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numerical simulation of solidification of liquid aluminum alloy flowing on cooling slope

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中国有色金属学会会刊：英文版 2010年第S3期20卷 898-905页

作者： n.K.KUnD p.DUTTA national Facility for Semisolid Forming Department of Mechanical EngineeringIndian Institute of Science

preparation of semisolid slurry using a cooling slope is increasingly becoming popular,primarily because of the simplicity in design and ease control of the *** this process,liquid alloy is poured down an inclined surface which is cooled from *** cooling enables partial solidification and the incline provides the necessary shear for producing semisolid ***,the final microstructure of the ingot depends on several process parameters such as cooling rate,incline angle of the cooling slope,length of the slope and initial melt *** this work,a CFD model using volume of fluid(VOF) method for simulating flow along the cooling slope was *** for conservation of mass,momentum,energy and species were solved to predict hydrodynamic and thermal behavior,in addition to predicting solid fraction distribution and *** was modeled using an enthalpy approach and a volume averaged technique for the different *** mushy region was modeled as a multi-layered porous medium consisting of fixed columnar dendrites and mobile equiaxed/fragmented *** alloy chosen for the study was aluminum alloy A356,for which adequate experimental data were available in the *** effects of two key process parameters,namely the slope angle and the pouring temperature,on temperature distribution,velocity distribution and macrosegregation were also studied.

关键词： simulation cooling slope slurry solidification A356 Al alloy semi-solid

Dielectric relaxation and magneto-electric characteristics of lead-free double perovskite: Sm2niMnO6

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Journal of Advanced Ceramics 2019年第2期8卷 174-185页

作者： Rutuparna DAS R.n.p.CHOUDHARY Department of physics Siksha ‘O’ Anusandhan University

The polycrystalline sample of a double perovskite, Sm2niMnO6 was synthesized by a solid-state reaction route. From the X-ray structural study, it is found that the structure of the material is monoclinic with lattice parameters: a = 4.1750(63) ?, b = 7.6113(63) ?, c = 5.9896(63) ?, and β = 112.70°. These parameters are very close to and consistent with those of such type of materials. The dielectric, impedance, AC conductivity, and electrical modulus properties of the sample were studied in the temperature range of 25–300℃ and the frequency range of 1 kHz–1 MHz. Typical relaxor behavior observed in the dielectric studies was confirmed by Vogel–Fulcher fitting. From the nyquist plots, the temperature dependent contribution of grain and grain boundary effect was confirmed. The non-Debye type of relaxation was found using the complex impedance spectroscopy. The magnetic study revealed that the sample had paramagnetic behavior at room temperature. Magneto-electric(ME) coefficient was obtained by changing DC bias magnetic field. This type of lead-free relaxor ferroelectric compound may be useful for high-temperature applications.

关键词： solid-state reaction X-ray diffraction(XRD) dielectric relaxation magneto-electric(ME) coupling

nonlinear parametric interactions in ion-implanted semiconductor plasmas having strain-dependent dielectric constants

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Chinese physics B 2017年第1期26卷 304-309页

作者： n Yadav S Ghosh p S Malviya School of Studies in physics Vikram University Ujjain 465010 India Department of physics Govt. J.N.S. Post Graduate College Shujalpur 465333 India

We report nonlinear parametric interactions using a hydrodynamic model of ion-implanted semiconductor plasmas having strain-dependent dielectric constants（SDDC）. High-dielectric-constant materials are technologically important because of their nonlinear properties. We find that the third-order susceptibility varies in the range 10^-14--10^-12m^2·V^-2 for ion-implanted semiconductor plasmas, which is in good agreement with previous results. It is found that the presence of SDDC in ion-implanted semiconductor plasma modifies the characteristic properties of the material.

关键词： nonlinear parametric interactions ion-implanted semiconductor plasmas strain-dependent dielectric constant

A new Lignan Glucoside from Lancea tibetica

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Chinese Chemical Letters 1999年第1期10卷 37-38页

作者： Su, Bn Yuan, cs Jia, ZJ Lanzhou Univ Natl Lab Appl Organ Chem Dept Chem Lanzhou 730000 Peoples R China

A new 7-9'-monoepoxy tetrahydrofuran type lignan glucoside with the cis-relationship of H-7 and H-8, named tibeticoside A 1, was isolated from the medicinal whole plants of Lancea tibetica. Its structure was elucidate... 详细信息

关键词： Lancea tibetica scrophulariaceae tibeticoside A

nanomechanical hydrodynamic force sensing using suspended microfluidic channels

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Microsystems & nanoengineering 2023年第3期9卷 95-102页

作者： Alberto Martín-pérez Daniel Ramos Optomechanics Lab Instituto de Ciencia de Materiales de Madrid(ICMMCSIC)3 Sor Juana Inés de la Cruz(Madrid)E-28049 MadridSpain

Microfluidics has demonstrated high versatility in the analysis of in-flow particles and can even achieve mechanical properties measurements of biological cells by applying hydrodynamic ***,there is currently no available technique that enables the direct measurement and tracking of these hydrodynamic forces acting on a flowing *** this work,we introduce a novel method for the direct measurement of the hydrodynamic force actuating on an in-flow particle based on the analysis of the induced resonance changes of suspended microchannel resonators(SMRs).This hydrodynamic force sensitivity depends on the device used;therefore,we considered the geometry and materials to advance this dependency on the SMR resonance frequency.

