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Electron Acceleration by microwave Radiation Inside a Rectangular Waveguide

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Plasma Science and Technology 2011年第3期13卷 357-361页

作者： b. F. mOHAmED A.m. GOUDA Plasma Physics Department N.R.C. Atomic Energy Authority Cairo Egypt

Electron dynamics in the fields associated with a transverse magnetic （Tm） wave propagating inside a rectangular waveguide is analytically studied. The relativistic momentum and energy equations for an electron are solved, which was injected initially along the propagation direction of the microwave. Expressions of the acceleration gradient and deflection angle are obtained. In principle, it is shown that the electron can be accelerated in this condition and there is no deflection when the electron is injected from the centre of the waveguide front. However, it is found that the acceleration gradient and deflection angle depend strongly on the parameters of the microwave （intensity, frequency, etc.） and the dimensions of the waveguide.

关键词： waveguide electron acceleration polarized microwave

Hole burning in the Fock Space: from Single to Several Holes

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Chinese Physics Letters 2001年第11期18卷 1467-1469页

作者： b.baseia J.m.C.malbouisson Instituto de Fisica Universidade Federal de Goias74001-970GoianiaGOBrazil Instituto de Fisica Universidade Federal da Bahia40210-340SalvadorBABrazil

In our previous papers we have studied the production of a single hole in the photon number distribution of a field state [Phys. Lett. A 240 (1998) 277;253 (1999) 123]. In this letter we extend the procedure for the c... 详细信息

关键词： letter creation distribution

Palaeoskapha sichuanensis gen. et sp. nov. (menispermaceae) from the Eocene Relu Formation in western Sichuan, West China

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植物分类学报 2007年第4期45卷 576-582页

作者： Frederic m. b. JACQUES GUO Shuang-Xing museum National d＇Histoire Naturelle D~partement Histoire de la Terre CP 38 UMR 5143 - USM 0203 8 rue Buffon 75231 Pads Cedex 05 France Nanjmg Institute of Geology and Palaeontology the Chinese Academy of Sciences Nanjing 210008 China Kunming lnstitute of botany the Chinese Academy of Sciences Ktmming 650204 China

Palaeoskapha sichuanensis gen. et sp. nov. of menispermaceae is described here for the first time based on a well preserved fossil fruit. The specimen was found in the Relu Formation of western Sichuan, West China. The specimen, straight, boat-shaped endocarp with large ventral condyle, clearly belongs to the tribe Tinosporeae. The wide aperture of the double condyle, combined with a whole shape not deeply invaginated, indicates a genus different from what was already known to science for this tribe. This fossil widens the distribution of the tribe during Eocene from North America and Europe to Asia, where it was formerly unknown.

关键词：防已科始新世四川群系新种植物化石果实

Comparisons of electrical and optical properties between graphene and silicene A review

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Chinese Physics b 2018年第2期27卷 299-313页

作者： Wirth-Lima A J Silva m G Sombra A S b Laboratory of Telecommunications and materials Science and Engineering-www.locem.ufc.br-Fortaleza CearaBrazil Department of Physics Science CenterFederal University of Ceara(U.F C.)-FortalezaCear4Brazil State University of Vale do Acarau SobralCeardBrasil

Two-dimensional （2D） metamaterials are considered to be of enormous relevance to the progress of all exact sciences. Since the discovery of graphene, researchers have increasingly investigated in depth the details of electrical/optical proper- ties pertinent to other 2D metamaterials, including those relating to the silicene. In this review are included the details and comparisons of the atomic structures, energy diagram bands, substrates, charge densities, charge mobilities, conductivities, absorptions, electrical permittivities, dispersion relations of the wave vectors, and supported electromagnetic modes related to graphene and silicene. Hence, this review can help readers to acquire, recover or increase the necessary technological basis for the development of more specific studies on graphene and silicene.

关键词： graphene silicene electrical/optical properties

The Radiation Loss of a Cylindrical methane-Argon Plasma Arc

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Plasma Science and Technology 2010年第2期12卷 218-223页

作者： b.LIANI R.bENALLAL m.LEmERINI Theoretical Physics Laboratory Sciences Faculty University of Tlemcen

Calculation of the net radiation emitted by a CH4-Ar mixture, in a temperature range of 5,000-30,000 K with the assumption of local thermodynamic equilibrium （LTE）, is conducted. Continuum and line emissions are taken into account. The radiative transfer of each line is calculated by means of an escape factor depending on the shape and broadening of the line. Assuming a cylindrical, homogeneous, and isothermal plasma, the net emission coefficient is calculated for different pressures between 1 atm and 10 atm and arc radia of 0 mm to 1 mm. Results show that the argon presence in the CH4-Ar mixture has a significant effect on the total radiation emitted for the temperature above 17,000 K and the results for pure argon agree with those of bAUDER and EVANS.

