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Plasma Science and Technology 2019年第1期21卷 63-71页

作者： A m eL SHeRBINI m m HAGRASS m R m RIZK e A eL-BADAWY Laboratory of Laser and New materials Faculty of Science Cairo University Faculty of engineering Electrical Engineering Department Alexandria University

Plasma ignition threshold of nanoparticle-based and bulk silver targets was measured in air. The plasma was initiated by a Nd:YAG laser at wavelengths of 355, 532, and 1064 nm. The plasma ignition was monitored utilizing the prominent Ag I line at 546.5 nm. Lower ignition thresholds of the nanoparticle-based silver target were estimated at 0.4?±?0.02, 0.34?±?0.04, and 0.27?±?0.035 J cm^(-2) coupled with the different laser wavelengths, respectively. In contrast, the bulk silver target plasma exhibited an order of magnitude higher ignition threshold. A three orders of magnitude enhanced emission intensity from the nano-based target over the bulk target was achieved at lower levels of laser irradiation. A reduction of the the.m.l diffusion length of the nanosilver was assumed in order to theoretically predict this reduction in the plasma threshold. In addition, the effect of self-reversal on the resonance lines was taken into consideration.

关键词： NeLIBS enhancement nanosilver laser plasma threshold

Ion-acoustic waves at the night side of Titan's ionosphere:higher-order approximation

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Communications in Theoretical Physics 2020年第5期72卷 70-77页

作者： S m Ahmed e R Hassib U m Abdelsalam R e Tolba W m moslem Department of mathematics Faculty of ScienceSuez UniversitySuezEgypt Department of mathematics Faculty of ScienceFayoum UniversityFayoumEgypt Department of mathematics Rustaq College of EducationOman Centre for Theoretical Physics The British University in Egypt(BUE)El-Shorouk CityCairoEgypt Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt

Nonlinear solitary waves are investigated for a plasma system at the night side of Titan's *** plasma model consists of three positive ions,namely C2H5^+,HCNH^+,and C3H5^+,as well as maxwellian *** basic set of fluid equations is reduced to a Korteweg de-Vries(KdV)equation and linear inhomogeneous higher order KdV(LIHO-KdV)*** solitary wave solutions of both equations are obtained using a renormalization *** solitary waves'existence region and the wave profile are investigated,and their dependences on the plasma parameters at the night side of Titan's ionosphere are *** solitary waves'phase velocities are subsonic or supersonic,and the propagating pulses are usually *** effect of higher-order corrections on the perturbation theory is *** is found that the higher-order contribution makes the amplitude slightly taller,which is suitable for describing the solitary waves when the amplitude augments.

关键词： plasmas ion-acoustic waves planets and satellites:atmospheres

experimental approaches and analytical technique for dete.m.ning heavy metals in fallen dust at ferrosilicon production factory in edfu, Aswan,egypt

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 708-718页

作者： SOLTAN m.e RAGeH H.m RAGeH N.m AHmeD m.e Department of Chemistry Faculty of Science at Aswan South Valley UniversityEgypt Department of Chemistry Faculty of Science at Qena South Valley UniversityEgyptDepartment of Chemistry Faculty of Science at Qena South Valley UniversityEgyptDepartment of Environment Egyptian Ferroalloy Edfu AswanEgypt

In this study aimed to evaluate the pollution extent of metals and nonmetals inside and outside the ferrosilicon production factory in edfu, Aswan, egypt, raw materials (quartz, cokes, iron oxides), ferrosilicon alloy, silica fume, dust and suspended dust (at different sites) samples were collected from the factory, and fallen dust samples were collected from outside the factory, horizontally (at different sites and different distance and directions) and vertically (at different floors in the selected buildings). Gravimetric methods, X-ray fluorescence (XRF), flame photometer, wide range carbon dete.m.nator and atomic absorption spectroscopy tools were used for elements dete.m.nation. The results indicating that the fallen dust and its element contents on southern factory walls being higher than those on eastern factory walls may be due to the nature of the dusts and effects of wind force and wind direction. Fallen dust levels in different regions outside the factory were found to be affected by the distance, direction and floors. The nature of dust samples was affected by gravity and the suspended dust in different factory units depended on the work capacity and method of handling materials by personnel in different production units. Silica fume was a complicated problem, had dangerous effect against the workers' health, and was characterized by high concentrations of SiO2(90.6%～93.6%) and heavy metals (mn, 420.6×10-6～520.3×10-6; Fe, 2354×10-6～2685×10-6; Co, 80.7×10-6～101.6×10 6 and Ni,5.3× 10-6～6.05× 10-6). The TSP (Total Suspended Particulate) levels in all factory units were higher than the recommended air quality value (70 μg/m3) under egyptian law. The effect of ferrosilicon factory fallen dust on the surrounding regions decreased with increasing distance between the factory and these regions. The suspended dust samples in the factory units and their components greatly exceeded national and international standards, so health and environmental criteria must be

