检索结果-南通市图书馆

SLT: UNDERLYING MECHANISMS

在线全文

学校读者我要写书评

暂无评论

国际眼科杂志 2003年第1期3卷 111-111页

作者： j.a.alvarado Department of Ophthalmology University of California CA USA

When the Selecta-7000 is used in a clinical setting to perform SLT, the SP conditions specified by Parrish (1) are met completely. After SLT there is a distinct loss of pigmentation in the trabecular meshwork as melanin is preferentially targeted. Heat production is spatially confined intracellularly within the targeted chromophores as predicted by the SP concept Similarly, examination of human TM tissues by scanning electron

关键词：青光眼色素弥散激光光凝固疗法组织损伤 SLT

Nucleation and growth kinetics of La0.7Sr0.3Cr0.4Mn0.6O3-δ SOFC perovskite:Symmetry alteration evolution induced by Cu2+ and Ni2+ impregnation

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2016年第6期26卷 665-670页

作者： A.Concha-Balderrama G.Rojas-George j.alvarado-Flores H.Esparza-Ponce M.H.Bocanegra-Bernal A.Reyes-Rojas Centro de Investigación en Materiales Avanzados S.C.(CIMAV) Laboratorio Nacional de NanotecnologíaMiguel de Cervantes 120 Complejo Industrial ChihuahuaCd.de Chihuahua

La0.7Sr0.3Cr0.4Mn0.6O3-δperovskite nanoparticles have been synthetized using an ethylene glycol modified solgel method and impregnated by Cu0.75Ni0.25nanoparticles. The phase transitions and nucleation kinetics were studied by time resolved x-ray diffraction, Rietveld, Raman spectroscopy and high resolution transmission electron microscopy. Findings have shown that, an atomic disorder dominates from room temperature to 400 °C. Nanoparticles with crystal size johnson-Mehl-Avrami model had described the whole process, where the existence of two phases was shown before it reached its complete D3d6point group symmetry.

关键词： Perovskite structure Sol-gel method Composite Kinetics Rietveld

Microstructural evaluation and nanohardness of an AlCoCuCrFeNiTi high-entropy alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International journal of Minerals,Metallurgy and Materials 2019年第5期26卷 634-641页

作者： C.D.Gómez-Esparza R.Peréz-Bustamante j.M.alvarado-Orozco j.Mu?oz-Salda?a R.Martínez-Sánchez j.M.Olivares-Ramírez A.Duarte-Moller Centro de Investigación en Materiales Avanzados (CIMAV) Laboratorio Nacional de Nanotecnología CONACYT-Corporación Mexicana de Investigación en Materiales S.A.de C.V.(COMIMSA) Centro de Ingeniería y Desarrollo Industrial Querétaro Campus Centro de Investigación y de Estudios Avanzados del IPN Unidad Querétaro Universidad Tecnológica de San juan del Río Escuela de Ingeniería Civil Industrialy Mecánica Universidad De La Salle Bajío

An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA.

关键词： high-entropy alloys mechanical alloying microstructure nanoindentation

Carbon coating of air-sensitive insulating transition metal fluorides:An example study on α-Li3FeF6 high-performance cathode for lithium ion batteries

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2020年第20期52卷 107-115页

作者： Anna Basa Sławomir Wojtulewski Beata Kalska-Szostko Maciej Perkowski Elena Gonzalo Olga Chernyayeva Alois Kuhn Flaviano García-alvarado Institute of Chemistry University of Bialystokul.K.Ciolkowskiego 1K15-245 BialystokPoland Departamento de Química y Bioquímica Facultad de FarmaciaUniversidad CEU San Pablo28668 Boadilla del MonteMadridSpain Polish Institute of Physical Chemistry Kasprzaka St.44/5201-224 WarsawPoland CIC Energigune Parque Tecnologico de Alava01510 MinanoAlavaSpain

