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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

determination of Time-dependent Coefficients for a Weakly degenerate Heat Equation

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Computer modeling in Engineering & Sciences 2020年第5期123卷 475-494页

作者： m.J.Huntul d.Lesnic department of mathematics Faculty of ScienceJazan UniversityJazanSaudi Arabia department of Applied mathematics University of LeedsLeedsLS29JTUK

In this paper,we consider solving numerically for the first time inverse problems of determining the time-dependent thermal diffusivity coefficient for a weakly degenerate heat equation,which vanishes at the initial moment of time,and/or the convection coefficient along with the temperature for a one-dimensional parabolic equation,from some additional information about the process(the so-called over-determination conditions).Although uniquely solvable these inverse problems are still ill-posed since small changes in the input data can result in enormous changes in the output *** finite difference method with the Crank-Nicolson scheme combined with the nonlinear Tikhonov regularization are *** resulting minimization problem is computationally solved using the mATLAB toolbox routine *** both exact and noisy input data,accurate and stable numerical results are obtained.

关键词： Inverse problem weakly degenerate heat equation Tikhonov’s regularization

On the Time Fractional Generalized Fisher Equation：Group Similarities and Analytical Solutions

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Communications in Theoretical Physics 2016年第1期65卷 11-16页

作者： m.S.Hashemi d.Baleanu department of mathematics Basic Science Faculty University of Bonab P.O. Box 55517-61167 Bonab Iran department of mathematics Cankaya University Ogretmenler Caddesi 14 Balgat 06530 Ankara Turkey Institute of Space Sciences Magurele-Bucharest Romania

In this letter,the Lie point symmetries of the time fractional Fisher(TFF) equation have been derived using a systematic *** the obtained Lie point symmetries,TFF equation has been transformed into a different nonlinear fractional ordinary differential equations with the Erd′elyi–Kober fractional derivative which depends on the parameter α.After that some invariant solutions of underlying equation are reported.

关键词： Erdelyi -Kober derivative time fractional Fisher equation Lie point symmetry

Propagation of plane waves in poroviscoelastic anisotropic media

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Applied mathematics and mechanics(English Edition) 2008年第9期29卷 1141-1153页

作者： A.K.Vashishth m.d.Sharma department of mathematics Kurukshetra University

This study discusses wave propagation in perhaps the most general model of a poroelastic medium. The medium is considered as a viscoelastic, anisotropic and porous solid frame such that its pores of anisotropic permeability are filled with a viscous fluid. The anisotropy considered is of general type, and the attenuating waves in the medium are treated as the inhomogeneous waves. The complex slowness vector is resolved to define the phase velocity, homogeneous attenuation, inhomogeneous attenuation, and angle of attenuation for each of the four attenuating waves in the medium. A non-dimensional parameter measures the deviation of an inhomogeneous wave from its homogeneous version. An numerical model of a North-Sea sandstone is used to analyze the effects of the propagation direction, inhomogeneity parameter, frequency regime, anisotropy symmetry, anelasticity of the frame, and viscosity of the pore-fluid on the propagation characteristics of waves in such a medium.

关键词： inhomogeneous waves anisotropy poroviscoelastic solid phase velocity,attenuation

INFLUENCE OF ALLOYING ELEmENTS ON HYdROGEN dIFFUSION USING SCm-dV-X_α

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Acta metallurgica Sinica(English Letters) 2004年第1期17卷 71-76页

作者： Y.Huang d.m.Xing School of materials Science and Engineering Tianjin University Tianjin 300072 ChinaSchool of Physics Tianjin Normal UniversityTianjin 300071China

The influence of alloy composition (Ti, mn, TiN) on hydrogen diffusion in Fe was studied in detail using SCm-dV-Xα method. The voltage barriers were obtained via calculation on Fe clusters containing the alloy elements such as Ti, mn as well as the chemical compound TiN respectively. The results showed that Ti element produced deep trap in Fe, decreasing the diffusion coefficient of hydrogen elements, mn element did not produce deep trap in Fe, decreasing the diffusion coefficient slightly and TiN in Fe produced very deep "trap" decreasing the diffusion coefficient obviously. The calculation results were in agreement with experiment results.

关键词： hydrogen diffusion SCm-dV-Xα method cluster

Generalized Rayleigh Wave dispersion in a Covered Half-space made of Viscoelastic materials

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Computers, materials & Continua 2017年第4期53卷 307-341页

作者： S.d.Akbarov m.Negin Yildiz Technical University Faculty of Mechanical EngineeringDepartment of Mechanical EngineeringYildiz Campus34349 BesiktasIstanbulTurkey Institute of mathematics and mechanics of National Academy of Sciences of Azerbaijan 37041 BakuAzerbaijan Bahcesehir University Department of Civil Engineering34353 BesiktasIstanbulTurkey

dispersion of the generalized Rayleigh waves propagating in a covered halfspace made of viscoelastic materials is investigated by utilizing the exact equations of the theory of linear *** dispersion equation is obtained for an arbitrary type of hereditary operator of the materials of the constituents and a solution algorithm is developed for obtaining numerical results on the dispersion of the waves under *** curves are presented for certain attenuation cases and the influence of the viscosity of the materials is studied through three rheological parameters of the viscoelastic materials which characterize the characteristic creep time,long-term values and the mechanical behaviour of the viscoelastic material around the initial state of the *** results are presented and discussed for the case where the viscoelasticity of the materials is described through fractional-exponential operators by *** the result of this discussion,in particular,how the rheological parameters influence the dispersion of the generalized Rayleigh waves propagating in the covered half-space under consideration is established.

关键词： Generalized Rayleigh wave viscoelastic material rheological parameters dispersion fractional-exponential operator

2d CFd Analysis and Experimental Analysis on the Effect of Hub to Tip Ratios on the Performance of 0.6 m Impulse Turbine

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Journal of Thermal Science 2004年第4期13卷 315-320页

作者： A. THAKKER m.El. HEmRY Wave Energy Research Team department of mechanical and Aeronautical Engineering University of Limerick IrelandWave Energy Research Team Department of Mechanical and Aeronautical Engineering University of Limerick Ireland

The objective of this paper is to present the performance comparison of 2d Computational Fluid dynamics (CFd) analysis with experimental analysis of 0.6 m impulse turbine with fixed guide vanes for both 0.6 and 0.7 hub to tip ratio (H/T). Also the comparison of 2d CFd analysis of the said turbine with different values of H/T ranging from 0.5 to 0.7. A 2d-cascade model was used for CFd analysis while uni-directional steady flow was used for experimental analysis. The blade and guide vane geometries are based on 0.6 m rotor diameter, with optimum profile, and different H/T of 0.5, 0.6 and 0.7. It was concluded from 2d CFd analysis that 0.5 H/T ratio performances was higher than that of 0.6 and 0.7 H/T at peak efficiency and the operational flow range for 0.5 H/T was found to be wider than that of 0.6 and 0.7 H/T ratio.

关键词： wave energy impulse turbine computational fluid dynamics (CFd).

management of stage Ⅳ rectal cancer: Palliative options

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World Journal of Gastroenterology 2011年第7期17卷 835-847页

作者： Sean m Ronnekleiv-Kelly Gregory d Kennedy department of Surgery Section of Colon and Rectal Surgery University of Wisconsin School of Medicine and Public Health 600 HighlandAvenue G4/701A CSC Madison WI 53792 United States

Approximately 30% of patients with rectal cancer present with metastatic disease. many of these patients have symptoms of bleeding or obstruction. Several treatment options are available to deal with the various complications that may afflict these patients. Endorectal stenting, laser ablation, and operative resection are a few of the options available to the patient with a malignant large bowel obstruction. A thorough understanding of treatment options will ensure the patient is offered the most effective therapy with the least amount of associated morbidity. In this review, we describe various options for palliation of symptoms in patients with metastatic rectal cancer. Additionally, we briefly discuss treatment for asymptomatic patients with metastatic disease.

关键词： Palliative therapy Rectal cancer malignant bleeding malignant obstruction Endorectal stenting Laser ablation

Optical nonlinearities of tetracarbonyl-chromium triphenyl phosphine complex

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Chinese Physics B 2017年第4期26卷 214-218页

作者： m d Zidan A W Allaf A Allahham A AL-Zier department of Physics Atomic Energy CommissionP.O.Box 6091DamascusSyria department of Chemistry Atomic Energy CommissionP.O.Box 6091DamascusSyria

The new tetracarbonyl - chromium-triphenyl phosphine complex was synthesized and characterized using ultraviolet（UV）-visible,Fourier transform infrared（FTIR）,and nuclear magnetic resonance（NmR） *** characterization results confirm the molecular structure of the new *** z-scan measurements were done by diode laser[continuous wave（CW）]to estimate the nonlinear optical parameter（X^3）.The results led to calculate three parameters：the groundstate cross sections（σ_g）,the excited-state cross sections（σ_（ex））,and thermo-optic coefficient of the new *** study indicated that our complex is a suitable for photonic applications.

关键词： tetra carbonyl-chromium triphenyl phosphine Z-scan technique nonlinear optical materials