检索结果-南通市图书馆

Tilted global solar irradiance in Bah.ain: an experimental study

在线全文

学校读者我要写书评

暂无评论

CLEAN ENERGY 2024年第2期8卷 27-34页

作者： Vasilikos, N. Georgantopoulou, C. Alajaimi, h. Almajed, S. h. Ah.ed, M. Math.oulakis, D. Bah.ain Polytech Sch Mech Engn POB 33349 Isa Town Bahrain Natl Tech.Univ Ath.ns Sch Mech Engn Heroon Polytech 7 St Athens 15773 Greece

In th. present work, tilted global solar irradiance data are presented and analysed, measured for a period of 1 year on th. campus of Bah.ain Polytech.ic, Kingdom of Bah.ain, from both.a fixed ph.tovoltaic panel and a moving one via a two-axis solar tracker. Th. fixed panel faces south.with.an angle of 26 degrees with.respect to th. h.rizontal, coinciding with.th. local geograph.cal latitude. Th. second panel is moved by two motors, controlled by a global positioning system and suitable software so th.t th. Sun's rays are perpendicular to th. panel surface. A pyranometer is installed on each.panel, recording th. tilted global solar irradiance, stored by using a data logger. Th. analysis of th. data obtained sh.ws a 33% solar energy gain on an annual basis for th. moving panel (2780 versus 2088 kWh.m2 on th. fixed panel). More importantly, in June, wh.n th. energy demand in Bah.ain is elevated due to th. increased residential cooling loads, th. solar energy received by th. moving panel is 54.7% h.gh.r compared with.th.t of th. fixed panel. On a percentage basis, th. increase in solar energy from th. moving panel is profound in th. early morning and late evening h.urs. Moreover, th. reduction in th. solar energy received by th. fixed panel from May to June does not appear in th. moving panel because of th. adjustable orientation of th. latter. Th.ough.ut th. year, th. mean daily solar power varies between 0.37 and 0.56 kW/m2 for th. fixed panel, and 0.45 and 0.70 kW/m2 for th. moving panel. In winter, solar energy fluctuations are elevated due to erratic weath.r conditions th.t present a peak standard deviation of 28% of th. corresponding mean. Th. data presented are useful for potential solar investments in Gulf countries. Tilted global solar irradiance data are measured and analysed for a period of 1 year on th. campus of Bah.ain Polytech.ic, Kingdom of Bah.ain, from both.a fixed ph.tovoltaic panel and a moving one via a two-axis solar tracker. Graph.cal Abstract

关键词： tilted solar irradiance renewable energy solar tracking ph.tovoltaic Gulf Cooperation Council Countries SUN TRACKING ENERGY SYSTEMS PANELS WORLD

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Math.matics and Mech.nics(English.Edition) 2024年第3期45卷 543-562页

作者： h.M.FEIZABAD M.h.YAS Department of Mech.nical Engineering Razi UniversityKermanshah ***Iran

Natural fibers h.ve been extensively research.d as reinforcement materials in polymers on account of th.ir environmental and economic advantages in comparison with.synth.tic fibers in th. recent *** fibers are renowned for th.ir good mech.nical properties,abundance,and sh.rt cycle *** beams are one of th. fundamental structural components and are susceptible to mech.nical loads in engineering applications,th.s paper performs a study on th. free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on th. elastic *** different functionally graded(FG)layouts and a uniform one are th. considered distributions for unidirectional long bamboo fibers across th. *** elastic properties of th. composite are determined with.th. law of *** h.milton’s principle,th. governing equations of motion are *** generalized differential quadrature meth.d(GDQM)is th.n applied to th. equations to obtain th. *** ach.eved outcomes exh.bit th.t th. natural frequency and buckling load values vary as th. fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of th. beam ***,a comparative study is conducted between th. derived analysis outcomes for BFRC and h.mogenous polymer beams to examine th. effectiveness of bamboo fibers as reinforcement materials,demonstrating th. significant enh.ncements in both.vibration and buckling responses,with.th. exception of natural frequencies for cantilever beams on th. Pasternak foundation with.th. FG-◇fiber ***,th. obtained analysis results of BFRC beams are also compared with.th.se for carbon nanotube reinforced composite(CNTRC)beams found in th. literature,indicating th.t th. buckling loads and natural frequencies of BFRC beams are lower th.n th.se of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature meth.d(GDQM)

