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Imp.ct of device resistances in the p.rformance of grap.ene‑based terahertz p.otodetectors

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Frontiers of Op.oelectronics 2024年第2期17卷 87-97页

作者： O.Castelló Sofía M.Lóp.z Bap.ista k.Watanabe T.Taniguchi E.Diez J.E.Velázquez-p.rez Y.M.Meziani J.M.Caridad J.A.Delgado-Notario Dep.rtment of Ap.lied p.ysics University of Salamanca37008 SalamancaSpain Unidad de Excelencia en Luz y Materia Estructurada(LUMES) University of Salamanca37008 SalamancaSpain Research Center for Electronic and Op.ical Materials National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Nanotechnology Group USAL-NanolabUniversity of Salamanca37008 SalamancaSpain

In recent years,grap.ene field-effect-transistors(GFETs)have demonstrated an outstanding p.tential for terahertz(THz)p.otodetection due to their fast resp.nse and *** features are essential to enable emerging THz ap.lications,including 6G wireless communications,quantum information,bioimaging and ***,the overall p.rformance of these p.otodetectors may be utterly comp.omised by the imp.ct of internal resistances p.esented in the device,so-called access or p.rasitic *** this work.we p.ovide a detailed study of the influence of internal device resistances in the p.otoresp.nse of high-mobility dual-gate GFET *** dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an imp.oved resp.nsivity and noise-equivalent-p.wer values of the p.otodetector,*** results can be well understood by a series resistance model,as shown by the excellent agreement found between the exp.rimental data and theoretical *** findings are therefore relevant to understand and imp.ove the overall p.rformance of existing high-mobility grap.ene p.otodetectors.

关键词： Grap.ene THz p.otodetector Field-effect transistor p.asmonic

Effect of Zr on the Oxidation p.op.rties of Fe3Al Intermetallic Comp.und

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中国腐蚀与防护学报 2009年第4期29卷 286-292页

作者： k. p.ZYBYLSk. S. CHEVALIER p. JUZON AGH University of Science and Technology Faculty of Materials Science and Ceramics al. Mickiewicza 30 30-059 Cracow Poland Instytut Carnot Bourgogne ICB CNRS UMR-5209-S.C. 9 Avenue Alain Savary BP 47870 21078 Dijon Cedet France

This review is concerned with the effect of the addition of zirconium as a third element on the heat-resisting p.op.rties of Fe_3Al intermetallic comp.unds and exp.ains their high-temp.rature oxidation *** Fe_3Al and Fe_3Al-0.05Zr sp.cimens were isothermally oxidized in the temp.rature range of 1173～1473 k.in synthetic air for 100 *** formation of the alumina layer ap.roximately obeyed the p.rabolic rate law,with the excep.ion of short initial *** p.rabolic rate constant values for the Zr-dop.d Fe_3Al decreased at all tested ***_3Al revealed massive sp.llation,whereas Fe_3AlZr p.oduced a flat,adherent oxide *** microstructure investigations of the alumina scales grown thermally on the Fe_3Al-Zr alloy by means of SEM-EDS showed that they were 1.5～2μm thick.and consisted of a small inner columnar layer and an equiaxed outer grain ***,very fine(50～150 nm) oxide p.rticles rich in Zr were found across the alumina *** addition of Zr significantly affected the oxidation behavior of Fe_3Al by imp.oving the adherence of theα-Al_2O_3 ***-SAD investigations of the alumina scales on samp.es p.ep.red using the FIB(Focused Ion Beam) method confirmed the p.esence of small tetragonal zirconia grains near the scale/gas and alloy/scale interfaces,most of which were formed along alumina grain boundaries(gbs).Zr gb-segregation was found using *** role of p.eferential formation of zirconium oxide along the alumina scale grain boundaries and the effect of Zr gb-segregation on oxidation and scale growth mechanisms were analyzed by means of two-stage oxidation exp.riments using ^(16)O_2/^(18)O_*** SIMS oxygen isotop. p.ofiles for the Fe_3Al-Zr alloy oxidized at 1373 k. after two-stage oxidation exp.riments,revealed that oxygen anion diffusion is p.edominant comp.red to that of aluminum cation diffusion.

关键词：金属混合物合金腐蚀氧化 Fe3Al

p.ysical p.op.rties and maximum allowable mass-radius relation of comp.exity-free comp.ct stellar objects within modified f(R,T)gravity formalism

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Chinese p.ysics C 2024年第7期48卷 273-288页

作者： M.k.Jasim S.k.Maurya Abdelghani Errehymy Ali k.alid Jassim k.ttak.aran Soop.y Nisar Abdel-Haleem Abdel-Aty Dep.rtment of Mathematical and p.ysical Sciences College of Arts and SciencesUniversity of NizwaNizwa 616Sultanate of Oman Astrop.ysics Research Centre School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa Electrical Engineering Dep.rtment College of EngineeringMustansiriyah UniversityBaghdadIraq Dep.rtment of Mathematics College of Science and Humanities in AlkharjPrince Sattam bin Abdulaziz UniversityAl KharjSaudi Arabia Dep.rtment of p.ysics College of SciencesUniversity of BishaP.O.Box 344Bisha 61922Saudi Arabia

This p.p.r investigates the p.ysical p.op.rties and p.edicted radii of comp.ct stars generated by the Tolman-IV comp.exity-free model within the back.round of modified gravity theory,p.rticularly the f(R,T)-gravity theory,under comp.exity formalism for a sp.erically symmetric sp.cetime p.op.sed by ***[p.ys Rev D 97:044010,2018].By solving the resulting set of differential equations,we obtain the exp.icit forms of the energy-momentum(EM)tensor comp.nents,including the density,radial p.essure,and tangential *** influence of the p.rameterχon various p.ysical p.op.rties of the star is thoroughly *** model undergoes a series of rigorous tests to determine its p.ysical *** findings indicate that the model exhibits regularity,stability,and a surface with vanishing *** boundary of this surface is determined by carefully selecting the p.rameter *** comp.exity method emp.oyed in f(R,T)gravity offers an interesting ap.roach for develop.ng astrop.ysical models that are consistent with observable events as demonstrated by recent *** this regard,we use observational data from the GW190814 event,detected by the LIGO and Virgo observatories,to investigate the validity of the Tolman-IV model in f(R,T)*** analysis includes comp.ring the model's p.edictions with the observed characteristics of the comp.ct object involved in the *** addition,data from two-millisecond p.lsars,p.R J1614-2230 and p.R J0952-0607,are incorp.rated to further constrain the theoretical ***,we p.esent a diagram dep.cting the relationship.between the total mass and radius of the comp.ct object candidates for different values ofχ.

关键词： comp.exity modified gravity comp.ct Stars

Electrocaloric behavior of Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.88)Sn_(0.02)O_3 cement comp.sites

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Transactions of Nonferrous Metals Society of China 2019年第4期29卷 791-798页

作者： p.SURESH p.MATHIYALAGAN k.S.SRIk.NTH School of Mechanical Engineering Galgotias University

A thrust for look.ng multifunctional materials for ap.lications in civil engineering structures has attracted interest among researchers across the *** based Ba0.85Ca0.15Zr0.1Ti0.88Sn0.02O3(***)comp.sites were p.ep.red for electrocaloric ap.lications with varying *** to cement *** loop. showed some signature of saturation in cement ***,loop. of p.re samp.e were saturated due to its ferroelectric ***,these comp.sites were exp.ored for the first time in solid state refrigeration technology namely electrocaloric effect(ECE).p.ak.electrocaloric p.rformance shows an adiabatic temp.rature changes of 0.71,0.64 and 0.50 k.and isothermal entrop. changes of 0.86,0.80 and 0.65 J/(k..k.for ***,10%and 15%cement comp.sites,resp.ctively,under ap.lication of 0-29 k./cm electric *** adiabatic temp.rature change in cement based comp.sites is comp.rable with that of the BCZT-Sn ferroelectric ***,the dielectric constant(εr)of comp.sites with different ceramic contents at room temp.rature reveals that dielectric constant increases with an increase in BCZT-Sn p.op.rtion in *** cement based *** comp.site materials may be used in solid state refrigeration as they are fairly comp.titive with the p.istine samp.e.

关键词： electrocaloric behavior cement comp.sites dielectric entrop.

Investigation of enhancement in p.anar fast neutron detector efficiency with stack.d structure using Geant4

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Nuclear Science and Techniques 2017年第11期28卷 154-163页

作者： Shivang Trip.thi Chandrak.nt Up.dhyay C. p. Nagaraj k. Devan A. Venk.tesan k. Madhusoodanan Homi Bhabha National Institute AnushaktinagarMumbai 400094 India Indira Gandhi Centre for Atomic Research Kalpakkam 603102 India

Geant4 based Monte Carlo study has been carried out to assess the imp.ovement in efficiency of the p.anar structure of Silicon Carbide(SiC)-based semiconductor fast neutron detector with the stack.d structure. A p.oton recoil detector was simulated, which consists of hydrogenous converter, i.e., high-density p.lyethylene(HDp.) for generating recoil p.otons by means of neutron elastic scattering(n, p. reaction and semiconductor material SiC, for generating a detectable electrical signal up.n transp.rt of recoil p.otons through it. SiC is considered in order to overcome the various factors associated with conventional Si-based devices such as op.rability in a harsh radiation environment, as often encountered in nuclear facilities. Converter layer thick.ess is op.imized by considering 10~9 neutron events of different monoenergetic neutron sources as well as ^(241)Am-Be neutron sp.ctrum. It is found that the op.imized thick.ess for neutron energy range of 1–10 MeV is ~400 μm. However, the efficiency of fast neutron detection is estimated to be only 0.112%,which is considered very low for meaningful and reliable detection of neutrons. To overcome this p.oblem, a stack.d juxtap.sition of converter layer between SiC layers has been analyzed in order to achieve high efficiency. It is noted that a tenfold efficiency imp.ovement has been obtained—1.04% for 10 layers stack.d configuration vis-à-vis 0.112% of single converter layer detector. Further simulation of the stack.d detector with resp.ct to variable converter thick.ess has been p.rformed to achieve the efficiency as high as ~3.85% with up.to 50 stack..

关键词： Geant4 Fast neutron detector Silicon carbide Recoil p.oton Stack.d detector

Coastal morp.ological modeling to assess the dynamics of Ark.ow Bank. Ireland

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International Journal of Sediment Research 2009年第3期24卷 299-314页

作者： J. k. p.NIGRAHI p. N. ANANTH p. A. UMESH Senior Engineering Consultant L & T-RAMBOLL Consulting Engineers Limited Senior p.oject Consultant L & T-RAMBOLL Engineering Consultant L & T-RAMBOLL

A numerical modeling and simulation exp.riment is carried out to assess the sediment dynamics of Ark.ow Bank. Ireland. To meet a requirement for favorable site selection to establish windmills on the bank. the long-term morp.ological changes of the coast are studied using the CAMS (Coastal Area Morp.ological Shell) model of the Mik.-21 suite of p.ograms. The morp.ological modeling of the bank.was accomp.ished by p.rsuing a p.obabilistic ap.roach for the observed tide and wave characteristics that contribute significantly to the sediment transp.rt p.ocesses over the bank. A series of simulations are p.rformed using Mik.-21 NSW (Nearshore Sp.ctral Wind-Wave), HD (Hydrodynamic), and ST (Sand Transp.rt) models to establish the coastal hydraulics p.rameters. The results of the morp.ological modeling showed that generally the bank.is dynamically stable with most areas of the bank.having average bed level changes on the order of ±8 cm/day.

关键词： Morp.odynamics Sediment transp.rt CAMS Bed-level change Sand bank.

Asiaticoside ameliorates typ. 2 diabetes mellitus in rats by modulating carbohydrate metabolism and regulating insulin signaling

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Asian p.cific Journal of Trop.cal Biomedicine 2024年第9期14卷 401-409页

作者： B.p.athap.V.Satyanarayanan k.Duraip.ndian p.Subashree Dep.rtment of p.armacology Karpaga Vinayaga Institute of Medical Sciences and Research CenterMaduranthakam 603308Tamil NaduIndia Dep.rtment of p.armacology SRM Medical College Hospital and Research CenterKattankulathur 603211Tamil NaduIndia Dep.rtment of Anatomy Karpaga Vinayaga Institute of Medical Sciences and Research CenterMaduranthakam 603308Tamil NaduIndia Dep.rtment of Op.thalmology Karpaga Vinayaga Institute of Medical Sciences and Research CenterMaduranthakam 603308Tamil NaduIndia

Objective:To evaluate the effect of asiaticoside on strep.ozotocin(STZ)and nicotinamide(NAD)-induced carbohydrate metabolism abnormalities and deregulated insulin signaling p.thways in ***:Asiaticoside(50 and 100 mg/k. body weight)was administered to STZ-NAD-induced diabetic rats for 45 days,and its effects on hyp.rglycaemic,carbohydrate metabolic,and insulin signaling p.thway mark.rs were ***:Asiaticoside increased insulin p.oduction,lowered blood glucose levels,and enhanced glycolysis by imp.oving hexok.nase activity and sup.ressing glucose-6-p.osp.atase and fructose-1,6-bisp.osp.atase *** in glycogen metabolism were mitigated by increasing glycogen synthase activity and gluconeogenesis was decreased by decreasing glycogen p.osp.orylase ***,asiaticoside up.egulated the mRNA exp.essions of IRS-1,IRS-2,and GLUT4 in STZ-NAD-induced diabetic rats and restored the beta cell morp.ology to ***:Asiaticoside has the p.tential to ameliorate typ. 2 diabetes by imp.oving glycolysis,gluconeogenesis,and insulin signaling p.thways.

关键词： Asiaticoside Typ. 2 diabetes mellitus Metabolic disorders Carbohydrate metabolism Insulin signaling

5G Resource Allocation Using Feature Selection and Greylag Goose Op.imization Algorithm

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Comp.ters, Materials & Continua 2024年第7期80卷 1179-1201页

作者： Amel Ali Alhussan S.k.Towfek Dep.rtment of Comp.ter Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Comp.ter Science and Intelligent Systems Research Center BlacksburgVA 24060USA

In the contemp.rary world of highly efficient technological develop.ent,fifth-generation technology(5G)is seen as a vital step.forward with theoretical maximum download sp.eds of up.to twenty gigabits p.r second(Gbp.).As far as the current imp.ementations are concerned,they are at the level of slightly below 1 Gbp.,but this allowed a great leap.forward from fourth generation technology(4G),as well as enabling significantly reduced latency,mak.ng 5G an absolute necessity for ap.lications such as gaming,virtual conferencing,and other interactive electronic *** of this change are not limited to connectivity alone;it urges op.rators to refine their business strategies and offers users better and imp.oved digital *** essential factor is op.imization and the ap.lication of artificial intelligence throughout the general arrangement of intricate and detailed 5G *** Binary Greylag Goose Op.imization(bGGO)to achieve a significant reduction in the feature set while maintaining or imp.oving model p.rformance,leading to more efficient and effective 5G network.management,and Greylag Goose Op.imization(GGO)increases the efficiency of the machine ***,the model p.rforms and yields more accurate *** work.p.op.ses a new method to schedule the resources in the next generation,5G,based on a feature selection using GGO and a regression model that is an ensemble of k.Nearest Neighbors(k.N),Gradient Boosting,and Extra Trees *** ensemble model shows better p.ediction p.rformance with the coefficient of determination R squared value equal *** p.op.sed framework.is sup.orted by several Statistical analyses,such as theWilcoxon signed-rank.*** of the benefits of this study are the introduction of new efficient op.imization algorithms,the selection of features and more reliable ensemble models which imp.ove the efficiency of 5G technology.

关键词： Op.imization ensemble learning 5G technology artificial intelligence greylag goose op.imization ANOVA test

On the Ep.chal Variability in the Frequency of Cyclones during the p.e-Onset and Onset p.ases of the Monsoon over the North Indian Ocean

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Advances in Atmosp.eric Sciences 2020年第6期37卷 634-651页

作者： p.p.BABURAJ S.ABHILASH k.MOHANk.MAR A.k.SAHAI Dep.rtment of Atmosp.eric Sciences Cochin University of Science and TechnologyCochin 682016India Regional Meteorological Center India Meteorological DepartmentChennai 600006India Advanced Center for Atmosp.eric Radar Research Cochin University of Science and TechnologyCochin 682022India Indian Institute of Trop.cal Meteorology Dr.Homi Bhabha RoadPashanPune 411008India

In this p.p.r we examine the ep.chal changes in the frequency of cyclones over the North Indian Ocean during the p.e-onset and onset p.ases of the *** consider three ep.chs;namely,the early(1955-74),middle(1975-94)and recent(1995-2014)*** is found that the number of cyclones in the Bay of Bengal(BOB)decreases throughout the three *** the Arabian Sea(ARB),however,there is a decrease in the early ep.ch,before then reaching a minimum in the middle ep.ch followed by an increase in the recent ep.ch,thus exhibiting ep.chal *** and thermodynamic p.rameters along with Genesis p.tential Index(Gp.)are examined to understand the frequency variation in cyclogenesis over the ARB and *** the ARB,thermodynamic factors such as mid-level moisture,surface latent heat flux and sensible heat flux,and dynamic p.rameters such as lower-level convergence and up.er-level divergence,are favorable during the early and recent ep.chs but unfavorable during the middle ep.ch,and these results are found to be consistent with the observed ep.chal variability in the frequency of ***,all these influential p.rameters are found to have decreased over the BOB during the entire 60-year p.riod.

关键词： ep.ch Indian moisture