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In-situ synchrotron high energy X-ray diffraction study on the internal strain evolution of D019-α2 phase during high-temperature compression and subsequent annealing in a tiAl alloy

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journal of Materials Science & technology 2023年第32期163卷 212-222页

作者： X.Liu L.Song A.Stark F.Pyczak t.b.Zhang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Innovation Center NPU Chongqing Northwestern Polytechnical UniversityChongqing 400000China Institute of Materials Physics Helmholtz-Zentrum HereonMax Planck-Str.1Geesthacht 21502Germany

the residual stress in the D019-α2 phase is known to be significantly higher than that in the L10-γphase in tiAl alloys after deformation due to the poor plasticity and strong mechanical anisotropy of theα2 ***,the internal stress accumulation and relaxation in theα2 phase during high-temperature deformation and annealing are scarcely *** this study,for the first time,the internal strain evolution and load partitioning between theα2 andγphases at high temperatures are characterized by in-situ synchrotron high energy X-ray diffraction(HEXRD)*** plastic deformation is at least initiated at a stress of roughly 200 MPa in theγphase and 775 MPa in theα2 *** intergranular strains in theα2 phase are generated by the onset of dislocation glide in theγphase,and accentuated with the accumulated dislocations and the ensuing twinning *** unloading,great intergranular strains are preserved in theα2 phase constrained by the heavily plastically deformedγ*** subsequent heating from 400 to 1000℃,the internal strains in theα2 phase are almost fully relaxed by substantial dislocation annihilation and rearrangement in theγ*** annealing at 800℃,the internal strain relaxation is rapid in the initial 10 min,whereas considerably retarded *** extent of relaxation after holding at 800℃for 1 h is equivalent to that of heating in an effective temperature range of 680-880℃for 10 *** in-situ lattice strain measurements with various thermal relaxation schemes provide guidance for the stress relief annealing of tiAl components.

关键词： tiAl alloys Synchrotron radiation Intergranular strain Stress relaxation

Loaded Rubber-Like Materials Subjected to Small-Amplitude Vibrations

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Chinese journal of Polymer Science 2014年第5期32卷 620-632页

作者： t.beda J.b.Casimir K.E.Atcholi Y.Chevalier Industrial and Mechanical Engineering Department Ecole Nationale Supérieure Polytechnique (ENSP) Département de Physique Faculté des Sciences Université de NGaoundéré Laboratoire d’Ingénierie des Structures Mécanique et des Matériaux (LISMMA) SUPMECA de Paris Institut de Recherche sur les transports l’Energie et la Société (IRTES EA7274) Laboratoire Systèmes et Transport (SeT EA 3317) Université de Technologie de Belfort-Montbéliard (UTBM)

this paper proposes a constitutive law and a method for characterizing highly preloaded viscoelastic materials subjected to linear （small-amplitude） vibrations. A multiplicative non-separable variables law has been suggested to model the behavior that depends on both stretch and time/frequency. this approach allows splitting the intricate combined test performed simultaneously on both stretch and frequency, generally in a limited experimental domain up to 100 Hz, into two independent tests. thus, on one hand, the dynamic complex modulus dependent on frequency alone is evaluated on the basis of vibration tests in a large experimental domain up to 100 kHz. On the other hand, energetic parameters are determined from a quasi-static hyperelastic tensile test. the complex modulus, dependent on both stretch and frequency, is then deduced from the results acquired from uncoupled investigations. this work shows that, in extension, the elastic modulus increases with increasing stretch, and the loss factor decreases with increasing stretch; while, in compression, around the material undeformed state, the modulus increases as the stretch increases till a certain value of compression stretch （upturn point depending on material characteristics）, and then the modulus decreases as the stretch increases. Globally, preload rigidifies materials but reduces their damping property. these results closely match a well-known observation in solid mechanics.

关键词： Elastomers Viscoelasticity Hyperelasticity Vibrations Modeling Characterization Combined modulus.

two-Factor Cancelable biometrics Authenticator

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journal of Computer Science & technology 2007年第1期22卷 54-59页

作者：彭颖涵 Andrew t. b. J David N. C. L Faculty of Information Science and technology Multimedia University dalan Ayev Keroh Lama 75450 Melaka Malaysia

biometrics-based authentication system offers advantages of providing high reliability and accuracy. However the contemporary authentication system is impuissance to compromise. If a biometrics data is compromised, it cannot be replaced and rendered unusable. In this paper, a cancelable biometrics-based authenticator is proposed to solve this irrevocability issue. the proposed approach is a two-factor authentication system, which requires both of the random data and facial feature in order to access the system. In this system, tokenized pseudo-random data is coupled with momentbased facial feature via inner product algorithm. the output of the product is then discretized to generate a set of private binary code, coined as 2factor-Hashing code, which is acted as verification key. If this biometrics-based verification key is compromised, a new one can be issued by replacing a different set of random number via token replacement. then, the compromised one is rendered completely useless. this feature offers an extra protection layer against biometrics fabrication since the verification code is replaceable. Experimental results demonstrate that the proposed system provides zero Equal Error Rate in which there is a clear separation in between the genuine and the imposter distribution populations.

