quantum information processing tasks,which differs from the scalar field ***,the degradation of physically accessible correlations is more pronounced for small-mass black *** contrast,the physically inaccessible correlations separated by the CEH monotonically increase with the radiation temperature,and such correlations are not decisively influenced by the effect of particle creation at the ***,a similar phenomenon is observed for the inaccessible correlations separated by the *** result differs from the single event spacetime,in which the physically inaccessible entanglement is a monotonic function of the Hawking temperature.

关键词： multi-event horizon spacetime Dirac field SdS spacetime quantum entanglement

Fault Identification for Shear-Type Structures Using Low-Frequency Vibration Modes

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2769-2791页

作者： cuihong Li Qiuwei Yang Xi Peng School of Civil Engineering Shaoxing UniversityShaoxing312000China School of Civil and Transportation Engineering Ningbo University of TechnologyNingbo315211China Engineering Research Center of Industrial Construction in Civil Engineering of Zhejiang Ningbo University of TechnologyNingbo315211China

Shear-type structures are common structural forms in industrial and civil buildings,such as concrete and steel frame *** diagnosis of shear-type structures is an important topic to ensure the normal use of *** main drawback of existing damage assessment methods is that they require accurate structural finite element models for damage ***,for many shear-type structures,it is difficult to obtain accurate *** order to avoid finite elementmodeling,amodel-freemethod for diagnosing shear structure defects is developed in this *** method only needs to measure a few low-order vibration modes of the *** proposed defect diagnosis method is divided into two *** the first stage,the location of defects in the structure is determined based on the difference between the virtual displacements derived from the dynamic flexibility matrices before and after *** the second stage,damage severity is evaluated based on an improved frequency sensitivity *** innovations of this method lie in two *** first innovation is the development of a virtual displacement difference method for determining the location of damage in the shear *** second is to improve the existing frequency sensitivity equation to calculate the damage degree without constructing the finite *** has been verified on a numerical example of a 22-story shear frame structure and an experimental example of a three-story steel shear *** on numerical analysis and experimental data validation,it is shown that this method only needs to use the low-order modes of structural vibration to diagnose the defect location and damage degree,and does not require finite element *** proposed method should be a very simple and practical defect diagnosis technique in engineering practice.

关键词： Fault diagnosis shear steel structure vibration mode dynamic flexibility frequency sensitivity

H_∞ Output Feedback Control of Linear Time-invariant Fractional-order Systems over Finite Frequency Range

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IEEE/CAA Journal of Automatica Sinica 2016年第3期3卷 304-310页

作者： cuihong Wang Huanhuan Li YangQuan Chen Department of Mathematics and Computer Science Shanxi Normal University IEEE School of Engineering University of California

This paper focuses on the H∞output feedback control problem of linear time-invariant fractional-order systems over finite frequency range. Based on the generalized Kalman-Yakubovic-Popov (KYP) Lemma and a key projection lemma, a necessary and sufficient condition is established to ensure the existence of the H∞output feedback controller over finite frequency range, a desirable property in control engineering practice. By using the matrix congruence transformation, the feedback control gain matrix is decoupled and further parameterized by a scalar matrix. Two iterative linear matrix inequality algorithms are developed to solve this problem. Finally, numerical examples are provided to illustrate the effectiveness of the proposed method. © 2014 Chinese Association of Automation.

关键词： Algebra Feedback control Iterative methods Linear matrix inequalities Linear transformations Matrix algebra Numerical methods