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bouncing scenario of general relativistic hydrodynamics in extended gravity

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Communications in Theoretical Physics 2021年第2期73卷 96-101页

作者： A Y Shaikh b Mishra Department of Mathematics Indira Gandhi MahavidyalayaRalgaon-445402India Department of Mathematics Birla Institute of Technology and Science PilaniHyderabad CampusHyderabud-500078India

In this paper,we have framed bouncing cosmological model of the Universe in the presence of general relativistic hydrodynamics in an extended theory of *** metric assumed here is the flat Friedmann–Robertson–Walker space–time and the stress energy tensor is of perfect *** general relativity(GR)has certain issues with late time cosmic speed up phenomena,here we have introduced an additional matter geometry coupling that described the extended gravity to *** dynamical parameters are derived and *** dynamical behavior of the equation of state parameter has been *** have observed that the bouncing behavior is mostly controlled by the coupling parameter.

关键词： FRW metric extended gravity bouncing scenario energy conditions

Application of multi-criteria decision making methods for selection of micro-EDM process parameters

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Advances in Manufacturing 2014年第3期2卷 251-258页

作者： A.P.Tiwary b.b.Pradhan b.bhattacharyya Department of Mechanical Engineering Sikkim Manipal Institute of TechnologyEast Sikkim.Majitar 737136.India Department of Production Engineering Jadavpur UniversityKolkata 700032India

Ti-6A1-4V super alloy is an important engi- neering material with good strength to weight ratio and a wide range of applications in a number of engineering fields because of its excellent physical and mechanical properties. This work determines optimum process parameters such as pulse on time, peak current, gap voltage and flushing pressure, which influence the micro-electro discharge machining （EDM） process during machining of Ti-6AI-4V using combined methods of response surface methodology （RSM） and fuzzy-technique for order pref- erence by similarity to ideal solution （TOPSIS）. Central composite design （CCD） is used in the experimental investigation. A decision making model is developed to identify the optimum process parameters in the micro- EDM process, which influences several machining criteri- ons such as material removal rate （MRR）, tool wear rate （TWR）, overcut （OC） and taper. Triangular fuzzy numbers are used to determine the weighting factor for each process criterion. Further a fuzzy-TOPSIS method is used to select the most desirable factor level combinations. The proposed technique can be used to select optimal process parameters from various sets of combinations of process parameters in a micro-EDM process.

关键词： Micro-EDM - Ti-6A1-4V Fuzzy-techniquefor order preference by similarity to ideal solution(TOPSIS) Micromachining

Generalized Supersymmetric Perturbation Theory

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Chinese Physics Letters 2004年第12期21卷 2330-2333页

作者： b.Goenül DepartmentofEngineeringPhysics UniversityofGaziantep27310GaziantepTurkey

Using the basic ingredient of supersymmetry, a simple alternative approach is developed to perturbation theory in one-dimensional non-relativistic quantum mechanics. The formulae for the energy shifts and wavefunctions do not involve tedious calculations which appear in the available perturbation theories. The model applicable in the same form to both the ground state and excited bound states, unlike the recently introduced supersymmetric perturbation technique which, together with other approaches based on logarithmic perturbation theory, are involved within the more general framework of the present formalism.

关键词： Quantum information and quantum mechanics

Perturbative Quantum Chromodynamics α_(s)^(4)-Order Corrections to the Ratio R for τ Decay

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Chinese Physics Letters 1998年第10期15卷 711-712页

作者： b.P.Nigam Department of Physics&Astronomy Box 871504Arizona State University TempeArizonaUSA 85287-1504

The perturbative quantum chromodynamics correction to the semihadronic decay rate R of the heavy leptonτwas expressed by braaten as an expansion in powers ofαs to orderα*** had found theα_(s)^(4)order correction to be significant and conjectured that theα_(s)^(4)order corrections might also be *** et *** corrected theα_(s)^(4)-order *** have extended the analytic calculations to orderαs4;it involves an unknown constant K3 which occurs inαs4 *** order to estimate the effect ofα_(s)^(4)order correction,we have chosen K3 to range from-1000 to+1000 and we find that the value of R changes by about-11%to+10%,respectively,compared to the value of R=3.5 obtained toα_(s)^(4)-order result.

关键词： correction α dynamics

Forced motion of an elastic filament through a narrow tube

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Acta Mechanica Sinica 2015年第6期31卷 789-790页

作者： L.b.Freund Department of Materials Science and Engineering University of Illinois at Urbana Champaign

A polymer filament consisting of many similar molecules linked in a one-dimensional array is very flexible. As a result, shapes with a relatively large curvature can be accommodated elastically. When loosely confined in a thermal environment, such a flexible strand may become tangled owing to its flexibility. When confined within a narrow ＂tube＂ over its full length, a flexible molecule may behave quite differently. Here, we consider the qualitative nature of deformation of an individual filament when confined within a tube. Commonly the tube is formed within the cluster by a large number of surrounding filaments of the same type.

