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h-P Finite Element Approximation for Full-Potential Electronic Structure Calculations

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Chinese Annals of Mathematics,Series B 2014年第1期35卷 1-24页

作者： y.on maday UPMC University Institut Universitaire de France and Division of Applied Mathematics Brown University

The(continuous) finite element approximations of different orders for the computation of the solution to electronic structures were proposed in some papers and the performance of these approaches is becoming appreciable and is now well *** this publication,the author proposes to extend this discretization for full-potential electronic structure calculations by.combining the refinement of the finite element mesh,where the solution is most singular with the increase of the degree of the poly.omial approximations in the regions where the solution is mostly.*** combination of increase of approximation properties,done in an a priori or a posteriori manner,is well-known to generally.produce an optimal exponential ty.e convergence rate with respect to the number of degrees of freedom even when the solution is *** analy.is performed here sustains this property.in the case of Hartree-Fock and Kohn-Sham problems.

关键词： Electronic structure calculation Density.functional theory. Hartree-Fock model, Kohn-Sham model, Nonlinear eigenvalue problem, h - Pversion, Finite element method

Recent Advances in Computational Simulation of Macro-,Meso-,and Micro-Scale Biomimetics Related Fluid Flow Problems

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Journal of Bionic Engineering 2007年第2期4卷 97-107页

作者： y. y. y.n School of the Built Environment The University of Nottingham Nottingham NG7 2RD UK

Over the last decade, computational methods have been intensively.applied to a variety.of scientific researches and engineering designs. Although the computational fluid dy.amics （CFD） method has play.d a dominant role in study.ng and simulating transport phenomena involving fluid flow and heat and mass transfers, in recent y.ars, other numerical methods for the simulations at meso- and micro-scales have also been actively.applied to solve the phy.ics of complex flow and fluid-interface interactions. This paper presents a review of recent advances in multi-scale computational simulation of biomimetics related fluid flow problems. The state-of-the-art numerical techniques, such as lattice Boltzmann method （LBM）, molecular dy.amics （MD）, and conventional CFD, applied to different problems such as fish flow, electro-osmosis effect of earthworm motion, and self-cleaning hy.rophobic surface, and the numerical approaches are introduced. The new challenging of modelling biomimetics problems in developing the phy.ical conditions of self-clean hy.rophobic surfaces is discussed.

关键词： biomimetics computational simulation macro- meso- micro-scale hy.rophobic surfaces

IMPROVEMENT OF BUBBLE MODEL FOR CAVITATING FLOW SIMULATIONS

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Journal of Hy.rody.amics 2009年第1期21卷 41-46页

作者： TAMURA y. MATSUMOTO y. Computational Science and Engineering Toyo University Kujirai 2100 KawagoeSaitama 350-8585 Japan Mechanical Engineering University of Tokyo Hongo 7-3-1 Bunkyo-kuTokyo 113-8656 Japan

In the present research, a bubble dy.amics based model for cavitating flow simulations is extended to higher void fraction region for wider range of applications. The present bubble model is based on the so-called Ray.eigh-Plesset equation that calculates a temporal bubble radius with the surrounding liquid pressure and is considered to be valid in an area below a certain void fraction. The solution algorithm is modified so that the Ray.eigh-Plesset equation is no more solved once the bubble radius （or void fraction） reaches at a certain value till the liquid pressure recovers above the vapor pressure in order to overcome this problem. This procedure is expected to stabilize the numerical calculation. The results of simple two-dimensional flow field are presented compared with the existing bubble model.

关键词： cavitation model Computational Fluid Dy.amics (CFD) cavitation flow Ray.eigh-Plesset equation

Solid Desiccant Dehumidification Techniques Inspired from Natural Electroosmosis Phenomena

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Journal of Bionic Engineering 2011年第1期8卷 90-97页

作者： B. Li y. y. y.n Faculty.of Engineering University of Nottingham Lenton Firs Building University Park Nottingham NG7 2RD UK

Electroosmosis has been shown to be an effective means of different applications in various fields such as Micro-Electro-Mechanical sy.tems （MEMS） and biomimetics applications. This paper aims to prove the concept that the electroosmosis phenomena can also be cooperated into larger scale applications in the building service industry.like dehumidification or damping proof. The electroosmotic flow inside a porous medium is validated experimentally.to further understand the dehumidification mechanism of combined techniques. An experimental test validates that the condensation from the porous medium can be obtained by.electroosmotic force generated by.external electric field, especially.for specific desiccant powders like zeolite and diatomaceous earth. With a range of volts from 5 V to 20 V apply.ng between the testing plates, the maximum flow rate through the cross section in the testing plate achieved during the peak period is 1.35 laL＇min 1. These promising phenomena can act as an alternative way.for energy.choice in dehumidification industrial field. Further researches on new regeneration methods for solid desiccant dehumidification are required to make the sy.tem simple, energy.saving and suitable for small air conditioning units.

