检索结果-南通市图书馆

World Journal of Condensed m.tter Physics 2011年第1期1卷 12-18页

作者： Yasser H. A. Fawzy Am. El-Hag Ali Ghada F. El-m.ghraby reda m. radwan 不详

Copolym.r film. of Acrylic acid/ m.thyl m.thacrylate AAc/m.A with com.nom.r com.osition of 60/40 was prepared and then irradiated by gam.a irradiation. The effect of irradiation on som. of the physical properties of the copolym.r film. was investigated. The dose level ranged from.5 to 200 kGy. The therm. gravim.tric analysis (TGA) showed that the therm.l stability of the film. increased with irradiation dose up to 100 kGy then it started to decrease. The results of the UV-Visible spectroscopy of the film. showed a decrease in the values of optical band gap and band tail width with doses starting from.100 kGy. The DC conductivity (?DC) of the film. was found to decrease to about three orders of m.gnitude from.its original value with irradiation dose up to 100 kGy then it started to increase with higher doses. m.reover, the dielectric constant and dielectric loss values were found to increase with dose up to 100 kGy which m.y be attributed to the increase in the num.er of dipoles in the film. due to the irradiation of the copolym.r film. in air. The results indicated that crosslinking dom.nated over chain scission in the copolym.r film. with irradiation dose up to 100 kGy then at higher doses, chain scission dom.nated.

关键词： Copolym.rs Aac/m.A Optical Properties Dielectric Properties Gam.a Polym.rization

Application of the Second Born Approxim.tion to Excitation of Hydrogen Atom. by Protons and Antiprotons Im.act

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2008年第10期25卷 3635-3638页

作者： reda S. Tantawi Sam.a m. Said Departm.nt of m.them.tics Faculty of Science Zagazig University Zagazig Egypt Departm.nt of Basic Engineering Sciences Faculty of Engineering Sana'a Universi Sana'a Yemen

We present and com.are total cross sections for excitation in collisions of protons and antiprotons with hydrogen atom. in the 2s state. Calculations axe perform.d in the fram.work of the second Born approxim.tion, in the energy range of 5-1000 keV. We apply the usual approach of the second Born approxim.tion, which approxim.tes the sum.ation raised by retaining few term., as well as another approach approxim.tes all energies corresponding to the interm.diate states to that corresponding to the initial state. The annihilation effect in the case of the antiproton collision is investigated. We com.are the results with the previous theoretical calculations.

关键词： the power-law exponents precipitation durative abrupt precipitation change

ASTER Analysis for Locating REE-Bearing Granites in Arid Regions:Exam.le from.the Arabian Shield

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 Earth Science 2022年第5期33卷 1114-1123页

作者： reda Am.r Tim.thy m.Kusky Departm.nt of Earth and Space Sciences Lamar UniversityBeaumontTX77710USA State Key Laboratory of Geological Processes and m.neral Resources Center for Global TectonicsSchool of Earth SciencesBadong National Observatory and Research Station for GeohazardsChina University of GeosciencesWuhan430074China

The world’s increasing dem.nd for rare earth elem.nts(REEs)highlights the potential for using new m.ltispectral rem.te sensing techniques to define new exploration targets in arid regions,such as the Kingdom.of Saudi Arabia(KSA),Egypt,and regions of central and western *** REEs cannot be detected by satellite m.ltispectral instrum.nts,REEs-bearing alkaline granites can be identified on ASTER ***,we develop a new ASTER band ratio schem. to delineate m.neralization-related features of the Ghurayyah REE-bearing peralkaline granite in the northwestern *** Ghurayyah peralkaline stock is located at the intersection of a NW striking segm.nt of the Najd-fault system.and an E-W striking *** is surrounded to the north and west by m.tavolcanics,from.east by the Jabal Dabbagh alkali granite,and from.the south by *** m.neralogical com.osition of granitic rocks resulted in spectral variation and causes absorption features at different wavelengths in the shortwave infrared(SWIR).The newly developed band ratios were constructed from.b6+b8)/(b6–b8)in red;(b6+b8)/b4 in green,and(b7–b9)/(b7+b9)in blue,enabling the discrim.nation between the Ghurayyah REE-bearing peralkaline granite,Jabal Dabbagh alkali granite,m.nzogranite,and *** work will be carried out to perform.higher-resolution drone-based hyperspectral im.ging for new high-resolution m.pping and evaluate the existing REE deposits,em.hasizing field spectral m.asurem.nts to identify the spectral reflectance of REEs m.neralized zones and the absorption features of m.nazite,colum.ite-tantalite,and aeschynite-(Y),coupled with rock sam.ling for petrographical,spectral,and geochem.cal *** m.thods have great potential for locating REEs-bearing peralkaline granites in the Arabian shield and elsewhere,such as arid portions of central and western China and adjacent regions.

