检索结果-南通市图书馆

Analysis of the hydrological safety of dams combining two numerical tools:Iber and DualSPHysics

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 Hydrodynamics 2018年第1期30卷 87-94页

作者： J.González-Cao o.garcía-Feal J.M.Domínguez A.J.C.Crespo M.Gómez-Gesteira Environmental Physics Laboratory (EPHYSLAB) Universidade de Vigo Campus AsLagoas

The upgrade of the hydrological safety of dams is a critical issue to avoid failures that can dramatically affect people and assets. This paper shows a numerical methodology to analyse the safety of the Belesar dam（NW, Spain） based on two different numerical codes. First, a mesh-based code named Iber, suited to deal with large 2-D domains, is used to simulate the impoundment. The initial conditions and the inlet provided to Iber correspond to the maximum water elevation and the maximum expected inflow to the impoundment defined in the technical specifications of the dam, which are associated to the more hazardous operation conditions of the dam. Iber provides information about the time needed for water to attain the crest of the dam when floodgates are closed. In addition, it also provides the velocity of discharge when gates are opened. Then, a mesh-free code named DualSPHysics, which is especially suited to deal with complex and violent 3-D flows, is used to reproduce the behaviour of one of the spillways of the dam starting from the results obtained with Iber, which are used as inlet conditions for DualSPHysics. The combined results of both model show that the left spillway can discharge the surplus of water associated to the maximum inflow to the reservoir if the gates of the spillways are opened before the overtopping of the dam was observed. In addition, water depth measured on the spillway is considerably lower than the lateral walls, preventing overtopping. Finally, velocities at different points of the spillway showed to be in good agreement with theoretical values.

关键词： Hydrological safety dam numerical simulation Iber DualSPHysics

Equivalent circuit for the characterization of the resonance mode in piezoelectric systems

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Dielectrics 2015年第4期5卷 37-41页

作者： Y.Fernández-Afonso o.garcía-Zaldívar F.Calderón-Piñar Centrode Estudios Avanzadosde Cuba Kilómetro 1y 1/2 Carreter a San Antonio de los Baños Valle Grande La LisaHabanaCuba Facultadde Física-Instituto de Cienciay Tecnología de Materiales Universidad de La Habana.San LázaroyL Vedado.La Habana 10400 Cuba CINVESTAV-Unidad Querétaro Libramiento Norponiente No.2000 Realde Juriquilla QuerétaroQro.76230México

The impedance properties in polarized piezoelectric can be described by electric equivalent *** classic circuit used in the literature to describe real systems is formed by one resistor(R),one inductance(L)and one capacitance C connected in series and one capacity(C_(0))connected in parallel with the ***,the equation that describe the resonance and anti-resonance frequencies depends on a complex manner of R,L,C and C_(0).In this work is proposed a simpler model formed by one inductance(L)and one capacity(C)in series;one capacity(C_(0))in parallel;one resistor(R_(p))in parallel and one resistor(Rs)in series with other *** the traditional circuit,the equivalent circuit elements in the proposed model can be simply determined by knowing the experimental values of the resonance frequency fr,anti-resonance frequency fa,impedance module at resonance frequency|Z|,impedance module at anti-resonance frequency|Za|and low frequency capacitance C_(0),without ftting the im-pedance experimental data to the obtained equation.

关键词： Piezoelectric equivalent circuit electromechanic

BiFeo_(3) codoping with Ba,La and Ti:Magnetic and structural studies

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 Advanced Dielectrics 2015年第4期5卷 53-60页

作者： o.garcía-Zaldívar S.Díaz-Castañón F.J.Espinoza-Beltran M.A.Hernández-Landaverde G.López J.Faloh-Gandarilla F.Calderón-Piñar Facultad de Física-Instituto de Ciencia y Tecnología de Materiales Universidad de La Habana San Láazaro y L VedadoLa Habana 10400Cuba CINVESTAV-Unidad Querétaro Libramiento Norponiente No.2000 Real de JuriquillaQuerétaroQro.76230México Instituto Latino-Americanode Ciênciasda Vidaeda Natureza Universidade Federalda Integração Latino-Americana (ILCVN-UNILA)Avenida Tancredo NevesPTIBloco 6 CEP:85866-000-Foz do Iguaçu-ParanaBrazil División Materiales Avanzados Instituto Potosinode Investigación Científica Tecnológica San Luis Potosí CP78216Méexico

