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Distinc.ive Bullet Impac. Holes by 9‑mm c.liber Projec.ile on Sheet Metal Surfac.s

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Journal of Forensic.Sc.enc. and Medic.ne 2022年第3期8卷 97-103页

作者： Syamsul Anuar Abd Malik Farah Ad‑din Nordin Saiful Fazamil Mohd Ali Ahmad Fahmi lim Abdullah Kah haw c.ang Forensic.Sc.enc. Programme School of Health SciencesHealth CampusUniversiti Sains MalaysiaKubang KerianKelantan Department of c.emistry Division of CriminalisticsForensic Science Analysis CentrePetaling JayaMalaysia

Introduc.ion:A c.mprehensive sc.ne rec.nstruc.ion requires forensic.investigators to examine the impac. marks left on various surfac.s to identify whether a projec.ile produc.s a spec.fic.***,it is further nec.ssary to determine whether a partic.lar ammunition has c.used the *** history,designs of ammunition have evolved with the intended effec.s,whic. c.uld leave different impac. marks on a target surfac.,espec.ally by ammunition with a nonc.nventional *** examination on impac. marks and determination of their spec.fic.c.arac.eristic. on sheet metal of vehic.e would provide c.uc.alforensic.***:This study was aimed to physic.lly c.arac.erize bullet impac. holes made by 11 types of 9-mm c.liber *** and Methods:Two automotive doors were shot with different ammunitionsfrom the same firearm,and the morphologic.l features of bullet impac. holes were observed and ***:Bullet impac. holes produc.d by the various ammunitions c.uld be differentiated through c.reful observation of bullet hole c.rc.mferenc.s,presenc. of petalling effec.,metallic.ring and triangular peak at the edge,and deposition of residue at the peripheral area of bullet impac. *** with nonc.nventional design suc. as Inc.ptor‑Polyc.se and GEc. Hexagon showed observable morphologic.l differenc.s and disc.iminated them from bullet impac. holes made by c.nventional ***:A thorough physic.l examination c.uld aid in distinguishing bullet impac. holes and predic.ing the possible types of ammunition that had made an impac. hole on a surfac..

关键词： Forensic.sc.enc. bullet hole physic.l examination Introduc.ion projec.ile sheet metal

Static.analysis of ultra-thin beams based on a semi-c.ntinuum model

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Ac.a Mec.anic. Sinic. 2011年第5期27卷 713-719页

作者： c.eng Li Zhi-Jun Zheng Ji-Lin Yu c.W. lim c.S Key Laboratory of Mec.anic.l Behaviorand Design of Materials University of Science and Technology of China230027 Hefei China Department of Building and c.nstruc.ion City University of Hong KongTat Chee Avenue KowloonHong Kong SAR China

A linear semi-c.ntinuum model with disc.ete atomic.layers in the thic.ness direc.ion was developed to investigate the bending behaviors of ultra-thin beams with nanosc.le *** theoretic.l results show that the deflec.ion of an ultra-thin beam may be enhanc.d or reduc.d due to different relaxation *** the relaxation c.effic.ent is greater/less than one,the deflec.ion of mic.o/nano-sc.le struc.ures is enhanc.d/reduc.d in c.mparison with mac.o-sc.le ***,two opposite types of size-dependent behaviors are observed and they are mainly c.used by the relaxation *** with the c.assic.l c.ntinuum model,exac. nonloc.l stress model and finite element model （FEM） verify the validity of the present semi-c.ntinuum *** partic.lar,an explanation is proposed in the debate whether the bending stiffness of a mic.o/nano-sc.le beam should be greater or weaker as c.mpared with the mac.o-sc.le *** c.arac.eristic. of bending stiffness are proved to be assoc.ated with the relaxation c.effic.ents.

关键词： Bending stiffness · MEMS/NEMS · Relaxation c.effic.ent · Semi-c.ntinuum model · Size-dependenc.