关键词： thermal plasma methane argon radiation loss radiative transfer equation

Effects of magnetic Reynolds number on swimming of gyrotactic microorganisms between rotating circular plates filled with nanofluids

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Applied mathematics and mechanics(English Edition) 2020年第4期41卷 637-654页

作者： Lijun ZHANG m.b.ARAIN m.m.bHATTI A.ZEESHAN H.HAL-SULAmI College of mathematics and Systems Science Shandong University of Science and Technology Nonlinear Analysis and Applied mathematics (NAAm)-Research Group Department of Mathematics Faculty of Science King Abdulaziz University Department of mathematics and Statistics International Islamic University

The three-dimensional(3D) nano?uid ?ow among the rotating circular plates ?lled with nanoparticles and gyrotactic microorganisms is studied. A generalized form of the magnetic Reynolds number is used for the mathematical modeling of the ferro-nano?uid ?ow. The torque e?ects on the lower and upper plates are calculated.A di?erential transform scheme with the Pad′e approximation is used to solve the coupled highly nonlinear ordinary di?erential equations. The results show that the squeeze Reynolds number signi?cantly suppresses the temperature, microorganism, and nanoparticle concentration distribution, and agree well with those obtained by the numerical method.

关键词： swimming of microorganism generalized magnetic Reynolds number nanofluid differential transform solution circular rotating plate

Effect of the textural properties of rocks on their crushing and grinding features

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Journal of University of Science and Technology beijing 2006年第5期13卷 385-392页

作者： b. Kekec m. Unal C. Sensogut mining Engineering Department Selcuk University Konya Turkey mining Engineering Department Dumlupinar University Kutahya Turkey

To study the effect of the textural properties of rocks on their crushing feature, the distribution of particle size, the texture, grinding and crushing characteristics of the rocks were investigated, and the relations among them were then analyzed using statistical methods. The relations between the textural properties and the physical and mechanical features of rocks were determined.

关键词： rock textural properties crushing grinding

Efficiency enhancement of a two-beam free-electron laser using a nonlinearly tapered wiggler

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Chinese Physics b 2012年第3期21卷 201-207页

作者： maryam Zahedian b.maraghechi m.H.Rouhani Department of Physics Amirkabir University of Technology

A nonlinear and non-averaged model of a two-beam free-electron laser （FEL） wiggler that is tapered nonlinearly in the absence of slippage is presented. The two beams are assumed to have different energies, and the fundamental resonance of the higher energy beam is at the third harmonic of the lower energy beam. by using maxwell＇s equations and the full Lorentz force equation of motion for the electron beams, coupled differential equations are derived and solved numerically by the fourth-order Runge-Kutta method. The amplitude of the wiggler field is assumed to decrease nonlinearly when the saturation of the third harmonic occurs. by simulation, the optimum starting point of the tapering and the slopes for reducing the wiggler amplitude are found. This technique can be applied to substantially improve the efficiency of the two-beam FEL in the XUV and X-ray regions. The effect of tapering on the dynamical stability of the fast electron beam is also studied.

关键词： free-electron lasers harmonic generation Kolmogorov entropy emciency enhancement

Distribution and geochemical significance of dibenzofurans,phenyldibenzofurans and benzo[b]naphthofurans in source rock extracts from Niger Delta basin,Nigeria

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Acta Geochimica 2020年第6期39卷 973-987页

作者： Abiodun b.Ogbesejana Oluwasesan m.bello Department of Applied Chemistry Federal University Dutsin-MaP.M.B.5001Dutsin-MaKatsina StateNigeria

The distribution and geochemical significance of dibenzofurans,phenyldibenzofurans and benzo[b]naptho-furans in source rocks from Niger Delta basin,Nigeria,were investigated by Rock-Eval pyrolysis and gas chro-matography--mass spectrometry(GC--mS).The data obtained from the source rocks evaluation showed that the rock samples contained type 1/III kerogen capable of generating oil and gas and were within immature to early mature *** relative abundance of the Cor,C1-and C2-dibenzofurans range from 1.75%to 29.82%,27.60%to 40.52%and 29.66%to 6889%,*** diben-zofurans were dominated by *** the C1-dibenzofurans,2-+3-methyldibenzofuran was the most abundant in the rock samples while 1-methy ldibenzofuran appeared to be the *** relative abundance of benzo[b]naphtho[1,2-d]furan(1,2]bNF),benzo[b]naph-tha[2,1-d]furan(2.1]bNF)and benzo[b]naphtha[2,3-d]fu-ran([2.3]bNF)in the rock extracts range from 12.01%to 52.58%,32.61%to 75.219%and 10.27%to 52.43%.The wide range of values recorded for the three isomers of benzo[b lnapthofurans in the samples suggest source rocks formed from mixed organic *** the pheny ldibenzofuran isomers,4-pheny ldibenzofuran was the most abundant while 1-phenyldibenzofuran was the *** ratio-1(PhFR-1)and pheny ldibenzofuran ratio-2(PhFR-2)values range from 0.13 to 1.20 and 0.11 to 2.11,*** resuls showed that the relative abundance of PhFR-1 and PhFR-2 increase gradually with increasing burial depth and maturity(VRo≤0.77%,mPI-1≤*** s 443℃),and have a good correlations with calculated vitrinite ***-I and maximum Temperature(Tmax)-This range of values suggested immature to early mature source *** source rocks were found to have shale and coul lithologics and deposited in a lacustrine/fuvial deltaic settings within immature to early mature stages based on the distribution of dibenzofurans,pheny ldiben-zofurans and benzo[b]naphthofurans in the source rock

关键词： Dibenzofurans benzo[b]napthofurans Source rocks Niger delta Gas chromatography-mass spectrometry