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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 thermal 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

Evaluation of Al and Some of Its Alloys as Anode materials vs γ-mnO_2 as Cathode material and Ore Produced γ-mnO_2 vs Zn Anode in KOH Solution

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Journal of materials Science & technology 2006年第1期22卷 25-30页

作者： A.m.A.Hashem Kh.S.Abou-el-sherbini S.Zein el Abedin H.Abbas Inorganic Chemistry Department National Research CentreBehoes StreetDokkiCairoEgypt Physical Chemistry Department National Research CentreBehoes StreetDokkiCairoEgypt

In this study electrochemical performance of Al and some of its alloys （Al-Zn, Al-rvlg and Al-rvln） anodes vs mnO2 cathode were carried out in alkaline solution. the results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn〉Al-mg〉Al〉Al-mn. this result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy （SEm）. SEm morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-mn morphology shows a needle-like structure. electrolytic manganese dioxide （EmD） produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore （β-mnO2） by sulfur slag was characterized as cathode in alkaline Zn-mnO2 batteries. Ore produced sample （EmD1） was performed well in comparison with EmD standard （EmD2）（commercial battery grade electrolytic manganese dioxide, tOSOH-Hellas GH-S）. SEm morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.

关键词： electrolytic mnO2 Zn Al Alkaline batteries

Alternating current characterization of nano-Pt(Ⅱ)octaethylporphyrin(PtOEP) thin film as a new organic semiconductor

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Chinese Physics B 2016年第6期25卷 426-432页

作者： m Dongol m m el-Nahass A el-Denglawey A A Abuelwafa t Soga Nano and thin Film Laboratory Physics DepartmentFaculty of ScienceSouth Valley University Physics Department Faculty of EducationAin Shams University Physics Department Faculty of Applied Medical ScienceTaif University Department of Frontier materials Nagoya Institute of Technology

Alternating current（AC） conductivity and dielectric properties of thermally evaporated Au/Pt OEP/Au thin films are investigated each as a function of temperature（303 K–473 K） and frequency（50 Hz–5 mHz）.the frequency dependence of AC conductivity follows the Jonscher universal dynamic *** AC-activation energies are determined at different *** is found that the correlated barrier hopping（CBH） model is the dominant conduction *** variation of the frequency exponent s with temperature is analyzed in terms of the CBH *** barrier height Wm,hopping distance Rω,and the density of localized states N（EF） are valued at different *** constant ε1（ω,t） and dielectric loss ε2（ω,t） are discussed in terms of the dielectric polarization *** dielectric modulus shows the non-Debye relaxation in the *** extracted relaxation time by using the imaginary part of modulus（m’’）is found to follow the Arrhenius law.

关键词： PtOEP thin films AC conductivity dielectric constants organic semiconductors solar cell nano materials

Preparation and Properties of Some Chemical and electrochemical γ-mnO_2

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Journal of materials Science & technology 2001年第3期17卷 351-354页

作者： H.m.Abbas, Kh. S.Abou-el-sherbini, m.H.Askar and A. m. Hashim Dept.of Physical Centre, National Research Centre, tahiu, Dokki, Cairo, Egypt E-mail: sherbini@*** Natl Res Ctr Dept Phys Ctr Cairo Egypt

Chemically prepared electrolytic 2-mn02 and an electrodeposited mnO2 doped with Ce(Ⅲ) were subjected to physicochemical studies. X-ray diffractometry, density measurements, chem-ical analysis and thermal analysis were used to determine the structure and chemical disorder present. the samples prepared chemically (CmD) or electrochemically (EmD) showed a variable amount of de Wolff disorder (Pr) and microtwinning (tw). manganese dioxide prepared in the presence of Ce(Ⅲ) showed appreciable decrease in de Wolff defect and a large amount of microtwinning. thermal analysis showed a loss of weight due to the physically adsorbed and the structural (OH) water, from which the activation energy was calculated. Chemical composition and formulae calculated on the bases of cation vacancy model, cleared that Ce(lIl)-doped sample has a remarkable increase in the vacancies population associated with higher structural water content. this leads to lower activation energy of water release, and consequently it is supposed to acquire higher electrochemical activity.

关键词： EmD mnO2

Some studies of the interaction between two two-level atoms and SU(1,1) quantum systems

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Chinese Physics B 2018年第10期27卷 116-122页

作者： t m el-Shahat m Kh Ismail Faculty of Science Al-Azhar University. Assiut 71524 Egypt

Herein, we present an approach to look for the best phenomenon to measure quantum correlation. the system of two isolated qubits each interacting with a single-mode cavity was theoretically created to study the quantum correlation. Some of the phenomena, such as the quantum discord and concurrence, were generated through such a system. the influences of initial state purity, qubit motion, and detuning parameters were discussed for the phenomena. these parameters for a specific value show that the behavior of phenomena are analogous. It is interesting to mention that some values of detuning undergo a sudden death of phenomena, and the quantum discord still captures the qubits quantum correlation. We predict that the quantum discord may be a better measure of quantum correlation than concurrence.

