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Correlation of the meishucunian Stage in South Asia

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Acta Geologica Sinica(English Edition) 1989年第1期63卷 1-9页

作者： m.D.brasier b.Hamdi Department of Geology University of Hull Hull Hu6 7RX England. Geological Survey of Iran P. O. Box 1964. Teheran Iran.

The determination of boundary points and their correlation are prerequisites for defining the PrecambrianCambrian boundary and the intercontinental correlation. A large number of good Precambrian-Cambrian boundary sections in South Asia not only possess the conditions for selection of a boundary stratotype, but also provide the basis for the long-distance correlation of those boundary sections.Through a detailed study of the latest data obtained from the typical sections in South China, the Lesser Himalaya mountains and the Alborz mountains. the locations of boundary points have been defined, and a correlation scheme is proposed, which contributes to the solution of the problem of worldwide correlation of boundary sections.

关键词： Correlation of the meishucunian Stage in South Asia

Performance Enhancement of PV based boost Cascaded Fifteen Level Inverter for AC Loads

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Computer Systems Science & Engineering 2022年第7期42卷 165-181页

作者： m.P.Viswanathan b.Anand Department of Electrical and Electronics Engineering Hindusthan College of Engineering and TechnologyCoimbatore641032India

In this research work,single-stageﬁfteen levels cascaded DC-interface converter(CDDCLC)is proposed for sun arranged photovoltaic technology(PV)*** proposed geography is joined with help DC chopper and H-associate inverter to upgrade the power converter to accomplish the diminished harmonic proﬁ*** assessment with the customary inverter structures,the proposed system is used with diminished voltage stress,decreased switch count and DC source *** proposed research work with cascaded DC link conver-ter design requires three DC sources for combiningﬁfteen-level AC *** investigation structure switching technique is phase opposition and disposition pulse width modulation technique(POPD)which results in improved quality of obtained output AC power with 6.73%THD and also determinedly recommended for power converters used in UPS and drive applications since it is extremely affordable.A simulation and prototype model ofﬁfteen-level CDDCLC system is deployed and its performance is analyzed for various operating conditions.

关键词： Cascaded DClinkconverter(CDDCLC) modified phaseopposition and disposition(mPOPDPWm) photovoltaic(PV) DCinterfaceboostconverter

STAbILITY AND RESONANCES OF mULTISTEP COSINE mETHODS

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Journal of Computational mathematics 2012年第5期30卷 517-532页

作者： b. Cano m.J. moreta Departamento de matemdtica Aplicada IMUVA. Facultad de Ciencias. Paseo Belen 7 CP 47011 Valladolid Spain Departamento de Fundamentos del Andlisis Econdmico I. Universidad Complutense de madrid. Campus de Somosaguas Pozuelo de Alarcdn 28223 Madrid Spain

In a previous paper, some particular multistep cosine methods were constructed which proved to be very efficient because of being able to integrate in a stable and explicit way linearly stiff problems of second-order in time. In the present paper, the conditions which guarantee stability for general methods of this type are given, as well as a thorough study of resonances and filtering for symmetric ones （which, in another paper, have been proved to behave very advantageously with respect to conservation of invariants in Hamiltonian wave equations）. What is given here is a systematic way to analyse and treat any of the methods of this type in the mentioned aspects.

关键词： Exponential integrators multistep cosine methods Second-order partial dif-ferential equations Stability Resonances

Nonlinear static response of piezoelectric plates considering electro-mechanical coupling

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Journal of Central South University 2012年第5期19卷 1182-1188页

作者： b.behjat m.R.Khoshravan mechanical Engineering Department Tabriz UniversityTabrizIran

Nonlinear static analysis of piezoelectric plates has been carried out using nonlinear finite element method considering electro-mechanical coupling,The geometrical nonlinearity has been taken into account and electric potential is assumed to be quadratic across the plate thickness,The governing equations are obtained using potential energy and Hamilton's principle that includes elastic and piezoelectric *** finite element model is derived based on constitutive equation of piezoelectric material accounting for coupling between elasticity and electric effect using higher order plate elements,Results are presented for piezoelectric plate under different mechanical boundary conditions,Numerical results for the plate are given in dimensionless graphical *** of boundary conditions on linear and nonlinear response of the plate are also *** numerical results obtained by the present model are in good agreement with the available solutions reported in the literature.

关键词： piezoelectric plate nonlinear finite element method static analysis of plate geometrical nonlinearity

Influence of surface roughness on flotation kinetics of quartz

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Journal of Central South University 2012年第5期19卷 1206-1211页

作者： m.Rahimi m.R.Aslani b.Rezai Department of mining and metallurgical Engineering Amirkabir University of TechnologyTehranIran Department of mining Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Surface roughness of quartz particles was determined by measuring the specific surface area of *** wettability characteristics of particles were determined by measuring the flotation rate using a laboratory flotation *** results show that the rod mill product has higher roughness than the ball mill *** the particles with larger surface roughness,the flotation kinetics constant is also ***,empirical relationships between surface roughness(r) and the flotation kinetics constant(k) of quartz particles as k=A+br+Cr0.5lnr+D/lnr+E/r and k=A+br are presented,in which A,b,C,D and E are constants related to experimental conditions and mineralogical properties of mineral.

关键词： grinding flotation kinetics surface roughness ball mill rod mill

The method of Fundamental Solutions for Two-Dimensional Elastostatic Problems with Stress Concentration and Highly Anisotropic materials

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Computer modeling in Engineering & Sciences 2022年第3期130卷 1349-1369页

作者： m.R.Hematiyan b.Jamshidi m.mohammadi Department of mechanical Engineering Shiraz UniversityShiraz71936Iran Department of mechanical Engineering College of EngineeringShiraz BranchIslamic Azad UniversityShiraz71993Iran

The method of fundamental solutions(mFS)is a boundary-type and truly meshfree method,which is recognized as an efficient numerical tool for solving boundary value *** geometrical shape,boundary conditions,and applied loads can be easily modeled in the *** capability makes the mFS particularly suitable for shape optimization,moving load,and inverse ***,it is observed that the standard mFS lead to inaccurate solutions for some elastostatic problems with stress concentration and/or highly anisotropic *** thiswork,by a numerical study,the important parameters,which have significant influence on the accuracy of the mFS for the analysis of two-dimensional anisotropic elastostatic problems,are *** studied parameters are the degree of anisotropy of the problem,the ratio of the number of collocation points to the number of source points,and the distance between main and pseudo *** is observed that as the anisotropy of the material increases,there will be more errors in the *** is also observed that for simple problems,increasing the distance between main and pseudo boundaries enhances the accuracy of the results;however,it is not the case for complicated ***,it is concluded that more collocation points than source points can significantly improve the accuracy of the results.

关键词： meshfree method degree of anisotropy location of source points anisotropic elasticity least squares mFS

Generation of sub-wavelength and super-resolution longitudinally polarized non-diffraction beam using lens axicon

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Chinese Optics Letters 2008年第10期6卷 785-787页

作者： K.b.Rajesh P.m.Anbarasan Department of Physics Periyar UniversitySalem 636011India

It is well known that a light spot of sub-wavelength will diverge in all directions. In this letter, A method is presented for generating sub-wavelength （0.44λ） longitudinally polarized beam, which propagates without divergence over lengths of about 2λ in free space. This is achieved by a high numerical aperture （NA） lens axicon that utilizes spherical aberration to duplicate the performance of an axicon and to create an extended focal line.

关键词： Azimuthally polarized beams Fresnel zones High numerical aperture optics Laser beams Optical data storage Superresolution

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