关键词： hydrodynamic applying flow

Microstructure and Deformation Behavior of Ti-10V-2Fe-3Al Alloy during Hot Forming process

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Journal of Wuhan University of Technology(Materials Science) 2015年第6期30卷 1332-1337页

作者：管仁国 ZHAO Zhanyong Choi KS Lee cs Key Laboratory of Electromagnetic processing of Materials of Ministry of Education Northeastern University College of Materials Science and Engineering Northeastern University Materials and Metallurgical School Pohang University of Science and Technology

The microstructure evolution and formability of Ti-10V-2Fe-3Al alloy related to the initial microstructures and processing variables were investigated during hot forming process. The experimental results show that the α-phase growth is controlled by solute diffusion during the heat treatment processes. Four different microstructures were established by combinations of several heat treatments, and Ti-10V-2Fe-3Al alloy shows excellent formability both above and below the β transus temperature. The alloy possesses low deformation resistance and active restoration mechanism during the deformation. A constitutive equation describing the hot deformation behavior of Ti-10V-2Fe-3Al alloy was obtained. Higher fl ow stress was observed for the acicular morphology of α phase in microstructures with large aspect ratios as compared with that of small aspect ratios. Due to the dynamic recovery in soft β phase, and the dynamic recrystallization and breakage of acicular α-phase, fl ow softening occurred signifi cantly during deformation. Dynamic recrystallization also occurred especially in the severely deformed regions of forged parts.

关键词： Ti-10V-2Fe-3Al alloy microstructure evolution hot forging constitutive equation recovery dynamic recrystallization

Conversion of an atomic to a molecular argon ion and low pressure argon relaxation

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Chinese physics B 2016年第1期25卷 697-705页

作者： M n Stankov A p Jovanovie V Lj Markovic S n Stamenkovic Department of physics Faculty of Sciences and MathematicsUniversity of Ni Viegradska 33Ni 18001Serbia

The dominant process in relaxation of DC glow discharge between two plane parallel electrodes in argon at pressure 200 pa is analyzed by measuring the breakdown time delay and by analytical and numerical models. By using the approx- imate analytical model it is found that the relaxation in a range from 20 to 60 ms in afterglow is dominated by Ar＋ ions, produced by atomic-to-molecular conversion of Ar＋ ions in the first several milliseconds after the cessation of the discharge. This conversion is confirmed by the presence of double-Gaussian distribution for the formative time delay, as well as con- version maxima in a set of memory curves measured in different conditions. Finally, the numerical one-dimensional （1D） model for determining the number densities of dominant particles in stationary DC glow discharge and two-dimensional （2D） model for the relaxation are used to confirm the previous assumptions and to determine the corresponding collision and transport coefficients of dominant species and processes.

关键词： argon discharge afterglow relaxation fluid model plasma reactions

Limsup Results and LIL for partial Sum processes of a Gaussian Random Field

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Acta Mathematica Sinica,English Series 2008年第9期24卷 1497-1506页

作者： Yong-Kab CHOI Mikls csRG Department of Mathematics and RInS Gyeongsang National University Jinju 660-701 Republic of Korea School of Mathematics and Statistics Carleton University 1125 Colonel By DriveOttawa K1S 5B6 Canada

Let {ξ j ; j ∈ ℤ+ d be a centered stationary Gaussian random field, where ℤ+ d is the d-dimensional lattice of all points in d-dimensional Euclidean space ℝd, having nonnegative integer coordinates. For each j = (j ... 详细信息

Let {ξ j ; j ∈ ℤ+p> d p>be a centered stationary Gaussian random field, where ℤ+p> d p>is the d-dimensional lattice of all points in d-dimensional Euclidean space ℝp>dp>, having nonnegative integer coordinates. For each j = (j 1 , ..., jd) in ℤ+p> d p>, we denote |j| = j 1 ... j d and for m, n ∈ ℤ+p> d p>, define S(m, n] = Σ mn ζ j , σp>2p>(|n−m|) = ES p>2 p>(m, n], S n = S(0, n] and S 0 = 0. Assume that σ(|n|) can be extended to a continuous function σ(t) of t > 0, which is nondecreasing and regularly varying with exponent α at b ≥ 0 for some 0 nder some additional conditions, we study limsup results for increments of partial sum processes and prove as well the law of the iterated logarithm for such partial sum processes.

关键词： stationary Gaussian random field regularly varying function large deviation probability law of the iterated logarithm

Malpractice or masterful practice?navigating vicarious liability in healthcare

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World Journal of Clinical Cases 2025年第2期13卷 10-13页

作者： Satvik n pai naveen Jeyaraman Madhan Jeyaraman Swaminathan Ramasubramanian Department of Orthopaedics PES University Institute of Medical Sciences and ResearchBengaluru 560100KarnatakaIndia Department of Orthopaedics ACS Medical College and HospitalDr MGR Educational and Research InstituteChennai 600077Tamil NaduIndia Department of Orthopaedics Government Medical CollegeOmandurar Government EstateChennai 600002Tamil NaduIndia

In the intricate landscape of healthcare,vicarious liability looms large,shaping the responsibilities and actions of healthcare practitioners and administrators *** by a poignant scenario of a medication error,this article navigates the complexities of vicarious liability in *** explains the legal basis and ramifications of this theory,emphasizing its importance in fostering responsibility,protecting patient welfare,and easing access to *** paper explores the practical effects of vicarious responsibility on day-to-day operations,leadership practices,and decision-making processes via the eyes of senior consultants,junior doctors,and hospital *** comprehensive insights and real-world examples,it underscores the imperative of fostering a culture of accountability,communication,and quality care to navigate the intricate web of liabilities inherent in modern healthcare.

关键词： Vicarious liability Healthcare Responsibility Litigation patient welfare