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Tri-directional shaking table tests of vibration sensitive equipment with static dynamics interchangeable-ball pendulum system

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Earthquake Engineering and Engineering Vibration 2010年第1期9卷 103-112页

作者： C.s. Tsai Yung-Chang Lin Wen-shin Chen H.C. su D G epartment of Civil Engineering Feng Chia University Taichung Chinese Taipei Graduate Institute of Civil and Hydraulic Engineering Feng Chia University Taichung Chinese Taipei Department of Water Resources Engineering and Conservation Feng Chia University Taichung Chinese Taipei

Recently, the high-tech industry has become a key industry for economic development in many countries. However, vibration sensitive equipment located in these industrial buildings is vulnerable during earthquakes, which may cause huge economic loss. In this study, an innovative isolator for safeguarding the vibration sensitive equipment, namely, the static dynamics interchangeable^all pendulum system （sDI-BPs） is proposed and investigated to examine its protective capability for the vibration sensitive equipment during earthquakes through a series of tri-directional shaking table tests. The experimental results illustrate that the sDI-BPs isolator can provide significant damping to rolling types of base isolation systems for reducing the bearing displacement and size, and avoid the stress concentration, which can cause damage or scratches on the rolling surface of the isolator, to prolong its life span of service. The sDI-BPs isolator also provides excellent capability in protecting the vibration sensitive equipment and exhibits a stable behavior under long terms of service loadings and earthquakes.

关键词： ball pendulum system critical equipment base isolation vibration sensitive equipment base isolator passive control earthquake engineering structural control

Tunable ferroelectricity in oxygen-deficient perovskites with Grenier structure

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npj Computational Materials 2023年第1期9卷 118-125页

作者： Yongjin shin Giulia Galli Pritzker school of Molecular Engineering University of ChicagoChicagoIL 60637USA Department of Chemistry University of ChicagoChicagoIL 60637USA Center for Molecular Engineering and Materials science Division Argonne National LaboratoryLemontIL 60439USA

using first-principles calculations,we predict that tunable ferroelectricity can be realized in oxide perovskites with the Grenier structure and ordered oxygen ***,we show that R_(1/3)A_(2/3)FeO_(2.67) solids(where R is a rare-earth ion and A an alkaline-earth cation)exhibit polar phases,with a spontaneous polarization tunable by an appropriate choice of R and *** find that larger cations combined with small R elements lead to a maximum in the polarization and to a minimum in the energy barriers required to switch the sign of the *** arises from cooperative distortions of octahedral and tetrahedral units,where a combination of rotational and sliding modes controls the emergence of polarization within three-dimensional connected *** results indicate that polar Grenier phases of oxide perovskites are promising materials for microelectronic applications and,in general,for the study of phenomena emerging from breaking inversion symmetry in solids.

关键词： polarization ferroelectric structure

Dynamic Recrystallization and Texture Evolution of GW94 Mg Alloy During Multi-and unidirectional Impact Forging

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Acta Metallurgica sinica(English Letters) 2018年第9期31卷 923-932页

作者： s.s.A.shah M.G.Jiang D.Wu u.Wasi R.s.Chen The Group of Magnesium Alloys and Their Applications Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China university of Chinese Academy of sciences Beijing 100049China school of Materials science and Engineering University of Science and Technology of ChinaHefei 230026China

Multi- and unidirectional impact forgings were successfully applied to a （GW94） Mg-RE alloy. The microstructure and texture evolution were investigated systematically. The obtained results indicated that during unidirectional impact forging, a bimodal chain deform microstructure was sustained till last forging pass, whereas { 10-12} extension twins-assisted continuous dynamic recrystallization took place during the multidirectional impact forging （MDIF）. The coalescence and intersection of {10-12} extension twins during MDIF efficiently refined the original coarse grains and led to an almost recrystallized homogeneous microstructure. The texture analysis demonstrated that unidirectional impact forging yielded out the strong basal texture; however, MDIF resulted in non-basal texture, which was attributed to the cooperative effects of continuous DRX, twinning, and MDIF itself during the deformation process.