关键词： cancelable biometrics face recognition Geometric moments,pseudo Zernike moment

Numerical modelling of a low power non-transferred arc plasma reactor for methane conversion

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Plasma Science and technology 2019年第6期21卷 29-37页

作者： b I MIN D K DINH D H LEE t H KIM S CHOI Institute for Nuclear Science and technology Jeju National University 102 Jejudaehak-ro Jeju 63243Republic of Korea University of Science and technology(USt) 217 Gajeong-ro Yuseong-gu Daejeon 34113 Republic of Korea Korea Institute of Machinery and Materials 156 Gajeongbuk-ro Yuseong-gu Daejeon 34103 Republic of Korea Department of Nuclear and Energy Engineering Jeju National University 102 Jejudaehak-ro Jeju 63243Republic of Korea

thermal flow characteristics and the methane conversion reaction in a low power arc plasma reactor for efficient storage and transport of methane,which is the main component of shale gas,were *** temperature and velocity distributions were calculated according to the type of discharge gases and arc current level by a self-developed magnetohydrodynamics (MHD)code and a commercial ANSYS-FLUENt code;the transport of chemical species was analyzed as including the chemical reactions of methane *** simulated results were verified by the comparison of calculated and measured arc voltages with permissible low error as under 4%.three C2 hydrocarbon gases with ethane (C2H6),ethylene (C2H4),and acetylene (C2H2)were selected as the converted species of methane from experimental *** mass fraction of C2 hydrocarbons and hydrogen as the product of the conversion reaction at the reactor was also *** values show good agreement with the actual experimental results in that the major conversion reaction occurred in C2H2 and hydrogen,and the conversions to C2H6,C2H4,and hydrogen were minor reactions of methane pyrolysis conversion.

关键词： numerical modelling non-transferred arc plasma methane chemical reaction

CONtINUOUS StIFFNesS MODE NANOINDENtAtION ResPONSE OF POLY(MEtHYL MEtHACRYLAtE) SURFACes

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Chinese journal of Polymer Science 2013年第8期31卷 1096-1107页

作者： t. Iqbal b.J. briscoe S. Yasin P.F. Luckham Chemical Engineering Department University of Engineering & Technology Chemical Engineering Department Imperial College

Indentation is a comparatively simple and virtually nondestructive method of determining mechanical properties of material surfaces by means of an indenter inducing a localized deformation. the paper present experimental results of the load-displacement curves, the hardness and the elastic modulus data, and associated analysis for poly（methyl methacrylate）（PMMA） surfaces as a function of contact displacement. the experimental results include continuous stiffness indentations performed using constant loading rate and constant displacement rate experiments. the continuous stiffness indentation involves continuous calculation of a material stiffness, and hence hardness and elastic modulus of surfaces, during discrete loading-unloading cycles, as in a conventional indentation routine, and in a comparatively smaller time constant, the dependence of the compliance curves, the hardness, the elastic modulus and the plasticity index upon the imposed penetration depth, the applied normal load and the deformation rate are described. tip area and load frame calibrations for the continuous stiffness indentation are also reported. the paper includes practical considerations encountered during indentation of polymers specifically at low penetration depths. the experimental results show a peculiarly harder response of PMMA surfaces at the submicron （near to surface） layers.

关键词： Nanoindentation PMMA Hardness Modulus Continuous stiffness.

ON tHE IDENtItIes OF bOL-MOUFANG tYPE

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Acta Mathematica Scientia 1987年第2期7卷 149-157页

作者： A.R.t.Solarin ,b.L.Sharma.

In this work we study properties of five identities of bol-Moufang type (1), which had received little or no attention. We establish a necessary and sufficient condition for a right alternative loop to be an RC-loop. A corollary to this is the condition for a bol loop to be an RC-loop. Some properties of a generalization of RC-loops are discussed. We also state the connection of the supernucleus M(G) of a loop G with various nucleii of loops which do not have the inverse property. Finally, we give some constructions of non-associative RC-loops of order 4n, where n is a positive even integer, which are not bol loops.

关键词： bOL ON tHE IDENtItIes OF bOL-MOUFANG tYPE

Late immune consequences of combat trauma: A review of trauma-related immune dysfunction and potential therapies

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Military Medical Research 2019年第4期6卷 340-353页

作者： Kelly b.thompson Luke t.Krispinsky Ryan J.Stark Division of Critical Care Medicine Department of PediatricsVanderbilt University School of Medicine2200 Children’s WayNashvilleTN 37232USA Division of Pediatric Critical Care Medicine Department of PediatricsUniformed Services UniversityNaval Medical Center PortsmouthPortsmouthVA 23708USA

With improvements in personnel and vehicular body armor,robust casualty evacuation capabilities,and damage control resuscitation strategies,more combat casualties are surviving to reach higher levels of care throughout the casualty evacuation *** such,medical centers are becoming more accustomed to managing the deleterious late consequences of combat trauma related to the dysregulation of the immune *** this review,we aim to highlight these late consequences and identify areas for future research and therapeutic *** leads to the dysregulation of both the innate and adaptive immune responses,which places the injured at risk for several late consequences,including delayed wound healing,late onset sepsis and infection,multi-organ dysfunction syndrome,and acute respiratory distress syndrome,which are significant for their association with the increased morbidity and mortality of wounded *** mechanisms by which these consequences develop are complex but include an imbalance of the immune system leading to robust inflammatory responses,triggered by the presence of damage associated molecules and other immune-modifying agents following *** strategies to improve outcomes have been difficult to develop as the immunophenotype of injured personnel following trauma is variable,fluid and difficult to *** more information regarding the triggers that lead to immune dysfunction following trauma is elucidated,it may be possible to identify the immunophenotype of injured personnel and provide targeted treatments to reduce the late consequences of trauma,which are known to lead to significant morbidity and mortality.

关键词： trauma Sepsis Compensatory anti-inflammatory response syndrome Persistent inflammationimmunosuppression and catabolism syndrome Immune dysfunction

Spatially biased dispersal of acorns by a scatter-hoarding corvid may accelerate passive restoration of oak habitat on California＇s largest island

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Current Zoology 2017年第4期63卷 363-367页

作者： Mario b. PesENDORFER t. sco.t SILLEtt sco.t A. MORRISON School of biological Sciences University of Nebraska - Lincoln 348 Manter Hall Lincoln NE 68588-0118 USA Migratory bird Center Smithsonian Conservation Biology Institute National Zoological Park MRC 5503 Washington D.C. 20013-7012 USA Cornell Lab of Ornithology 159 Sapsucker Woods Rd Ithaca NY 14850 USA the Nature Conservancy 4th Floor 201 Mission Street San Francisco CA 94105 USA

Scatter hoarding by corvids （crows, jays, magpies, and nutcrackers） provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germin- ation and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns （Quercus spp.） on Santa Cruz Island. We use a large behavioral data set on the birds＇ behavior in combination with seedling surveys and spatial analysis to determine whether 1） island scrub jays disproportionally cache seeds in specific habitat types, and 2） whether the preferred habitat type is suitable for oak regeneration. Our results show that the jays nonrandomly cache acorns across the landscape; they use chaparral and coastal sage scrub disproportionally while avoiding open and grassy areas. the areas used most often for caching were also the areas with the highest oak seedling densities. We discuss the potential role of these findings for the recovery of Santa Cruz Island＇s oak habitat since the 1980s.

关键词： Aphelocoma insularis directional dispersal habitat restoration Quercus spp. scatter hoarding seed dispersal.

Monarch butterfly Optimization for Reliable Scheduling in Cloud

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Computers, Materials & Continua 2021年第12期69卷 3693-3710页

作者： b.Gomathi S.t.Suganthi Karthikeyan Krishnasamy J.bhuvana Department of Information technology Hindusthan College of Engineering and TechnologyCoimbatore641032India Department of Computer Networking Lebanese French UniversityErbil44001Iraq Department of Information technology Coimbatore Institute of TechnologyCoimbatore641014India Department of MCA School of Computer Science and ITJain(Deemed to be)UniversityBangalore560069India

Enterprises have extensively taken on cloud computing environment since it provides on-demand virtualized cloud application *** scheduling of the cloud tasks is a well-recognized NP-hard *** task scheduling problem is convoluted while convincing different objectives,which are dispute in *** this paper,Multi-Objective Improved Monarch butterfly Optimization(MOIMbO)algorithm is applied to solve multi-objective task scheduling problems in the cloud in preparation for Pareto optimal *** different dispute objectives,such as makespan,reliability,and resource utilization,are deliberated for task scheduling *** Epsilonfuzzy dominance sort method is utilized in the multi-objective domain to elect the foremost solutions from the Pareto optimal solution ***,together with the Self Adaptive and Greedy Strategies,have been incorporated to enrich the performance of the proposed *** capability and effectiveness of the proposed algorithm are measured with NSGA-II and MOPSO *** simulation results prompt that the proposed MOIMbO algorithm extensively diminishes the makespan,maximize the reliability,and guarantees the appropriate resource utilization when associating it with identified existing algorithms.

关键词： Improved monarch butterfly optimization cloud computing makespan reliability fuzzy dominance task scheduling