Conventional solid state reaction method,from oxides and carbonates,was employed to prepare bismuth(Bi)-based multiferroic *** undoped BiFeo_(3)(BFo)and the codoped system with Ba,La and Ti(Bi_(1-x)Ba_(x)Fe_(1-y)Ti_(y)o_(3),Bi_(1-x-z)Ba_(x)LazFe_(1-y)Tiyo_(3))with x,y,z=0.1 were prepared stoichiometrically and sintered at two different *** structural and magnetic properties were investigated at room *** measurements confirm the obtaining of the rhombohedral perovskite structure of the BFo family *** the undoped system,some reflections of undesired phases are present for two different sintering temperatures,while for the doped system only one phase is present for both *** magnetic characterization at room temperature revealed remarkable differences between the ceramic *** results show that for undoped BFo system,spontaneous magnetization is not observed at room ***,in doped one,a well-defined ferromagnetic behavior is observed at room temperature,possible,due to the suppression of the spatially modulated spin structure of BFo promoted by the reduction of the rhombohedral distortion and the weakening of the Bi-o *** XPS results confirm the presence of oxygen vacancies and the coexistence of Fe^(3+)and Fe^(2+) in all the studied *** measurements reveal that the dopant incorporation has not a direct effect in Neel temperature but possibly yes in ferroelectric-paraelectric transition.

关键词： Multiferroics XPS magnetic bismuth ferrite BiFeo_(3)

Energy storage and relaxor behavior in(Pb_(0.8)Ba_(0.2))[(Zn_(1/3)Nb_(2/3))_(0.7)Ti_(0.3)]o_(3)ferroelectric ceramic

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 Advanced Dielectrics 2023年第6期13卷 45-48页

作者： A.Pelaiz-Barranco Y.Perez-Martín o.garcía-Zaldívar Y.Gagou Grupo de Materiales Ferroicos Facultad de Física-IMRE Universidad de la Habana.San Lazaroy LVedado.La Habana 10400Cuba LPMC Universite de Picardie Jules Verne 33 rue Saint-Leu80039 Amiens CedexFrance

(Pb_(0.8)Ba_(0.2))[(Zn_(1/3)Nb_(2/3))_(0.7)Ti_(0.3)]o_(3)relaxor-type ferroelectric ceramics was obtained via classical solid-state *** hysteresis loop results were discussed in the frame of ergodicity criterium around the characteristic ferroelectric relaxor freezing *** hysteresis loops were observed below the freezing temperature reflecting an ergodic relaxor *** this temperature,estimated around 223K for the studied system,larger and unsaturated like ferroelectric hysteresis loops were *** temperature also coincides with the slope change on maximum polarization and inflection point of remnant polarization *** storage,energy loss and efficiency values were determined in a wide temperature *** the recoverable energy density shows relatively low values(0.23 J/cm^(3)),there are interesting behaviors for this parameter and for the efficiency,since the two physical quantities increase versus temperature and the efficiency even reaches the value of 97%.

关键词： Relaxors ferroelectrics energy storage freezing temperature

Photo-physical Characterisation of Novel organic Dye-doped Solid-state Laser Materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

复旦学报（自然科学版） 2007年第5期46卷 593-页

作者： A.Penzkofer A.Tyagi T.Susdorf D.del Agua o.garcía R.Sastre A.Costela I.garcía-Moreno Institut Ⅱ-Experimentelle und Angewandte Physik Universitat Regensburg Universitatsstrasse 31 93053 Regensburg Germany Instituto de Ciencia y Tecnología de Polímeros CSICJuan de la Cierva 328006 MadridSpain Instituto de Química Física "Rocasolano" CSIC Serrano 119 28006 MadridSpain

1 Results The development of tuneable solid-state organic dye lasers is a subject of considerable interest and research *** to conventional liquid dye lasers they have the advantage of being free of solvent handling,having small size,and being easy to *** high-performance solid-state dye lasers highly photo-stable dyes with low quantum yield of triplet formation and low triplet-triplet absorption cross-section in the lasing wavelength region are *** solid state dye lasers ...

关键词： pyrromethene dye PM597 solid-state laser dye characterisation polymer matrices

Relaxor ferroelectric behavior:An approach considering both the dipolar and electrical conductivity contributions

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Dielectrics 2021年第3期11卷 51-55页

作者： C.Carreras-Casas o.garcía-Zaldívar A.Peláiz-Barranco Y.González-Abreu F.Calderón-Pinar J.D.S.Guerra Grupo de Materiales Ferroicos Facultad de Física-Instituto de Ciencia y Tecnología de Materiales Universidad de La Habana La Habana 10400Cuba Grupo de Ferroelétricos e Materiais Multifuncionais Instituto de Física Universidade Federal de Uberlandia UberlandiaMinas Gerais38408-100Brazil

The relaxor behavior of PLZT ferroelectric ceramics has been analyzed in a wide frequency and temperature ranges,below and above the temperature for the formation of the so-called polar nano-regions(PNRs).An approximation to the dynamical behavior of the PNRs has been discussed using Cole-Cole’s relaxation model and Jonscher’s Universal Relaxation *** analysis considers both the dipolar contribution and those ones associated with DC and AC electric conductivities,this latter not being previously reported in the literature for relaxor *** effectiveness of the developed model has been verified from the agreement between the experimental data and the theoretical *** study also offers an indirect method to predict the DC component of the electrical conductivity.