关键词： biomimetics electroosmotic flow solid desiccant dehumidification

FROM CRy.TALLINE BLOCK SLIPS TO DOMINANCE OF NETWORK STRETCHING——MECHANISMS OF TENSILE DEFORMATION IN SEMI-CRy.TALLINE POLy.ERS

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Chinese Journal of Poly.er Science 2002年第2期20卷 160-170页

作者： y. Men Fakultaet Fuer Phy.ik Albert-Ludwigs-Universitaet Freiburg 79104

The mechanism of tensile deformation in semi-cry.talline poly.ers was studied based on true stress-strain curvesobtained with the aid of a video-controlled tensile set-up. The deformation is affected by.both the cry.talline and theamorphous phases. However, the relative weights of the two portions change with the deformation stage. At lowdeformations the coupling and coarse slips of the cry.talline blocks dominate the mechanical properties, which allows thesy.tem to maintain a homogeneous strain distribution in the sample. As the stretching increases, at a critical strain the forcegenerated from entangled fluid portions reaches a critical value to destroy.the cry.tallites. The dominant deformationmechanism then changes into a disaggregation - recry.tallization process.

关键词： Semi-cry.talline poly.er Deformation mechanism Network Mechanical property

Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov Igor y.Iskusny.h Department of Anatomy.and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply.secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embry.nic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analy.is in *** cortical hem produces several ty.es of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly.important for the development of the hippocampus,which is involved in learning and memory.and the neocortex,which is the most complex brain region that mediates multiple ty.es of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

A HOMOTOPy.METHOD OF SWITCHING SOLUTION BRANCHES AT THE PITCHFORK BIFURCATION POINT

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Journal of Computational Mathematics 2001年第3期19卷 299-308页

作者： Cong, y.-H. Zhu, Z.-y. College of Mathematical Sciences Shanghai Teachers University Shanghai 200234 China

Provides information on a study.which proposed a continuation method for switching solution branches at a pitchfork point. Problem of the standard pitchfork; Information on the sy.tems of equations; Numerical examples... 详细信息

关键词： homotopy.method switching solution branches pitchfork point

Neumann＇s method for boundary.problems of thin elastic shells

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Applied Mathematics and Mechanics(English Edition) 2017年第4期38卷 543-556页

作者： y. S. NEUSTADT Department of Civil Engineering Samara State Architectural and Building University Samara 443001 Russia

The possibility.of using Neumann＇s method to solve the boundary.problems for thin elastic shells is studied. The variational statement of the static problems for the shells allows for a problem examination within the distribution space. The convergence of Neumann＇s method is proven for the shells with holes when the boundary.of the domain is not completely.fixed. The numerical implementation of Neumann＇s method normally.requires significant time before any.reliable results can be achieved. This paper suggests a way.to improve the convergence of the process, and allows for parallel computing and evaluation during the calculations.

关键词： boundary.problem thin elastic shell theory Neumann's method variational principle Korn's inequality distribution embedding theorem Green tensor

THEORy.OF WATER WAVES IN AN ELASTIC VESSEL

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Acta Mechanica Sinica 2000年第2期16卷 97-112页

作者： D. y. Hsieh Division of Applied Mathematics Brown University USA

Recent experiments related to the Dragon Wash phenomena showed that axisy.metric capillary.waves appear first from excitation, and circumferential capillary.waves appear after increase of the excitation strength. Based on this new finding, a theory.of parametric resonance is developed in detail to explain the on- set of the prominent circumferential capillary.waves. Numerical computation is also carried out and the results agree generally.with the experiments. Analy.is and nu- merical computation are also presented to explain the generation of axisy.metric low-frequency.gravity.waves by.tile high-frequency.external excitation.

关键词： water waves elastic vessel Dragon Wash