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Introducing voids around the interlayer of AlN by high temperature annealing

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Chinese Physics B 2022年第7期31卷 448-453页

作者： Jianwei Ben Jiangliu Luo Zhichen Lin Xiaojuan Sun Xinke Liu Xiaohua Li College of Materials Science and Engineering Shenzhen University-Hanshan Normal University Postdoctoral WorkstationShenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

Introducing voids into AlN layer at a certain height using a simple method is meaningful but *** this work,the AlN/sapphire template with AlN interlayer structure was designed and grown by metal-organic chemical vapor ***,the AlN template was annealed at 1700℃for an hour to introduce the *** was found that voids were formed in the AlN layer after high-temperature annealing and they were mainly distributed around the AlN ***,the dislocation density of the AlN template decreased from 5.26×10^(9)cm^(-2)to 5.10×10^(8)cm^(-2).This work provides a possible method to introduce voids into AlN layer at a designated height,which will benefit the design of AlN-based devices.

关键词： AlN template AlN interlayer voids high-temperature annealing

Numerical evaluation of segmental tunnel lining with voids in outside backfill

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Underground Space 2022年第5期7卷 786-797页

作者： Jia-Xuan Zhang Ning Zhang Annan Zhou Shui-Long Shen Department of Civil Engineering School of Naval ArchitectureOceanand Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Intelligent Manufacturing Technology Department of Civil and Environmental EngineeringCollege of EngineeringShantou UniversityShantouGuangdong 515063China Discipline of Civil and Infrastructure School of EngineeringRoyal Melbourne Institute of Technology(RMIT)Victoria 3001Australia

This paper presents a numerical investigation of the mechanical behaviour of segmental linings owing to the existence of voids in the composite *** composite lining was formed by mining outside and shield tunnelling inside with backfill in *** element method was conducted to analyse the axial forces and bending moment for voids of different diameters at different *** results show that the axial forces in the transverse section increase near the crown and then invert and decrease on the left and right sides with an increase in the void centre angle(β)measured from the vertical *** increase in void diameter(dvoids leads to an increase in the bending moment in the entire segment section with an angle β.

关键词： Jointly constructed tunnel Composite lining voids Axial force Bending moment

Effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids by using the Lord-Shulman and dual-phase-lag models

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Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1135-1154页

作者： S.M.ABO-DAHAB A.M.ABD-ALLA A.A.KILANY Department of Mathematics Faculty of SciencesTaif UniversityTaif 888Saudi Arabia Department of Mathematics Faculty of ScienceSouth Valley UniversityQena 83523Egypt Department of Mathematics Faculty of ScienceSohag UniversitySohag 82524Egypt

The effects of rotation and gravity on an electro-magneto-thermoelastic medium with diffusion and voids in a generalized thermoplastic half-space are studied by using the Lord-Shulman (L-S) model and the dual-phase-lag (DPL) model. The analytical solutions for the displacements, stresses, temperature, diffusion concentration, and volume fraction field with different values of the magnetic field, the rotation, the gravity, and the initial stress are obtained and portrayed graphically. The results indicate that the effects of gravity, rotation, voids, diffusion, initial stress, and electromagnetic field are very pronounced on the physical properties of the material.

关键词： electromagnetic field gravity field rotation initial stress voids diffusion normal mode analysis Lord-Shulman (L-S) model dual-phase-lag (DPL) model

Some basic principles in dynamic theory of viscoelastic materials with voids

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Science China(Physics,Mechanics & Astronomy) 2007年第3期50卷 370-378页

作者： LUO En LI WeiHua Department of Applied Mechanics and Engineering Sun Yat-sen UniversityGuangzhou 510275China

According to the basic idea of classical yin-yang complementarity and modern dual-complementarity, in a simple and unified way proposed by Luo, some basic principles in the dynamic theory of viscoelastic materials with voids can be estab- lished systematically. In this paper, an important integral relation in terms of con- volutions is given, which can be considered as the generalized principle of virtual work in mechanics. Based on this relation, it is possible not only to obtain the principle of virtual work and the reciprocal theorem, but also to derive systemati- cally the complementary functionals for the eight-field, six-field, four-field simpli- fied Gurtin-type variational principles and the potential energy-functional for the two-field one in the dynamic theory of viscoelastic materials with voids by the generalized Legendre transformations given in this paper. Furthermore, with this approach, the intrinsic relationship among various principles can be explained clearly.

关键词： dynamic theory of viscoelastic materials with voids principle of virtual work reciprocal theorem simplified Gurtin-type variational principle complementary relation

The influence of Thomson effect and inclined loads in an electro-magneto-thermoelastic solid with voids under green-Naghdi theories

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Journal of Ocean Engineering and Science 2018年第3期3卷 253-264页

作者： Elsayed M.Abd-Elaziz Mohamed I.M.Hilal Department of Mathematics Zagazig UniversityFaculty of ScienceP.O.Box 44519ZagazigEgypt

The present investigation deals with the 2-dimensional deformation in a homogeneous thermoelastic solid with voids subjected to inclined *** heat conduction equation is affected with the Thomson *** basic governing equations are modified by using Green-Naghdi theory of *** normal mode analysis technique is used to obtain the components of stress,strain,temperature,induced magnetic field and change in volume fraction *** variations of these quantities have been depicted graphically in the Green-Naghdi theories of type-II and III for an insulated *** numerical calculations,the effect of Thomson parameter and angle of inclination on a homogeneous,isotropic,electro-magneto-thermoelastic material with voids is revealed and discussed.