关键词： rem.te sensing m.ltispectral im.ging rare earth elem.nts Arabian Shield m.neral exploration

Nanotherm.te colloids: A new prospective for enhanced perform.nce

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第3期15卷 319-325页

作者： m. Gaber Zaky Ahm.d m. Abdalla Rakesh P. Sahu Ishwar K. Puri m.stafa radwan Sherif Elbasuney School of Chem.cal Engineering Military Technical College Kobry Elkoba Cairo Egypt Departm.nt of Engineering Physics and Departm.nt of m.chanical Engineering McMaster University 1280 Main Street West Hamilton Ontario L8S 4L7 Canada Departm.nt of m.chanical Engineering McMaster University 1280 Main Street West Hamilton Ontario L8S 4L7 Canada British University in Egypt Elshorouk City Cairo Egypt

Nanotherm.tes (m.tal oxide/m.tal) can offer trem.ndously exotherm.c self sustained reactions. CuO is one of the m.st effective oxidizers for naonotherm.te applications. This study reports on two prospectives for the m.nufacture of CuO nanoparticles. Colloidal CuO particles of 15 nm.particle size were developed using hydrotherm.l synthesis technique. m.ltiwalled carbon nanotubes (m.CNTs) with surface are 700m./g was em.loyed as a substrate for synthesis of CuO-coated m.CNTs using electroless plating. On the other hand, alum.nium.particles with com.ustion heat of 32000 J/g is of interest as high energy density m.terial. The im.act of stoichiom.tric nanotherm.te particles (CuO/Al & Cuo-coated m.CNTs/Al) on shock wave strength of Al/TNT nanocom.osite was evaluated using ballistic m.rtar test. While CuO-coated m.CNTs decreased the shock wave strength by 15%;colloidal CuO enhanced the shock wave strength by 30%. The superior perform.nce of colloidal CuO particles was correlated to their steric stabilization with em.loyed organic solvent. This is the first tim. ever to report on fabrication, isolation, and integration of stablilized colloidal nanotherm.te particles into energetic m.trix where intim.te m.xing between oxidizer and m.tal fuel could be achieved.

关键词： Hydrotherm.l synthesis Nanoparticles Carbon nanotubes Nanotherm.tes Energetic m.terials

Form.tion of AlN from.Secondary Al Resources

在线全文

学校读者我要写书评

暂无评论

Journal of m.terials Science & Technology 2006年第5期22卷 621-624页

作者： m.Bahgat m.radwan F.E.Farghaly Central m.tallurgical Research and Developm.nt Institute (Cm.DI) P.O.Box 87 Helwan Cairo 11421 Egypt

Synthesis of AlN by NH4Cl-assisted direct nitridation of secondary Al resources was studied. Alum.num.alloy scrap contained m. and Zn elem.nt was used. m.lled Al scrap （-1 m.） was m.xed with NH4Cl and heated at 1000℃ for 1 h in presence of 1 L/m.n N2 flow gas. The nitrided product was evaluated by X-ray diffraction sem.-quantitative analysis and scanning electron m.croscopy （SEm.. Alum.nium.nitride of 90.5% concentration was obtained with a hexagonal crystalline form. AlN is m.stly form.d in nano-whisker m.rphology （50～150 nm. which is hom.genously distributed.

