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Reassessment of Prejanopterus curvirostris, a Basal Pterodactyloid Pterosaur from the Early Cretaceous of Spain

Acta Geologica Sinica(English Edition) 2012年第6期86卷 1389-1401页

作者： Xabier PEREDA-SUBERBIOLA Fabien KNOLL José Ignacio RUIZ-OMEACA Julio COMPANY Fidel TORCIDA FERNNdeZ-BALDOR Universidad del País Vasco/Euskal Herriko Unibertsitatea Facultad de Cienciay TecnologíaDpto.Estratigrafíay Paleontología departamento de Paleobiología Museo Nacional de Ciencias Naturales-CSIC Museo del Jurásico de Asturias (MUJA) departamento de Geología Universidad de Oviedo departamento de ingeniería del terreno Universidad Politécnica de Valencia Colectivo Arqueológico-Paleontológico de Salas (C.A.S.) Museo de Dinosaurios

Prejanopterus curvirostra, from the Early Cretaceous of La Rioja province, was the first pterosaur genus and species described from Spain. The material comprises disarticulated cranial and postcranial remains from several individuals. The fossil-bearing bed is assigned to the lacustrine Leza Formation （eastern Cameros Basin, NW margin of the Iberian Range）. This unit is regarded as either Berriasian-Valanginian or Barremian-Aptian. Prejanopterus curvirostris （specific name emended） was originally diagnosed on the basis of several characters of which the most significant was a lateral curvature of the rostrum. Re-examination of the holotype （rostrum） and paratype （partial rostrum with teeth） indicates that there is no genuine sideways bend of the preserved premaxilla-maxilla segments, but a slight dorsal curvature. Prejanopterus is characterized by a unique combination of characters： an emended diagnosis is provided. In contrast with previous estimates, the wing span of Prejanopterus was probably not much （if ever） in excess of 2 m. A phylogenetic analysis suggests that Prejanopterus is a basal pterodactyloid positioned between Pterodactylus and Cycnorhamphus- Gallodactylus. Prejanopterus represents the first evidence of Pterodactylidae in the Early Cretaceous of the Iberian Peninsula.

关键词： Pterosauria Prejanopterus Leza Formation Early Cretaceous La Rioja Spain

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Corrosion protection of AZ91D magnesium alloy by a cerium-molybdenum coating-The effect of citric acid as an additive

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Journal of Magnesium and Alloys 2018年第4期6卷 356-365页

作者： I.L.Lehr S.B.Saidman Instituto de ingeniería Electroquímica y Corrosión(INIEC) Departamento de Ingeniería QuímicaUniversidad Nacional del Sur(UNS)CONICETBahía BlancaArgentina

In order to improve the corrosion resistance of AZ91D magnesium alloy,a coating was formed by a potentiostatic technique from a solutions containing Ce(NO_(3))_(3),Na_(2)MoO_(4)and citric acid(H_(3)Cit).The degree of corrosion protection achieved was evaluated in simulated physiological solution by monitoring the open circuit potential,polarization techniques and electrochemical impedance spectroscopy(EIS).Surface analysis techniques(SEM,EDS,X-ray diffraction and X-ray photoelectron spectroscopy(XPS))were used for coating *** film is mainly composed by cerium and molybdenum oxides and magnesium oxides and *** obtained results show that the corrosion resistance of the coated electrodes has been increased *** improvement in the anticorrosive performance is in part due to the corrosion inhibition properties of H_(3)Cit.