关键词： an isolated atom with a cavity SU (1,1) quantum discord concurrence

Spectrometric measurement of Plasma Parameters Utilizing the target Ambient Gas O I &N I Atomic Lines in LIBS Experiment

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Optics and Photonics Journal 2012年第4期2卷 286-293页

作者： Ashraf m. el sherbini Abdel Aziz Saad Al Amer Ahmed t. Hassan t.arwat.m. el sherbini Department of Physics Collage of Science Al Imam Muhammad Ibn Saud Islamic University (AIMSIU) Al Riyadh KSA Laboratory of lasers and New materials (LLNm) Department of physics Faculty of Science Cairo University Giza Egypt

In this article, we shall report the results of the spectroscopic measurements of the plasma parameters utilizing the spectral lines emitted from the air atoms surrounding plasma (O I line at 777.19 nm and N I at 746.83 nm). the plasma was created via irradiation of plane solid aluminum target in open air by a high peak power Nd: YAG laser pulses at fundamental wavelength of 1064 nm. the emission spectra were recorded using Echelle type spectrograph in conjunction with a time gated ICCD camera at different delay time from 1 to 5 μs and at a fixed gate time of 1 μs. the plasma electron density was measured utilizing the Stark broadening of the N I and O I lines and then compared to the reference density as deduced from the optically thin Hα-line at 656.27 nm appeared in the same emission spectra. the results show that under our experimental conditions the air lines are subjected to moderate absorption. the plasma electron temperature was measured utilizing the relative spectral intensity of the air (O I to N I) lines after correcting their spectral radiance against absorption. the standard temperature was measured utilizing the Al II ionic lines. A comparison to the reference temperatures shows a very close agreement after correcting the emission spectral radiance of the air lines against self absorption, which emphasizes the importance of correction process.

关键词： LIBS Self Absorption O I-N I Lines Plasma Parameters

CO oxidation and 4-nitrophenol reduction over ceria-promoted platinum nanoparticles impregnated with ZSm-5 zeolite

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Journal of Rare Earths 2022年第8期40卷 1247-1254页

作者： Zeinhom m.el-Bahy mohammed t.Alotaibi Salah m.el-Bahy Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt Department of Chemistry Turabah University CollegeTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

Active new ceria-promoted platinum supported on ZSm-5 catalysts were prepared and characterized by X-ray diffraction(XRD),Fourier transform infrared spectra(FtIR),transform electron microscopy(tEm),temperature programmed desorption(tPD),and FtIR of CO *** samples were prepared by the incipient wetness impregnation method and calcined at 500℃.the XRD patterns and FtIR spectra prove that the zeolite framework is kept unaltered after metal *** images prove the presence of Pt nanoparticles with particle size starting from 14 to 27 *** FtIR data suggest the formation of Pt-O-Ce ***-situ FtIR of CO adsorption over reduced samples proves the presence of Pt~0 only,and no Pt^(n+)-CO species are *** prepared catalysts were tested in both oxidation reaction(CO oxidation) in the gas phase and in reduction reaction(4-nitrophenol reduction) in the aqueous ***,CO oxidation by O_(2) results in the formation of a CO_(2) peak at 2347 cm^(-1) as the only CO oxidation product in the studied frequency *** intensity of the CO_(2) peak increases after the addition of Ce,and it is 4 times higher in Pt_(1) Ce_(0.5)ZSm-5 than that in the Ce-free *** to the FtIR data and previous reports,the increase in the catalytic activity may be due to the formation of Pt-O-Ce ***,Ce-promoted Pt_(1) ZSm5 also exhibits enhanced catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol by NaBH_(4) in the aqueous *** first-order rate constant of the reduction increases ≈13 times after incorporating equal ratios of Pt and Ce(Pt_(1) Ce_(1)ZSm-5),and the activation energy(E_(a)) decreases to 40% of that in the reaction over Pt_(1) ZSm-5.