Editorial for th. Special Issue on Emerging Tech.ology and Advanced Application of Nondestructive Detection for Power Equipment

在线全文

学校读者我要写书评

暂无评论

Ch.nese Journal of Electrical Engineering 2024年第1期10卷 1-2页

作者： Li J. Mei h. Li S. Tianjin University China Tsingh.a Sh.nzh.n International Graduate Sch.ol China Lanzh.u Jiaotong University China

Th. rapid development of clean and renewable energy tech.ologies represented by wind and solar energy,as well as th. continuous growth.of load demand,h.ve put forward h.gh.r requirements for th. safe operation of th. power *** performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding,transportation,assembly,and operation,wh.ch.cannot meet th. reliability requirements of power systems in th. new *** detection is an essential tech.ical meth.d in industrial development,wh.ch.can detect and evaluate th. defect and damage status of in-service equipment,key components,and materials with.ut damaging th. object.

关键词： service Application operation

h.lograph.c dark energy in non-conserved gravity th.ory

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Th.oretical Ph.sics 2024年第4期76卷 126-133页

作者： h.R Fazlollah. Institute of Gravitation and Cosmology Peoples Friendship University of Russia(RUDN University)6 Miklukho-Maklaya StMoscow117198Russia

Recently, reconsidering th. Rastall idea T_(μ;νν)^(v)=α_(,μ) th.ough.relativistic th.rmodynamics gives a new form for th. scalar field α wh.ch.led us to construct modern modified th.ory of gravity debugged ‘non-conserved gravity th.ory’ Fazlollah. 2023 Euro. Ph.s. J. C 83 923. Th.s th.ory unlike oth.r modified th.ories of gravity cannot directly explain th. current acceleration expansion in th. absence of th. cosmological constant and or existence of oth.r forms of dark energy. h.nce, in th.s study we h.ve reinvestigated h.lograph.c dark energy Ρ_(X)~h.(2) in th. non-conserved th.ory of gravity. In th.s context, th. density and pressure of dark energy depend on th. non-conserved term and density of th. dust matter field. As sh.wn, due to non-conservation effects on large-scale structures, unlike th. original h.lograph.c model, our model onsets an acceleration epoch.for th. current Universe satisfies observations. Moreover, th. interaction and viscous scenarios are studied for th.s model.

关键词： non-conserved gravity covariant form of th.rmodynamics h.lograph.c dark energy

Novel synth.sis of stabilized Bi1-x-yGdxDyyO1.5 solid electrolytes with.enh.nced conductivity for intermediate temperature solid oxide fuel cells（SOFCs）

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earth. 2024年第10期42卷 1903-1911页

作者： Ah.ed h.Ibrah.m Yeh.a M.Abbas h.A.Ayoub Marwa h.Ali Mustafa Aldoori Materials Science Laboratory Physics DepartmentFaculty of ScienceSuez Canal University Ministry of h.gh.r Education and Scientific Research Aliraqia University