关键词： Cerium and molybdenum-based coatings AZ91D alloy Citric acid Anticorrosive properties

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Oxidative degradation of Thermoplastic Starch Induced by UV Radiation

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Journal of Renewable Materials 2019年第4期7卷 383-391页

作者： Mayte M.Quispe Olivia V.López Marcelo A.Villar Planta Piloto de ingeniería Química PLAPIQUI(UNS CONICET)Bahía Blanca(8000)Argentina departamento de ingeniería Química Universidad Nacional del Sur(UNS)Bahía Blanca(8000)Argentina

Among biopolymers,thermoplastic starch(TPS)is a good candidate to obtain biomaterials because of its natural origin,biodegradable character,and *** to ultraviolet(UV)radiation causes significant degradation of starch-based materials,inducing photooxidative reactions which result in breaking of polymer chains,production of free radical,and reduction of molar *** changes produce a deterioration of TPS mechanical properties,leading to useless materials after an unpredictable *** this work,changes induced on TPS by UV radiation,analyzing structural properties and mechanical behavior,are *** was obtained through thermo-mechanical processing of native corn starch in the presence of water(45%w/w)and glycerol(30%w/w)as *** were obtained by thermocompression and,before testing,specimens were conditioned to reduce material *** process was performed by exposing TPS to 264 h UV radiation in a weathering test ***’s weight loss was determined *** changes were studied by Fourier Transform Infrared Spectroscopy(FTIR)and morphological modifications were analyzed by Scanning Electron Microscopy(SEM).Reduction of weight average molar mass was measured by Static Light Scattering(SLS).Changes in mechanical properties were studied from tensile *** 96 h exposure,TPS specimens presented a weight reduction of 4-6%,mainly attributed to plasticizers lost by *** observations showed that UV radiation induced morphological changes on TPS,evidenced by an increment of specimens *** FTIR,it was detected the presence of an additional band located at 1726 cm-1 in samples submitted to UV radiation,attributed to the formation of-C=O *** average molar mass of native starch was in the order of 107 g *** exposure to UV radiation decreased significantly its molar mass,confirming molecular degradation of the *** TPS was exposed during 48 h,it

关键词： Thermoplastic starch UV radiation structural properties mechanical behavior

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Temporal decay of the catalytic oxidation of methane over palladium supported on silica

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Science China Chemistry 2013年第11期56卷 1601-1607页

作者： CORTS Joaquín VALENCIA Eliana PINEDA Marcelo ARAYA Paulo departamento de ingeniería Química y Biotecnología Universidad de Chile departamento de Ciencia de Materiales Universidad de Chile

The temporal decay of the oxidation of methane(CH4-O2reaction)over palladium supported on silica is determined experimentally at different temperatures,comparing the results with those of various classical models which show the behavior of the adsorbed phase as the cause of the *** effect is visualized through Monte Carlo simulations of the CH4-O2reaction on a mixed lattice whose partial poisoning,due to the configuration of the OH groups on the surface of the adsorbate,is translated into a gradual decay of the reaction’s activity.

关键词： catalytic CH4-O2 reaction surface heterogeneity in superficial reaction Monte Carlo simulation superficial catalyticreaction CH4-O2 reaction over palladium

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Gas-phase electrocatalytic conversion of CO_2 to chemicals on sputtered Cu and Cu–C catalysts electrodes

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Journal of Energy Chemistry 2019年第4期28卷 46-53页

作者： N.Gutiérrez-Guerra J.A.González J.C.Serrano-Ruiz E.López-Fernández J.L.Valverde A.de Lucas-Consuegra departamento de ingeniería Química Facultad de Ciencias y Tecnologías Químicas Universidad de Castilla-La Mancha Instituto Regional de Investigación Científica Aplicada (IRICA) and departamento de Física Aplicada Universidad de Castilla-La Mancha departamento de ingeniería Universidad Loyola Andalucía

