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New frontiers in metamaterials research： Novel electronic materials and inhomogeneous metasurfaces

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Frontiers of physics 2013年第4期8卷 386-393页

作者： Kun ding shi-Yi Xiao Lei Zhou State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and Physics Department Fudan University Shanghai 200433 China

In reviewing some recent work in metamaterials, we highlight two exciting new frontiers just emerg- ing in this field metamaterials made by new electronic materials （particularly graphene） and inhomogeneous metasurf... 详细信息

关键词： metamaterial new electronic material graphene inhomogeneous metasurfaces wavefront control

Asymptotic Stability for One-dimensional Motion of Non-Newtonian Compressible Fluids

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Acta Mathematicae Applicatae Sinica 2014年第1期30卷 99-110页

作者： Xiao-ding shi Teng WANG Zhen ZHANG School of Science Beijing University of Chemical Technology Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mechanical and Electrical Engineering Beijing University of Chemical Technology

Rarefaction wave solutions for a one-dimensional model system associated with nomNewtonian compressible fluid are investigated in terms of asymptotic stability. The rarefaction wave solution is proved to be asymptotically stable, provided the initial disturbance is suitably small. The proof is given by the elemental L2 energy method.

关键词： non-Newtonian fluid asymptotic stability global solution

Stability of the Phase Separation State for Compressible Navier-Stokes/Allen-Cahn System

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 45-74页

作者： Ya-zhou Chen Hakho Hong Xiao-ding shi Department of Mathematics College of Mathematics and PhysicsBeijing University of Chemical TechnologyBeijing100029China Institute of Mathematics State Academy of SciencesPyongyangKorea

This paper is concerned with the large time behavior of the Cauchy problem for Navier-Stokes/AllenCahn system describing the interface motion of immiscible two-phase flow in 3-D. The existence and uniqueness of global solutions and the stability of the phase separation state are proved under the small initial perturbations. Moreover, the optimal time decay rates are obtained for higher-order spatial derivatives of density,velocity and phase. Our results imply that if the immiscible two-phase flow is initially located near the phase separation state, then under small perturbation conditions, the solution exists globally and decays algebraically to the complete separation state of the two-phase flow, that is, there will be no interface fracture, vacuum, shock wave, mass concentration at any time, and the interface thickness tends to zero as the time t → +∞.

关键词： Navier-Stokes/Allen-Cahn system existence uniqueness large time behavior decay rate

Econometric modeling of risk measures: A selective review of the recent literature

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Applied Mathematics(A Journal of Chinese Universities) 2019年第2期34卷 205-228页

作者： TIAN ding-shi CAI Zong-wu FANG Ying Wang Yanan Institute for Studies in Economics Department of StatisticsSchool of EconomicsMinistry of Education Key Laboratory of Econometrics and Fujian Key Laboratory of Statistical ScienceXiamen UniversityXiamenFujian 361005China Department of Economics University of KansasLawrenceKS 66045USA

Since the financial crisis in 2008, the risk measures which are the core of risk management, have received increasing attention among economists and practitioners. In this review, the concentration is on recent developments in the estimation of the most popular risk measures, namely, value at risk (VaR), expected shortfall (ES), and expectile. After introducing the concept of risk measures, the focus is on discussion and comparison of their econometric modeling. Then, parametric and nonparametric estimations of tail dependence are investigated. Finally, we conclude with insights into future research directions.

关键词： Expectile Expected Shortfall Network Risk Nonparametric Estimation Tail Dependence Value at Risk

Partial Regularity of Suitable Weak Solutions to the System of the Incompressible Shear-thinning Flow

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Acta Mathematicae Applicatae Sinica 2021年第2期37卷 348-363页

作者： Ya-zhou CHEN Hai-liang LI Xiao-ding shi College of Mathematics and Physics Beiing University of Chemical TechnologyBejing 100029China School of Mathematical Sciences Capital Normal UniversityBejing 100048China

This paper is devoted to the partial regularity of suitable weak solutions to the system of the incompressible shear-thinning flow in a bounded domainΩ■R^(n),n≥*** is proved that there exists a suitable weak solution of the shear-thinning fluid in the n-D smooth bounded domain(for n≥2).For 3 D model,it is proved that the singular points are concentrated on a closed set whose 1 dimensional Hausdorff measure is zero.

关键词： partial regularity suitable weak solutions shear-thinning flow

Magnetic and Optical Properties of the TiO_2-Co-TiO_2 Composite Films Grown by Magnetron Sputtering

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Chinese Journal of Aeronautics 2007年第2期20卷 162-167页

作者： LIU Fa-min ding Peng shi Wei-mei WANG Tian-min Department of Physics School of Sciences Beijing University of Aeronautics and Astronautics Beijing 100083 China

The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction （XRD）, Raman spectra and X-ray photoemission spectra （XPS）. It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 mn, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.

