检索结果-南通市图书馆

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Powe.s of Octonions

Applie. Mathe.atics 2021年第2期12卷 75-84页

作者： W. e. ahmed Mathe.atics and Statistics De.artme.t Faculty of Science Imam Mohammad Ibn Saud Islamic University Riyadh KSA De.artme.t of Basics and e.gine.ring Scie.ce. Faculty of Engineering University of Khartoum Khartoum Sudan

As it is known, Binomial e.pansion, De.Moivre.s formula, and e.le.’s formula are.suitable.me.hods for computing the.powe.s of a comple. numbe., but to compute.the.powe.s of an octonion numbe. in e.sy way, we.ne.d to de.ive.suitable.formulas from the.e.me.hods. In this pape., we.pre.e.t a nove. way to compute.the.powe.s of an octonion numbe. using formulas de.ive. from the.binomial e.pansion.

关键词： Octonion Matrix Alge.ra

Fabrication of Se.iconductor Polyme. Me.brane. Combine. with a Colore. Charge.Transfe. Comple.e. Use. in the.Manufacture.of Solar Ce.ls as a Source.of Alte.native.e.e.gy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

光谱学与光谱分析 2019年第7期39卷 2307-2315页

作者： ahmed. I. e.-She.awy Ishaq. F. e. ahmed Moame.. S. Re.at De.artme.t of Che.istry Colloge of EducationImam Abdulrahman Bin Faisal University

The.main task of this article.was to pre.are. of ne. pigme.t mode. in situ solar ce.ls accordance.to charge.transfe. comple.e. of rhodamine.C(RhC) donor as dye.lase. gain me.ia with iodine.σ-acce.tor) and chloranilic acid, CLA(π-acce.tor). The.synthe.is stoichiome.ry of the.e.comple.e. we.e.of 1∶2(donor∶acce.tor) with ge.e.al formulas [(RhC)]I·I3 and [(RhC)(CLA)2]. The.discusse. data of e.e.e.tal analysis, conductivity me.sure.e.ts, FT-IR, UV-Vis spe.troscopy and photome.ric titration data visualize. the.stoichiome.ry, formula and comple.ity of the.comple.e.. The.physicoche.ical and spe.troscopic analyse. obtaine. sugge.te. that the.e.e.tron transfe. occurre. through nitroge. atom in a te.tiary amine.—N(C2H5)2 of RhC donor with acce.tor. The.synthe.ize. solid comple.e. we.e.unde. go to the.mogravime.ric analyse. to inve.tigate.the.r the.mal stability and de.omposition ste.s. The.molar conductance.me.sure.e.ts re.e.le. that RhC comple.e. have.an e.e.trolytic state.e.t. The.the.mal stability of rhodamine.C comple.e. was e.hance. in comparable.with RhC itse.f. The.polyme. me.brane. of poly-me.hyl me.hacrylate.(PMMA) combine. with the.RhC charge.transfe. comple.e. in chloroform solve.t have.be.n pre.are. and characte.ize. by(infrare. & e.e.tronic) spe.troscopy and scanning e.e.tron microscopy(Se.) morphological e.amination. The.photo-stability prope.tie. of the.RhC comple.e. have.be.n inve.tigate..

关键词： Charge.transfe. Rhodamine C Photostability Comple.ity Spe.troscopic Polyme. Dye

Fue. ce.l stack de.ign and mode.ling with a double.stage.boost conve.te. couple. to a single.phase.inve.te.

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CLe.N e.e.GY 2024年第1期8卷 188-196页

作者： e.nagi, Base. e. Ismaie., ahmed M. Mansour, Hany S. e. Abd-Alwahab, M. N. Sue. Canal Univ Fac Engn Elect Engn Dept Ismailia 41522 Egypt

A compre.e.sive.proton-e.change.me.brane.fue. ce.l stack mode. was de.e.ope. and inte.rate. with a two-stage.DC/DC boost conve.te.. It was dire.tly couple. to a single.phase.(two le.e.s-four pulse.) inve.te. without a transforme.. The.pulse.width modulation signal was use. to inde.e.de.tly re.ulate.e.e.y conve.te. phase. The.conve.te. was mode.le. using a MATLAB (R)/Simulink (R) e.vironme.t and an appropriate.voltage.control me.hod. The.analysis fe.ture. of the.sugge.te. circuit we.e.cre.te. and, through e.tablishe. e.pe.ime.ts, the.simulation re.ults we.e.ve.ifie.. A single.phase.(two le.e.s-four pulse.) inve.te. control circuit was te.te. and it produce. a pure.sinusoidal wave.orm with voltage.control. It matche. the.voltage.of the.ne.work in te.ms of amplitude.and fre.ue.cy. A sinusoidal pulse.width modulation approach was pe.forme. using a single.phase.(two le.e.s-four pulse.) pulse.width modulation inve.te.. The.re.ults de.onstrate. an e.hance.e.t in the.standard of the.output wave.and tune. the.de.d time.with a re.uction of 63 mu s compare. with 180 mu s in conve.tional te.hnique.. A compre.e.sive.mode. of a proton-e.change.me.brane.fue. ce.l stack is inte.rate. with a single.phase.(two le.e.s-four pulse.) inve.te. without a transforme.. Pulse.width modulation is use. to inde.e.de.tly re.ulate.e.e.y conve.te. phase. As a re.ult, the.de.d time.is re.uce. compare. to conve.tional te.hnique.. Graphical Abstract

关键词： Pe. fue. ce.l pulse.width modulation single.phase.inve.te. and double.stage.DC/DC boost conve.te. Pe.FORMANCe SYSTe.

Natural Conve.tion Flow and He.t Transfe. e.hance.e.t of a Nanofluid past a Truncate. Cone.with Magne.ic Fie.d e.fe.t

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Me.hanics 2012年第5期2卷 272-279页

作者： Same. e. ahmed A. Mahdy Mathe.atics De.artme.t Faculty of Science South Valley University Qena Egypt

A nonsimilarity analysis is pe.forme. to inve.tigate.the.laminar, fre. conve.tion boundary laye. flow ove. a pe.me.ble.isothe.mal truncate. cone.in the.pre.e.ce.of a transve.se.magne.ic fie.d e.fe.t. A suitable.se. of dime.sionle.s variable. is use. and non-similar e.uations gove.ning the.proble. are.obtaine.. Fourth orde. Runge.Kutta with shooting te.hnique.is e.ploye. for the.nume.ical solution of the.obtaine. e.uations. Diffe.e.t wate.-base. nanofluids containing Cu, Ag, CuO, Al2O3, and TiO2 are.take. into conside.ation. The.e.fe.ts of pe.tine.t parame.e.s such as the.solid volume.fraction of nanoparticle., and magne.ic fie.d parame.e. have.be.n inve.tigate.. Furthe.more. diffe.e.t mode.s of nanofluid base. on diffe.e.t formulas for the.mal conductivity and dynamic viscosity on the.flow and he.t transfe. characte.istics are.discusse.. Various comparisons with pre.iously publishe. work for the.case.of a ve.tical plate.are.pe.forme. and the.re.ults are.found to be.in e.ce.le.t agre.me.t.

关键词： Nanofluid Truncate. Cone Magne.ic Fie.d Natural Conve.tion Non-Similarity Solution

The.e.fe.t of Oil Price.Shocks on the.Saudi Manufacturing Se.tor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

e.onomics World 2017年第3期5卷 230-238页

作者： Abde.hamid A. Mahboub He.a e. ahmed Unive.sity of Busine.s and Te.hnology Jeddah Saudi Arabia Qassim Unive.sity Qassim Saudi Arabia

This pape. aims to e.amine.the.e.fe.ts of oil price.shocks on the.manufacturing se.tor in Saudi Arabia during the.pe.iod 2002-2014, using quarte.ly data. The.pape. has conducte. a unit root te.t. The.data are.shown to be.non-stationary in the.le.e., and the. be.ame.stationary in the.first diffe.e.ce.for all variable.. The.co-inte.ration mode. was applie., and the.re.ults indicate. that no co-inte.rating e.uation e.ists, which me.ns that the.e.is no long run e.fe.t of oil price.shocks on the.manufacturing se.tor. The.e.ore. the.pape. e.timate. a VAR mode., the.re.ults of which implie. that oil price.shocks do not affe.t the.manufacturing se.tor in the.short run, and it may have.an e.fe.t on the.manufacturing se.tor afte. 10 quarte.s according to the.Impulse.Re.ponse.Function~ The.re.e.t fall of oil price. since.June.2014 is just one.round of a se.ie. of fluctuations, in the.form of shocks, in oil price.. Ne.e.the.e.s, a de.ate.has arise. about the.e.fe.t of this price.falls on the.world e.onomy in ge.e.al and on oil e.porting countrie. in particular. The.e.onomy of Saudi Arabia, the.major oil e.porting country, is not an e.ce.tion in this matte. of course. The.main obje.tive.of this pape. is to e.timate.quantitative.y, in the.e.onomy of Saudi Arabia, whe.he. the.e.e.ists an impact of oil price.shockson the.output of the.manufacturing se.tor, and whe.he. it is a positive.（dire.t） or a ne.ative.（inve.se. re.ationship. The.focus on the.manufacturing se.tor he.e.is for two re.sons. First, the.Saudi e.onomic planning and policy have.long targe.e. to dive.sify the.source. of ge.e.ating GDP. The.manufacturing se.tor is, no doubt, a ve.y important e.e.e.t in this dive.sification proce.s. Se.ond, the.incre.se.in manufacturing se.tor （as a pe.ce.tage.of GDP） is one.of the.important me.sure. and/or indicators of e.onomic de.e.opme.t. For both re.sons, the.re.e.rche.s have.chose. to study ＂the.e.fe.t of oil price.shocks on the.Saudi manufacturing se.tor＂ in this pape..

关键词： oil price. Saudi manufacturing output VAR impulse.re.ponse.function

Sliding Mode.Control for Singularly Pe.turbe. Syste.s Using Accurate.Re.uce. Mode.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Inte.national Journal of Mode.n Nonline.r The.ry and Application 2021年第1期10卷 1-12页

作者： Ayman e. M. ahmed Mohame. Zohdy Re.e.rch De.artme.t Egyptian Armed Force Cairo Egypt e.e.trical and Syste.s e.gine.ring Oakland University Rochester MI USA

In orde. to de.l with unmode.e. dynamics in large.ve.icle.syste.s, which have.an ill condition of the.state.matrix, the.use.of mode. orde. re.uction me.hods is a good approach. This article.pre.e.ts a ne. construction of the.sliding mode.controlle. for singularly pe.turbe. syste.s. The.controlle. de.ign is base. on a line.r diagonal transformation of the.singularly pe.turbe. mode.. Furthe.more. the.use.of a single.sliding mode.controlle. de.igne. for the.slow compone.t of the.diagonalize. syste. is inve.tigate.. Simulation re.ults indicate.the.pe.formance.improve.e.t of the.propose. controlle.s.

关键词： Singular Pe.turbation Sliding Mode.Control Diagonalization Me.hod

Re.istance.and Se.ke.ping Inve.tigation for Optimization of the.Floating Hull of Wave.Glide.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of e.gine.ring and Te.hnology 2016年第3期4卷 235-249页

作者： Alaae.de.n M. e. ahmed We.yang Duan Shipbuilding e.gine.ring De.artme.t Military Technical College Cairo Egypt Colle.e.of Shipbuilding e.gine.ring Harbin Engineering University Harbin China

Wave.glide. is the.first unmanne. autonomous marine.robot to use.only the.oce.n’s e.dle.s supply of wave.e.e.gy for propulsion. Wave.glide. comprise. fin syste., te.he. and float which harve.t all of its e.e.gy from wave. and sun to produce.forward thrust. As a conse.ue.ce.of the.lack of de.ign information and data for the.wave.glide., the.main aim of the.study is using computational fluid dynamics (CFD) to pre.e.t a me.hod to pre.ict calm wate. re.istance.for the.floating hull through calculations of 3 diffe.e.t hull forms using the.same.me.h ge.e.ation unde. the.same.conditions. Calculations are.carrie. out using 3 diffe.e.t me.h size. for Froude.numbe. in the.range.of 0.10 to 0.40 and compare. for accuracy of the.solution parame.e.s. Wigle. parabolic hull, high spe.d round bilge.form (NPL) and Se.ie. 60 have.be.n comparative.y inve.tigate. in orde. to e.timate.the.hydrodynamics pe.formance.of the.hull. The.line.r se.ke.ping analysis, couple. he.ve.and pitch motions, roll motion, in irre.ular wave., with one.parame.e. Bre.schne.de. and JONSWAP spe.tra. Nume.ical computations have.be.n pe.forme. for motion re.ponse.pre.ictions of the.thre. hulls which cove. wave.angle. from 0? to 180? at 45? inte.vals for six diffe.e.t forward spe.ds from 0 to 4.304 knots using Maxsurf Motion software. The.close.agre.me.t be.we.n the.nume.ical pre.ictions shows the.importance.of CFD applications in e.timating the.hydrodynamics pe.formance.to de.ign the.floating hull and the.nume.ical me.hod is use.ul in glide. de.ign. The.fine.grid is fit to the.calculation and shows the.most appropriate.re.ults be.ause.conve.ge.t re.ults are.obtaine. as the.me.h size.de.re.se.so the.fine.grid is the.one.which will be.applie. for the.othe. hulls. Also it can be.obse.ve. that the.adde. re.istance.and the.RAOs for NPL hull are.le.s than the.othe. hulls. The.e.ore.from the.comparisons, the.NPL hull is the.optimum hull compare. to the.othe. hulls from the.re.istance.and se.ke.ping point of vie..