Li_(3)FeF_(6)has been the focus of research of fluorine-based cathode materials for lithium-ion *** of the low electronic conductivity of Li3 FeF6,the decrease of particle size,by an energyconsuming long-time ball milling process with carbon,is necessary to achieve a high electrochemical *** most successful method to enhance electrochemical activity,carbon coating,seemed to be impracticable,so far,for sensitive fluorides like Li3 *** this work,carbon coating on Li3 FeF6 particles has been successfully achieved for the first time,while avoiding both extended hydrolysis and Fe(Ⅲ)-Fe(Ⅱ)*** heat treatment and atmosphere,yielding the maximal transformation of organic carbon to both graphitised and disordered carbon,has been *** coating,with a thickness of approximately 2.5 nm,has been achieved by controlled thermal decomposition of glucose,under air,at 300℃.Raman and X-ray photoelectron spectroscopy(XPS)experiments have proved the existence of carbon and Fe2O3 on the surface of Li3FeF6 *** spectroscopy indicates the presence of organic residues from glucose *** to further reduce the orga nic carbon content results in a decrease of the amorphous carbon coating *** carbon-coated Li3 FeF6 nanoparticles deliver 122 mA h g^(-1)(85%of theoretical capacity)significantly higher than that of a noncoated sample(58 mA h g^(-1)).Even more,a significant beneficial effect of carbon coating on both capacity retention and coulombic efficiency is observed.

关键词： Lithium iron fluoride Hydrolysable fluoride Lithium battery Cathode Carbon coating

Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAD-7) functionalized with D_(2)EHPA

在线全文

学校读者我要写书评

暂无评论

journal of Rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： P.A.Martínez-Montoya R.G.Sanchez-alvarado D.Y.Medina-Velazquez M.L.Carrera-jota P.Garnica-Chávez A.de j.Morales-Ramirez Higher School of Chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery Rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

Antimicrobial properties of sea anemone Anthopleura nigrescens from Pacific coast of Costa Rica

在线全文

学校读者我要写书评

暂无评论

Asian Pacific journal of Tropical Biomedicine 2016年第5期6卷 418-421页

作者： Henry Borbn Sandra Vldes javier alvarado-Mesn Roy Soto Ilena Vega Laboratory of Research and Development in Chemical Technology Department of ChemistryNational University Laboratory of Biochemistry and Biotechnology of Proteins Department of Biological ScienceNational University Laboratory of Natural Products and Biological Essays Department of ChemistryNational University

Objective: To evaluate the antimicrobial and antifungal activities of the aqueous and partitioned extract of sea anemone Anthopleura nigrescens(A. nigrescens).Methods: The sea anemone A. nigrescens was collected, minced, homogenized,lyophilized and then further partitioned with diethyl ether, acetone, ethanol and *** fractions were evaluated for antimicrobial activity against bacterial and fungal ***: Acetone extract was found to produce a pronounced inhibition of 7.0 mm against Proteus vulgaris and diethyl ether extract inhibited Pseudomonas aeruginosa with an inhibition zone of 6.5 mm. In antifungal activity, ethanol extract showed good activity against Botrytis cinerea, Trichoderma harzianum and Rhizopus oryzae compared with other strains. Acetone and ethanol extract of A. nigrescens showed activity against all of pathogens tested. Slight activity was observed in the water extract with inhibition zone of 1.5 ***: The present study revealed that sea anemone A. nigrescens may also contain some biologically active agents which have potential activity against pathogenic microorganisms.

关键词： Biological activity Antibacterial Antifungal Bioactive Sea anemone

The significance of U-Pb zircon ages in zoned plutons:the case of the Flamenco pluton, Coastal Range batholith, northern Chile

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

Geoscience Frontiers 2019年第3期10卷 1073-1099页

作者： Natalia Rodríguez juan Díaz-alvarado Carlos Fernández Paulina Fuentes Christoph Breitkreuz Colombo Celso Gaeta Tassinari Departamento de Geología Universidad de Atacama Departamento de Ciencias de la Tierra Universidad de Huelva Institut für Geologie TU Bergakademie Freiberg High Resolution Geochronological Laboratory University of S?o Paulo

