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perfectly planar CoB^-18 as a motif for metallo-borophenes

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Nano Research 2016年第7期9卷 1877-1878页

作者： Yadong Li Department of Chemistry and Collaborative Innovation Center for Nanomaterials Science and Engineering Tsinghua University Beijing 100084 China

Over the past decade, extensive collaborative experimental and theoretical researches have systematically elucidated the structures and chemical bonding of boron clusters as a function of size and have revealed an intriguing set of structures, ranging from planar hydrocarbon-analogs to nanotubular and fullerenelike structures （borospherenes） [1-7]. Small boron clusters have the propensity for planarity with delocalized σ and π electrons over the whole molecular plane, giving rise to the concept of multiple aromatidty.

关键词： perfectly CoB_(18)~- metallo-borophenes

Dynamic soil-structure interaction analysis in time domain based on a modified version of perfectly matched discrete layers

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第1期12卷 168-179页

作者： Dong Van Nguyen Dookie Kim Department of Civil Engineering Kunsan National University558 Daehak-roGunsan-si54150Republic of Korea

Analysis of soil-structure interaction is commonly conducted by dividing the infinite domain of the soil into two domains:interior and exterior domains.The interior domain is bounded in a small region,while the exterior domain is replaced by artificial boundary conditions.The choice of artificial boundary conditions is a critical issue in the analysis of soil-structure interaction problems.perfectly matched discrete layer(PMDL)has been proved as a good approach for modeling the exterior domain.In this study,a modified version of the PMDLs,i.e.PMDLs with analytical wavelengths(AW-PMDLs),is used in the soil-structure interaction analysis in time domain,which essentially can be regarded as an extension of the analysis in frequency domain,being previously proven to be effective.Numerical verifications are implemented.The results demonstrate that the proposed method performs well in the analysis of soilstructure interaction problems in time domain.

关键词： Soil-structure interaction Time domain Wave propagation Wavelength Infinite domain perfectly matched discrete layer(PMDL)

Numerical Method for Solving Electromagnetic Wave Scattering by One and Many Small perfectly Conducting Bodies

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American Journal of Computational Mathematics 2017年第4期7卷 413-434页

作者： Nhan T. Tran Department of Mathematics Kansas State University Manhattan USA

In this paper, we investigate the problem of electromagnetic (EM) wave scattering by one and many small perfectly conducting bodies and present a numerical method for solving it. For the case of one body, the problem is solved for a body of arbitrary shape, using the corresponding boundary integral equation. For the case of many bodies, the problem is solved asymptotically under the physical assumptions a d a is the characteristic size of the bodies, d is the minimal distance between neighboring bodies, λ = 2π/k is the wave length and k is the wave number. Numerical results for the cases of one and many small bodies are presented. Error analysis for the numerical method is also provided.

关键词： Electromagnetic Scattering Many Bodies perfectly Conducting Body Integral Equation EM Waves

Adventures and lessons of an American biochemist in China

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Protein & Cell 2011年第8期2卷 601-603页

作者： Christopher J.Vavricka CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

It’s very interesting how events often lead up to each other seemingly by chance,but appear almost perfectly planned out when looking back.For the past two years,I have worked as an International Young Scientist Research Fellow at the Institute of Microbiology,Chinese Academy of Sciences in Beijing,China.Many people ask me,especially Chinese graduate students,why an American would choose to come to China as a postdoctoral researcher.

关键词： looking doctor perfectly

Single polarization photonic crystal fiber filter based on surface plasmon resonance

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Frontiers of Optoelectronics 2019年第2期12卷 157-164页

作者： Md. Nazmul HOSSEN Md. FERDOUS Kawsar AHMED Md. Abdul KHALEK Sujan CHAKMA Bikash Kumar PAUL Department of Information and Communication Technology(ICT) Mawlana Bhashani Science and Technology University(MBSTU)SantoshTangail 1902Bangladesh Group of Biophotomatix SantoshTangail 1902Bagladesh Department of Software Enineering(SWE) Daffodil International UniversityShukrabadDhaka 1207Bangladesh

In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)characteristics.Gold nanowire is used as the active plasmonic material.Light into silica core becomes coupled to gold nanowire stimulating SPR. It soplits light into two orthogonal(x-polarization and y-polarization)polarization in the second order of surface plasmon polarization.Numerical investigations of the proposed PCF filter is finite element method(FEM).By position,the performance of the propsed PCF filter is inspected rigorously.Filtering of any polarization can be obtained by properly placing the metal wires.The maximum cnfinement loss of x-polarization is 692.25dB/cm and y-polarization is 1.13dB/cm offers at resonance position 1.42μm.Such a confinement loss difference between two orthogonal polarizations makes PCF a talented candidate to filter devicees.Consequently,the recommended PCF structure is useful for polarization device.