关键词： Magnesium alloys Forging Twinning Recrystallization Texture

The Blood Flow of Prandtl Fluid Through a Tapered stenosed Arteries in Permeable Walls with Magnetic Field

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Communications in Theoretical Physics 2015年第3期63卷 353-358页

作者： R.Ellahi s.u.Rahman s.Nadeem K.Vafai Department of Mechanical Engineering University of California Riverside Department of Mathematics and statistics Faculty of Basic Applied sciences International Islamic University Department of Mechatronics University of Engineering and Technology TexilaChakwal Campus Department of Mathematics Quaid-i-Azam University

This Communication deals with the blood flow of Prandtl fluid through a tapered stenosed arteries having permeable *** governing equations of two-dimensional Prandtl fluid model are modelled in cylindrical *** highly nonlinear equations are simplified with the help of non-dimensional variables under the assumption of mild *** solution of reduced nonlinear equation subject to boundary condition of porous walls having the effects of Darcy's number and slip parameter are computed analytically with the help of perturbation *** of emerging parameters such as impedance A,slip parameter a,stenosis height 6,magnetic parameter and stress component srz on velocity are illustrated *** streamlines have also been presented to discuss the trapping bolus discipline.

关键词： Prandtl fluid magnetic field blood flow tapered stenosed arteries permeable walls analytical solutions

Petrology and geochemical characteristics of Precambrian granitic basement complex rocks in the southernmost part of North-Central Nigeria

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Chinese Journal Of Geochemistry 2009年第4期28卷 377-385页

作者： Obiora s.C. ukaegbu V.u. National Geophysical Research Institute Geological Studies DivisionUppal Road Hyderabad-500007 India Department of Geology University of NigeriaNsukka Nigeria Department of Geology University of Port HarcourtPort Harcourt Nigeria

The Precambrian basement complex in the southernmost part of North-Central Nigeria is underlain by migmatitic banded gneisses, granitic intrusions and dykes of dolerite, rhyolite porphyry and pegmatite. The rocks are generally felsic, containing modal and normative hypersthene, as well as normative corundum. The basement complex has experienced high-grade regional metamorphism as indicated by the presence of hypersthene and plagioclase of andesine composition. Anatectic melting is suggested by the occurrence of ptygmatic folds, folded gneissose foliation, numerous quartzo-feldspathic veins and lenses of dark-colured, micaceous schistose rocks. Geochemically, the rocks have magnesian, calc-alkalic and strongly peraluminous characteristics. Their overall characteristics suggest derivation from progressive (fractional) partial melting of pelitic rocks during high-grade regional metamorphism, possibly associated with intense hydrothermal activities. The magnesian characteristics reflect close affinity to relatively hydrous, oxidizing melts and source regions in settings broadly related to subduction.

关键词：岩石地球化学特征前寒武纪基底尼日利亚花岗岩中央区域变质作用流纹斑岩叶状结构

Influence of cold plasma treatment on insecticidal properties of wheat seeds against red flour beetles

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Plasma science and Technology 2019年第8期21卷 97-102页

作者： s AFsHEEN u FATIMA T IQBAL M ABRAR s MuHAMMAD A sAEED M IsA M F MALIK s sHAMAs Department of Zoology Faculty of ScienceUniversity of GujratHafiz Hayat CampusGujrat50700Pakistan Department of Physics Faculty of ScienceUniversity of GujratHafiz Hayat CampusGujrat50700Pakistan3Department of PhysicsHazara University MansehraMansehra21300Pakistan4Department of PhysicsGovernment College Women UniversitySialkot51310Pakistan

For the long-term fortification of warehoused crops, the insecticidal impact of cold plasma treated wheat seeds against red flour beetles are *** this study, the gain weight loss,mortality and repellency tests of cold plasma treated seeds are investigated and statistical analysis is carried out by sPss *** plasma treatment is carried out at 800 V for 1 and 4 *** results show that the minimum grain weight loss is observed in plasma treated seeds as compared to controlled *** is also observed that the mortality rate is minimum in the controlled seed while maximum at 4 min plasma ***, the repellent effect has a very small variation as compared to the controlled seed for Tribolium ***, plasma treatment can be considered as a practical and effective method for seed protection against red floor beetles particularly during long-term storage by controlling the insecticidal effects.