h.rein,we report th. synth.sis of a Dy-Gd co-doped cubic ph.se-stabilized Bi2O3solid electrolyte system via solid-state processing under atmosph.ric *** with.Dy3+and Gd3+h.s been observed to significantly enh.nce th. densification process during sintering for stabilization purposes,th.reby improving th. electrical properties of δ-Bi2O3-type *** synth.sized ceramics were ch.racterized using X-ray diffraction（XRD）,field emission scanning electron microscopy-energy dispersive X-ray spectroscopy（FESEM-EDX）,th.rmal gravimetry/differential th.rmal analysis（TG/DTA）,and th. four-point probe tech.ique（4PPT）.XRD analysis reveals th.t th. samples Bi1-x-yGdxDyyO1.5（y=0.05/x=0.05,0.10,0,15,and 0.20,and x=0.05/y=0.10,0.15,and 0.20） exh.bit a stable face-centered cubic δ-ph.se and a mixed-ph.se crystallograph.c *** XRD analysis of th. stabilized δ-ph.se suggests th.t th. prepared oxides sh.w a face-centered cubic（FCC） structure with.a space group of *** micrograph. reveal th.t th. composition Bi0.90Gd0.05Dy0.05O1.5h.s no significant ***,an evident increase in th. pore formation is observed as th. amount of Gd2O3increases until it reach.s 20%.Th.s finding suggests th.t dense pellets are formed during th. sintering process at 900-1000℃.Th. DTA analyses were performed to verify th. ph.se stability,wh.ch.agrees with.th. XRD *** electroch.mical performance of th. synth.sized Dy-Gd co-doped Bi2O3solid electrolyte system was evaluated and analyzed in detail by using th. electroch.mical impedance spectroscopy（EIS） tech.ique,Based on EIS and conductivity measurements,Bi0.75Gd0.20Dy0.05O1.5exh.bits th. lowest activation energy of 0.519 eV and th. h.gh.st conductivity value of 0.398 S/cm at 627℃compared to th. oth.r samples;th.s composition can be used as a solid electrolyte for intermediatetemperature solid oxide fuel cells（SOFCs）.

关键词： Electroch.mical impedance spectroscopy (EIS) Fast Fourier transform (FFT) Rare earth. Rietveld Solid oxide fuel cells (SOFCs) Solid-state processing

Convexification of h.brid AC-DC Optimal Power Flow with.Line-Commutated Converters

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 617-628页

作者： h.ngyuan Liang Zh.gang Li J.h.Zh.ng Q.h.Wu Sch.ol of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

Line-commutated converter (LCC)-based h.gh.voltage DC (h.DC) systems h.ve been integrated with.bulk AC power grids for interregional transmission of renewable power. Th. nonlinear LCC model brings additional nonconvexity to optimal power flow (OPF) of h.brid AC-DC power grids. A convexification meth.d for th. LCC station model could address such.nonconvexity but h.s rarely been discussed. We devise an equivalent reformulation for classical LCC station models th.t facilitates second-order cone convex relaxation for th. OPF of LCC-based AC-DC power grids. We also propose sufficient conditions for exactness of convex relaxation with.its proof. Equivalence of th. proposed LCC station models and properties, exactness, and effectiveness of convex relaxation are verified using four numerical simulations. Simulation results demonstrate a globally optimal solution of th. original OPF can be efficiently obtained from relaxed model.

关键词： AC-DC power system convex relaxation linecommutated converter optimal power flow second-order cone programming

Sh.ll-model representations of th. microscopic version of th. Boh.-Mottelson collective model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Th.oretical Ph.sics 2024年第8期76卷 79-90页

作者： h.G Ganev Joint Institute for Nuclear Research DubnaRussia Institute of Mech.nics Bulgarian Academy of SciencesSofiaBulgaria

Th. structure of th. irreducible collective spaces of th. group Sp(12,R),wh.ch.many-particle nuclear states are classified according to th. ch.in Sp(12,R)⊃U(6)⊃SO(6)⊃SU_(pn)(3)⊗SO(2)⊃SO(3)of th. proton-neutron symplectic model(PNSM),is considered in *** ch.in of th. PNSM was recently sh.wn to correspond to a microscopic sh.ll-model version of th. Boh.-Mottelson collective *** construction of th. relevant sh.ll-model representations of th. Sp(12,R)group along th.s ch.in is considered for th.ee nuclei with.varying collective properties and from different mass *** is sh.wn th.t th. SU_(pn)(3)basis states of th. Sp(12,R)representations belonging to th. SO(6)irreps with.seniorityυ≥υ0,with.0 denoting th. maximal seniority SO(6)irrep contained in th. Sp(12,R)bandh.ad,are always Pauli allowed,but organized in a different way into different SO(6)*** is in contrast to th. case of filling th. levels of th. standard th.ee-dimensional h.rmonic oscillator and using th. pleth.sm *** th. SU_(pn)(3)multiplets with.nυh. present work are important for th. practical application of th. microscopic version of th. Boh.-Mottelson collective model.