关键词： 4-Nitrophenol CO oxidation tPD-CO Platinum-cerium ZSm-5 Rare earths

Advanced Functional electromagnetic Shielding materials:A Review Based on micro‑Nano Structure Interface Control of Biomass Cell Walls

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Nano-micro Letters 2025年第1期17卷 98-134页

作者： Yang Shi mingjun Wu Shengbo Ge Jianzhang Li Anoud Saud Alshammari Jing Luo mohammed A.Amin Hua Qiu Jinxuan Jiang Yazeed m.Asiri Runzhou Huang Hua Hou Zeinhom m.el‑Bahy Zhanhu Guo Chong Jia Kaimeng Xu Xiangmeng Chen Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037People’s Republic of China State Key Laboratory of Efficient Production of Forest Resourced Beijing Forestry UniversityQinghua East Road 35Haidian DistrictBeijing 100083People’s Republic of China Department of Physics Faculty of Sciences‑ArarNorthern Border UniversityArar 91431Saudi Arabia Department of Chemistry College of ScienceTaif UniversityP.O.Box 1109921944 TaifSaudi Arabia Shaanxi Key Laboratory of macromolecular Science and technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Integrated Composites Lab Department of Mechanical and Construction EngineeringNorthumbria UniversityNewcastle Upon Tyne NE18STUK College of materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024People’s Republic of China Department of Chemistry Faculty of ScienceAl-Azhar UniversityNasr CityCairo 11884Egypt Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products International Joint Research Center for Biomass MaterialsSouthwest Forestry UniversityKunming 650224People’s Republic of China School of Science Henan Agricultural UniversityZhengzhou 450002People’s Republic of China

Research efforts on electromagnetic interference(EmI)shielding materials have begun to converge on green and sustainable biomass *** materials offer numerous advantages such as being lightweight,porous,and *** to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EmI shielding *** concerted efforts on the EmI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EmI shielding *** particular,a more comprehensive study and summary of the factors influencing biomass EmI shielding materials including the pore structure adjustment,preparation process,and micro-control would be *** preparation methods and characteristics of wood,bamboo,cellulose and lignin in EmI shielding field are critically discussed in this paper,and similar biomass EmI materials are summarized and *** composite methods and fillers of various biomass materials were *** paper also highlights the mechanism of EmI shielding as well as existing prospects and challenges for development trends in this field.

关键词： Biomass materials electromagnetic interference shielding micro-nano structure interface control Conductivity

A model for a Dual Universe

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第1期10卷 52-66页

作者： t.arwat.m.hmoud el-sherbini Physics Department Faculty of Science Cairo University Cairo Egypt

A model for a dual universe is proposed, based on the assumption that simultaneously with our universe an anti-matter counterpart was initiated immediately following the Big Bang. At the heart of the model is a primordial anti-particle that differentiates itself from its counterpart, a previously hypothesized S-particle responsible for the formation of our own universe, through its course of rotation. the angular rotation of the anti-particle, in accordance with space-time rotation, together with the counter rotation of the S-particle, resulted in a time difference in the formation processes of both universes and consequently led to a large distance between the spatial locations occupied by our universe and its dual counterpart in the same space-time continuum. the existence of this anti-matter universe might solve the present mystery of matter anti-matter asymmetry and thus explain why hardly any free anti-matter can be observed in our universe. moreover, the model implicates the possibility of the presence of a repulsive gravitational force exerted by the clusters of anti-particles in the anti-matter universe upon our universe. the repulsive gravitational force from the clusters of antiparticles in the dual universe as a whole upon our universe is completely different from the electrostatic repulsive force between similarly charged particles. It is also different from that due to possible gravitational or anti-gravitational interaction between individual matter and antimatter or particle and its antiparticle that might violate the CPt invariance, the theory of general relativity or the law of energy conservation. It is rather, a kind of negative gravity that affects our universe as a whole, due to the opposite course of rotation of the dual anti-universe relative to ours. the effect of this opposite rotation of the dual universe can cause anti-gravitational waves that penetrate our universe interacting with the space-time mesh around the galaxies in our universe a

关键词： Cosmology Antimatter High Energy Astrophysics Particle Physics

A Cosmological model for the Early Universe: the Formation of Fundamental Particles

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Journal of High Energy Physics, Gravitation and Cosmology 2022年第4期8卷 1073-1083页

作者： t.arwat.m.hmoud el-sherbini Physics Department Faculty of Science Cairo University Cairo Egypt

A cosmological model for the very early universe is proposed which may modify the present point of view of physicists and astrophysicists, concerning the very early universe at a miniscule fraction of a second, approximately 10-60 seconds after the Big Bang. the model proposes the presence of a primordial s-particle that, following the Big Bang, was violently ejected in all spatial directions together with extremely high-frequency radiation that dominates this era. the proposed s-particles underwent two geometrical phase transitions in space-time that led to the formation of the known fundamental particles (i.e., dark matter, quarks, electrons, neutrinos, etc.). Furthermore, in the model, the four fundamental forces may be accommodated within one structural framework. It shows that the electronic charge is not a fundamental quantity (intrinsic property of the particle), but rather that it can be derived from the tangential velocity of the s-particle. moreover, it appears that the masses of the fundamental particles are proportional to the curvature of the path of the s-particle.

关键词： Cosmology Nongalactic Astrophysics Particle Physics High Energy Physics Atomic Physics