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Effect of microstructural parameters on the properties of W-Ni-Fe alloys

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Rare Metals 2007年第3期26卷 200-204页

作者： s.h. islam QU Xuanhui s.J. Askari M. Tufail and hE Xinbo s.h.ol of Materials science and Engineering State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China Department of Industrial ＆ Manufacturing Engineering NED University of Engineering ＆ Technology Karachi-75270 Pakistan

The aim of this research was to examine the effect of microstructural parameters on the tensile properties of different compositions of tungsten heavy alloys. The microstructural parameters （grain size, connectivity, contiguity, and solid volume fraction） were measured and were found to have a significant effect on the tensile properties of tungsten-based heavy alloys. The microstructural parameters of W-Ni-Fe alloys are sufficiently different to present a range of mechanical properties. It is concluded that the mechanical properties of tungsten heavy alloys largely depend on the microstructural parameters and their ductility is particularly harmed when grains are contiguous.

关键词： tungsten heavy alloys tensile properties solid volume fraction contiguity

ON ThE GLOBAL sTABILITY CONJECTURE OF ThE GENOTYPE sELECTION MODEL

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Acta Mathematica scientia 2011年第2期31卷 512-528页

作者： s.h. saker Department of Mathematics King Saud University Department of Mathematics Faculty of Science Mansoura University

In 1994, Grove, Kocic, Ladas, and Levin conjectured that the local stability and global stability conditions of the fixed point -y= 1/2 in the genotype selection model should be equivalent. In this article, we give an affirmative answer to this conjecture and prove that local stability implies global stability. some illustrative examples are included to demonstrate the validity and applicability of the results.

关键词： Local stability global stability discrete genotype selection model

Variation of the mechanical properties of tungsten heavy alloys tested at different temperatures

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Rare Metals 2011年第4期30卷 392-395页

作者： s.h.islam Research Center College of EngineeringKing Saud University

The high-temperature mechanical properties of 95W-3.5Ni-1.5Fe and 95W-4.5Ni-0.5Co alloys were investigated in the temperature range of room temperature to1100℃. The yield strength and tensile strengths declined gradually, and the ductility of both alloys increased as the testing temperature was increased to 300℃. All the three properties reached a plateau at temperatures between 300 and 500℃ in the case of 95W-3.5Ni-l.5Fe and at temperatures between 350 and 700℃ in the case of 95W-4.5Ni-0.5Co. Thereafter, the ductility as well as yield and tensile strengths decreased considerably.

关键词： liquid phase sintering tungsten alloys tensile testing mechanical properties

Field-dependent resistive transitions in YBa_2Cu_3O_(7-δ) thin films:Influence of the pseudogap on vortex dynamics

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Chinese Physics B 2015年第1期24卷 467-473页

作者： s.h.Naqib R s islam Department of Physics University of RajshahiRajshahi-6205 Bangladesh

The nature of resistive transition of high-quality crystalline thin films of YBa2Cu3O7-δhas been studied under magnetic fields.h. applied along the c direction over a wide range of doped holes, p, in the Cu O2 planes. The field- and temperature-dependent in-plane resistivity, ρab（T, h）, has been analyzed within the thermally assisted flux-flow（TAFF）formalism. The flux activation energy, U（T, h）, has been extracted from this analysis. The low-T part of the ρab（T, h）data can be described by an activation energy having the functional form of U（T, h） =（1- t）m（h-0/h）β, where t = T /Tc（reduced temperature）, and h0 is a field scale that primarily determines the magnitude of U（T, h）. The temperature exponent, m, shows a systematic variation with p, whereas the field exponent, β, is insensitive to the p values and is close to unity. The h0, on the other hand, changes rapidly as p is varied. U（T, h） is linked to the pinning potential and consequently on the superconducting condensation energy. since the normal state pseudogap directly affects superconducting condensation energy, a clear correspondence between h0 and the PG energy scale, ε g, is found. Possible implications of these results are discussed.