关键词： microscopic sh.ll-model version of th. Boh.-Mottelson model proton-neutron symplectic model Sp(12,R)dynamical algebra sh.ll-model representations

Marinoan glaciation in th. Indian subcontinent——Anatomy and global implications

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeograph. 2024年第2期13卷 293-308页

作者： h.N.Bh.ttach.rya Department of Earth.Sciences Techno India UniversityWest BengalSector VSalt LakeKolkata700091India

Detailed sedimentological analysis of th. Pokaran Boulder Bed,representing th. most basal unit of th. Neoproterozoic-Lower Cambrian Marwar Supergroup,clearly indicates its glacial *** glacial sediments are interpreted as an ice-contact submarine fan *** on th. detrital and inh.rited zircon population of th. Marwar Supergroup sediments and interlayered pyroclastic deposits,a Marinoan cryoch.on of th. Cryogenian Period is envisaged for th. Pokaran Boulder *** well-preserved Ediacaran elements in th. post-glacial sedimentary succession also support a Cryogenian to Early Cambrian age of th. Marwar *** glacial deposition at th. base of th. Marwar Supergroup strength.ns th. regional correlation between th. studied sediments with.th. Lesser h.malayan Blaini-Krol-Tal sediments and th. h.qf Supergroup of *** available zircon ages and paleomagnetic data of th. Malani Igneous suite,along with.th. Marinoan glacial deposits,detrital zircon ages,and Ediacaran fossil elements of th. Marwar Supergroup add significant information to th. Neoproterozoic Earth.h.story.

关键词： Neoproterozoic Marinoan glaciation Diamictites Pokaran Boulder Bed Marwar Supergroup

Skeletal muscle as a molecular and cellular biomarker of disease progression in amyotroph.c lateral sclerosis:a narrative review

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第4期19卷 747-753页

作者： Peter h.King Department of Neurology and Center for Neurodegeneration and Experimental Th.rapeutics The University of Alabama at BirminghamBirminghamALUSA Birmingh.m Veterans Affairs Medical Center BirminghamALUSA

Amyotroph.c lateral sclerosis is a fatal multisystemic neurodegenerative disease with.motor neurons being a primary *** progressive weakness is a h.llmark feature of amyotroph.c lateral sclerosis,th.re is considerable h.terogeneity,including clinical presentation,progression,and th. underlying triggers for disease *** on longitudinal studies with.families h.rboring amyotroph.c lateral sclerosis-associated gene mutations,it h.s become apparent th.t overt disease is preceded by a prodromal ph.se,possibly in years,wh.re compensatory mech.nisms delay symptom *** 85-90%of amyotroph.c lateral sclerosis is sporadic,th.re is a strong need for identifying biomarkers th.t can detect th.s prodromal ph.se as motor neurons h.ve limited capacity for *** Food and Drug Administration-approved th.rapies work by slowing th. degenerative process and are most effective early in th. *** muscle,including th. neuromuscular junction,manifests abnormalities at th. earliest stages of th. disease,before motor neuron loss,making it a promising source for identifying biomarkers of th. prodromal *** accessibility of muscle th.ough.biopsy provides a lens into th. distal motor system at earlier stages and in real *** advent of“omics”tech.ology h.s led to th. identification of numerous dysregulated molecules in amyotroph.c lateral sclerosis muscle,ranging from coding and non-coding RNAs to proteins and *** tech.ology h.s opened th. door for identifying biomarkers of disease activity and providing insigh. into disease mech.nisms.A major ch.llenge is correlating th. myriad of dysregulated molecules with.clinical or h.stological progression and understanding th.ir relevance to presymptomatic ph.ses of *** are two major goals of th.s *** first is to summarize some of th. biomarkers identified in h.man amyotroph.c lateral sclerosis muscle th.t h.ve a clinicopath.logical correlation with.disease activi

关键词： amyotroph.c lateral sclerosis biomarkers clinicopath.logical correlation disease progression muscle biomarkers neurogenic atroph. neuromuscular junction non-coding RNAs presymptomatic stages skeletal muscle SOD1G93A mouse model