A novel gas-phase electrocatalytic cell containing a low-temperature proton exchange membrane(PEM)was developed to electrochemically convert CO_2into organic *** different Cu-based cathode catalysts(Cu and Cu–C)were prepared by physical vapor deposition method(sputtering)and subsequently employed for the gas-phase electroreduction of CO_2at different temperatures(70–90°C).The prepared electrodes Cu and Cu–C were characterized by X-ray diffraction(XRD),X-ray photoemission spectroscopy(XPS)and scanning electron microscopy(SEM).As revealed,Cu is partially oxidized on the surface of the samples and the Cu and Cu–C cathodic catalysts were comprised of a porous,continuous,and homogeneous film with nanocrystalline Cu with a grain size of 16 and 8 nm,*** influence of the applied current and temperature on the electro-catalytic activity and selectivity of these materials was *** the two investigated electrodes,the pure Cu catalyst film showed the highest CO_2specific electrocatalytic reduction rates and higher selectivity to methanol formation compared to the Cu–C electrode,which was attributed to the higher particle size of the former and lower Cu O/Cu *** obtained results show potential interest for the possible use of electrical renewable energy for the transformation of CO_2into valuable products using low metal loading Cu based electrodes(0.5 mg Cu cm^(-2))prepared by sputtering.

关键词： CO_2 valorization Electro-reduction Cu catalyst PEM Selectivity Methanol production

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Formation of a cerium conversion coating on magnesium alloy using ascorbic acid as *** and anticorrosive properties of the formed films

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Journal of Magnesium and Alloys 2016年第4期4卷 278-285页

作者： A.P.Loperena I.L.Lehr S.B.Saidman Instituto de ingeniería Electroquímica y Corrosión(INIEC) Departamento de Ingeniería QuímicaUniversidad Nacional del SurAv.Alem 12538000 Bahía BlancaArgentina

Cerium-based conversion coatings were formed on AZ91D magnesium alloy by immersion of the substrate in solutions containing Ce(NO_(3))_(3),H_(2)O_(2) and ascorbic acid(HAsc).The characterisation of the films was performed by electrochemical and surface analysis techniques such as SEM,EDS,X-ray diffraction and X-ray photoelectron spectroscopy(XPS).The degree of corrosion protection achieved was evaluated in simulated physiological solution by the open circuit potential monitoring,polarisation techniques and electrochemical impedance spectroscopy(EIS).The presence of HAsc in the conversion solution causes changes in the morphology,adherence and anticorrosive performance of the *** improvement in the corrosion resistance is closely associated with the corrosion inhibition properties of HAsc.

关键词： Cerium coatings AZ91D alloy Ascorbic acid Anticorrosive properties

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Envelopes of Commutative Rings

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Acta Mathematica Sinica,English Series 2012年第3期28卷 561-580页

作者： Rafael PARRA Manuel SAORIN departamento de Clculo. Escuela Bsica Facultad de Ingeniería Universidad de los Andes departamento de Matemticas Universidad de Murcia

Given a significative class F of commutative rings, we study the precise conditions under which a commutative ring R has an S-envelope. A full answer is obtained when F is the class of fields, semisimple commutative rings or integral domains. When .F is the class of Noetherian rings, we give a full answer when the Krull dimension of R is zero and when the envelope is required to be epimorphic. The general problem is reduced to identifying the class of non-Noetherian rings having a monomorphic Noetherian envelope, which we conjecture is the empty class.

关键词： Noetherian ring envelope local ring artinian ring Krull dimension

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Combined heat and mass transfer by mixed convection MHD flow along a porous plate with chemical reaction in presence of heat source

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Applied Mathematics and Mechanics(English Edition) 2010年第10期31卷 1217-1230页

作者： J.ZUECO S.AHMED ETS ingeniería Industrial Departamento de Ingeniería Térmicay FluidosUniversidad Politécnica de Cartagena Fluid Dynamics Research Department of MathematicsGoalpara College

An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass transfer are presented.A uniform magnetic field is assumed to be applied transversely to the direction of the flow with the consideration of the induced magnetic field with viscous and magnetic dissipations of *** porous plate is subjected to a constant suction velocity as well as a uniform mixed stream *** governing equations are solved by the perturbation technique and a numerical *** analytical expressions for the velocity field,the temperature field,the induced magnetic field,the skin-friction,and the rate of heat transfer at the plate are *** numerical results are demonstrated graphically for various values of the parameters involved in the *** effects of the Hartmann number,the chemical reaction parameter,the magnetic Prandtl number,and the other parameters involved in the velocity field,the temperature field,the concentration field,and the induced magnetic field from the plate to the fluid are *** increase in the heat source/sink or the Eckert number is found to strongly enhance the fluid velocity *** induced magnetic field along the x-direction increases with the increase in the Hartmann number,the magnetic Prandtl number,the heat source/sink,and the viscous *** is found that the flow velocity,the fluid temperature,and the induced magnetic field decrease with the increase in the destructive chemical *** of the study arise in the thermal plasma reactor modelling,the electromagnetic induction,the magnetohydrodynamic transport phenomena in chromatographic systems,and the magnetic field control of materials processing.

