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Discretized Miller approach to assess effects on boundary layer ingestion induced distortion

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Chinese Journal of Aeronautics 2017年第1期30卷 235-248页

作者： esteban valencia v.ctor Hidalgo Devaiah Nalianda Laskaridis Panagiotis Riti Singh Departamento de Ingeniería Mecánica Facultad de Ingeniería Mecánica Escuela Politécnica Nacional Ladron de Guevara E11-253 Quito 17-01-2759 Ecuador School of engineering Cranfield University Bedford MK430AL United Kingdom

The performance of propulsion configurations with boundary layer ingestion（BLI） is affected to a large extent by the level of distortion in the inlet flow field. Through flow methods and parallel compressor have been used in the past to calculate the effects of this aerodynamic integration issue on the fan performance; however high-fidelity through flow methods are computationally expensive, which limits their use at preliminary design stage. On the other hand, parallel compressor has been developed to assess only circumferential distortion. This paper introduces a discretized semi-empirical performance method, which uses empirical correlations for blade and performance calculations. This tool discretizes the inlet region in radial and circumferential directions enabling the assessment of deterioration in fan performance caused by the combined effect of both distortion patterns. This paper initially studies the accuracy and suitability of the semiempirical discretized method by comparing its predictions with CFD and experimental data for a baseline case working under distorted and undistorted conditions. Then a test case is examined,which corresponds to the propulsor fan of a distributed propulsion system with BLI. The results obtained from the validation study show a good agreement with the experimental and CFD results under design point conditions.

关键词： BLI Correlations Distortion embedded propulsors empirical Mean-line analysis Turbomachinery

Non-Canonical Functions of the e2F/DP Pathway with emphasis in Plants

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Phyton-International Journal of experimental Botany 2021年第2期90卷 307-330页

作者： v.ctor A.Sánchez-Camargo Samantha Romero-Rodríguez Jorge M.vázquez-Ramos Facultad de Química Departamento de BioquímicaUniversidad Nacional Autónoma de MéxicoAvenida Universidad y CopilcoCiudad de México04510México Plant Development and(epi)Genetics Group Swammerdam Institute for Life SciencesUniversiteit van AmsterdamAmsterdam1098XHNetherlands

The e2F/DP pathway is a widely conserved regulatory mechanism in pluricellular *** family of e2F and DP transcription factors was originally described having a role in the transition from the G1 to the S phase of the cell ***,the discovery of hundreds of possible gene targets and their involvement in many other biochemical processes,soon showed that they participated in cell development and differentiation,chromatin remodeling,DNA repair and *** e2F/DP transcription factors can act as either activators or repressors of transcription depending on their association to other regulatory proteins,particularly the retinoblastoma protein,or even depending to their protein structure that can define their *** plants the e2F/DP pathway also regulates endoreduplication,a process present along the life cycle,from organ elongation to root differentiation and *** transcription factors also help plant cells to respond to environmental disturbances such as those caused by different types of radiation,or by *** review focuses on the“so called”non-canonical functions of the e2F/DP family proteins in animal and plant cells,that are in fact essential activities that connect regulatory circuits among multiple metabolic pathways by means of their atypical functions.

关键词： e2F DP transcription factors atypical functions plant cells

effect of initial microstructure on austenite formation kinetics in high-strength experimental microalloyed steels

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International Journal of Minerals,Metallurgy and Materials 2015年第12期22卷 1304-1312页

作者： edgar López-Martínez Octavio vázquez-Gómez Héctor Javier vergara-Hernández Bernardo Campillo Faculty of Chemistry Metallurgical Engineering Department Autonomous National University of Mexico National Council for Science and Technology Metallurgy Science Postgraduate Programme Morelia Institute of Technology Institute of Physical Sciences Autonomous National University of Mexico

Austenite formation kinetics in two high-strength experimental microalloyed steels with different initial microstructures comprising bainite-martensite and ferrite-martensite/austenite microconstituents was studied during continuous heating by dilatometric analysis. Austenite formation occurred in two steps：（1） carbide dissolution and precipitation and （2） transformation of residual ferrite to austenite. Dilatometric analysis was used to determine the critical temperatures of austenite formation and continuous heating transformation diagrams for heating rates ranging from 0.03°C.s^-1 to 0.67°C.s^-1. The austenite volume fraction was fitted using the Johnson-Mehl-Avrami-Kolmogorov equation to determine the kinetic parameters k and n as functions of the heating rate. Both n and k parameters increased with increasing heat- ing rate, which suggests an increase in the nucleation and growth rates of austenite. The activation energy of austenite formation was determined by the Kissinger method. Two activation energies were associated with each of the two austenite formation steps. In the first step, the austenite growth rate was controlled by carbon diffusion from carbide dissolution and precipitation; in the second step, it was controlled by the dissolution of residual ferrite to austenite.

