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Existence and Uniqueness of Stochastic Differential Equations with Random Impulses and Markovian Switching under Non-Lipschitz Conditions

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Acta Mathematica Sinica,English Series 2011年第3期27卷 519-536页

作者： Shu jin WU bin ZHOU School of Finance and Statistics East China Normal University Shanghai 200241 P. R. China

In the paper, stochastic differential equations with random impulses and Markovian switching are brought forward, where the so-called random impulse means that impulse ranges are driven by a series of random variables and impulse times are a random sequence, so these equations extend stochastic differential equations with jumps and Markovian switching. Then the existence and uniqueness of solutions to such equations are investigated by employing the Bihari inequality under non-Lipschtiz conditions.

关键词： Stochastic differential equation random impulse Markovian switching existence uniqueness non-Lipschtiz condition

New Method to Obtain Strain Gradient Chirped Fiber Bragg Gratings

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Chinese Physics Letters 1999年第12期16卷 902-904页

作者： WANG Ling FU Li-bin XU Wan-jin AN hong-lin LIN Xiang-zhi LIU hong-du Department of Physics Peking UniversityBeijing 100871

We describe a new method for applying a strain gradient with different profiles to convert uniform fiber Bragg gratings into linear or non-linear chirped ones. The chirping profile and the chirp rate of the fiber gratings can be controlled by simply varying the tension applied. Both the theory and experimental results are presented.

关键词： fiber chirp convert

DOA estimation for attitude determination on communication satellites

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Chinese Journal of Aeronautics 2014年第3期27卷 670-677页

作者： Yang bin He Feng jin jin Xiong Huagang Xu Guanghan School of Electronic and Information Engineering Beihang University School of Aerospace Tsinghua University

In order to determine an appropriate attitude of three-axis stabilized communication satellites, this paper describes a novel attitude determination method using direction of arrival （DOA） estimation of a ground signal source. It differs from optical measurement, magnetic field measurement, inertial measurement, and global positioning system （GPS） attitude determination. The proposed method is characterized by taking the ground signal source as the attitude reference and acquiring attitude information from DOA estimation. Firstly, an attitude measurement equation with DOA estimation is derived in detail. Then, the error of the measurement equation is analyzed. Finally, an attitude determination algorithm is presented using a dynamic model, the attitude measurement equation, and measurement errors. A developing low Earth orbit （LEO） satellite which tests mobile communication technology with smart antennas can be stabilized in three axes by corporately using a magnetometer, reaction wheels, and three-axis magnetorquer rods. Based on the communication satellite, simulation results demonstrate the effectiveness of the method. The method could be a backup of attitude determination to prevent a system failure on the satellite. Its precision depends on the number of snapshots and the input signal-to-noise ratio （SNR） with DOA estimation.

关键词： Attitude determination Communication satellite Direction of arrival (DOA) estimation Low Earth orbit (LEO) Smart antennas

Application of CFD and FEA Coupling to Predict Structural Dynamic Responses of A Trimaran in Uni-and Bi-Directional Waves

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China Ocean Engineering 2024年第1期38卷 81-92页

作者： LIAO Xi-yu XIA jin-song CHEN Zhan-yang TANG Qin ZHAO Nan ZHAO Wei-dong GUI hong-bin Marine Design&Research Institute of China Shanghai 200011China Ship Structure Division China Ship Scientific Research CenterWuxi 214082China College of Ocean Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China School of Foreign Studies Jiangnan UniversityWuxi 214122China

To predict the wave loads of a flexible trimaran in different wave fields,a one-way interaction numerical simulation method is proposed by integrating the fluid solver(Star-CCM+)and structural solver(Abaqus).Differing from the existing coupled CFD-FEA method for monohull ships in head waves,the presented method equates the mass and stiffness of the whole ship to the hull shell so that any transverse and longitudinal section stress of the hull in oblique waves can be ***,verification study and sensitivity analysis are carried out by comparing the trimaran motions using different mesh sizes and time step *** on the wave elevation of uni-and bi-directional waves is also carried *** a comprehensive analysis on the structural responses of the trimaran in different uni-directional regular wave and bi-directional cross sea conditions is carried out,***,the differences in structural response characteristics of trimaran in different wave fields are *** results show that the present method can reduce the computational burden of the two-way fluid-structure interaction simulations.

关键词： CFD-FEA fluid-structure coupling structural responses trimaran bi-directional cross sea

Bedding parallel fractures in fine-grained sedimentary rocks:Recognition,formation mechanisms,and prediction using well log

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Petroleum Science 2022年第2期19卷 554-569页

作者： jin Lai bing-Chang Liu hong-bin Li Xiao-Jiao Pang Shi-Chen Liu Meng Bao Gui-Wen Wang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China

Core,thin section,conventional and image logs are used to provide insights into distribution of fractures in fine grained sedimentary rocks of Permian Lucaogou Formation in Jimusar *** parallel fractures are common in fine grained sedimentary rocks which are characterized by layered *** and thin section analysis reveal that fractures in Lucaogou Formation include tectonic inclined fracture,bedding parallel fracture,and abnormal high pressure *** parallel fractures are abundant,but only minor amounts of them remain open,and most of them are partly to fully sealed by carbonate minerals(calcite)and *** parallel fractures result in a rapid decrease in resistivity,and they are recognized on image logs to extend along bedding planes and have discontinuous surfaces due to partly-fully filled resistive carbonate minerals as well as late stage dissolution.A comprehensive interpretation of distribution of bedding parallel fractures is performed with green line,red line,yellow line and blue line representing bedding planes,induced fractures,resistive fractures,and open(bedding and inclined)fractures,*** strike of bedding parallel fractures is coinciding with bedding *** parallel fractures are closely associated with the amounts of bedding planes,and high density of bedding planes favor the formation of bedding parallel *** dark and bright layers have the most abundant bedding parallel fractures on the image logs,and the bedding parallel fractures are always associated with low resistivity *** results above may help optimize sweet spots in fine grained sedimentary rocks,and improve future fracturing design and optimize well spacing.

