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Journal of Advanced Ceramics 2019年第2期8卷 238-246页

作者： Evando s.ARAuJO Victor n.s.LEAO Research Group on Electrospinning and nanotechnology Applications(GPEA-nano) Department of Materials ScienceUniversidade Federal do Vale do Sao Francisco

Relative humidity(RH) is a critical environmental variable for transportation and storage of products and for the quality guarantee of several other production processes and services. Heterogeneous structures prepared from the selective semiconductor oxides may improve the sensitivity to humidity due to the better electronic and surface properties, when compared to pristine oxides. This work shows an alternative fabrication route for producing titanium dioxide/tungsten trioxide(TiO2/WO3) heterogeneous structures(by electrospinning and sintering) for potential application on the RH detection. The microstructural properties of the materials were analyzed by scanning electron microscopy(sEM), energy dispersive X-ray analysis(EDs), X-ray diffraction, and Raman spectroscopy. The electrical characterization of the structures was performed by electrical impedance spectroscopy in RH range of 10%–100%. Results indicated a p-to n-type conduction transition at around 30%–40% RH for all tested settings. The analysis of the impedance signature to humidity showed that the amount of fiber layers on the electrode and working temperature are important parameters to improve the humidity sensing of the TiO2/WO3 systems.

关键词： electrospinning heterogeneous structures preparation relative humidity semiconductors

Effects of induced magnetic field on peristaltic flow of Johnson-segalman fluid in a vertical symmetric channel

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Applied Mathematics and Mechanics(English Edition) 2010年第8期31卷 969-978页

作者： s.nADEEM n.s.AKBAR Department of Mathematics Quaid-i-Azam University

In this paper, the influence of heat transfer and induced magnetic field on peristaltic flow of a Johnson-segalman fluid is studied. The purpose of the present investigation is to study the effects of induced magnetic field on the peristaltic flow of non-newtonian fluid. The two-dimensional equations of a Johnson-segalman fluid are simplified by assuming a long wavelength and a low Reynolds number. The obtained equations are solved for the stream function, magnetic force function, and axial pressure gradient by using a regular perturbation method. The expressions for the pressure rise, temperature, induced magnetic field, pressure gradient, and stream function are sketched and interpreted for various embedded parameters.

关键词： induced magnetic field vertical symmetric channel Johnson-segalman fluid magnetohydrodynamics (MHD)

The importance of functional diversity in the stability of Mediterranean shrubland communities after the impact of extreme climatic events

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Journal of Plant Ecology 2017年第2期10卷 281-293页

作者： Enrique Gde la Riva Francisco Lloret Ignacio MPérez-Ramos Teodoro Marañón sandra saura-mas Ricardo Díaz-Delgado Rafael Villar Area de Ecología Facultad de CienciasUniversidad de Cordoba.14071 CordobaSpain CREAF Cerdanyola del Vallés08193 BarcelonaSpain Unitat d’Ecologia Dept.Biologia AnimalBiologia Vegetal i EcologiaUniversitat Autònoma BarcelonaEdifici CCampus UAB08193Cerdanyola del VallèsBarcelonaSpain IRnAs CSICAv.Reina Mercedes 10PO Box 1052.41080 SevillaSpain Estación Biológica de Doñana CSIC.c/Americo Vespucios/nIsla de la Cartuja.41092 SevillaSpain

Aims Extreme climatic events may have important consequences for plant community structure and *** 2005,a severe drought together with a cold winter promoted extensive damage and mortal-ity in shrubland communities of southwest spain(Doñana national Park).Here,we aim to identify the mechanisms underlying commu-nity stability(resistance and resilience)in response to this extreme climatic event,considering changes in the functional structure of these *** We used a trait-based approach,quantifying variations in 10 func-tional traits at the community level(community weighted means,CWM)and the functional diversity(functional richness,evenness and divergence)in 18 plots at three different times:predating the climatic event(estimated from the sum of the live and dead volume of each species in 2007),and 2 and 8 years after the 2005 *** also quantified the differences in functional traits and functional diversity between adult and recruit stages,which allowed us to bet-ter understand the contribution of the recruitment to the mainte-nance of the functional structure and diversity of the *** Findings Communities with higher functional divergence before the cli-matic event maintained nearly constant their levels of functional divergence 8 years after,but they were more prone to changes in species *** resistance in terms of vegeta-tion cover was positively correlated with root dry matter content,whereas community resilience was positively correlated with leaf chlorophyll(LChl).We also found that some values(weighted means)of functional community traits(such as root dry matter con-tent and LChl)had increased 2 years after the event,returning to the pre-event conditions after 8 *** addition,there was hardly any establishment of new species in the community and the recruits did not make substantial differences to the community functional *** seed mass differed significantly between the adult and se