关键词： Relaxor ferroelectrics dielectric response modeling conductivity Cole-Cole

Beyond neurodegeneration:engineering amyloids for biocatalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第10期20卷 2915-2916页

作者： Andrea Bartolomé-Nafría Javier garcía-Pardo Salvador Ventura Institut de Biotecnologia i de Biomedicina(IBB)and Departament de Bioquímica i Biologia Molecular Universitat Autònoma de BarcelonaBellaterraBarcelonaSpain Hospital Universitari Parc Taulí Institut d’Investigaciói InnovacióParc Taulí(I3PT-CERCA)Universitat Autònoma de BarcelonaSabadellSpain

Amyloid fibrils are highly organized protein or peptide aggregates,often characterized by a distinctive supramolecular cross-β-sheet *** formation and accumulation of these structures have been traditionally associated with neural or systemic human diseases,such as Alzheimer’s disease,Parkinson’s disease,type-2 diabetes,or amyotrophic lateral sclerosis(Wei et al.,2017;Wittung-Stafshede,2023).

关键词： structure amyloid

The emerging role of mesenchymal stem cell-derived extracellular vesicles to ameliorate hippocampal NLRP3 inflammation induced by binge-like ethanol treatment in adolescence

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1153-1163页

作者： Susana Mellado María JoséMorillo-Bargues Carla Perpiñá-Clérigues Francisco.garcía-garcía Victoria Moreno-Manzano Consuelo Guerri María Pascual Department of Physiology School of Medicine and DentistryUniversity of ValenciaValenciaSpain Bioinformatics and Biostatistics Unit Príncipe Felipe Research CenterValenciaSpain Neuronal and Tissue Regeneration Laboratory Príncipe Felipe Research CenterValenciaSpain

our previous studies have reported that activation of the NLRP3(NoD-,LRR-and pyrin domain-containing protein 3)-inflammasome complex in ethanol-treated astrocytes and chronic alcohol-fed mice could be associated with neuroinflammation and brain *** stem cell-derived extracellular vesicles(MSC-EVs)have been shown to restore the neuroinflammatory response,along with myelin and synaptic structural alterations in the prefrontal cortex,and alleviate cognitive and memory dysfunctions induced by binge-like ethanol treatment in adolescent *** the therapeutic role of the molecules contained in mesenchymal stem cell-derived extracellular vesicles,the present study analyzed whether the administration of mesenchymal stem cell-derived extracellular vesicles isolated from adipose tissue,which inhibited the activation of the NLRP3 inflammasome,was capable of reducing hippocampal neuroinflammation in adolescent mice treated with binge *** demonstrated that the administration of mesenchymal stem cell-derived extracellular vesicles ameliorated the activation of the hippocampal NLRP3 inflammasome complex and other NLRs inflammasomes(e.g.,pyrin domain-containing 1,caspase recruitment domain-containing 4,and absent in melanoma 2,as well as the alterations in inflammatory genes(interleukin-1β,interleukin-18,inducible nitric oxide synthase,nuclear factor-kappa B,monocyte chemoattractant protein-1,and C–X3–C motif chemokine ligand 1)and miRNAs(miR-21a-5p,miR-146a-5p,and miR-141-5p)induced by binge-like ethanol treatment in adolescent *** analysis further revealed the involvement of miR-21a-5p and miR-146a-5p with inflammatory target genes and NoD-like receptor signaling *** together,these findings provide novel evidence of the therapeutic potential of MSC-derived EVs to ameliorate the hippocampal neuroinflammatory response associated with NLRP3 inflammasome activation induced by binge drinking in adolescence.

关键词： adolescence binge-like ethanol treatment extracellular vesicles hippocampus mesenchymal stem cells neuroinflammation NoD-,LRR-and pyrin domain-containing protein 3(NLRP3)

Blood biomarkers of Alzheimer’s disease:important considerations for use in clinical practice

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 205-206页

作者： Sarah Fullam Sean o’Dowd Antoinette o’Connor Department of Neurology Tallaght University HospitalDublinIreland Academic Unit of Neurology Trinity College DublinIreland

Introduction:Fluid and positron emission tomography(PET)biomarkers that enable the detection of the hallmark proteins of Alzheimer’s disease(AD)(amyloid and tau)have revolutionized our approach to the diagnosis of *** evolution of AD diagnostic criteria to include biological characterization(Alzheimer’s Association Working Group,2023)provides an appropriate framework to reduce levels of clinico-pathologic mismatch and improve in-vivo diagnostic *** the therapeutic landscape for neurodegenerative disease evolves,it is increasingly incumbent on clinicians to provide timely,and pathologically precise diagnoses for ***,the expensive and invasive nature of these tests limits their scalability.

关键词： Blood Alzheimer diagnosis