关键词： non-isothermal kinetics microalloyed steel austenite heating dilatometry

early-Age Properties Development of Recycled Glass Powder Blended Cement Paste:Strengths,Shrinkage,Nanoscale Characteristics,and environmental Analysis

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Journal of Renewable Materials 2023年第4期11卷 1835-1852页

作者： Zhihai He Menglu Shen Jinyan Shi Jingyu Chang v.ctor Revilla-Cuesta Osman Gencel College of Civil engineering Shaoxing UniversityShaoxing312000China Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province Shaoxing312000China School of Civil engineering Central South UniversityChangsha410075China Department of Civil engineering Escuela Politécnica SuperiorUniversity of Burgosc/Villadiego s/nBurgos09001Spain Civil engineering Department Bartin UniversityBartin74100Turkey

Recycling solid waste in cement-based materials cannot only ease its load on the natural environment but also reduce the carbon emissions of building *** study aims to investigate the effect of recycled glass powder(RGP)on the early-age mechanical properties and autogenous shrinkage of cement pastes,where cement is replaced by 10%,20%and 30%of *** addition,the microstructure and nano-mechanical properties of cement paste with different RGP content and water to binder(W/B)ratio were also evaluated using SeM,MIP and nanoindentation *** results indicate that the early-age autogenous shrinkage decreases with the increase of RGP content and W/B *** the mechanical strength deteriorates due to the addition of RGP,it can be compensated by reducing the W/B *** the addition of RGP increases the total porosity of the hardened paste,it reduces the small size porosity(e proportions of different types of C-S-H are changed,and the volume fraction of porosity is increased,but that of hydration products of cement paste is reduced due to the incorporation of *** its pozzolanic activity,the mitigated shrinkage deformation that RGP is generating in cement pastes is encouraging for its use as a novel supplementary cementitious material that reduces the early-age cracking risk of cement-based ***,the life cycle assessments indicate that the RGP-cement component is an economical and eco-friendly novel engineering material.

关键词： Cement paste waste glass powder autogenous shrinkage microstructure nanoindentation

Contrasting arthropod communities associated with dwarf mistletoes Arceuthobium globosum and A. vaginatum and their host Pinus hartwegii

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Journal of Forestry Research 2018年第5期29卷 1351-1364页

作者： León F.Chávez-Salcedo Mónica e.Queijeiro-Bolanos v.ctor López-Gómez Zenón Cano-Santana Blanca e.Mejía-Recamier Aurea Mojica-Guzmán Laboratorio de Interacciones y Procesos ecologicos Departamento de Ecología y Recursos Naturales Facultad de Ciencias Universidad Nacional Autonoma de Moico Av.Universidad 3000 04510 Mexico City Mexico Laboratorio de ecología y Sistemática de Microartr dpodos Departamento de Ecología y Recursos Naturales Facultad de Ciencias Universidad Nacional Autónoma de M4xico Av.Universidad 3000 04510 Mexico City Mexico Instituto de Biologia Universidad Nacional Autdnoma de Mexico Av. Universidad 3000 04510 Mexico City Mexico Departamento de ecologia Facultad de Ciencias Naturales Universidad Autdnoma de Quer6taro Av.de las Ciencias s/n 76230 Queretaro Queretaro Mexico

Arthropod communities and epiphytic plants associated with tree canopies have been widely studied and have revealed a great diversity of organisms; however,the community hosted by parasitic plants,such as dwarf mistletoes,remains poorly *** the coniferous forests of North America,dwarf mistletoe infection（Arceuthobium spp.） significantly damages the health of the forest,causing large financial losses for the forest industry,but it also positively affects diversity,especially of mammals and *** study examined the attributes of the arthropod communities associated with two species of dwarf mistletoe [Arceuthobium globosum Hawksw.＆ Wiens and ***（Humb.＆ *** Willd.） ***] and their host Pinus hartwegii *** 2010,in five sites located in Zoquiapan（Central Mexico）,we collected plant tissue from the three species *** were separated from the plant tissue and identified to the finest level *** collected 32,059 individuals,for which51 morphospecies were identified,belonging to 15 taxonomic orders; the most abundant orders for the three plants were Prostigmata,Thysanoptera and *** community associated with *** had the highest value of diversity（H＇= 1.47; ***,H＇= 0.64; ***,H＇= 0.68） and species richness（S = 40; ***,S = 30; ***,S = 35）; while abundance was significantly higher for the mistletoes（***,n = 407 individuals/sample; ***,n = 536 individuals/sample; ***,n = 134 individuals/sample）.Species richness,abundance and diversity were significantly different for the three studied plants,as well for sampling month and the interaction of these two factors（except for diversity）.The results suggest that the canopy of *** is an important element in the ecosystem,providing a mosaic of resources and conditions to the associated *** also propose that mistletoes are key species within the forest canopy,as they greatly influence the establishment of d