关键词： climate change Doñana drought functional trait recruitment resilience resistance

Magnetosonic shocks in Ultra-Relativistic Dissipative Degenerate Plasmas

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Chinese Physics Letters 2016年第8期33卷 77-80页

作者： s.Hussain n.Akhtar n.Mustafa Theoretical Physics Division PINSTECHP.O.Nilore

Magnetosonic shock structures in dissipative magnetized degenerate electron ion plasma are studied. The two fluid quantum magnetohydrodynamic equations for non-degenerate ions and ultra-relativistic degenerate electron fluids with the Maxwell equations are presented. Using the reductive perturbation technique the Korteweg de Vries Burgers （KdVB） equation is derived and its solution is presented with the tanh method. Astrophysical plasma parameters are used to study the effects of variation of plasma density, magnetic field intensity and kinematic viscosity on the propagation characteristics of nonlinear shock structures in such plasma systems.

关键词： in on is et de of that

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage

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neural Regeneration Research 2025年第9期20卷 2454-2463页

作者： Victoria Jiménez Carretero IrisÁlvarez-Merz Jorge Hernández-Campano sergei A.Kirov Jesús M.Hernández-Guijo Department of Pharmacology and Therapeutic School of MedicineUniv.Autónoma de MadridMadridSpain Ramón y Cajal Institute for Health Research(IRYCIs) Neurobiology-Research ServiceHospital Ramón y CajalMadridSpain Institute of neurobiology Faculty of Mathematics and Natural SciencesHeinrich Heine University DüsseldorfDüsseldorfGermany Department of neuroscience and Regenerative Medicine&Department of neurosurgery Medical College of Georgia at Augusta UniversityAugustaGAUSA

The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is ***,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely *** release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the *** findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma *** amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by n-methyl-D-aspartate *** n-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during *** is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system n transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through n-methyl-D-aspartate receptor ***,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain *** these pathways co uld highlight new therapeutic targets to mitigate brain injury.

关键词： cell swelling n-methyl-D-aspartate receptor non-excitatory amino acids stroke synaptic transmission

CFD simulation of helicopter rotor flow based on unsteady actuator disk model

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Chinese Journal of Aeronautics 2020年第9期33卷 2313-2328页

作者： G.n.BARAKOs T.FITZGIBBOn A.n.KUsYUMOV s.A.KUsYUMOV s.A.MIKHAILOV James Watt school of Engineering Glasgow UniversityGlasgow G128QQUnited Kingdom Department of Aerohydrodynamics Kazan National Research Technical University named after A.N.TupolevKazan 420111Russia

Actuator Disks(AD)can provide characterizations of rotor wakes while reducing computational expense associated with modeling the fully resolved *** work presents an unsteady actuator disk method based on surface circulation distribution combined with empirical data,blade element theory and rotor momentum *** nonuniform circulation distribution accounts for 3 D blade load effects,and in particular,tip *** simulations were conducted for the isolated pressure sensitive paint model rotor blade in hover and forward flight using the HMB3 CFD solver of Glasgow *** of CFD results in comparison with published numerical data was performed in hover,for a range of blade pitch angles using fully turbulent flow and the k-x ssT *** forward flight,the vortex structures predicted using the unsteady actuator disk model showed configurations similar to the ones obtained using fully resolved rotor *** the reduced grid cells number,the CFD results for AD models captured well the main vortical structures around the rotor disk in comparison to the fully resolved cases.

关键词： CFD Fully resolved blades rotor PsP rotor surface circulation distribution Unsteady actuator disk model

Influence of thermomechanical processing on microstructure,mechanical and strain hardening properties of single-phase Mg-4Li-0.5Ca alloy for structural application

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Journal of Magnesium and Alloys 2020年第4期8卷 1262-1268页

作者： n.sriraman s.Kumaran sathiya narayanan n school of Mechanical Engineering SASTRA Deemed to be University ThirumalaisamudramThanjavurTamilnadu 613401India Department of Metallurgical and Materials Engineering National Institute of Technology TiruchirappalliTamil Nadu 620015India

The single-phase Mg-4Li-0.5Ca alloy was rolled at three different temperatures(250,300 and 350℃)and followed by annealing at 200°C for 10 *** evaluate the mechanical properties,the tensile test was conducted at a constant strain rate of 10^(-3)s^(-1).Factors influencing the tensile strength and strain hardening properties were assessed by microscopy,XRD and EBsD ***,Kocks-Mecking plots(K-M)were used to determine the different stages of strain hardening exhibited by the variously processed Mg-4Li-0.5Ca alloy test *** ultimate tensile strength has decreased as hot-rolling temperature in creases with increased *** strain hardening properties such as hardening capacity(Hc),strain hardening exponent(n)are increased significantly with an increase in hot rolling temperature and subsequent annealing.

