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Optical emission enhancement of bent InSe thin films

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Science China(Information Sciences) 2021年第4期64卷 149-156页

作者： Jiahao xie Lijun ZHANG State Key Laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOESchool of Materials Science and Engineering Jilin University

In contrast to the majority of two-dimensional semiconductors such as transition metal dichalcogenides, indium selenide(InSe) possesses an intrinsic large out-of-plane oriented band-edge luminescent dipole. This unique anisotropic feature of band-edge optical emissions can be exploited to achieve enhanced optical signal in bent regions of materials created by geometrical modification. We herein investigate based on first-principle calculations the mechanism of this optical emission enhancement by modelling the photoluminescence processes in bent and flat regions of the InSe thin film. We propose in our model that the shorter-wavelength interband transition, labelled as transition B′, between the second-highest valence band and the bottom of conduction band plays an important role in the enhancing process. Our model robustly describes the dependence of optical emission enhancement in the bent InSe thin films on thickness, incident light orientation, and excitation photon energy. In particular, we found that when excitation photon energy is lower than the energy of transition B′, strong enhancement up to hundreds of times can be obtained by applying an incident light at an angle less than 70° to the InSe layers. Our results provide useful references for modulating luminescent properties of InSe films toward flexible optoelectronic device applications.

关键词： InSe enhanced luminescence 2D semiconductor optical transition optical anisotropy

Linking minerals to bacterial genes

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National Science Review 2023年第1期10卷 103-104页

作者： Shucheng xie State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences (Wuhan)

The biogeochemical roles of microbes in the Earth system are relatively well known [1],but their biogeophysical roles in Earth history are yet to be *** bacteria(MTB) may have been the earliest organisms to sense Earth’s magnetic field and to form intracellular nanocrystals of magnetic minerals,so-called magnetotaxis and magnetosomes,respectively[2].These magnetos ome minerals are highly resistant to diagenesis and generally well-preserved in sediments or sedimentary rocks as magnetofossils[3],making excellent archives of the biogeophysical activity of microbes.

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A Characterization of Counterexamples to the Kodaira-Ramanujam Vanishing Theorem on Surfaces in Positive Characteristic

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Chinese Annals of Mathematics,Series B 2011年第5期32卷 741-748页

作者： Qihong xie School of Mathematical Sciences Fudan University Shanghai 200433 China.

The author gives a characterization of counterexamples to the Kodaira-Ramanujam vanishing theorem on smooth projective surfaces in positive *** precisely,it is reproved that if there is a counterexample to the Kodaira-Ramanujam vanishing theorem on a smooth projective surface X in positive characteristic,then X is either a quasi-elliptic surface of Kodaira dimension 1 or a surface of general ***,it is proved that up to blow-ups,X admits a fibration to a smooth projective curve,such that each fiber is a singular curve.

关键词： Characterization Counterexample Kodaira-Ramanujam vanishing

Limit behaviors of extended Kalman filter as a parameter estimator for a sinusoidal signal

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Control Theory and Technology 2018年第3期16卷 203-211页

作者： Li xie State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of Control and Computer Engineering North China Electric Power University Beijing 102206 China

In this note, the basic limit behaviors of the solution to Riccati equation in the extended Kalman filter as a parameter estimator for a sinusoidal signal are analytically investigated by using lira sup and lim inf in... 详细信息

关键词： Extended Kalman filter parameter estimator sinusoidal signal covariance matrix limit behavior

Hall Polynomials for Affine Quivers of Type _m(m≥1)

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Acta Mathematica Sinica,English Series 2008年第3期24卷 387-396页

作者： Tao xie Department of Mathematics Hubei Normal University Huangshi 435002 P. R. China

It is well known that Hall polynomials as structural coefficients play an important role in the structure of Lie algebras and quantum groups. By using the properties of representation categories of affine quivers, the task of computing Hall polynomials for affine quivers can be reduced to counting the numbers of solutions of some matrix equations. This method has been applied to obtain Hall polynomials for indecomposable representations of quivers of type Am（m≥1）

关键词： affine quiver preprojective module preinjective module regular module Hall polynomial

Standard tri-point transition function

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Science China Mathematics 2005年第7期48卷 904-914页

作者： xie Yuquan School of Mathematics and Computational Science Xiangtan University Xiangtan 411105 China

It is usually difficult to express a family of tri-point transition function (TTF)by a transition matrix as Markov processes with one parameter. In this paper, we define three kinds of connection matrixes on the states of standard tri-point transition function (STTF) and study their essential character, give a constructive method on the constantvalue standard tri-point transition function and a general expression of the state-symmetric standard tri-point transition function by a sequence of the transition matrixes of special and simple Markov processes with one parameter.