关键词： Arceuthobium spp Pinus hartwegii Arthropod community Thrips Mites Hemiparasitic plants

Non-linear modeling of kinetic and equilibrium data for the adsorption of hexavalent chromium by carbon nanomaterials:Dimension and functionalization

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Chinese Journal of Chemical engineering 2019年第4期27卷 912-919页

作者： Miguel de la Luz-Asunción eduardo e.Pérez-Ramírez Ana L.Martínez-Hernández v.ctor M.Castano v.ctor Sánchez-Mendieta Carlos velasco-Santos Facultad de Quimica Universidad Autonoma del Estado de Mexico Km. 12 de la carretera Toluca-Atlacomulco C.P. 50200 San Cayetano Toluca Estado de Mexico Mexico Tecnologico Nacional de Mexico-Instituto Tecnologico de Queretaro Division de Estudios de Posgrado e Investigacion Av. Tecnologico s/n esq. GraL Mariano Escobedo Col. Centro Historico C.P. 76000 Santiago de Queretaro Queretaro Mexico Centro de Fisica Aplicada y Tecnologia Avanzada Universidad Nacional Autonoma de Mexico Boulevard Juriquilla 3001 Queretaro 76230 Mexico

The adsorption capacities for the removal of hexavalent chromium from aqueous solutions by six carbon nanomaterials have been evaluated. Single-walled and multi-walled carbon nanotubes as received and after oxidation treatment, graphene oxide and reduced graphene oxide are the materials with different dimension and functionalization compared in this research. Carbon nanotubes have been modified using hydrogen peroxide as oxidizing agent under microwave radiation. The oxidation treatment on carbon nanotubes has a positive effect increasing the adsorbent–adsorbate interaction. Rate-controlling mechanisms and equilibrium data are analyzed using non-linear models. Non-linear method is proposed as the most suitable method for determining the kinetic and equilibrium parameters. The values of adsorption energy(e) obtained from the Dubinin–Radushkevich isotherm,have been found around 0.371 and 0.870 k J·mol-1, indicating physical adsorption. Therefore, the pseudo-second order model represents better the kinetic experimental data. The results show that the Langmuir isotherm provides a slightly better fit to the experimental data compared with the Freundlich isotherm, indicating homogeneous distribution of active sites on carbon nanomaterials and monolayer adsorption. The separation factors RLare found in the range of 0–1, suggesting that the adsorption process is suitable for all adsorbents. The mechanisms for hexavalent chromium removal have been proposed as electrostatic interactions and hydrogen bonding.

关键词： Carbon nanotubes Graphene Adsorption Hexavalent chromium Kinetic

Phylogeny,genetics,and the partial life cycle of Oncomegas wageneri in the Gulf of Mexico

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Current Zoology 2020年第3期66卷 275-283页

作者： Andrés MARTINeZ-AQUINO v.ctor M.vIDAL-MARTINeZ F.Sara CeCCAReLLI Oscar MeNDeZ Lilia C.SOLeR-JIMeNeZ M.Leopoldina AGUIRRe-MACeDO Facultad de Ciencias Universidad Autonoma de Baja CaliforniaCarretera Transpeninsular 3917Fraccionamiento PlayitasEnsenadaBaja California 22860Mexico Laboratorio de Patologia Acuatica Departamento de Recursos del MarCentro de Investigacion y de Estudios Avanzados del Instituto Politecnico NacionalUnidad MeridaCordemexCarretera Antigua a Progreso Km.6MeridaYucatan 97310Mexico Departamento de Biologia de la Conservacion CONACYT-Centro de Investigacion Cientifica y de Educacion Superior de EnsenadaCarretera Ensenada-TjuanaEnsenadaBaja California 22860Mexico Laboratorio de Hidrobiologia Facultad de Biologia-XalapaUniversidad VeracruzanaCircuito Gonzalo Aguirre Beltran S/N Zona UniversitariaXalapaVeracruz 91090Mexico