关键词： photonic crystal fiber (PCF) surface plasmon resonance (SPR) perfectly match layer polarization filter

Acoustic wave propagation simulation in a poroelastic medium saturated by two immiscible fluids using a staggered finite-difference with a time partition method

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Science China(Physics,Mechanics & Astronomy) 2008年第7期51卷 723-744页

作者： ZHAO HaiBo WANG XiuMing Institute of Acoustics Chinese Academy of SciencesBeijing 100080China

Based on the three-phase theory proposed by Santos, acoustic wave propagation in a poroelastic medium saturated by two immiscible fluids was simulated using a staggered high-order finite-difference algorithm with a time partition method, which is firstly applied to such a three-phase medium. The partition method was used to solve the stiffness problem of the differential equations in the three-phase theory. Considering the effects of capillary pressure, reference pressure and coupling drag of two fluids in pores, three compressional waves and one shear wave predicted by Santos have been correctly simulated. Influences of the parameters, porosity, permeability and gas saturation on the velocities and amplitude of three compressional waves were discussed in detail. Also, a perfectly matched layer (PML) absorbing boundary condition was firstly implemented in the three-phase equations with a staggered-grid high-order finite-difference. Comparisons between the proposed PML method and a commonly used damping method were made to validate the efficiency of the proposed boundary absorption scheme. It was shown that the PML works more efficiently than the damping method in this complex medium. Additionally, the three-phase theory is reduced to the Biot's theory when there is only one fluid left in the pores, which is shown in Appendix. This reduction makes clear that three-phase equation systems are identical to the typical Biot's equations if the fluid saturation for either of the two fluids in the pores approaches to zero.

关键词： acoustic waves poroelastic media immiscible fluids staggered grids perfectly matched layers

A LIOUVILLE THEOREM FOR STATIONARY INCOMPRESSIBLE FLUIDS OF VON MISES TYPE

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Acta Mathematica Scientia 2019年第1期39卷 1-10页

作者： Martin FUCHS Jan MüLLER Fachbereich 6.1 Mathematik Universit?t des Saarlandes

We consider entire solutions u of the equations describing the stationary flow of a generalized Newtonian fluid in 2 D concentrating on the question, if a Liouville-type result holds in the sense that the boundedness of u implies its constancy. A positive answer is true for p-fluids in the case p > 1(including the classical Navier-Stokes system for the choice p = 2), and recently we established this Liouville property for the Prandtl-Eyring fluid model,for which the dissipative potential has nearly linear growth. Here we finally discuss the case of perfectly plastic fluids whose flow is governed by a von Mises-type stress-strain relation formally corresponding to the case p = 1. It turns out that, for dissipative potentials of linear growth, the condition of μ-ellipticity with exponent μ < 2 is sufficient for proving the Liouville theorem.

关键词： generalized Newtonian fluids perfectly plastic fluids von Mises flow Liouville theorem

Stability analysis of FDTD to UPML for time dependent Maxwell equations

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Science China Mathematics 2009年第4期52卷 794-816页

作者： FANG NengSheng YING Lung-An School of Finance Southwestern University of Finance and EconomicsChengdu 610074China School of Mathematical Sciences Xiamen UniversityXiamen 361005China School of Mathematical Sciences Peking UniversityBeijing 100871China

We study an finite-difference time-domain (FDTD) system of uniaxial perfectly matched layer (UPML) method for electromagnetic scattering problems. Particularly we analyze the discrete initial-boundary value problems of the transverse magnetic mode (TM) to Maxwell's equations with Yee's algorithm. An exterior domain in two spacial dimension is truncated by a square with a perfectly matched layer filled by a certain artificial medium. Besides, an artificial boundary condition is imposed on the outer boundary of the UPML. Using energy method, we obtain the stability of this FDTD system on the truncated domain. Numerical experiments are designed to approve the theoretical analysis.

关键词： Maxwell’s equations uniaxial perfectly matched layer initial-boundary value problem stability FDTD

Ch-pao, the Merging of Chinese and Western Dress Cultures

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中国新书:英文版 2023年第4期 6-9页

作者： Yi Yang Beijing Institute of Fashion Technology

The Chi-pao is a traditional Chinese dress with many variations in terms of style.Generally,it features a stand-up collar and sideway button placket,perfectly closed hi-Pao by exquisite,knotted buttons,forming a unique style.Its flexible,soft outlines highlight the female body curve romantically and elegantly.Dressed in a Chi-pao,a woman looks extremely charming while walking gracefully.

关键词： perfectly button dress