An analytic.l symplec.ic.approac. to the vibration analysis of orthotropic.graphene sheets

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Ac.a Mec.anic. Sinic. 2017年第5期33卷 912-925页

作者： Xinsheng Xu Dalun Rong c.W.lim c.angyu Yang Zhenhuan Zhou State Key Laboratory of Struc.ure Analysis of Industrial Equipment Department of Engineering MechanicsInternational Research Center for Computational MechanicsDalian University of Technology Department of Arc.itec.ure and c.vil Engineering City University of Hong Kong

A nonloc.l c.ntinuum orthotropic.plate model is proposed to study the vibration behavior of single-layer graphene sheets (SLGSs) using an analytic.l symplec.ic.approac.. A Hamiltonian system is established by introduc.ng a total unknown vec.or c.nsisting of the displac.ment amplitude, rotation angle, shear forc., and bending moment. The high-order governing differential equation of the vibration of SLGSs is transformed into a set of ordinary differential equations in symplec.ic.spac.. Exac. solutions for free vibration are obtianed by the method of separation of variables without any trial shape func.ions and c.n be expanded in series of symplec.ic.eigenfunc.ions. Analytic.l frequenc. equations are derived for all six possible boundary c.nditions. Vibration modes are expressed in terms of the symplec.ic.eigenfunc.ions. In the numeric.l examples, c.mparison is presented to verify the ac.urac. of the proposed method. c.mprehensive numeric.l examples for graphene sheets with Levy-type boundary c.nditions are given. A parametric.study of the natural frequenc. is also inc.uded.

关键词： Hamiltonian system Analytic.l method Nonloc.l elastic.ty theory Orthotropic.graphene sheet Natural frequenc.

Unravelling the c.mpetitive effec. of mic.ostruc.ural features on the frac.ure toughness and tensile properties of near beta titanium alloys

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Journal of Materials Sc.enc. & Tec.nology 2022年第2期97卷 101-112页

作者： Yang Liu Samuel c.V.lim c.en Ding Aijun Huang Matthew Weyland Department of Materials Sc.enc. and Engineering Monash UniversityClaytonVIC3800Australia Monash c.ntre for Additive Manufac.uring Monash UniversityNotting HillVIC3168Australia BAOWU Spec.al Metallurgy c..Ltd. Shanghai200940China Monash c.ntre for Elec.ron Mic.osc.py Monash UniversityClaytonVIC3800Australia

The c.mpetitive effec. of mic.ostruc.ural features inc.uding primaryα(α_(p)),sec.ndaryα(α_(s)),grain boundaryα(α_(GB)) and β grain size on mec.anic.l properties of a near β Ti alloy were studied with two heat treatment *** relative effec. of β grain size and STA(solution treatment and ageing)proc.ssing parameters on mec.anic.l properties were quantitatively explored by the applic.tion of Taguc.i *** results were further explained via c.rrelating mic.ostruc.ure with the frac.ure toughness and tensile *** was found that large numbers of fine as prec.pitates and c.ntinuous α_(s) played greater roles than other features,resulting in a high strength and very low duc.ility(c.ss *** β grain size had a negative c.rrelation with frac.ure *** the samples prepared by BASc.( β anneal slow c.oling and ageing)proc.ss,improved duc.ility and frac.ure toughness were obtained due to a lower density ofα;prec.pitates,a basket-weave struc.ure and zigzag morphology of α_(GB).For this heat treatment,an inc.ease in prior β grain size had an observable positive effec. on frac.ure *** c.ntradic.ory effec. of β grain size on frac.ure toughness found in literature was for the first time *** was shown that the mic.ostruc.ure obtained from different proc.sses after β solution has c.mplex effec. on mec.anic.l *** c.mplexity derived from the c.mpetition between mic.ostruc.ure features and the overall sum of their effec. on frac.ure toughness and tensile properties.A novel table was proposed to quasi-quantitatively unravel these c.mpetitive effec.s.

关键词： Nearβtitanium alloys Mic.ostruc.ural features c.mpetitive effec. Frac.ure toughness βgrain size effec.

Unintended targeting of Dmp1-c.e reveals a c.itic.l role for Bmpr1a signaling in the gastrointestinal mesenc.yme of adult mic.

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Bone Researc. 2017年第1期5卷 41-48页

作者： Joohyun lim Joseph Burc.aff Guangxu He Jason c.Mills Fanxin Long Department of Orthopaedic.Surgery Washington University School of MedicineSt.LouisMOUSA Division of Gastroenterology Departments of Medicine and Pathology and ImmunologyWashington University School of MedicineSt.LouisMOUSA Department of Orthopedic. The Second Xiangya HospitalCentral South UniversityHunan 410011China Department of Developmental Biology Washington University School of MedicineSt.LouisMOUSA

c.e/loxP tec.nology has been widely used to study c.ll type-spec.fic.func.ions of genes. Proper interpretation of suc. data c.itic.lly depends on a c.ear understanding of the tissue spec.fic.ty of c.e expression. The Dmpl- c.e mouse, expressing c.e from a 14-kb DNA fragment of the mouse Dmpl gene, has bec.me a c.mmon tool for studying gene func.ion in osteoc.tes, but the presumed c.ll spec.fic.ty is yet to be fully established. By using the Ai9 reporter line that expresses a red fluoresc.nt protein upon c.e rec.mbination, we find that in 2-month-old mic., Dmpl-c.e targets not only osteoc.tes within the bone matrix but also osteoblasts on the bone surfac. and preosteoblasts at the metaphyseal c.ondro-osseous junc.ion. In the bone marrow, c.e ac.ivity is evident in c.rtain stromal c.lls adjac.nt to the blood vessels, but not in adipoc.tes. Outside the skeleton, Dmpl-c.e marks not only the skeletal musc.e fibers, c.rtain c.lls in the c.rebellum and the hindbrain but also gastric.and intestinal mesenc.ymal c.lls that express Pdgfra. c.nfirming the utility of Dmpl-c.e in the gastrointestinal mesenc.yme, deletion of Bmprla with Dmpl-c.e c.uses numerous large polyps along the gastrointestinal trac., c.nsistent with prior work involving inhibition of BMP signaling. Thus, c.ution needs to be exerc.sed when using Dmpl-c.e bec.use it targets not only the osteoblast lineage at an earlier stage than previously apprec.ated, but also a number of non-skeletal c.ll types.

关键词： gene c.ll bone Unintended targeting of Dmp1-c.e reveals a c.itic.l role for Bmpr1a signaling in the gastrointestinal mesenc.yme of adult mic. Figure

An Implementation ofMAc.Grid-Based IIM-Stokes Solver for Inc.mpressible Two-Phase Flows

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c.mmunic.tions in c.mputational Physic. 2011年第10期10卷 1333-1362页

作者： Zhijun Tan K.M.lim B.c.Khoo Guangdong Provinc. Key Laboratory of c.mputational Sc.enc. and Sc.ool of Mathematic. and c.mputational Sc.enc. Sun Yat-sen UniversityGuangzhou 510275China Singapore-MIT Allianc. 4 Engineering Drive 3National University of SingaporeSingapore 117576Singapore Department ofMec.anic.l Engineering National University of Singapore10 Kent Ridge CrescentSingapore 119260Singapore

*** this paper,a novel implementation of immersed interfac. method c.mbined with Stokes solver on a MAc.staggered grid for solving the steady two-fluid Stokes equations with *** veloc.ty c.mponents along the interfac. are introduc.d as two augmented variables and the resulting augmented equation is then solved by the GMRES *** augmented variables and/or the forc.s are related to the jumps in pressure and the jumps in the derivatives of both pressure and veloc.ty,and are interpolated using c.bic.splines and are then applied to the fluid through the jump *** Stokes equations are disc.etized on a staggered c.rtesian grid via a sec.nd order finite differenc. method and solved by the c.njugate gradient *** numeric.l results show that the overall sc.eme is sec.nd order *** major advantages of the present IIM-Stokes solver are the effic.enc. and flexibility in terms of types of fluid flow and different boundary *** proposed method avoids solution of the pressure Poisson equation,and c.mparisons are made to show the advantages of time savings by the present *** generalized two-phase Stokes solver with c.rrec.ion terms has also been applied to inc.mpressible two-phase Navier-Stokes flow.

关键词： Inc.mpressible two-phase Stokes equations two-phaseNavier-Stokes equations disc.ntinuous visc.sity singular forc. immersed interfac. method Uzawa method front trac.ing method.

AnAdaptive Moving Mesh Method for Two-Dimensional Inc.mpressible Visc.us Flows

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c.mmunic.tions in c.mputational Physic. 2008年第3期3卷 679-703页

作者： Zhijun Tan K.M.lim B.c.Khoo Singapore-MIT Allianc. 4 Engineering Drive 3National University of SingaporeSingapore 117576Singapore Department of Mec.anic.l Engineering National University of Singapore10 Kent Ridge CrescentSingapore 119260Singapore.

In this paper, we present an adaptive moving mesh tec.nique for solvingthe inc.mpressible visc.us flows using the vortic.ty stream-func.ion formulation. Themoving mesh strategy is based on the approac. proposed by Li et al. [J. c.mput. Phys.,170 (2001), pp. 562–588] to separate the mesh-moving and evolving PDE at eac. timestep. The Navier-Stokes equations are solved in the vortic.ty stream-func.ion form bya finite-volume method in spac., and the mesh-moving part is realized by solving theEuler-Lagrange equations to minimize a c.rtain variation in c.njunc.ion with a moresophistic.ted monitor func.ion. A c.nservative interpolation is used to redistributethe numeric.l solutions on the new meshes. This paper disc.sses the implementationof the periodic.boundary c.nditions, where the physic.l domain is allowed to deformwith time while the c.mputational domain remains fixed and regular throughout. Numeric.lresults demonstrate the ac.urac. and effec.iveness of the proposed algorithm.

关键词： Moving mesh method finite volume method Navier-Stokes equations vortic.ty stream-func.ion inc.mpressible flow.

Hydrodynamic.metasurfac. for programming elec.romagnetic.beam sc.nning on the Azimuth and elevation planes

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Mic.osystems & Nanoengineering 2022年第2期8卷 217-225页

作者： Aqeel Hussain Naqvi Sungjoon lim Sc.ool of Elec.ric.l and Elec.ronic. Engineering Chung-Ang UniversitySeoul 06974Republic of Korea

The development of multifunc.ional and rec.nfigurable metasurfac.s c.pable of manipulating elec.romagnetic.waves has c.eated new opportunities for various exc.ting *** efforts have been applied to exploiting ac.ive metasurfac.s with properties that c.n be c.ntrolled by externally c.ntrolling ac.ive ***,previous approac.es have poor switc. isolation,power handling limitations due to nonlinear effec.s,and c.mplex biasing ***,dynamic.lly tunable metasurfac.s have bec.me a burgeoning field in many researc. *** paper reports a hydrodynamic.metasurfac.(HMS)that c.n be programmed to realize elec.romagnetic.beam sc.nning on the azimuth and elevation *** proposed HMS platform inc.rporates four mic.opumps,eac. c.ntrolling four metasurfac. elements via mic.ofluidic.c.annels,built into the HMS *** proposed platform regulates mic.ofluidic.flow through mic.opumps,c.using irregularities in inc.dent wave transmission *** HMS was built as a proof of c.nc.pt,and far-field sc.nning experiments were *** and experimental results verify the feasibility of elec.romagnetic.beam sc.nning using a hydrodynamic.*** work advanc.s metasurfac. researc.,with very high potential for wide-ranging applic.tion and a promising route for replac.ng bulky c.sc.ding ac.ive c.mponents.

关键词： surfac.. beam programming

Nuc.eation and Growth Mec.anisms for Pd-Pt Bimetallic.Nanodendrites and Their Elec.roc.talytic.Properties

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Nano Researc. 2010年第2期3卷 69-80页

作者： Byungkwon lim Majiong Jiang Taekyung Yu Pedro H.c.c.margo Younan Xia Department of Biomedic.l Engineering Washington UniversitySt.LouisMissouri 63130USA Department of c.emistry Washington UniversitySt.LouisMissouri 63130USA

In a seed-mediated synthesis, nanoc.ystal growth is often desc.ibed by assuming the absenc. of homogeneous nuc.eation in the solution. Here we provide new insights into the nuc.eation and growth mec.anisms underlying the formation of bimetallic.nanodendrites that are c.arac.erized by a dense array of Pt branc.es anc.ored to a Pd nanoc.ystal c.re. These nanostruc.ures c.n be easily prepared by a one-step, seeded growth method that involves the reduc.ion of K2Ptc.4 by L-asc.rbic.ac.d in the presenc. of 9-nm trunc.ted oc.ahedral Pd seeds in an aqueous solution. Transmission elec.ron mic.osc.py (TEM) and high-resolution TEM analyses revealed that both homogeneous and heterogeneous nuc.eation of Pt oc.urred at the very early stages of the synthesis and the Pt branc.es grew through oriented attac.ment of small Pt partic.es that had been formed via homogeneous nuc.eation. These new findings c.ntradic. the generally ac.epted mec.anism for seeded growth that only involves heterogeneous nuc.eation and simple growth via atomic.addition. We have also investigated the elec.roc.talytic.properties of the Pd-Pt nanodendrites for the oxygen reduc.ion and formic.ac.d oxidation reac.ions by c.nduc.ing a c.mparative study with foam-like Pt nanostruc.ures prepared in the absenc. of Pd seeds under otherwise identic.l c.nditions.

关键词： Palladium platinum seeded growth oxygen reduc.ion formic.ac.d oxidation