检索结果-南通市图书馆

Study of the (Ca1–xSrx) RuO3System with nano-Crystals Prepared by the Solid-State Reaction Method

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Materials Sciences and Applications 2015年第1期6卷 16-22页

作者： Adolfo Quiroz Elizabeth Chavira José Eduardo Espinosa Rodolfo Palomino-Merino Ernesto Esteban Marinero Masaya nishioka valentín garcía-vázquez Facultad de Ciencias Fí sico-Matemá ticas Postgrado en F&iacute sica Aplicada Benem&eacute rita Universidad Autónoma Puebla Ciudad Universitaria Puebla M&eacute xico Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de M&eacute xico M&eacute xico D.F. M&eacute xico Purdue University West Lafayette IN USA Hitachi San José Research Center San Jos&eacute California USA Instituto de Fí sica LRT Benem&eacute rita Universidad Autónoma de Puebla Puebla M&eacute xico

We present a study of their structure, morphology, electrical and magnetic properties on the (Ca1–xSrx) RuO3 system for x = 0.0, 0.07, 0.10, 0.15 and 1.0. The samples were prepared by the solidstate reaction method in air at ambient pressure and heat in the 700℃ - 800℃ range for 48 h. By X-ray powder diffraction (XRD), we determine a solid solution until x = 0.15. Scanning electron microscopy (SEM) indicates that the particle size is 77 - 266 nm. The resistance measurements, as a function of temperature measurements from 7 to 300 K the (Ca1–xSrx) RuO3 system for x = 0.0, 0.07, 0.10, 0.15 and 1.0 show a metallic behaviour. We can even observe that the resistance of the samples is due to the partial substitution of Sr2+ ions and Ru ion valence. Finally, the sample x = 0.07 has a magnetization applied high field to 10 K, whereas that to 300 K does not have a magnetization.

关键词： Solid-State Reaction XRD SEM Electric Resistivity Magnetic Properties

Solar-assisted photocatalytic water splitting using defective UiO-66 solids from modulated synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

nano Research 2024年第5期17卷 4134-4150页

作者： Celia M.Rueda-navarro María Cabrero-Antonino Paula Escamilla valentín Díez-Cabanes Dong Fan Pedro Atienzar Belén Ferrer Ignacio vayá Guillaume Maurin Herme G.Baldoví Sergio navalón Departamento de Química Universitat Politècnica de ValènciaCamino de Vera s/nValencia 46022Spain Instituto de Ciencia Molecular(ICMOL) Universitat de ValènciaPaterna 46980Spain ICGM Univ.MontpellierCNRSENSCMMontpellier34095France Instituto de Tecnología Química(UPv-CSIC) Universitat Politècnica de ValènciaAvenida de los Naranjos s/nValencia 46022Spain

Metal-organic frameworks(MOFs)are attracting increasing interests as photocatalysts for solar-driven hydrogen production from *** paper reports on a comparative study of using either acetic acid(AA)or trifluoroacetic acid(TFA)as the representative UiO-66 organic modulators for synthesizing visible light responsive UiO-66(Zr)-X(X:nH_(2) or nO_(2))photocatalysts for water *** results show that photocatalytic hydrogen generation from a water/methanol mixture can be improved by varying the nature and amount of the modulator employed to prepare the different UiO-66(Zr)-X(X:nH_(2) or nO_(2))solid ***-66(Zr)-nH_(2) was the most active photocatalyst,followed by UiO-66(Zr)-nO_(2),both prepared with 12 equivalents of AA with respect to the organic *** UiO-66(Zr)-nH_(2) solid was more active than the parent MOF in photocatalytic overall water splitting(OWS)(H_(2) and O_(2) production of 450 and 160μmol·g^(-1),respectively,in 5 h;apparent quantum yield(AQY)at 400 nm of 0.06%)in the absence of methanol and compares favourably with analogous *** on the photocatalytic activity of the most active solids of both series was obtained by means of a series of techniques,including ultraviolet-visible(Uv-vis)diffuse reflectance,X-ray photoelectron spectroscopy(XPS),laser flash photolysis(LFP),electron spin resonance(ESR),photoluminescence and photoelectrochemical measurements together with density functional theory(DFT)*** results showed that organic acid modulators can be used to enhance the photocatalytic activity of missing linker UiO-66 defective materials in solar-powered water splitting.

关键词： heterogeneous photocatalysis metal-organic frameworks(MOFs) UiO-66 materials carboxylic acid modulators water splitting solar light

Generalized Height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Forestry 2024年第3期14卷 214-232页

作者： Jonathan Hernández-Ramos valentín José Reyes-Hernández Héctor Manuel De los Santos-Posadas Aurelio Manuel Fierros-González Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza Instituto nacional de Investigaciones Forestales Agrcolas y Pecuarias (INIFAP)-Campo Experimental Bajo Celaya Guanajuato Mxico Colegio de Postgraduados (COLPOS) Campus Montecillo Mxico InIFAP Campo Experimental Valle de Mxico Texcoco Mxico InIFAP Campo Experimental Valle del Guardiana Durango Mxico

Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized H-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of nuevo San Juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (nLS), 10 generalized H-d models were fitted to 883 and 1226 pairs of H-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with nLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots.