Compositionally zoned plutons, both layered and concentrically arranged, provide granitic exposures where the mechanisms and timing of the magmatic emplacement processes can be studied. The importance of in-situ geochemical differentiation and the magma replenishment rates are revealed by geochemistry and field relations, together with the increasingly accurate U-Pb geochronology, which has promoted the knowledge about the pluton incremental assembly *** Flamenco pluton, located in the Coastal Range of northern Chile, is part of the Upper Triassic to Early Cretaceous Andean intrusives formed in the western active margin of South America, and present a normal zoned structure with mafic magmatic facies(mostly gabbros and Qtz-diorites) close to the contacts with the host metasediments, and tonalites, granodiorites and granites in the inner areas. A combined study of the field relations, geochemistry and zircon geochronology of the magmatic facies was applied to determine the emplacement sequence of the Flamenco pluton, revealing three distinguishable domains separated by metasedimentary septa. The SW area is constituted by mostly homogeneous leucocratic granodiorites that yielded an age of 213 Ma as the best estimation for their emplacement age. Distinctive geochemical characteristics, such as the absence of an Eu anomaly, the depletion in HREE, or the highest Sr, Sr/Y and Ce/Yb values among the granodioritic facies of the pluton,involve lower T and/or higher P conditions at the magmatic source according to experimental *** conditions were established during an early stage of the Andean magmatic arc building that is firstly defined here as Upper Triassic. The NW and E domains of the pluton were sequentially emplaced between 194 Ma and 186 Ma and both the field relations and the detailed geochronological results suggest that the mafic facies intruded latter in the emplacement sequence. To the NW, Qtz-dioritic and gabbroic externally emplaced pulses ga

关键词： Zircon U-Pb geochronology Zoned plutons Andean magmatic arc Sequential emplacement Individual and statistical zircon ages

Investigating missing sources of glyoxal over China using a regional air quality model (RAMS-CMAQ)

在线全文

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2018年第9期30卷 108-118页

作者： jialin Li Meigen Zhang Guiqian Tang Fangkun Wu Leonardo M.A. alvarado Mihalis Vrekoussis Andreas Richter john P. Burrows State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPQ) Institute of Atmospheric Physics (IAP)Chinese Academy of Sciences (CAS) Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Center for Excellence in Urban Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China Institute of Environmental Physics and Remote Sensing IUP University of Bremen D-28203 Bremen Germany Center of Marine Environmental Sciences MARUM University of Bremen D-28203 Bremen Germany Energy Environment and Water Research Center the Cyprus Institute CY2121 Nicosia Cyprus

Currently, modeling studies tend to significantly underestimate observed space-based glyoxal （CHOCHO） vertical column densities （VCDs）, implying the existence of missing sources of giyoxal. Several recent studies suggest that the emissions of aromatic compounds and molar yields of glyoxal in the chemical mechanisms may both be underestimated, which can affect the simulated glyoxal concentrations. In this study, the influences of these two factors on glyoxal amounts over China were investigated using the RAMS-CMAQ modeling system for january and july 2014. Four sensitivity simulations were performed, and the results were compared to satellite observations. These results demonstrated significant impacts on glyoxal concentrations from these two factors. In case 1, where the emissions of aromatic compounds were increased three-fold, improvements to glyoxal VCDs were seen in high anthropogenic emissions regions. In case 2, where molar yields of glyoxal from isoprene were increased five-fold, the resulted concentrations in july were B-B-fold higher, achieving closer agreement between the modeled and measured glyoxal VCDs. The combined changes from both cases 1 and 2 were applied in case B, and the model succeeded in further reducing the underestimations of glyoxal VCDs. However, the results over most of the regions with pronounced anthropogenic emissions were still underestimated. So the molar yields of giyoxal from anthropogenic precursors were considered in case 4. With these additional mole yield changes （a two-fold increase）, the improved concentrations agreed better with the measurements in regions of the lower reaches of the Yangtze River and Yellow River in january but not in july.

关键词： Glyoxal Volatile organic compounds Molar yields RAMS-CMAQ China

Promoting Golbal Governance and Keeping Balanced Development

在线全文

学校读者我要写书评

暂无评论

Peace 2018年第4期 55-57页

作者： Fernando Alameda alvarado the First Colombia Think Tank Foundation

Before discussing the issue of global security governance today, we should review the past and see how we have come to today step by step and how we have established the present multipolar structure.I. World WarⅡand Bipolar Pattern After World WarⅡ, the world was divided into two camps headed by the United States and the Soviet Union respectively. The political and economic systems of the two comps were totally different.

关键词： Promoting Golbal Governance Balanced Development