Despite the diversity and ecological importance of cestodes,there is a paucity of studies on their life stages(i.e.,complete lists of intermediate,paratenic,and definitive hosts)and genetic *** example,in the Gulf of Mexico(GoM)98 species of cestodes have been reported to date;however,data on their intraspecific genetic variation and population genetic studies are *** trypanorhynch cestode,Oncomegas wageneri,is found(among other places)off the American Western Atlantic Coast,including the GoM,and has been reported as an adult from stingrays and from several teleost species in its larval form(as plerocerci).This study represents the first report of 2 previously unregistered definitive hosts for ***,namely the Atlantic sharpnose shark Rhizoprionodon terraenovae and the southern stingray Hypanus *** this work,partial sequences of the 28S(region D1-D2)ribosomal DNA were analyzed to include *** within an eutetrarhynchoid phylogenetic *** *** individuals(which included plerocerci and adults)were recovered as monophyletic and Oncomegas celatus was identified as the sister species of ***,population genetic analyses of *** from the southern GoM were carried out using DNA sequences of the mitochondrial cytochrome c oxi-dase subunit 1(COI)gene,which reflected high genetic variation and a lack of genetic structure among the 9 oceanographic sampling *** on these results,*** is panmictic in the southern *** extensive sampling along the species entire distribution is necessary to make more accurate inferences of population genetics of ***.

关键词： barcode Cyclopsetta chittendeni population genetics Hypanus americanus Oncomegas Rhizoprionodon terraeno-vae 28S rDNA(D1-D2)

effect of the interfacial electric field on the HeR on Pt(111)modified with iron adatoms in alkaline media

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Chinese Journal of Catalysis 2022年第11期43卷 2826-2836页

作者： Francisco J.Sarabia v.ctor Climent Juan M.Feliu Instituto Universitario de electroquímica Universidad de AlicanteCarretera San Vicente del Raspeig s/nE-03690 San Vicente del RaspeigAlicanteSpain

The study of the hydrogen evolution reaction(HeR)aimed to reach a deeper understanding of the parameters that control the rate of this reaction is of great importance given the technical relevance of hydrogen production as an energy v.ctor in the so-called hydrogen *** previous works,laser-induced temperature jump(LITJ)experiments on Pt(111)modified with Ni(OH)_(2)in alkaline media have revealed the importance of the interfacial electric field in the rate of the *** was hypothesised that small amounts of Ni(OH)_(2)cause a decrease of the electric field because of a negative shift of the pzfc toward the onset of the hydrogen *** this work,to test the validity of this hypothesis,the study has been extended to Pt(111)surfaces modified with Fe(OH)_(2).The modified surfaces have been studied voltammetrically,and the voltammetric charges have been *** voltammograms show a peak in the hydrogen evolution region that suggest the transformation in the adlayer from Fe(II)to Fe(0).In agreement with the coulometric analysis,the voltammetric features in the OH adsorption region would be related with the oxidation to the+3 valence *** results obtained with LITJ method reflect the existence of a strong interaction of the Fe oxophilic species with the water molecules,shifting the potential of maximum entropy away from the onset of the ***,the most catalytic surface is the one with the lowest Fe coverage.

关键词： Hydrogen evolution reaction Iron adatoms Platinum single crystal Pt(111) Laser induced temperature jump Interfacial electric field Potential of zero charge

Kinetic Rates of the Fischer Tropsch Synthesis on a Co/Nb_2O_5 Catalyst

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Journal of Natural Gas Chemistry 2006年第4期15卷 307-312页

作者： v.ctor R.Ahón Paulo L.C.Lage Carlos D.D.de Souza Fabiana M.Mendes Martin Schmal Federal University of Rio de Janeiro Programa de engenharia Química COPPE/UFRJ C.P.6850221941-972Rio de JaneiroRJBrazil

The kinetics of the Fischer-Tropsch reaction over a Co/Nb2O5 catalyst in a fixed bed reactor was investigated experimentally. experiments were carried out under isothermal and isobaric conditions （T=543 K, P=2.1 MPa） and under different conditions of several H2/CO feed molar ratio （0.49-4.79）, space velocities （0.2-3.8 h^-1）, mass of catalyst （0.3-1.5 g）, and CO conversion （10%-29%）. Synthesis gas conversion was measured and data were reduced to estimate the kinetic parameters for different Langmuir-Hinshelwood rate expressions. Differential and integral reactor models were used for the nonlinear regression of kinetics parameters. One of the rate equations could well explain the data. The hydrocarbon product distributions that were experimentally determined exhibited an unusual behavior, and a possible explanation was discussed.

关键词： Fischer-Tropsch natural gas kinetics selectivity