关键词： tri-point transition function, standard, constant-value, state-symmetry, connection matrix, Markov processes.

GL Method for Solving Equations in Math-Physics and Engineering

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 391-404页

作者： Lee xie GL Geophysical Laboratory USA

In this paper, we propose a GL method for solving the ordinary and the partial differential equation in mathematical physics and chemics and engineering. These equations govern the acustic, heat, electromagnetic, elastic, plastic, flow, and quantum etc. macro and micro wave field in time domain and frequency domain. The space domain of the differential equation is infinite domain which includes a finite inhomogeneous domain. The inhomogeneous domain is divided into finite sub domains. We present the solution of the differential equation as an explicit recursive sum of the integrals in the inhomogeneous sub domains. Actualy, we propose an explicit representation of the inhomogeneous parameter nonlinear inversion. The analytical solution of the equation in the infinite homogeneous domain is called as an initial global field. The global field is updated by local scattering field successively subdomaln by subdomain. Once all subdomains are scattered and the updating process is finished in all the sub domains, the solution of the equation is obtained. We call our method as Global and Local field method, in short , GL method. It is different from FEM method, the GL method directly assemble inverse matrix and gets solution. There is no big matrix equation needs to solve in the GL method. There is no needed artificial boundary and no absorption boundary condition for infinite domain in the GL method. We proved several theorems on relationships between the field solution and Green＇s function that is the theoretical base of our GL method. The numerical discretization of the GL method is presented. We proved that the numerical solution of the GL method convergence to the exact solution when the size of the sub domain is going to zero. The error estimation of the GL method for solving wave equation is presented. The simulations show that the GL method is accurate, fast, and stable for solving elliptic, parabolic, and hyperbolic equations. The GL method has advantages and wide a

关键词： GL method electromagnetic acoustic nanometer materials dispersion analytical and numerical Quantum

Exact solution of the two-mode quantum Rabi model

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Communications in Theoretical Physics 2020年第6期72卷 57-64页

作者： Qiong-Tao xie College of Physics and Electronic Engineering Hainan Normal UniversityHaikou 571158China

An analytical method is developed to study the two-mode quantum Rabi *** certain specific parameter conditions,especially for the resonant conditions,we obtain an infinite number of the exact solutions of the eigenfunctions and associated *** is shown that there exist new types of the exact energies which do not correspond to the *** analytical method may find applications in some related models.

关键词： exact solutions two-mode quantum Rabi model level-crossings

Fast nonnegative tensor ring decomposition based on the modulus method and low-rank approximation

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Science China(Technological Sciences) 2021年第9期64卷 1843-1853页

作者： YU YuYuan xie Kan YU JinShi JIANG Qi xie ShengLi School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong-Hong Kong-Macao Joint Laboratory for Smart Manufacturing Guangzhou 510006China Key Laboratory of Intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangdong University of TechnologyGuangzhou 510006China

Nonnegative tensor ring(NTR) decomposition is a powerful tool for capturing the significant features of tensor objects while preserving the multi-linear structure of tensor data. The existing algorithms rely on frequent reshaping and permutation operations in the optimization process and use a shrinking step size or projection techniques to ensure core tensor nonnegativity, which leads to a slow convergence rate, especially for large-scale problems. In this paper, we first propose an NTR algorithm based on the modulus method(NTR-MM), which constrains core tensor nonnegativity by modulus transformation. Second, a low-rank approximation(LRA) is introduced to NTR-MM(named LRA-NTR-MM), which not only reduces the computational complexity of NTR-MM significantly but also suppresses the noise. The simulation results demonstrate that the proposed LRA-NTR-MM algorithm achieves higher computational efficiency than the state-of-the-art algorithms while preserving the effectiveness of feature extraction.

关键词： nonnegative tensor ring decomposition modulus method low-rank approximation