关键词： cold plasma mortality repellency grain weight loss quality stored seeds protection

Heat transfer on peristaltic flow of fourth grade fluid in inclined asymmetric channel with partial slip

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Applied Mathematics and Mechanics(English Edition) 2012年第10期33卷 1313-1328页

作者： O.u.MEHMOOD N.MusTAPHA s.sHAFIE Department of Mathematics Faculty of ScienceUniversiti Teknologi Malaysia81310 UTM JohorJohor BharuMalaysia

In this paper, the effects of slip and heat transfer are studied on the peristaltic transport of a magnetohydrodynamic （MHD） fourth grade fluid. The governing equations are modeled and solved under the long wavelength approximation by using a regular perturbation method. Explicit expressions of solutions for the stream function, the velocity, the pressure gradient, the temperature, and the heat transfer coefficient are presented. Pumping and trapping phenomena are analyzed for increasing the slip parameter. Further, the temperature profiles and the heat transfer coefficient are observed for various increasing parameters. It is found that these parameters considerably affect the considered flow characteristics. Comparisons with published results for the no-slip case are found in close agreement.

关键词： peristaltic flow fourth grade fluid heat transfer slip condition inclinedchannel

Cross-Domain Bilateral Access Control on Blockchain-Cloud Based Data Trading system

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Computer Modeling in Engineering & sciences 2024年第10期141卷 671-688页

作者： Youngho Park su Jin shin sang uk shin Electronics and Information Communications Research Center Pukyong National UniversityBusan48513Republic of Korea Department of Information security Graduate SchoolPukyong National UniversityBusan48513Republic of Korea Division of Computer Engineering Pukyong National UniversityBusan48513Republic of Korea

Data trading enables data owners and data requesters to sell and purchase *** the emergence of blockchain technology,research on blockchain-based data trading systems is receiving a lot of ***,to reduce the on-chain storage cost,a novel paradigm of blockchain and cloud fusion has been widely considered as a promising data trading ***,the fact that data can be used for commercial purposes will encourage users and organizations from various fields to participate in the data *** the data marketplace,it is a challenge how to trade the data securely outsourced to the external cloud in a way that restricts access to the data only to authorized users across multiple *** this paper,we propose a cross-domain bilateral access control protocol for blockchain-cloud based data trading *** consider a system model that consists of domain authorities,data senders,data receivers,a blockchain layer,and a cloud *** proposed protocol enables access control and source identification of the outsourced data by leveraging identity-based cryptographic *** the proposed protocol,the outsourced data of the sender is encrypted under the target receiver’s identity,and the cloud provider performs policy-match verification on the authorization tags of the sender and receiver generated by the identity-based signature ***,data trading can be achieved only if the identities of the data sender and receiver simultaneously meet the policies specified by each *** demonstrate efficiency,we evaluate the performance of the proposed protocol and compare it with existing studies.

关键词： Bilateral access control blockchain data sharing policy-match

In search of a pan-coronavirus vaccine:next-generation vaccine design and immune mechanisms

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Cellular & Molecular Immunology 2024年第2期21卷 103-118页

作者： s.Cankat M.u.Demael L.swadling Division of Infection and Immunity Institute of Immunity and TransplantationUniversity College LondonPears BuildingLondon NW32PPUK

Members of the coronaviridae family are endemic to human populations and have caused several epidemics and pandemics in recent *** this review,we will discuss the feasibility of and progress toward the ultimate goal of creating a pan-coronavirus vaccine that can protect against infection and disease by all members of the coronavirus *** will detail the unmet clinical need associated with the continued transmission of sARs-CoV-2,MERs-CoV and the four seasonal coronaviruses(HCoV-OC43,NL63,HKu1 and 229E)in humans and the potential for future zoonotic *** will highlight how first-generation sARs-CoV-2 vaccines and natural history studies have greatly increased our understanding of effective antiviral immunity to coronaviruses and have informed next-generation vaccine *** will then consider the ideal properties of a pan-coronavirus vaccine and propose a blueprint for the type of immunity that may offer ***,we will describe a subset of the diverse technologies and novel approaches being pursued with the goal of developing broadly or universally protective vaccines for coronaviruses.

关键词： Vaccine Coronavirus Cross-reactive immunity Cross-protection universal