检索结果-南通市图书馆

Form.tion of m.lticharg.d m.tal Ions in Vacuum.Arc Plasm. heated by g.rotron Radiation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasm. Science and Technolog. 2011年第5期13卷 596-599页

作者： g. Yu. YUShKOV K. P. SAVKIN A. g. NIKOLAeV e. m. OKS A.V. VOdOPYANOV I. V. IZOTOV d. A. m.NSFeLd hig. Current electronics Institute Siberian Branch of Russian Academ. of Sciences Tomsk 634055 Russia Institute of Applied Physics Russian Academ. of Science Nizhniy Novgorod 603950 Russia

A new m.thod for the g.neration of hig. charg.d state m.tal ion beam. is developed. This m.thod is based on m.crowave heating.of vacuum.arc plasm. in a m.g.etic trap under electron cyclotron resonance （eCR） conditions. Two g.rotrons for plasm. heating.were used, which were with the following.param.ters. The first is with a wave frequency of 37.5 g.z, a pulse duration of 1 m. and power of 100 kW, another is with 75 g.z, 0.15 m. and 400 kW. Two different m.g.etic traps were considered for vacuum.arc plasm. confinem.nt. The first one is a sim.le m.rror trap. Such system.was already investig.ted and could provide hig. charg. state ions. The second trap was with a cusp m.g.etic field config.ration with native ＂m.nim.m.B＂ field structure. Two different ways of m.tal plasm. injection into the m.g.etic trap were used. The first one is an axial injection from.an arc source located out of the trap, and the second is a radial injection from.four arc sources m.unted at the center of the trap. Both traps provide up to 200 em. of ion beam.current for platinum.ions with hig.est charg. state 10＋. Ion beam. were successfully extracted from.the plasm. and accelerated by a voltag. of up to 20 kV.

关键词： ion source eCR heating vacuum.arc m.lticharg.d ions

Interaction between B-doped C60 Fullerene and g.ycine Am.no Acid from. First-Principles Sim.lation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第4期27卷 83-86页

作者： m. d. g.nji h. Yazdani departm.nt of Chem.stry Islamic Azad University Ghaemshahr branch Mazandaran Iran

The possibility of form.tion of com.lexes between g.ycine and boron doped C60 （C59B） fullerene is investig.ted and com.ared with that of C60 fullerene by using.the density functional theory calculations. It has been found that the binding.of g.ycine to C59B g.nerated the m.st stable com.lexes via its carbonyl oxyg.n active site, with a binding.energ. of-37.89 kcal/m.l, while the g.ycine m.lecule prefers to bind to the pure C60 cag. via its am.no nitrog.n active site, consistent with the recent experim.ntal and theoretical studies. We have also tested the stability of the m.st stable g.y-C59B com.lex with ab initio m.lecular dynam.cs sim.lation, carried out at room.tem.erature. These indicate that the B-doped C60 fullerenes seem.to be m.re suitable m.terials for binding. to proteins than pure C60 fullerenes.

关键词： Surfaces interfaces and thin film. Biolog.cal physics Condensed m.tter: structural m.chanical & therm.l Chem.cal physics and physical chem.stry

efficient approaches of determ.ning.the m.tion of a spherical particle in a swirling.fluid flow using.weig.ted residual m.thods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuolog. 2015年第6期13卷 68-74页

作者： Seiyed e. g.asem. m. Vatani d.d. g.nji Young.Researchers and elite Club Qaemshahr Branch Islamic Azad University Qaemshahr lran departm.nt of m.chanical eng.neering Babol University of Technology Babol lran

The m.tion of a spherical particle released in a swirling.fluid flow is studied em.loying.the least-squares m.thod and m.thod of m.m.nts. The g.verning.equations are obtained and solved em.loying.the two m.thods. The accuracy of the results is exam.ned ag.inst the results of a fourth-order Rung.-Kutta num.r- ical m.thod. The effects of various param.ters, nam.ly the initial radius, initial radial velocity, initial ang.lar velocity, and drag.to-inertia ratio, on the non-dim.nsional velocity profiles and particle position distribution are considered. The results show that the radial velocity increases over tim. while the ang.lar velocity decreases, and that an increase in the initial radial velocity increases the particle radial distance and ang.lar velocity but decreases the radial velocity profile.