关键词： Wave.Glide. Calm Wate. Re.istance Se.ke.ping CFD Maxsurf

Chaotic and Hype.chaotic Comple. Je.k e.uations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Inte.national Journal of Mode.n Nonline.r The.ry and Application 2012年第1期1卷 6-13页

作者： Gamal M. Mahmoud Mansour e. ahmed De.artme.t of Mathe.atics Faculty of Science Assiut University Assiut Egypt

The.aim of this pape. is to introduce.and inve.tigate.chaotic and hype.chaotic comple. je.k e.uations. The.je.k e.uations de.cribe.various phe.ome.a in e.gine.ring and physics, for e.ample. e.e.trical circuits, lase. physics, me.hanical oscillators, dampe. harmonic oscillators, and biological syste.s. Prope.tie. of the.e.syste.s are.studie. and the.r Lyapunov e.pone.ts are.calculate.. The.dynamics of the.e.syste.s is rich in wide.range.of syste.s parame.e.s. The.control of chaotic attractors of the.comple. je.k e.uation is inve.tigate.. The.Lyapunov e.pone.ts are.calculate. to show that the.chaotic be.avior is conve.te. to re.ular be.avior.

关键词： Hype.chaotic Chaotic Attractors Lyapunov e.pone.ts Je.k Function Control Comple.

Unste.dy MHD Mixe. Conve.tion Flow with Slip of a Nanofluid in the.Stagnation Re.ion of an Impulsive.y Rotating Sphe.e.with e.fe.ts of The.mal Radiation and Conve.tive.Boundary Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Me.hanics 2018年第5期8卷 137-160页

作者： Same. e. ahmed Z. Z. Rashe. Mathe.atics De.artme.t Faculty of Science South Valley University Qena Egypt Mathe.atics De.artme.t Faculty of Science and Arts Jouf University Qurayyat KSA

Unste.dy magne.ohydrodynamic mixe. conve.tion flow of an e.e.trically conducting nanofluid in a stagnation re.ion of a rotating sphe.e.is studie. nume.ically in the.pre.e.t article. Slip and conve.tive.boundary conditions are.impose. to surface.of the.sphe.e.and the.the.mal radiation e.fe.ts are.take. into account. The.nanofluid is simulate. using Buongiorno’s nanofluid mode. and the.nanofluid particle.fraction on the.boundary is conside.e. to be.passive.y rathe. than active.y controlle.. Non-similar solutions are.applie. on the.gove.ning e.uations and the.MATLAB function bvp4c is use. to solve.the.re.ulting syste.. e.fe.ts of the.ke.-parame.e.s such as slip parame.e., Biot numbe., radiation parame.e., rotation parame.e., Le.is numbe. and Brownian motion parame.e. on the.fluid flow, te.pe.ature.and nanoparticle.volume.fraction characte.istics are.e.amine.. De.ails of the.nume.ical solution and a compre.e.sive.discussion with the.physical me.ning for the.obtaine. re.ults are.pe.forme.. The.re.ults indicate. that the.incre.se.in slip parame.e. e.hance. the.ve.ocity profile., while.it de.re.se. the.te.pe.ature.distributions. Also, the.incre.se.in e.the. slip parame.e. or Biot numbe. cause. an improve.e.t in the.rate.of he.t transfe..

关键词： MHD Slip Nanofluids Conve.tive Condition Radiation