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Integral Equation Method for a Non-Selfadjoint Steklov Eigenvalue Problem

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Communications in Computational Physics 2022年第5期31卷 1546-1560页

作者： Yunyun Ma jiguang sun School of Computer Science and Technology Dongguan University of TechnologyDongguan 523808P.R.China Department ofMathematical Sciences Michigan TechnologicalUniversityHoughtonMI 49931U.S.A.

We propose a numerical method for a non-selfadjoint Steklov eigenvalue problem of the Helmholtz *** problem is formulated using boundary *** Nyström method is employed to discretize the integral operators,which leads to a non-Hermitian generalized matrix eigenvalue *** spectral indicator method(SIM)is then applied to calculate the(complex)*** convergence is proved using the spectral approximation theory for(non-selfadjoint)compact *** examples are presented for validation.

关键词： Steklov eigenvalues non-selfadjoint problems integral equations Nyström method spectral projection

A spectral projection method for transmission eigenvalues

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Science China Mathematics 2016年第8期59卷 1613-1622页

作者： ZENG Fang sun jiguang XU LiWei Institute of Computing and Data Sciences College of Mathematics and StatisticsChongqing University Department of Mathematical Sciences Michigan Technological University

We consider a nonlinear integral eigenvalue problem, which is a reformulation of the transmission eigenvalue problem arising in the inverse scattering theory. The boundary element method is employed for discretization, which leads to a generalized matrix eigenvalue problem. We propose a novel method based on the spectral projection. The method probes a given region on the complex plane using contour integrals and decides whether the region contains eigenvalue(s) or not. It is particularly suitable to test whether zero is an eigenvalue of the generalized eigenvalue problem, which in turn implies that the associated wavenumber is a transmission eigenvalue. Effectiveness and efficiency of the new method are demonstrated by numerical examples.

关键词： spectral projection boundary element method transmission eigenvalues

Study of Carbon Contaminated Epitaxial Silicon

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Rare Metals 1989年第4期9卷 64-66页

作者： Li, Yuzhen sun, jiguang Liu, Mingdeng Quan, Baofu General Research Inst for Non-ferrous Metals China

The properties of the carbon contaminated silicon epitaxial layer and its surface have been studied by means of JAMP-10 Auger electron microprobe and JEM-2000FX transmission scanning electron microscope. The results show that the fog defects on the surface are due to carbon contamination. The existence of SiC in the silicon epitaxial layer has been identified by the electron diffraction analysis.

关键词： Carbon Effects Crystals Epitaxial Growth Microscopic Examination Transmission Electron Microscopy Semiconductor Materials Defects Spectroscopy, Auger Electron

A Shifted-Inverse Adaptive Multigrid Method for the Elastic Eigenvalue Problem

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Communications in Computational Physics 2020年第1期27卷 251-273页

作者： Bo Gong Jiayu Han jiguang sun Zhimin Zhang Beijing Computational Science Research Center Beijing 100193China School of Mathematical Sciences Guizhou Normal UniversityGuiyang550025China Department of Mathematical Sciences Michigan Technological UniversityHoughtonMI 49931USA Department of Mathematics Wayne State UniversityDetroitMI 48202USA

A shifted-inverse iteration is proposed for the finite element discretization of the elastic eigenvalue *** method integrates the multigrid scheme and adaptive algorithm to achieve high efficiency and *** estimates and optimal convergence for the proposed method are *** examples show that the proposed method inherits the advantages of both ingredients and can compute low regularity eigenfunctions effectively.

关键词： Elastic eigenvalue problem shifted-inverse iteration adaptive multigrid method

Band Structure Calculations of Dispersive Photonic Crystals in 3D using Holomorphic Operator Functions

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Communications in Computational Physics 2023年第2期33卷 628-646页

作者： Wenqiang Xiao Bo Gong Junshan Lin jiguang sun Beijing Computational Science Research Center Beijing100193China Faculty of Science Beijing University of TechnologyBeijing100124China Department of Mathematics and Statistics Auburn UniversityAuburnAL 36849United States Department of Mathematical Sciences Michigan Technological UniversityHoughtonMI 49931United States.

We propose a finite element method to compute the band structures of dispersive photonic crystals in *** nonlinear Maxwell’s eigenvalue problem is formulated as the eigenvalue problem of a holomorphic operator *** N´ed´elec edge elements are employed to discretize the operators,where the divergence free condition for the electric field is realized by a mixed form using a Lagrange *** convergence of the eigenvalues is proved using the abstract approximation theory for holomorphic operator functions with the regular approximation of the edge *** spectral indicator method is then applied to compute the discrete *** examples are presented demonstrating the effectiveness of the proposed method.

关键词： Band structure dispersive photonic crystal Maxwell’s equations nonlinear eigenvalue problem edge element holomorphic operator function

Solubility of β-cyclodextrin in different mixed solvents

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Petroleum Science 2008年第3期5卷 263-268页

作者： Yu Yong Li jiguang sun Yan Liang Qianqing Peng Xiaoming Liu Yansheng Hu Yufeng Laboratory of Green Chemistry and Chemical Engineering China University of Petroleum Beijing 102249 China

The solubility of β-cyclodextrin （β-CD） in ionic liquid/N, N-dimethyl-acetamide （IL/DMAC） mixed solvent and in LiCI/DMAC mixed solvent was investigated at 323.15 K and 353.15 K. The results showed that the solubility of β-CD in IL/DMAC system increased with increasing temperature, but decreased in LiCI/DMAC system. β-CD had the highest solubility in IL/DMAC system with [Cl]- or [Br]- anions. The solubility of β-CD in LiCl/DMAC system was lower than that in IL/DMAC system with [Cl]- or [Br]- anions but higher than that in IL/DMAC system with weak-coordinated anions （e.g [BF4]- or [PF6]-）. The effects of substituent groups （benzyl and butyl） of cation and the structure of cations on β-cyclodextrin solubility were also investigated.

关键词： β-cyclodextrin ionic liquid solubility mixed solvent

he adaptive chirplet transform and its application in GPR target detection

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Applied Geophysics 2009年第2期6卷 192-200页

作者： Zeng Zhaofa Wu Fengshou Huang Ling Liu Fengshan sun jiguang Collage of Exploration Science and Technology Jilin University Changchun 130026 China Applied Mathematic Research Center Delaware State University Dover DE 19901 USA

GPR has become an important geophysical method in UXO and landmine detection, for it can detect both metal and non-metallic targets. However, it is difficult to remove the strong clutters from surface-layer reflection and soil due to the low signal to noise ratio of GPR data. In this paper, we use the adaptive chirplet transform to reject these clutters based on their character and then pick up the signal from the UXO by the transform based on the Radon-Wigner distribution. The results from the processing show that the clutter can be rejected effectively and the target response can be measured with high SNR.

关键词： GPR target detection clutter rejection chirplet transform

基于控制受限MIMO预测控制的超超临界机组集中式协调控制

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中国电力 2019年第5期52卷 21-28页

作者：张金营孙蓟光国家能源投资集团有限责任公司北京100011 国华定州发电有限责任公司河北定州073000

当前超超临界机组协调系统采用的控制方案在变负荷过程中不能将主汽压力与中间点温度同时很好的控制在设计值附近,这严重影响机组安全性、经济性。基于控制受限MIMO(multiple input multiple output)预测控制的集中式协调控制方案在不... 详细信息

当前超超临界机组协调系统采用的控制方案在变负荷过程中不能将主汽压力与中间点温度同时很好的控制在设计值附近,这严重影响机组安全性、经济性。基于控制受限MIMO(multiple input multiple output)预测控制的集中式协调控制方案在不解耦、无前馈的情况下即可解决MIMO系统的强耦合、大迟延问题。首先给出了控制受限MIMO预测控制的算法,然后在MATLAB中仿真实现。仿真结果表明,集中式协调控制方案与传统PID控制方案在功率具有基本相同跟踪性能的情况下,主汽压力与中间点温度的跟踪性能更优、鲁棒性更强。

关键词：超超临界机组控制受限 MIMO预测控制集中式协调控制

Effect　of　Dislocations　on　Helium　Bubble　Nucleation　in　316L　SS　During　Hot－implantation　at　550℃

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IMP & HIRFL Annual Report 1994年 173-174页

作者： Zhang Chonghong Chen Keqin Wang Yinshu and sun jiguang(General Research Institute of Nonferrous Metals,Beijing.)

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ＥｆｆｅｃｔｏｆＤｉｓｌｏｃａｔｉｏｎｓｏｎＨｅｌｉｕｍＢｕｂｂｌｅＮｕｃｌｅａｔｉｏｎｉｎ３１６ＬＳＳＤｕｒｉｎｇＨｏｔ－ｉｍｐｌａｎｔａｔｉｏｎａｔ５５０℃￥ＺｈａｎｇＣｈｏｎｇｈｏｎｇ；ＣｈｅｎＫｅｑｉｎ；ＷａｎｇＹｉ...

关键词： Bubble implantation Nucleation Effect Helium Hot Dislocations SS During in