关键词： Spherical particle Swirling.flow Radial velocity Ang.lar velocity Least-squares m.thod m.thod of m.m.nts

An efficient m.lti-Scale m.delling.Approach for ssdNA m.tion in Fluid Flow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic eng.neering 2008年第4期5卷 299-307页

作者： m. Benke e. Shapiro d. drikakis Fluid m.chanics and Com.utational Science g.oup Department of Aerospace Sciences Cranfield University

The paper presents a m.lti-scale m.delling.approach for sim.lating.m.crom.lecules in fluid flows. m.crom.lecule transport at low num.er densities is frequently encountered in biom.dical devices, such as separators, detection and analysis system.. Accurate m.delling.of this process is challeng.ng.due to the wide rang. of physical scales involved. The continuum.approach is not valid for low solute concentrations, but the larg. tim.scales of the fluid flow m.ke purely m.lecular sim.lations prohibitively expensive. A prom.sing.m.lti-scale m.delling.strateg. is provided by the m.ta-m.delling.approach considered in this paper. m.ta-m.dels are based on the coupled solution of fluid flow equations and equations of m.tion for a sim.lified m.chanical m.del of m.crom.lecules. The approach enables sim.lation of individual m.crom.lecules at m.croscopic tim. scales. m.ta-m.dels often rely on particle-corrector alg.rithm., which im.ose leng.h constraints on the m.chanical m.del. Lack of robustness of the particle-corrector alg.rithm.em.loyed can lead to slow converg.nce and num.rical instability. A new FAst Linear COrrector （FALCO） alg.rithm.is introduced in this paper, which sig.ificantly im.roves com.utational efficiency in com.arison with the widely used ShAKe alg.rithm. Validation of the new particle corrector ag.inst a sim.le analytic solution is perform.d and im.roved converg.nce is dem.nstrated for ssdNA m.tion in a lid-driven m.cro-cavity.

关键词： m.lti-scale m.delling dNA m.crom.lecule transport m.ta-m.delling particle corrector

Unsteady unidirectional m.cropolar fluid flow

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied m.chanics Letters 2011年第6期1卷 36-40页

作者： m. S. Faltas h. h. Sherief e. A. Ashm.wy m. g. Nashwan departm.nt of m.them.tics Faculty of Science Alexandria University Alexandria Egypt

This paper considers the unsteady unidirectional flow of a m.cropolar fluid, produced by the sudden application of an arbitrary tim. dependent pressure g.adient, between two parallel plates. The no-slip and the no-spin boundary conditions are used. exact solutions for the velocity and m.crorotation distributions are obtained based on the use of the com.lex inversion form.la of Laplace transform. The solution of the problem.is also considered if the upper boundary of the flow is a free surface. The particular cases of a constant and a harm.nically oscillating.pressure g.adient are then exam.ned and som. num.rical results are illustrated g.aphically.

关键词： Laplace transform m.cropolar fluid unidirectional flow

Com.arative studies for the fractional optim.l control in transm.ssion dynam.cs of West Nile virus

在线全文

学校读者我要写书评

暂无评论

International Journal of Biom.them.tics 2017年第7期10卷 75-105页

作者： N. h. Sweilam.O.m.Saad d. g. m.ham.d departm.nt of m.them.tics Faculty of Science Cairo University Giza Egypt departm.nt of m.them.tics Faculty of Science Helwan University Cairo Egypt

In this paper, optim.l control for a novel West Nile virus （WNV） m.del of fractional order derivative is presented. The proposed m.del is g.verned by a system.of fractional differential equations （Fdes）, where the fractional derivative is defined in the Caputo sense. An optim.l control problem.is form.lated and studied theoretically using.the Pon- tryag.n m.xim.m.principle. Two num.rical m.thods are used to study the fractional- order optim.l control problem. The m.thods are, the iterative optim.l control m.thod （OCm. and the g.neralized euler m.thod （g.m.. Positivity, boundedness and conver- g.nce of the IOCm.are studied. Com.arative studies between the proposed m.thods are im.lem.nted, it is found that the IOCm.is better than the g.m.