关键词： Bedding parallel fracture Fine-grained sedimentary rocks Image logs Lucaogou Formation

Dual recombinases-based genetic lineage tracing for stem cell research with enhanced precision

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Science China(Life Sciences) 2021年第12期64卷 2060-2072页

作者： Hengwei jin Kuo Liu bin Zhou State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell BiologyCenter for Excellence in Molecular Cell ScienceUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200031China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China School of Life Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

Stem cell research has become a hot topic in biology,as the understanding of stem cell biology can provide new insights for both regenerative medicine and clinical treatment of *** deciphering the fate of stem cells is the basis for understanding the mechanism and function of stem cells during tissue repair and ***-loxP-mediated recombination has been widely applied in fate mapping of stem cells for many ***,nonspecific labeling by conventional cell lineage tracing strategies has led to discrepancies or even controversies in multiple ***,dual recombinase-mediated lineage tracing strategies have been developed to improve both the resolution and precision of stem cell fate *** new genetic strategies also expand the application of lineage tracing in studying cell origin and ***,we review cell lineage tracing methods,especially dual genetic approaches,and then provide examples to describe how they are used to study stem cell fate plasticity and function in vivo.

关键词： lineage tracing dual recombination Cre-loxP Dre-rox stem cell cell fate plasticity tissue regeneration

Phase constitution,microstructure and mechanical properties of a Ni-based superalloy specially designed for additive manufacturing

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China Foundry 2021年第4期18卷 397-408页

作者： bin Wu jing-jing Liang Yan-hong Yang jin-guo Li Yi-zhou Zhou Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Space Manufacturing Technology(CAS Key Lab) Beijing 100094China

In this study,a kind of Ni-based superalloy specially designed for additive manufacturing(AM)was ***-Calc simulation and differential scanning calorimetry(DSC)analysis were used to determine phases and their transformation *** specimens were prepared by laser metal deposition(LMD)and traditional casting ***,phase constitution and mechanical properties of the alloy were characterized by scanning electron microscopy(SEM),transmission scanning electron microscopy(TEM),X-ray diffraction(XRD)and tensile *** results show that this alloy contains two basic phases,γ/γ’,in addition to these phases,at least two secondary phases may be present,such as MC carbides and Laves ***,the as-deposited alloy has finer dendrite,its mean primary dendrite arm space(PDAS)is about 30-45μm,and the average size ofγ’particles is 100-150 ***,the dendrite size of the as-cast alloy is much larger and its PDAS is 300-500μm with secondary and even third dendrite ***,the alloy displays different tensile behavior with different processing methods,and the as-deposited specimen shows better ultimate tensile stress(1,085.7±51.7 MPa),yield stress(697±19.5 MPa)and elongation(25.8%±2.2%)than that of the as-cast *** differences in mechanical properties of the alloy are due to the different morphology and size of dendrites,γ’,and Laves phase,and the segregation of elements,*** important information would be helpful for alloy application as well as new alloy development.

关键词： additive manufacturing laser metal deposition Ni-based superalloy tensile behavior

An extended stress-based method for orientation angle optimization of laminated composite structures

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Acta Mechanica Sinica 2011年第6期27卷 977-985页

作者： jin Zhang Wei-hong Zhang Ji-hong Zhu Engineering Simulation and Aerospace Computing （ESAC） The Key Laboratory of Contemporary Design ＆ Integrated Manufacturing Technology Northwestern Polytechnical University 710072 Xi＇ an China

Orientation optimization plays an important role in the lay-up design of composite *** orientation optimization methods face the main problem of huge number of design ***,a patch concept is proposed to reduce the number of design ***,the traditional stress-based method can not deal with patch orientation optimization of composite *** this paper,we propose an extended stress-based method to deal with such *** considered problems are to minimize the mean compliance under multiple load cases or to maximize the eigenvalues of a composite *** numerical examples are solved to demonstrate the efficiency of the new *** is shown that the new method has the ability to deal with constraints on orientation angle,such as symmetric,antisymmetric and discrete orientation angle *** iteration is less time-consuming because no sensitivity analysis is needed and a quick convergence rate can be achieved.

关键词： Structural optimization Composites Laminates Orientation angle optimization

REAL-TIME FLOOD FORECASTING METHOD WITH 1-D UNSTEADY FLOW MODEL

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Journal of Hydrodynamics 2007年第2期19卷 150-154页

作者： MU jin-bin ZHANG Xiao-feng State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072China

A real-time forecasting method coupled with the I-D unsteady flow model with the recursive least-square method was developed. The 1-D unsteady flow model was modified by using the time-variant parameter and revising it dynamically through introducing a variable weighted forgetting factor, such that the output of the model could be adjusted for the real time forecasting of floods. The application of the new real time forecasting model in the reach from Yichang to Luoshan of the Yangtze River was demonstrated. Computational result shows that the forecasting accuracy of the new model is much higher than that of the original 1-D unsteady flow model. The method developed is effective for flood forecasting, and can be used for practical operation in the flood forecasting.

关键词： unsteady flow hydraulic model least squares,time variant forgetting factor real-time forecasting