关键词： Mg-4Li-0.5Ca Hot rolling Twins Mg2Ca Hardening capacity

Plant-herbivore assemblages under natural conditions are driven by plant size,not chemical defenses

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Journal of Plant Ecology 2017年第6期10卷 1012-1021页

作者： Eva Castells Maria Morante sandra saura-mas Anabel Blasco-Moreno Departament de Farmacologia Terapèutica i ToxicologiaUniversitat Autònoma de BarcelonaCerdanyola del Vallès 08193Spain CREAF Cerdanyola del Vallès 08193Spain Department de Biologia Animal Vegetal i EcologiaUniversitat Autònoma de BarcelonaCerdanyola del Vallès 08193Spain servei d’Estadística Aplicada Universitat Autònoma de BarcelonaCerdanyola del Vallès 08193Spain

Aims Plant secondary metabolites have been traditionally recognized as key traits regulating plant-herbivore ***,the ecological relevance of secondary metabolites as resistance mecha-nisms in comparison to other plant attributes,including physical,morphological or ecological traits,has been recently *** aim to evaluate the role of chemical defenses,plant size and the presence of insect competitors on driving the differences in her-bivory damage under natural *** We performed a replicated field study on the herbivore commu-nity associated with four senecio species(***,***,*** and ***)during a full-reproductive season in Montseny natural Park(catalonia,nE spain).Pyrrolizidine alka-loids(PAs),the most characteristic chemical defenses of senecio due to their toxic effects on herbivores,were analyzed by gas *** plant size was estimated by the number of flower heads produced over the entire reproductive *** used linear mixed models to explore the relationships between total PA concentrations,plant size and herbivory *** Findings PA concentrations were not related to the natural guild of herbivores within any plant species or insect ***,no significant interactions were found between insect species sharing the same host *** contrast,herbivore abundance was positively related to plant size in ***,*** and *** found no evidence that PAs confer an increased plant resistance against herbivores in *** study supports the hypothesis that plant chemical defenses have a secondary role in determining plant-her-bivore assemblages in comparison to other plant traits under the complexity of natural conditions.

关键词： senecio herbivory chemical defenses pyrrolizidine alkaloids plant traits

TWO-DIMEnsIOnAL APPROXIMATIOnOF EIGEnVALUE PROBLEMs In sHELL THEORY:FLEXURAL sHELLs

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Chinese Annals of Mathematics,series B 2000年第1期21卷 1-16页

作者： s.KEsAVAn n.sABU InstituteofMathematicalsciences C.I.T.CampusTaramaniChennai-600113India.

The eigenvalue problem for a thin linearly elastic shell, of thickness 2c, clamped along its lateral surface is considered. Under the geometric assumption on the middle surface of the shell that the space of inextensional displacements is non-trivial, the authors obtain, as e - 0, the eigenvalue problem for the two-dimensional "flexural shell" model if the dimension of the space is infinite. If the space is finite dimensional, the limits of the eigenvalues could belong to the spectra of both flexural and membrane shells. The method consists of rescaling the variables and studying the problem over a fixed domain. The principal difficulty lies in obtaining suitable a priori estimates for the scaled eigenvalues.

关键词： Approximation Eigenvalue problem shell theory Flexural shells

Conversion of an atomic to a molecular argon ion and low pressure argon relaxation

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Chinese Physics B 2016年第1期25卷 697-705页

作者： M n stankov A P Jovanovie V Lj Markovic s n stamenkovic Department of Physics Faculty of Sciences and MathematicsUniversity of Ni Viegradska 33Ni 18001Serbia

The dominant process in relaxation of DC glow discharge between two plane parallel electrodes in argon at pressure 200 Pa is analyzed by measuring the breakdown time delay and by analytical and numerical models. By using the approx- imate analytical model it is found that the relaxation in a range from 20 to 60 ms in afterglow is dominated by Ar＋ ions, produced by atomic-to-molecular conversion of Ar＋ ions in the first several milliseconds after the cessation of the discharge. This conversion is confirmed by the presence of double-Gaussian distribution for the formative time delay, as well as con- version maxima in a set of memory curves measured in different conditions. Finally, the numerical one-dimensional （1D） model for determining the number densities of dominant particles in stationary DC glow discharge and two-dimensional （2D） model for the relaxation are used to confirm the previous assumptions and to determine the corresponding collision and transport coefficients of dominant species and processes.

关键词： argon discharge afterglow relaxation fluid model plasma reactions