关键词： TiO2-Co-TiO2 sandwich films surface structure and properties optical and magnetic properties

Rural Heritage: Value, Conservation and Revitalisation-From the Perspective of the Human-Land Relationship

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Built Heritage 2019年第2期3卷 1-6页

作者： Xiaofan Du ding shi Department of Cultural Heritage and Museology Fudan UniversityShanghaiChina

Today,rural revitalisation has become a national issue for China,and it is one that many countries also have to ***,a rural area is not some wilderness that is open to any type of *** long history of agricultural civilisation has left an extensive,precious heritage in rural areas;thus,revitalising rural areas has to be based on conserving that *** special issue adopts the theme of‘rural heritage’:we provide a platform for dialogue between China and overseas scholars with the focus on conserving and revitalising rural *** are six contributions in this special issue on matters that affect rural heritage in various *** them,it is possible to understand methods of conservation design with respect to Japan’s rural heritage and follow the role of rural tourism in *** is also possible to grasp the importance of promoting a building culture in rural parts of *** these contributions offer profound insights for conserving and revitalising China’s rural *** special issue also presents the thoughts of Chinese and foreign experts on recent issues related to China’s rural heritage;it provides a comprehensive introduction to the rural heritage protection system in *** heritage is a complex ***,the topics addressed in this special issue reflect the various characteristics ***,if readers study these articles from the perspective of the human-land relationship,they will be able to identify the deep correlations among them.

关键词： rural heritage value conservation revitalisation sustainable development cultural landscape human-land relationship

Multipoint Heave Motion Prediction Method for ships Based on the PSO-TGCN Model

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China Ocean Engineering 2023年第6期37卷 1022-1031页

作者： ding shi-feng MA Qun ZHOU Li HAN Sen DONG Wen-bo School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

During ship operations,frequent heave movements can pose significant challenges to the overall safety of the ship and completion of cargo *** existing heave compensation systems suffer from issues such as dead zones and control system time lags,which necessitate the development of reasonable prediction models for ship heave *** this paper,a novel model based on a time graph convolutional neural network algorithm and particle swarm optimization algorithm(PSO-TGCN)is proposed for the first time to predict the multipoint heave movements of ships under different sea *** enhance the dataset's suitability for training and reduce interference,various filter algorithms are employed to optimize the *** training process utilizes simulated heave data under different sea conditions and measured heave data from multiple *** results show that the PSO-TGCN model predicts the ship swaying motion in different sea states after 2 s with 84.7%accuracy,while predicting the swaying motion in three different *** performing a comparative study,it was also found that the present method achieves better performance that other popular *** model can provide technical support for intelligent ship control,improve the control accuracy of intelligent ships,and promote the development of intelligent ships.

关键词： ship motion prediction time delay multipoint forecast time-graph convolutional neural network particle swarm optimization

Homologous Comparisons of Photosynthetic System I Genes among Cyanobacteria and Chloroplasts

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Journal of Integrative Plant Biology 2008年第8期50卷 929-940页

作者： Jie Yu Pei-Jun Ma ding-Ji shi shi-Ming Li Chang-Lu Wang School of Matin Science & Engineering Tianjin University of Science & Technology Tianjin 300457 China Institute of Botany the Chinese Academy of Sciences Beijing 100093 China

It has now believed that chloroplasts arose from cyanobacteria, however, during endosymbiosis, the photosynthetic genes in chloroplasts have been reduced. How these changes occurred during plant evolution was the focus of the present study. Beginning with photosystem I （PSI） genes, a homologous comparison of amino acid sequences of 18 subunits of PSI from 10 species of cyanobacteria, chloroplasts in 12 species of eucaryotic algae, and 28 species of plants （including bryophytes, pteridophytes, gymnospermae, dicotyledon and monocotyledon） was undertaken. The data showed that 18 genes of PSI can be divided into two groups： Part Ⅰ including seven genes （psaA, psaB, psaC, psal, psaJ, ycf3 and ycf4） shared both by cyanobacteria and plant chloroplasts; Part Ⅱ containing another 11 genes （psaD, psaE, psaF, psaK, psaL, psaM, btpA, ycf37, psaG, psaH and psaN） appeared to have diversified in different plant groups. Among Part Ⅰ genes, psaC, psaA and psaB had higher homology in all species of cyanobacteria and chloroplasts. Among Part Ⅱ genes, only psaG, psaH and psaN emerged in seed plants.

关键词： chloroplast cyanobacteria homologous comparison photosynthesis evolution PSI (photosystem I) genes