关键词： Air pollution Dust Heavy metals Fallen dust

Instability inspection of parametric vibrating rectangular mindlin plates lying on Winkler foundations under periodic loading of moving masses

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Acta mechanica Sinica 2019年第1期35卷 242-263,I0007页

作者： e.Torkan m.Pirmoradian m.Hashemian Young Researchers and elite Club Khomeinishahr Branch Islamic Azad UniversityKhomeinishahrIsfahan 84175-119Iran Department of mechanical engineering Khomeinishahr BranchIslamic Azad UniversityKhomeinishahrIsfahan 84175-119Iran

Parametric resonance is one of the.m.st important issues in the study of dynamical behavior of structures. In this paper, dynamic instability of a moderately thick rectangular plate on an elastic foundation is investigated in the case of parametric and external resonances due to periodic passage of moving masses. The governing coupled partial differential equations (PDes) of the system, with consideration of the first-order shear deformation theory (FSDT) or mindlin plate theory, are presented and they are reduced to a set of ordinary differential equations (ODes) with time-dependent coefficients using the Galerkin procedure. All inertial components of the.m.ving masses are adopted in the dynamical formulation. Instability survey is carried out for three different loading trajectories considerably interested in many practical applications of the issue, i.e. rectilinear, diagonal and orbiting trajectories. In order to analyze the resonance conditions, the incremental harmonic balance (IHB) method is introduced to calculate instability boundaries, as well as external resonance curves in parameters plane. A comprehensive study is done to assess effects of thickness ratio and foundation stiffness on the resonance conditions. It is found that an increase in the plate's thickness ratio leads to a reduction in values of critical parameters. moreover, it is observed that in creasing the foundation stiffness moves the in stability regions and resona nee curves to higher frequencies of the.m.ving masses and also leads to further stability of the parametrically excited system at lower frequencies. Time response simulations done via Runge-Kutta method confirmed the results predicted by IHB method.

关键词： mass-plate interaction mindlin plate Parametric resonance external resonance Incremental harmonic balanee method

enhancement of electric Conductivity in Transparent Glasse—Ceramic Nanocomposites of Bi_2O_3—BaTiO_3 Glasses

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Journal of materials Science & Technology 2013年第12期29卷 1166-1176页

作者： A.A.Bahgat m.G.moustafa e.e.Shaisha Department of Physics Faculty of ScienceAl-Azhar University

The frequency and temperature dependent electrical conductivity measurements for heat-treated binary glass system with composition of （lO0-x）Bi203-xBaTi03 （x = 20, 30, 40 and 50, in mol%） were carried out. The glass was prepared by melt quenching technique and their corresponding glass-ceramic nanocomposites were obtained by suitable heat treatment. Nanostructured behavior and electrical properties of these glasses and their corresponding glass-ceramic nanocomposites were studied. X-ray diffraction （XRD） and differential scanning calorimetry confirmed the amorphous nature of the glasses. moreover, XRD patterns of the samples indicate nanocrystallites embedded in the glass matrix. The Fourier transform infrared spectroscopy （FT-IR） spectral analysis showed that the band positions of glass system are within the wave number range of Bi06, Bi03 and Ti06 structural units. It is observed that the electrical conductivity is enhanced by 102-103 times in the transparent glass-ceramic nanocomposite phase. With further heat treatment, the conductivity decreased considerably in the stage of glass-ceramic nanocomposite phase as compared with the glassy phase sample. Therefore, partially devitrified phase is more suitable as cathode.m.terial in secondary batteries compared to its vitreous or fully crystalline counterpart. The conduction mechanism was confirmed to obey the adiabatic small polaron hopping （SPH）. AC conductivity measurements were performed as a function of temperature and frequency, showing a very slow increasing rate at low temperatures and then a fast rate at higher temperatures.