关键词： MHD perturbation technique network simulation method Eckert number mixed convection induced magnetic field viscous dissipation heat source/sink

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Analysis of the factors affecting LiDAR DTM accuracy in a steep shrub area

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International Journal of Digital Earth 2011年第6期4卷 521-538页

作者： J.Estornell L.A.Ruiz B.Vela´zquez-Martı´ T.Hermosilla departamento de ingenierı´a Cartogra´fica Geodesia y Fotogrametrı´aUniversidad Polite´cnica de ValenciaCamino de Vera s/nValencia 46022Spain departamento de ingenierı´a Rural y Agroalimentaria Universidad Polite´cnica de ValenciaValenciaSpain

The creation of a quality Digital Terrain Model(DTM)is essential for representing and analyzing the Earth in a digital *** continuous improvements in the acquisition and the potential of airborne Light detection and Ranging(LiDAR)data are increasing the range of applications of this technique to the study of the Earth *** aim of this study was to determine the optimal parameters for calculating a DTM by using an iterative algorithm to select minimum elevations from LiDAR data in a steep mountain area with shrub *** parameters were:input data type,analysis window size,and height *** effects of slope,point density,and vegetation on DTM accuracy were also *** results showed that the lowest root mean square error(RMSE)was obtained with an analysis window size of 10 m,5 m,and 2.5 m,rasterized data as input data,and height thresholds equal to or greater than 1.5 *** parameters showed a RMSE of 0.19 *** terrain slope varied from 010%to 5060%,the RMSE increased by 0.11 *** RMSE decreased by 0.06 m when point density was increased from 4 to 8 points/m2,and increased by 0.05 m in dense vegetation areas.

关键词： LiDAR digital earth Digital Terrain Model(DTM) filtering 3-D representation

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development and screening of(Ca-P-Si-F)-PEO coatings for biodegradability control of Mg-Zn-Ca alloys

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Journal of Magnesium and Alloys 2022年第8期10卷 2220-2237页

作者： Lara Moreno Marta Mohedano Raul Arrabal Endzhe Matykina departamento de ingeniería Química y de Materiales Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040 MadridSpain

PEO coatings were developed on MgZnxCayalloys for biomedical applications using different treatment times and a novel transparent electrolyte containing Ca,P,Si and *** characteristics and chemical composition of studied materials were evaluated using scanning electron microscopy,X-ray diffraction and optical *** investigations were performed for uncoated and coated materials using potentiodynamic polarization,electrochemical impedance spectroscopy and hydrogen evolution measurements in three media(0.9wt.%NaCl,α-MEM and inorganic part ofα-MEM).Findings revealed that Zn-rich intermetallics favour the formation of large voids in the ***,P,F and Si are successfully incorporated into the *** consist of crystalline phases(Mg O,Mg F_(2)and Ca,Si-rich compounds)and amorphous *** and organic components ofα-MEM solution accelerate corrosion of the bare substrates but have no significant influence on the corrosion resistance of coated ***,inorganicα-MEM can be considered as an appropriate medium for fast screening of PEO *** relatively small amount of F content in the barrier layer facilitates early failure of the coatings,which show undercoating ***-rich intermetallic particles in the undercoating crevice induce a more aggressive corrosive environment and enhanced micro-galvanic couple effect with the Mg *** leads to faster degradation of the coated alloys compared to the bare substrates.

关键词： Magnesium Biomaterials Plasma electrolytic oxidation Corrosion

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