关键词： Random Covariate Random Effects variance Structure Forest Inventories Forest Management Mixed Models

Coping with drought?Effects of extended drought conditions on soil invertebrate prey and diet selection by a fossorial amphisbaenian reptile

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2023年第4期69卷 367-376页

作者： José Martín Jesús Ortega Roberto garcía-Roa Gonzalo Rodríguez-Ruiz Ana Pérez-Cembranos valentín Pérez-Mellado Departamento de Ecología Evolutiva Museo Nacional de Ciencias NaturalesCSICMadridSpain Institute of Evolutionary Biology CSIC-Universitat Pompeu FabraBarcelonaSpain Ethology Lab Cavanilles Institute of Biodiversity and Evolutionary BiologyUniversity of ValenciaValenciaSpain Departamento de Biología Animal Universidad de SalamancaSalamancaSpain

Arid climates are characterized by a summer drought period to which animals seem ***,in some years,the drought can extend for unusually longer *** the effects of these current extreme weather events on biodiversity can help to understand the effects of climate change,as models predict an increase in drought ***,we examined the effects of“unusual”extended drought on soil invertebrate prey availability and on diet composition(based on fecal contents)and diet selection of a fossorial amphisbaenian,the checkerboard worm lizard Trogonophis *** data show interannual variations in summer drought *** abundance and diversity of soil invertebrates in spring were high,and similar to those found in a“normal”early autumn,after some rain had ended with the summer *** contrast,in years with“unusual”extended drought,abundance,and diversity of soil invertebrates in early autumn were very ***,there were seasonal changes in amphisbaenians’diet;in autumn with drought,prey diversity,and niche breadth decreased with respect to spring and autumns after some rain had *** did not eat prey at random in any season,but made some changes in prey selection that may result from drought-related restrictions in prey ***,in spite that amphisbaenians showed some feeding flexibility,their body condition was lower in autumn than in spring,and much lower in autumn with *** extended drought became the norm in the future,amphisbaenians might suffer important negative effects for their health state.

关键词： amphisbaenians drought feeding ecology soil invertebrates Trogonophis wiegmanni weather conditions

The protein-protein interaction landscape of transcription factors during gynoecium development in Arabidopsis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2023年第1期16卷 260-278页

作者： Humberto Herrera-Ubaldo Sergio E.Campos Pablo López-Gómez valentín Luna-garcía víctor M.Zúñiga-Mayo Gerardo E.Armas-Caballero Karla L.González-Aguilera Alexander DeLuna nayelli Marsch-Martínez Carlos Espinosa-Soto Stefan de Folter Unidad de Genómica Avanzada(UGA-LAnGEBIO) Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(CINVESTAV-IPN)IrapuatoGuanajuato 36824México Departamento de Biotecnología y Bioquímica Unidad IrapuatoCINVESTAV-IPNIrapuatoGuanajuato 36824México Instituto de Física Universidad de San Luis PotosíSan Luis PotosíSLP 78290México Present address:Department of Plant Sciences University of CambridgeCambridgeUK Present address:Department of Molecular and Cellular Biology University of California DavisDavisCAUSA Present address:COnACYT Instituto de FitosanidadColegio de PostgraduadosCampus MontecilloTexcocoMéxico

Flowers are composed of organs whose identity is defined by the combinatorial activity of transcription factors(TFs).The interactions between MADS-box TFs and protein complex formation have been schematized in the floral quartet model of flower *** gynoecium is the flower’s female reproductive part,crucial for fruit and seed production and,hence,for reproductive *** the establishment of carpel identity,many tissues arise to form a mature *** have been described as regulators of gynoecium development,and some interactions and complexes have been ***,broad knowledge about the interactions among these TFs and their participation during development remains *** this study,we used a systems biology approach to understand the formation of a complex reproductive unit—as the gynoecium—by mapping binary interactions between well-characterized *** analyzed almost 4500 combinations and detected more than 250 protein-protein interactions(PPIs),resulting in a process-specific interaction *** analyses suggest hidden functions and novel roles for many *** addition,we observed a close relationship between TFs involved in auxin and cytokinin-signaling pathways and other ***,we analyzed the network by combining PPI data,expression,and genetic data,which helped us to dissect it into several dynamic spatio-temporal subnetworks related to gynoecium development ***,we generated an extended PPI network that predicts new players in gynoecium *** together,all these results serve as a valuable resource for the plant community.