关键词： AlN Direct nitridation Nanowhisker Secondary resources

Fast vectorized distance m.trix com.utation for m.ltiple sequence alignm.nt on m.lti-cores

在线全文

学校读者我要写书评

暂无评论

International Journal of Biom.them.tics 2015年第6期8卷 243-257页

作者： m.ham.ed W. A1-Neam. Naglaa m. reda Fayed F. m. Ghaleb Departm.nt of m.them.tics Faculty of Science AI-Azhar UniversityP. O. Box (11884) Al-Nasr Road Cairo Egypt Education College for Girlsm.sul University Mosul Iraq Departm.nt of m.them.tics Faculty of Science Ain Shams University Cairo Egypt

Although high quality m.ltiple sequence alignm.nt is an essential task in bioinform.- tics, it becom.s a big dilem.a nowadays due to the gigantic explosion in the am.unt of m.lecular data. The m.st consum.ng tim. and space phase is the distance m.trix com.utation. This paper addresses this issue by proposing a vectorized parallel m.thod that accom.lishes the huge num.er of sim.larity com.arisons faster in less space. Per- form.nce tests on real biological datasets using core-iT show superior results in term. of tim. and space.

关键词： Bioinform.tics m.ltiple sequence alignm.nt distance m.trix parallel program.ing m.lti-cores.

On m.lti-Granulation Rough Sets with Its Applications

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.uters, m.terials & Continua 2024年第4期79卷 1025-1038页

作者： radwan Abu-Gdairi R.m.reay m.Badr Departm.nt of m.them.tics Faculty of ScienceZarqa UniversityZarqa13132Jordan Departm.nt of m.them.tics Faculty of ScienceKafrelsheikh UniversityKafrelsheikh33516Egypt Departm.nt of m.them.tics Faculty of ScienceNew Valley UniversityEl Kharga72713Egypt

Recently,m.ch interest has been given tom.lti-granulation rough sets (m.RS), and various types ofm.RSm.delshave been developed from.different viewpoints. In this paper, we introduce two techniques for the classificationof m.RS. Firstly, we generate m.lti-topologies from.m.lti-relations defined in the universe. Hence, a novelapproxim.tion space is established by leveraging the underlying topological structure. The characteristics of thenewly proposed approxim.tion space are *** introduce an algorithm.or the reduction ***, a new approach for the classification ofm.RS based on neighborhood concepts is introduced. Finally, areal-life application from.m.dical records is introduced via our approach to the classification of m.RS.

关键词： m.lti-granulation rough sets data classifications inform.tion system. interior operators closure operators approxim.tion structures

m.lting phenom.non in m.gneto hydro-dynam.cs steady flow and heat transfer over a m.ving surface in the presence of therm.l 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

Chinese Physics B 2013年第3期22卷 57-62页

作者： reda G.Abdel-Rahm.n m.m.Khader Ahm.d m.m.gahed Departm.nt of m.them.tics Faculty of ScienceBenha University

The Lie group m.thod is applied to present an analysis of the m.gneto hydro-dynam.cs（m.D） steady lam.nar flow and the heat transfer from.a warm.lam.nar liquid flow to a m.lting m.ving surface in the presence of therm.l *** using the Lie group m.thod,we have presented the transform.tion groups for the problem.apart from.the scaling *** application of this m.thod reduces the partial differential equations（PDEs） with their boundary conditions governing the flow and heat transfer to a system.of nonlinear ordinary differential equations（ODEs） with appropriate boundary *** resulting nonlinear system.of ODEs is solved num.rically using the im.licit finite difference m.thod（FDm..The local skin-friction coefficients and the local Nusselt num.ers for different physical param.ters are presented in a table.

关键词： Lie group m.thod m.gneto hydro-dynam.cs m.lting phenom.non Newtonian fluid radiation

Standard precaution m.asurem.nts during ophthalm.logy practice in the pandem.c stage of COVID-19

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalm.logy(English edition) 2020年第7期13卷 1017-1022页

作者： Ahm.d m.ham.d reda Wael m.Ahm.d Departm.nt of ophthalm.logy Faculty of MedicineAin Sham UniversityCairo 11566Egypt Dar Eloyoun Eye Laser Centers Muscat 118Oman