关键词： West Nile virus fractional optim.l control g.neralized euler m.thod Caputo's fractional derivative g.iinwald-Letnikovs definition iterative optim.l controlm.thod Pontryag.n's m.xim.m.principle.

effects of nano-voids and nano-cracks on the elastic properties of a host m.dium. xfem.m.deling.with level-set function and free surface energ.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta m.chanica Sinica 2019年第4期35卷 799-811页

作者： B.e. hachi d. hachi m. haboussi Laboratoire de développem.nt en m.canique et m.tériaux (Ldm.) Université de Djelfa PB 3117 Djelfa Algérie Laboratoire d’Autom.tique Appliquée et diag.ostics Industriels (LAAdI) Université de Djelfa PB 3117 Djelfa Algérie Laboratoire des Sciences des Procédés et des m.tériaux (LSPm. Université Paris 13 UPR 3407 CNRS Paris France

This work deals with the influences of nano-heterog.neities in the form.of voids/cavities or cracks on the elastic (please confirm.which word is correct. effective or elastic? According.to the title of paper, I choose elastic.) properties of a host m.dium. With a relatively larg. ratio of apparent-surface to volum. and particularly strong.physical interactions with the surrounding.m.dium.at nano-scale, nano-heterog.neities can potentially affect the elastic(effective or elastic?) properties of the parent m.dium.(m.trix) containing.them.in a sig.ificant m.nner. This has been reported by various theoretical and experim.ntal studies, som. of them.are discussed in the present paper. To describe the positive (reinforcem.nt) or neg.tive (deg.adation) effect of the nano-heterog.neities from.the m.deling.perspective, it is necessary to take into account the energ. of interfaces/surfaces between nano-heterog.neities and the m.trix which, by the fact of the relatively larg. extent of their apparent surface and their strong.physical interaction with their neig.borhood, can no long.r be neg.ected com.ared to those of the volum. energ.. Thus, to account for the effects of interfaces/surfaces in a nanostructured heterog.neous m.dium. the coherent interface m.del is considered in the present investig.tion within a periodic hom.g.nization procedure. In this interface/surface m.del, the displacem.nt vector is assum.d to be continuous across the interface while the stress vector is considered to be discontinuous and satisfying.the Laplace-Young.equations. To solve these equations coupled to the classical m.chanical equilibrium.problem. a num.rical sim.lation tool is developed in a two-dim.nsional (2d) context using.the eXtended Finite elem.nt m.thod (XFem. and the Level-Set functions. The developed num.rical tool is then used to carry out a detailed analysis about the effect of nano-heterog.neities on the overall m.chanical properties of a m.dium. The nano-heterog.neities are present

关键词： Interface/Surface energ. XFem Level-Set function Periodic hom.g.nization Nano-voids/Nano-cavities Nano-cracks Nano-inclusions/Nano-heterog.neities

The m.lti-im.urity system.in CdSe nanoplatelets:electronic structure and therm.dynam.c properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Com.unications in Theoretical Physics 2024年第3期76卷 165-173页

作者： d A Bag.dasaryan V A harutynyan e m.Kazaryan h A Sarkisyan Russian-Arm.nian University H Emin 1230051YerevanArmenia Institute of Applied Problem. of Physics 25 Nersisyan St0014YerevanArmenia

This paper theoretically studies the im.urity states and the effects of im.urity concentration and config.ration on the optical,electrical,and statistical properties of CdSe nanoplatelets(NPLs).An im.g. charg.-based m.del of electron-im.urity interaction is *** charg.-carrier energ. spectra and corresponding.wave functions depending.on the im.urity num.er and config.ration are *** electron binding.energ.es are calculated for different NPL *** is shown that the im.g. charg.-based interaction potential that arises due to the dielectric constants m.sm.tch is m.ch strong.r than the interaction potential that does not take such a m.sm.tch into ***,it is dem.nstrated that the binding.energ.es are increasing.with the num.er of *** calculate the canonical partition function using.the energ. levels of the electron,which in turn is used to obtain the m.an energ.,heat capacity,and entropy of the non-interacting.electron *** therm.dynam.c properties of the non-interacting.electron g.s that depend on the g.om.tric param.ters of the NPL,im.urity num.er,config.ration,and tem.erature are studied.

关键词： nanoplateletes therm.dynam.c properties im.urity states

FORm.FACTORS FOR RAdIATIVe PION ANd KAON deCAYS

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2016年第10期40卷 685-686页

作者： m. Bychkov g. d'Am.rosio University of Virg.nia INFN Sezione di Napoli

The radiative decays, π^± → l^±vγ and K^± →l^±vγ, with 1 standing.for an e or a μ, and γ for a real or virtual photon （e＋e- pair）, provide a powerful tool to investig.te the hadronic structure of pions and kaons. The structuredependent part Sdi of the am.litude describes the em.ssion of photons from.virtual hadronic states, and is param.trized in term. of form.factors V,A, （vector, axial vector）,

关键词：