关键词： interactome networks transcription factors gynoecium development

DnA metabarcoding the diet of Podarcis lizards endemic to the Balearic Islands

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2023年第5期69卷 514-526页

作者： Iris Alemany Ana Pérez-Cembranos valentín Pérez-Mellado JoséAurelio Castro Antònia Picornell Cori Ramon JoséA Jurado-Rivera Deptartment of Biology Universitat de les Illes BalearsCtra.Valldemossa km 7’5Palma de Mallorca07122Balearic IslandsSpain and Department of Animal Biology Universidad de SalamancaCampus Miguel de Unamuno s/n37007SalamancaSpain

Dietary studies are essential to unravel the functioning of ecosystems and ultimately to understand *** task,which at first may seem simple,becomes especially complex in those cases of omnivorous species with highly variable *** this regard,the emergence of next-generation DnA sequencing methodologies represents a powerful tool to address the *** we implement a high-throughput metabarcoding strategy based on the analysis of four molecular markers aimed at sequencing both mitochondrial(animal prey)and chloroplast(diet plants)genome fragments from fecal samples of two lizard species endemic to the Balearic Archipelago(Podarcis lilfordi and ***)obtained through non-invasive *** results allowed for the characterization of their diets with a high degree of taxonomic detail and have contributed a large number of new trophic *** reported diets are based mainly on the consumption of arthropods,mollusks and plants from a diversity of taxonomic orders,as well as carrion and marine *** analyses also reveal inter-and intra-specific differences both in terms of seasonality and geographical distribution of the sampled lizard *** molecular findings provide new insights into the trophic interactions of these threatened endemic lizards in their unique and isolated ecosystems.

关键词： Balearic archipelago COI metabarcoding Podarcis lilfordi Podarcis pityusensis psbA-trnH rbcL trophic ecology

Recent progress on oxygen and hydrogen peroxide reduction reactions on Pt single crystal electrodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Catalysis 2020年第5期41卷 732-738页

作者： valentín Briega-Martos Enrique Herrero Juan M.Feliu 阿利坎特大学电化学研究所阿利坎特西班牙

The oxygen reduction reaction(ORR)is probably the most important cathodic process in electrocatalysis because of its universal role as comburent in life and key applications in several fields such as fuel cells,corrosion processes or lithium-air *** many experimental and theoretical investigations that have been carried out during the last years and contributed to improve the knowledge about this reaction,the complete mechanism for the ORR is not elucidated yet[1].The ORR involves the exchange of 4 electrons and 4 protons for the complete reduction of O2 to water(Eq.1).The reaction mechanism is complex and implies the formation of several intermediates involving O=O bond scission and O–H bond formation.

关键词：巯基金纳米簇金属氧化物载体巯基配体一氧化碳氧化

Anterior tibiofemoral dislocation after total knee arthroplasty:A case report and literature review

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Traumatology 2022年第4期25卷 237-241页

作者： Alejandro Almoguera-Martinez Catarina Godinho-Soares valentín Calcedo Bernal Jose-Antonio Pareja Esteban Marta garcia-Lopez Miguel Angel Plasencia Arriba Orthopaedic and Traumatology Resident at Príncipe de Asturias Hospital Alcala de HenaresMadridSpain

Anterior tibiofemoral dislocation after total knee arthroplasty is an extremely rare and serious *** English-published papers,we found only 15 relevant cases,3 of which presented vascular *** manuscript aims to present a 77-year-old woman with a TC-Plus(Smith&nephew)cruciate-retaining type in first time of knee prosthesis,who suffered an anterior tibiofemoral dislocation and were admitted to our *** clinical management and outcome were ***,a review of literature was *** concluded that early detection and surgical intervention of vascular injury is the key in the survival of the *** there is still knee instability after acute recovery,it seems that revision surgery with constrained total knee arthroplasty can bring about good clinical and functional results.

关键词： Arthroplasty Knee dislocation Knee replacement Popliteal artery Risk factors

Phase diagram of a distorted kagome antiferromagnet and application to Y-kapellasite

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 79-88页

作者： Max Hering Francesco Ferrari Aleksandar Razpopov Igor I.Mazin Roser valentí Harald O.Jeschke Johannes Reuther Helmholtz-Zentrum Berlin für Materialien und Energie Hahn-Meitner Platz 114109BerlinGermany Dahlem Center for Complex Quantum Systems and Fachbereich Physik Freie Universität Berlin14195BerlinGermany Institute for Theoretical Physics Goethe University FrankfurtMax-von-Laue-Straße 160438Frankfurt am MainGermany Department of Physics and Astronomy and Quantum Science and Engineering CenterGeorge Mason UniversityFairfaxVA22030USA Research Institute for Interdisciplinary Science Okayama UniversityOkayama700-8530Japan

We investigate the magnetism of a previously unexplored distorted spin-1/2 kagome model consisting of three symmetry-inequivalent nearest-neighbor antiferromagnetic Heisenberg couplings J_(■),J,and J′,and uncover a rich ground state phase diagram even at the classical *** analytical arguments and numerical techniques we identify a collinear Q^(→)=0 magnetic phase,two unusual non-collinear coplanar Q^(→)=(1/3,1/3)phases and a classical spin liquid phase with a degenerate manifold of non-coplanar ground states,resembling the jammed spin liquid phase found in the context of a bond-disordered kagome *** further show with density functional theory calculations that the recently synthesized Y-kapellasite Y_(3)Cu_(9)(OH)_(19)C_(l8) is a realization of this model and predict its ground state to lie in the region of Q^(→)=(1/3,1/3)order,which remains stable even after the inclusion of quantum fluctuation effects within variational Monte Carlo and pseudofermion functional renormalization *** presented model opens a new direction in the study of kagome antiferromagnets.

关键词： group distorted diagram