关键词： Y123 superconductors thermally assisted flux-flow model activation energy pseudogap

Ideals Whose First Two Betti Numbers Are Close

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Algebra Colloquium 2015年第4期22卷 671-676页

作者： Keivan Borna s.h. hassanzadeh Faculty of Mathematical sciences and Computer Kharazmi University Tehran Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) Tehran Iran Faculty of Mathematical sciences and Computer Kharazmi University Tehran Iran Institute of Mathematics Universidade Federal de Rio de Janeiro Brasil

For an ideal I of a Noetherian local ring （R, m, k） one hasβR1（I） -β0R（I） ≥-1. It is demonstrated that some residual intersections of an ideal I for whichβ1R（I） -β0R（I） = -1 or 0 are perfect.

关键词： Betti numbers linlkage theory perfect Gorenstein ideals residual intersection

Investigation of Micro Formability of Bulk Amorphous Alloy in the supercooled Liquid state Based on Fluid Flow and Finite Element Analysis

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Journal of Materials science & Technology 2009年第2期25卷 277-280页

作者： M. Cheng s.h. Zhang Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Research results on the viscous flow deformation behavior of bulk amorphous alloy in different systems are reviewed. The material exhibits an ideal Newtonian fluid at a high temperature. Analytical solution of lamellar fluid flow behavior is used to discuss the viscous flow behavior of the bulk amorphous alloy in the supercooled liquid state. A material model, which describes such deformation behavior of Mg6oCusoYlo amorphous alloy, is introduced into the finite element method of microformin8 process. surface feature size was investigated and found not sensitive to the micro formability. Bulk amorphous alloy may possibly be applied to microelectro-mechanical-systems （MEMs） fabrication.

关键词： Bulk amorphous alloy supercooled liquid state Micro formability Lamellar fluid flow

Neuroinflammation as a therapeutic target in huntington's disease

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Neural Regeneration Research 2025年第3期20卷 817-818页

作者： Andrea Kwakowsky Thulani h.Palpagama Center for Brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CentreUniversity of GalwayGalwayIreland

In 1872, George huntington presented his essay “On Chorea” to the Meigs and Mason Academy of Medicine and, in doing so, detailed a disease that would later bear his name. huntington's disease(hD) is a genetic, neurodegenerative disease that manifests as the loss of motor control,cognitive impairment,and mood and psychiatric changes in paents.

关键词： huntington inflammation Medicine

Glial response in the midcingulate cortex in huntington’s disease

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Neural Regeneration Research 2025年第1期20卷 207-208页

作者： Thulani h.Palpagama Andrea Kwakowsky Center for Brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CenterUniversity of GalwayGalwayIreland

huntington’s disease(hD)is a genetic disease characterized by the progressive degeneration of the striatum and *** can present with a variety of symptoms that can broadly be classified into motor symptoms,inclusive of choreatic movements and rigidity,mood and psychiatric symptoms,such as depression and apathy,and cognitive symptoms,such as cognitive *** causal mutation underlying hD results from an expansion of a CAG repeat sequence on the IT15 gene,resulting in the formation and accumulation of a mutant huntingtin protein.

关键词： huntington degeneration cortex

General Cosmological solutions of Einstein's Equations for s.h.rical, Plane and hyperbolic symmetric space

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Chinese Physics Letters 2000年第2期17卷 79-81页

作者： Mohammed Ashraful islam Department of Mathematics and RCMPs Chittagong UniversityChittagongBangladesh

The analytic cosmological solutions of Einstein's field equations for a type of static metric representing plane, s.h.rical and hyperbolic symmetric spaces are presented and their properties are discussed separately. A general type of solution is obtained which represents the plane, s.h.rical and hyperbolic symmetric cosmological models. Its physical properties are also discussed in details.

关键词： Einstein hyperbolic symmetric