关键词： Barium titanat Transparent glass--ceramic nanocomposites DC electrical conductivity AC electrical conductivity Smallpolaron hopping

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霍华德庄园(英国)

电影创作 1997年第5期 39-42页

作者：Ｅ·Ｍ·福斯特詹姆斯·艾弗利云朵

霍华德庄园（英国）■原著：Ｅ·Ｍ·福斯特■剧本改编：詹姆斯·艾弗利■编写：云朵编者按：英国著名导演詹姆斯·艾弗利根据Ｅ·Ｍ·福斯特的名著改编成同名电影，通过“霍华德庄园”内的“客厅之战”，我们看到了具有良好艺术修养和... 详细信息

霍华德庄园（英国）■原著：Ｅ·Ｍ·福斯特■剧本改编：詹姆斯·艾弗利■编写：云朵编者按：英国著名导演詹姆斯·艾弗利根据Ｅ·Ｍ·福斯特的名著改编成同名电影，通过“霍华德庄园”内的“客厅之战”，我们看到了具有良好艺术修养和高尚品格的施莱盖尔两姐妹与富裕、贪...

关键词：霍华德庄园亨利夫人巴斯特玛格丽特威尔科克斯海伦盖尔英国大不列颠及北爱尔兰联合王国

efficient modeling of Photovoltaic Systems Using CmeX S-Function under mATLAB-Simulink environment

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Journal of environmental Science and engineering 2011年第7期5卷 857-865页

作者： m. Setti J. Tanouti A. Aziz Z. Kanev e.m. Aziz Laboratory of electrical engineering ＆ maintenance Department of Electrical Engineering Higher School of Technology of OujdaOujda BP 473 Morocco

This paper discusses an implementation based on CmeX S-functions to model and to check implementation feasibility of two most commonly used maximum Power Point Tracking （mPPT） algorithms, namely Hill Climbing/Perturb ＆ Observe （P＆O） and Incremental Conductance. This study can also be generalized to encompass the whole digital techniques family, including artificial intelligence like Neural Network and Fuzzy Logic Control.

关键词： Photovoltaic systems mPPT control algorithms mATLAB/Simulink CmeX S-functions.

exact Solutions of Nonlinear evolution equations in mathematical Physics Using the.m.dified Simple equation method

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Chinese Physics Letters 2012年第6期29卷 1-4页

作者： e.m.e.Zayed S.A.Hoda Ibrahim Department of mathematics Faculty of ScienceZagazig UniversityP.O.Box 44519ZagazigEgypt

The.m.dified simple equation method is employed to construct the exact solutions involving parameters of nonlinear evolution equations via the (1+1)-dimensional modified KdV equation,and the (1+1)-dimensional reaction-diffusion *** these parameters are taken to be special values,the solitary wave solutions are derived from the exact *** is shown that the proposed method provides a more powerful mathematical tool for solving nonlinear evolution equations in mathematical physics.

关键词： equation. exact equation

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海岛鏖兵 1945年美军收复吕宋岛纪实

国际展望 2005年第14期 76-81页

作者： e.m.小弗拉纳根姚进刘喆

战略争论 1945年1月9日拂晓，是攻击吕宋岛的发起时间。由运输舰、两栖登陆舰和战舰组成的庞大舰队在马尼拉以北100海里的仁牙因湾海而上停泊着。阴暗的天空射出一缕阳光，能见度非常好。海湾的海水开始涨潮，海岸上的浪花柔和，预示着... 详细信息

战略争论 1945年1月9日拂晓，是攻击吕宋岛的发起时间。由运输舰、两栖登陆舰和战舰组成的庞大舰队在马尼拉以北100海里的仁牙因湾海而上停泊着。阴暗的天空射出一缕阳光，能见度非常好。海湾的海水开始涨潮，海岸上的浪花柔和，预示着登陆部队将有一次顺利的登陆。而就在三年前，1941年12月，日军就是在黑暗的黎明前夜在同一个水域登陆上岸的。但是那个时候，天空阴暗，暴风雨使得能见度为零，粗重的浪花涌向海岸。

关键词： 1945年吕宋纪实收复美军海岛两栖登陆舰 1941年能见度运输舰马尼拉暴风雨天空海岸海水

A CONJUGATe GRADIeNT meTHOD FOR DISCReTe-TIme OUTPUT FeeDBACK CONTROL DeSIGN

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Journal of Computational mathematics 2012年第3期30卷 279-297页

作者： e1-Sayed m.e. mostafa Department of mathematics Faculty of Science Alexandria University Alexandria Egypt

In this paper, the discrete-time static output feedback control design problem is con- sidered. A nonlinear conjugate gradient method is analyzed and studied for solving an unconstrained matrix optimization problem that results from this optimal control prob- lem. In addition, through certain parametrization to the optimization problem an initial stabilizing static output feedback gain matrix is not required to start the conjugate gradi- ent method. Finally, the proposed algorithms are tested numerically through several test problems from the benchmark collection.

关键词： Output feedback control Nonlinear conjugate gradient methods Nonlinearprogramming.