关键词： Electro-magneto-thermoelasticity Normal mode method Inclined loads voids Thomson effect Green-Naghdi theory

THE YIELDING BEHAVIOR OF MATERIALS WITH RANDOM voids

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Chinese Science Bulletin 1992年第6期37卷 512-516页

作者：郑茂盛罗子健郑修麟 Department of Materials Science & Engineering Northwestem Polytechnical University Xi'an 710072 PRC

The unit cell model proposed by Gurson can only describe the yielding behavior of some materials with voids having typical structures, and therefore it is unrealistic. Oyane, Lee also put forward some other yielding criteria for porous materials, but some ambiguous parameters have been introduced into their criteria, so the application of these criteria is limited.

关键词： materials with random voids yielding criterion strength coefficient

How to Obtain a Mass of a Graviton, and Does This Methodology Lead to voids?

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Journal of High Energy Physics, Gravitation and Cosmology 2020年第3期6卷 416-439页

作者： Andrew Walcott Beckwith Department of Physics PRC (Visiting Scholar) Chongqing University Chongqing China

Using the Klauder enhanced quantization as a way to specify the cosmological constant as a baseline for the mass of a graviton, we eventually come up and then we will go to the relationship of a Planck Length to a De Broglie length in order to link how we construct a massive graviton mass, with cosmological constant and to interface that with entropy in the early universe. We then close with a reference to the possible quantum origins of e folding and inflation. This objective once achieved is connected with a possible mechanism for the creation of voids, in the later universe, using a construction of shock fronts from J. P. Onstriker, 1991 and followed up afterwards with Mukhanov’s physical foundations to Cosmology book section as to indicate how variable input into self reproduction of the Universe structures may lead to void formation in the present era. A connection with Wesson’s 5 dimensional cosmology is brought up in terms of a generalized uncertainty principle which may lead to variations of varying energy input into self reproducing cosmological structures which could enable non uniform structure formation and hence voids. One of the stunning results is that the figure of number of gravitons, about 1058, early on, is commensurate with a need for negative pressure, (middle of manuscript) which is a stunning result, partly based on Volovik and weakly interacting Bose gas model for pressure, which is completely unexpected. Note that in quantum physics, the idea statistically is that at large quantum numbers, we have an approach to classical physics results. We will do the same as to our cosmological work. This means that the , in our last set of equations, which as we indicate has the surprise condition that for Pre-Planckian space-time that a very large value for initial Pre Planckian dimensions dmin which is the dimensional input into the Pre Planckian state, prior to emerg

关键词： Black Holes Enhanced Quantization Gravitons voids

Surface Wave Propagation in a Generalized Thermoelastic Material with voids

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Applied Mathematics 2011年第5期2卷 521-526页

作者： Baljeet Singh Raj Pal 不详

In the present paper, the propagation of surface wave in a generalized thermoelastic solid with voids is considered. The governing equations are solved to obtain the general solution in x-z plane. The appropriate boundary conditions at an interface between two dissimilar half-spaces are satisfied by appropriate particular solutions to obtain the frequency equation of the surface wave in the medium. Some special cases are also discussed.

关键词： Thermoelasticity Surface Waves Boundary Conditions voids

Automated X-ray Defect Inspection on Occluded BGA Balls Using Hybrid Algorithm

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Computers, Materials & Continua 2023年第6期75卷 6337-6350页

作者： Ki-Yeol Eom Byungseok Min Department of AI Bigdata Suseong UniversityDaegu42078Korea R&D Center XAVIS Co.Ltd.Seongnam-si13202Korea

Automated X-ray defect inspection of occluded objects has been an essential topic in semiconductors,autonomous vehicles,and artificial intelligence ***,there are few solutions to segment occluded objects in the X-ray inspection *** particular,in the Ball Grid Array inspection of X-ray images,it is difficult to accurately segment the regions of occluded solder balls and detect defects inside solder *** this paper,we present a novel automatic inspection algorithm that segments solder balls,and detects defects fast and efficiently when solder balls are *** proposed algorithm consists of two *** the first stage,the defective candidates or defects are determined through the following four steps:(i)image preprocessing such as noise removal,contrast enhancement,binarization,connected component,and morphology,(ii)limiting the inspec-tion area to the ball regions and determining if the ball regions are occluded,(iii)segmenting each ball region into one or more regions with similar gray values,and(iv)determining whether there are defects or defective candidates in the regions using a weighted sum of local threshold on local *** there are defective candidates,the determination of defects is finally made in the following *** the second stage,defects are detected using the automated inspection technique based on oblique computed *** 3D precision inspection process is divided into four steps:(i)obtaining 360 projection images(one image per degree)rotating the object from 0 to 360 degrees,(ii)reconstructing a 3D image from the 360 projected images,(iii)finding the center slice of gravity for solder balls from the axial slice images in the z-direction,and getting the inspection intervals between the upper bound and the lower bound from the center slice,and(iv)finally determining whether there are defects in the averaged image of solder *** proposed hybrid algorithm is robust for segmenting the defects inside o

关键词： Hybrid voids BGA X-ray inspection defects