检索结果-南通市图书馆

Effects of layer interactions on instantaneous stability of finite Stokes flows

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： chen ZHAO Zhenli cHEN c.t.MUtASA Dong LI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

the stability analysis of a finite Stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite Stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. the oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. the effects of the Stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. the growth rates of two most unstable modes when δ t equal, and δ = δ*/h*, where δ*and h*are the Stokes-layer thickness and the half height of the channel, respectively. However, their vorticities are different. the vorticity of the most unstable mode is symmetric, while the other is asymmetric. the Stokes-layer interactions have a destabilizing effect on the most unstable mode when δ tabilizing effect when δ > 0.68. However, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the Stokes-layer interactions are strong. We also find that the stability of the Stokes layer is closely related to the inflectional points of the base-flow velocity profile. the effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. the energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. the effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite Stokes layer instantaneous stability Stokes-layer interaction asynchronous oscillation

Near resonance vibration isolation on a levered-dual response(LEDAR)coulomb-damped system by differential preloads/offsets in linear springs

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： t.I.tOLUWALOJU c.K.tHEIN D.HALIM Department of Mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Nottingham Ningbo china Beacons of Excellence Research and Innovation Institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

the levered-dual response(LEDAR)coulomb-damped system attains near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail friction for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result in the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant isolation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation functions and passive functions at extreme frequencies.

关键词： lever ratio coulomb damping preload tension/compression isolation band/depth offset potential

Efficient guiding and focusing of intense laser pulse using periodic thin slits

在线全文

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu t.W.Huang K.Jiang c.N.Wu H.Peng P.c.hen R.Li H.B.Zhuo c.t.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9

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

Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： Yan Guo c.Sengupta t.c.Scott P.Lagos Y.Luo Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA Porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a tidal Dwarf Galaxy(tDG) candidate. tDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. the quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved tDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

Radiative decays D*(s)→ D(s)γ in covariant confined quark model

在线全文

学校读者我要写书评

暂无评论

chinese Physics c 2024年第2期48卷 45-56页

作者： c.t.tran M.A.Ivanov P.Santorelli Q.c.Vo Department of Physics HCMC University of Technology and EducationVo Van Ngan 1700000 Ho Chi Minh CityVietnam Bogoliubov Laboratory of theoretical Physics Joint Institute for Nuclear Research141980 DubnaRussia Dipartimento di Fisica"E.Pancini" Universitàdi Napoli Federico ⅡComplesso Universitario di Monte S.AngeloVia CintiaEdificio 680126 NapoliItaly Istituto Nazionale di Fisica Nucleare Sezione di Napoli80126 NapoliItaly University of Science 700000 Ho Chi Minh CityVietnam

Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢ*** radiative couplings gD*Dγencoding nonperturbative QcD effects are calculated in the framework of the covariant confined quark model developed by *** compare our results with other theoretical studies and experimental *** couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).the most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QcD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QcD sum rules.

关键词： covariant quark model radiative decay charmed meson

Finite barrier bound state

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第4期13卷 664-671页

作者： tao Liu Kai Bai Yicheng Zhang Duanduan Wan Yun Lai c.t.chan Meng Xiao Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education and School of Physics and technology Wuhan University430072 WuhanChina. National Laboratory of Solid State Microstructures School of Physicsand Collaborative Innovation Center of Advanced MicrostructuresNanjing University210093 NanjingChina. Department of Physics The Hong Kong University of Science and TechnologyClear Water BayKowloon999077Hong KongChina. Wuhan Institute of Quantum technology 430206 WuhanChina

A boundary mode localized on one side of a finite-size lattice can tunnel to the opposite side which results in unwanted *** wisdom tells that the tunneling probability decays exponentially with the size of the system which thus requires many lattice sites before eventually becoming negligibly *** we show that the tunneling probability for some boundary modes can apparently vanish at specific ***,similar to bound states in the continuum,a boundary mode can be completely trapped within very few lattice sites where the bulk bandgap is not even *** intriguingly,the number of trapped states equals the number of lattice sites along the normal direction of the *** provide two configurations and validate the existence of this peculiar finite barrier-bound state experimentally in a dielectric photonic crystal at microwave *** work offers extreme flexibility in tuning the coupling between localized states and channels as well as a new mechanism that facilitates unprecedented manipulation of light.