关键词： Statistical mechanics. biofilament. Reptation Partition function

Improvement of True Green Porosity, Sinterability and Microstructure in Alumina Ceramics by Filter Pressing

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Journal of Materials Science & Technology 2005年第1期21卷 105-108页

作者： RenjieZENG b.Rand Dept.ofMaterialsScience&Engineering XiamenUniversityXiamen361005China Dept.ofProcess Environment&MaterialsEngineeringLeedsUniversityLeedsLS29JTUK

Comparison between filter pressing and isostatic pressing for submicrometer alumina powder has been systematically made. Obvious improvements in true porosity, sintering behaviour, and microstructure of green compacts... 详细信息

关键词： Porosimetry Agglomerate Sintering dilatometry pH PEG

Experimental study on the partition behaviour of Ta, Nb and W between different phases in the processes of crystallization differentiation of albite granitic magma

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Chinese Science bulletin 1997年第16期42卷 1372-1377页

作者： Zhao, JS Zhao, b Rao, b Chinese Acad Sci Guangzhou Inst Geochem Guangzhou 510640 Peoples R China Nanjing Univ Dept Earth Sci Nanjing 210008 Peoples R China

To counter the lack of consensus of opinion on mineralizations of Ta, Nb and W which have genetic relationship to fluorine-rich albite granite and the want of experimental evidence at present, some experiments reported in this study were carried out. The purpose of this study is to explain the genetic connection of Ta, Nb and W ore deposits and possible mechanism of their mineralization with the aid of the experimental results.

关键词： partition behaviour of Ta Nb and W process of crystallization differentiation of magma.

Conditioned duality between supercontinental’assembly’and’breakup’LIPs

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Geoscience Frontiers 2020年第5期11卷 1635-1649页

作者： Martin b.Klausen Department of Earth Sciences Stellenbosch UniversityPrivate Bag X1MatielandSouth Africa

A compilation of 178 more precise ages on 10 potential Large Igneous Provinces(LIPs)across southern Africa,is compared to Earth’s supercontinental cycles,where 5 more prominent LIP-events all formed during the assembly of supercontinents,rather than during *** temporal bias is confirmed by a focused review of field relationships,where these syn-assembly LIPs formed behind active continental arcs;whereas,the remaining postassembly-and likely breakup-related-LIPs never share such *** the possibility of two radically different LIP-types,only the two younger breakup events(the Karoo LIP and Gannakouriep Suite)produced basalts with more enriched asthenospheric OIb-signatures;whereas,all assembly LIPs produced basalts with stronger lithospheric,as well as more or less primitive asthenospheric,signatures.A counterintuitive observation of Precambrian breakup LIPs outcropping as smaller fragments that are more peripherally located along craton margins,compared to assembly LIPs as well as the Phanerozoic Karoo breakup LIP,is explained by different preservation potentials during subsequent supercontinental ***,further accentuating radical differences between(1)breakup LIPs,preferentially intruding along what evolves to become volcanic rifted margins that are more susceptible to deformation within subsequent orogens,and(2)assembly LIPs,typically emplaced along backarc rifts within more protected cratonic interiors.A conditioned duality is proposed,where assembly LIPs are primarily sustained by thermal blanketing(as well as local arc hydration and rifting)below assembling supercontinents and breakup LIPs more typically form above impinging mantle *** a duality is further related to an overall dynamic Earth model whereby predominantly supercontinent-orientated ocean lithospheric subduction establishes/revitalizes large low shear velocity provinces(LLSVPs)during assembly LIP-activity,and heating of such LLSVPs by the Earth’s core subsequ

关键词： Large igneous provinces Extrovert plate tectonics LLSVP Mantle dynamics Geochemical discrimination

On the pressure and stress singularities induced by steady flows of a pair of nonmiscible,incompressible,viscous fluids in contact with a wall

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Acta Mechanica Sinica 2010年第5期26卷 669-673页

作者： G.b.Sinclair Department of Mechanical Engineering Louisiana State University

Design for structural integrity requires an appreciation of where stress singularities can occur in structural configurations. While there is a rich literature devoted to the identification of such singular behavior in solid mechanics, only of late has there been much in the way of corresponding identifications of flow-induced stress singularities in fluid mechanics. These recent asymptotic identifications are for a single incompressible viscous fluid： Here the asymptotic approach is extended to apply to a configuration entailing two such fluids, For this configuration, various specifications leading to power or log singularities are determined. These results demonstrate that flow-induced stress singularities can occur in a structural container at a location where no singularities are identified within solid mechanics alone.

关键词： Incompressible viscous fluids - Navier-Stokes equations Fluid-structure interactions Stress singularities