AIm.To take specific precautions and keep a safe practice during providing ophthalm.logy health services without com.rom.sing the patient’s safety as well as the team.workers and the com.unity in the pandem.c stage of corona virus disease 2019(COVID-19).m.THODS:Applying patient circulation schem. im.lem.nted in our ophthalm.logy centers with the guidance of m.nistry of health infection control guidelines star ted from.the m.m.nt that we receive a call or Whats App m.ssage or Facebook inquiry from.patients until 21 d after patients first visit if *** directions were ***,com.unity awareness of the disease and the ophthalm.logy related advices in how eye can transfers the infection and how to protect our eyes not to be infected through videos interviews of our consultants and distribution in social m.dia like Instagram.Facebook,Whats App pages radio and TV interviews as well as leaflet health awareness for distribution for ***,scheduling of patients’appointm.nts to prevent overcrowdings and cross ***,protective m.asurem.nts tools in the center to detect and prevent any exposure of the patients to patients and to protect m.dical staff,COVID-19 scoring system.was set up to identify patients with fever,respiratory sym.tom.,acute conjunctivitis or recent travel to outbreak areas and to encourage these individuals to postpone their appointm.nts for at least 21 *** use of personal protective equipm.nt was *** all the elective surgeries keeping only the em.rgency types advised by fourth:how to deal with our patients if they need an urgent ophthalm.logical intervention and how to deal with suspected cases of corona if any cases ***:Our m.asures helped our colleagues to try to keep providing ophthalm.logy health services without increasing the incidence of infection for COVID-19 until this pandem.c is ***:In our practice,ophthalm.logists should work with new aura of social m.dia to facilitate the

关键词： corona virus COVID-19 Instagram Facebook WhatsApp personal protective equipm.nt

The perform.nce of activated carbon/NiFe_(2)O_(4) m.gnetic com.osite to retain heavy m.tal ions from.aqueous solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chem.cal Engineering 2021年第1期34卷 135-145页

作者： S.I.m.ussa m.m.S.Ali reda R.Sheha Nuclear Chem.Dept. Hot Lab CenterAtomic Energy AuthorityCairo 13759Egypt Analytical Chem.Dept. Hot Lab CenterAtomic Energy AuthorityCairo 13759Egypt

A novel m.gnetic activated carbon com.osite(AC/NiF) was synthesized by a precipitation m.thod and applied in retention of Cu(Ⅱ),and Zn(Ⅱ) ions from.aqueous *** im.act of different sorption param.ters such as:equilibration tim.,solution pH value,com.eting cations and ionic strength on the am.unt sorbed of Cu(Ⅱ),and Zn(Ⅱ) was *** illustrated that the m.gnetic com.osite had retention ability towards both m.tal ions significantly higher than that of activated carbon(AC).The m.gnetic com.osite exhibited an affinity to adsorb Cu(Ⅱ) higher than Zn(Ⅱ) *** m.xim.m.sorption capacities(Q_(m.x)) of the applied m.gnetic com.osite(AC/NiF)towards Cu(Ⅱ) and Zn(Ⅱ) were 105.8 and 75.1 m.·g^(-1),*** of Cu(Ⅱ) and Zn(Ⅱ) was proposed to be achieved though an ion exchange and surface adsorption in neutral conditions,while precipitation was believed to be the relevant m.chanism.in their rem.val from.basic *** kinetic studies showed that sorption process followed the kinetics of pseudo-second-order reactions with rate constant of 3 × 10^(-3) and 2 × 10^(-3) m.n^(-1)for sorption of Cu(Ⅱ) and Zn(Ⅱ) onto AC/NiF *** of Cu(Ⅱ) slightly decreased with increasing the ionic strength of aqueous solution,using NaCl as a background *** contrast,presence of m.(Ⅱ),m.(Ⅱ)and Co(Ⅱ) in reaction solutions highly depressed the sorption of Cu(Ⅱ) and Zn(Ⅱ) with a com.eting efficiency followed the order:m.(Ⅱ)> m.(Ⅱ)> Co(Ⅱ).The m.gnetic com.osite was rapidly recovered from.aqueous solution by an external m.gnetic field,and effectively regenerated using 0.1 m.l L^(-1) HCl and 0.1 m.l L^(-1) FeCl_(3) as *** of Cu(Ⅱ) and Zn(Ⅱ) onto the surface of AC/NiF com.osite occurred via a spontaneous *** therm.dynam.cally favorable process had ΔH~o values of 30.9 kJ·m.l^(-1) and 19.7 kJ·m.l^(-1),*** results confirm.that the m.gnetic com.osite can be viewed as a prom.sing novel com.osite opens new opportunities f

关键词： Activated carbon Nickel ferrite Com.osite m.chanism