关键词： boundary state eventually

thermoluminescence characterization of natural and synthetic irradiated ce-monazites

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

Journal of Rare Earths 2024年第4期42卷 643-650页

作者： V.correcher c.Boronat J.Garcia-Guinea J.F.Benavente t.Rivera-Montalvo cIEMAt Av.Complutense 4028040MadridSpain MNcN-cSIc J.Gutierrez Abascal 228006MadridSpain Instituto Politécnico Nacional CICATA-IPNAv.Legaria 694Mexico City11500Mexico

the thermoluminescence(tL)emission of synthetic and natural ce-monazites was characterized here to determine the potential application in the identification of microscopic defects from a qualitative point of view trying to link each tL peak to a chemical-physical *** kinetic parameters that lead the luminescence processes were calculated by means of variable heating rate and computing glow curve deconvolution methods and allow identifying three groups of components at~90,130 and 290℃(for the mineral sample)and~90,170,220,270 and 320℃(for the synthetic cePO_(4):Nd_(0.20),La_(0.25)).the main differences appreciated in these complex tL curves are mainly due to(i)the content of impurities(natural sample contains lanthanides as well as U 0.60%and th 5.22%)and(ii)the degree of crystallinity of the samples which is directly related to the type of impurities(synthetic monazite relies only on Nd and La).the behavior of the dose response in the range of 1-8 Gy is similar for both samples;the tL intensity increases linearly as the dose increases without changes in the position of the maxima,denoting first-order kinetic luminescence *** peak could be mostly associated with structural defects(i.e.,phase transitions),chemical reactions(i.e.,ce3+?ce4+redox reaction,dehydration or dehydroxylation processes)or intrinsic defects(i.e.,Frenkel defects,ODcs or NBOHcs).

关键词： thermoluminescence Kineticparameters Phosphate ce-monazite Defects Rare earths

A modular microfluidic platform to study how fluid shear stress alters estrogen receptor phenotype in ER+breast cancer cells

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第1期10卷 287-299页

作者： Braulio Andrés Ortega Quesada Jonathan cuccia Rachael coates Blake Nassar Ethan Littlefield Elizabeth c.Martin Adam t.Melvin cain Department of chemical Engineering Louisiana State UniversityBaton RougeLA 70803USA Department of chemical and Biological Engineering Clemson UniversityClemsonSC 29634USA Biological and Agricultural Engineering Louisiana State UniversityBaton RougeLA 70803USA Department Medicine Section Hematology and Medical OncologyTulane UniversityNew OrleansLA 70118USA

Metastatic breast cancer leads to poor prognoses and worse outcomes in patients due to its invasive behavior and poor response to *** is still unclear what biophysical and biochemical factors drive this more aggressive phenotype in metastatic cancer;however recent studies have suggested that exposure to fluid shear stress in the vasculature could cause *** this study a modular microfluidic platform capable of mimicking the magnitude of fluid shear stress(FSS)found in human vasculature was designed and *** device provides a platform to evaluate the effects of FSS on McF-7 cell line,an estrogen receptor positive(ER+)breast cancer cell line,during circulation in the *** of the effects of FSS on McF-7 cells was carried out utilizing two approaches:single cell analysis and bulk *** single cell analysis,cells were trapped in a microarray after exiting the serpentine channel and followed by immunostaining on the device(on-chip).Bulk analysis was performed after cells were collected in a microtube at the outlet of the microfluidic serpentine channel for western blotting(off-chip).It was found that cells exposed to an FSS magnitude of 10 dyn/cm^(2) with a residence time of 60 s enhanced expression of the proliferation marker Ki67 in the McF-7 cell line at a single cell *** understand possible mechanisms for enhanced Ki67 expression,on-chip and off-chip analyses were performed for pro-growth and survival pathways ERK,AKt,and JAK/*** demonstrated that after shearing the cells phosphorylation of p-AKt,p-mtOR,and p-StAt3 were ***,there was no change in p-ERK1/*** is a mediator of ER rapid signaling,analysis of phosphorylated ERαwas carried out and no significant differences between sheared and non-sheared populations were *** together these results demonstrate that FSS can increase phosphorylation of proteins associated with a more aggressive phenotype in circulating cancer *** findin

关键词： fluid breast estrogen

the ccD instrument background of the SMILE SXI

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

Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.W.J.Hubbard O.Hetherington D.J.Hall t.W.Buggey S.Parsons t.Arnold A.Holland c.Pagani S.Sembay centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

the ESA and cAS SMILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the ccDs(charge-coupled Devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic cosmic Rays(GcRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GcRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation