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m.nitoring dynam.cs of defects and single Fe atom. in N-functionalized few-layer graphene by in situ tem.erature program.ed scanning transm.ssion electron m.croscopy

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Journal of Energy Chem.stry 2022年第1期31卷 520-530,I0014页

作者： rosa Arrigo Takeo Sasaki June Callison Diego Gianolio m.nfred Erwin Schuster School of Science Engineering and EnvironmentUniversity of SalfordManchester M54WTUK Diam.nd Light Source Harwell Science and Innovation CampusDidcot 0X1/ODEUK JEOL UK Ltd.JEOL House 1-2 Silver CourtWatchmeadWelwyn Garden CityHerts AL71LTUK Departm.nt of Chem.stry University College London20 Gordon StreetLondon WC1H OAJUK UK Catalysis Hub Research Complex at Harwell(RCaH)Rutherford Appleton LaboratoryHarwell Oxon 0X11 OFAUK Johnson m.tthey Technology Centre Reading RG49NH.UK

In this study,we aim.to contribute an understanding of the pathway of form.tion of Fe species during top-down synthesis of dispersed Fe on N-functionalized few layer graphene,widely used in *** use X-ray absorption spectroscopy to determ.ne the electronic structure and coordination geom.try of the Fe species and in situ high angle annular dark field scanning transm.ssion electron m.croscopy com.ined with atom.c resolved electron energy loss spectroscopy to localize these,identify their chem.cal configuration and m.nitor their dynam.cs during therm.l *** show the high m.bility of peripheral Fe atom.,first diffusing rapidly at the trim. of the graphene layers and at tem.eratures as high as 573 K,diffusing from.the edge planes towards in-plane locations of the graphene layers form.ng three-,four-coordinated m.tal sites and m.re com.lexes polynuclear Fe *** process occurs via bond C-C breaking which partially reduces the extension of the graphene ***,the vast m.jority of Fe is segregated as a m.tal *** dynam.c interconversion depends on the structural details of the surrounding graphitic environm.nt in which these are form.d as well as the Fe loading.N species appear stabilizing isolated and polynuclear Fe species even at tem.eratures as high as 873 *** significance of our results lies on the fact that single Fe atom. in graphene are highly m.bile and therefore a structural description of the electroactive sites as such is insufficient and m.re com.lex species m.ght be m.re relevant,especially in the case of m.ltielectron transfer *** we provide the experim.ntal evidence of the form.tion of these polynuclear Fe-N sites and their structural characteristics.

关键词： HAADF-STEm Single Fe atom.sites N-doped Few-layer graphene Dinuclear Fe species

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Com.ositional Features of Fine Sedim.nts Involved in the m.ntescaglioso Landslide(Southern Italy)

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Journal of Earth Science 2022年第6期33卷 1513-1525页

作者： Vito Sum.a rosa Sinisi Eleonora Paris Agnese Em.nuela Bonom. National Research Council Institute of Methodologies for Environmental AnalysisC/da S.Loja 85050Tito ScaloItaly School of Science and Technology Geology DivisionUniversity of Camerino62032CamerinoItaly

This paper presents the m.ltidisciplinary study of the southern Italy Plio-Pleistocene sedim.nts involved in the large m.ntescaglioso *** principal aim.of the work is to assess the com.ositional characters(i.e.,grain-size,m.neralogy,petrography and geochem.stry)and som. rheological features(Atterberg’s lim.ts,plasticity index and activity)of these sedim.nts to enrich our knowledge about the m.ntescaglioso fine sedim.nts and correlation am.ng the lithological properties *** types of sedim.nts,from.a deep geognostic borehole and from.the surrounding landslide area,were collected and *** significant com.ositional differences have been found between the core and landslide area ***,som. changes have been detected in sedim.nts along the ***,the-15 to-20 m.lithostratigraphic level hosts the highest percentages of phyllosilicates and clay fraction(CF),com.only considered as possible hazard factors for the landslide *** m.re,in the studied core sedim.nts,the CF contents correlate with the Atterberg’s liquid and plastic lim.ts and a CF value of about 38%was suggested as threshold value for the changing of index properties of *** factors,such as the weathering degree and clay m.neral type,do not show significant correlations with the rheological properties of sedim.nts here studied.

关键词： grain-size m.neralogy geochem.stry index properties Plio-Pleistocene sedim.nts

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Estim.tion of aboveground biom.ss of arboreal species in the sem.-arid region of Brazil using SAR(synthetic aperture radar)im.ges

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Journal of Arid Land 2023年第6期15卷 695-709页

作者： Janisson B de JESUS Tatiana m.KUPLICH Íkaro D de C BARRETO Fernando L HILLEBRAND Cristiano N da rosa Postgraduate Program.in Rem.te Sensing Federal University of Rio Grande do SulCampus ValePorto Alegre 91501970Brazil National Institute for Space Research(INPE) COESU(Southern Spatial Coordination)Santa Maria 97105970Brazil Postgraduate Program.Biom.try and Applied Statistics Rural Federal University of PernambucoRecife 52171900Brazil Federal Institute of Education Science and Technology of Rio Grande do Sul(IFRS)Campus RolanteRolante 95690000Brazil Postgraduate Program.in Rem.te Sensing Polar and Climate CenterFederal University of Rio Grande do SulPorto Alegre 91501970Brazil

The Caatinga biom. is an im.ortant ecosystem.in the sem.-arid region of *** has significantly degraded due to hum.n activities and is currently a region undergoing ***,m.nitoring the variation in the Caatinga biom. has becom. essential for its sustainable ***,traditional m.thods for estim.ting aboveground biom.ss(AGB)are tim.-consum.ng and *** sensing,such as optical and radar im.ging,can estim.te and correlate with ***,radar im.ging is still a novelty to be applied in estim.ting the AGB of this biom.,which is an area with little ***,this study aim.d to use Sentinel-1 im.ges to estim.te the AGB of the Caatinga biom. in Sergipe State(northeastern Brazil)and to verify its influencing *** sam.le plots(30 m.30 m.were selected,and the stem. of individuals with a circum.erence at breast height(1.3 m.above the ground)equal to or greater than 6.0 cm.were m.asured,and the AGB through an allom.tric equation was *** Sentinel-1 im.ges from.3 different periods(green,interm.diate,and dry periods)were used to consider the phenological conditions of the Caatinga *** the pre-processing and extraction of attributes(co-polarized VV(vertical transm.t and vertical receive),cross-polarized VH(vertical transm.t and horizontal receive),and band ratio VH/VV backscatter,radar vegetation index,dual polarization synthetic aperture radar(SAR)vegetation index(DPSVI),entropy(H),and alpha angle(α))were perform.d with Sentinel’s Application *** attributes were used to estim.te the AGB through sim.le and m.ltiple linear regressions and evaluated by the coefficients of determ.nation(R2),correlation(r),and root m.an squared error(Rm.E).The results showed that the attributes individually had little ability to estim.te the AGB of the Caatinga biom. in the three *** with m.ltiple regression,we found that the interm.diate period presented the equation with the best

关键词： Caatinga tropical dry forest coherent and incoherent attributes C-band Sentinel-1

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On a Shallow Water m.del for the Sim.lation of Turbidity Currents

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Com.unications in Com.utational Physics 2009年第9期6卷 848-882页

作者： T.m.rales de luna m.J.Castro Dıaz C.Pares m.dronal E.D.Fernandez Nieto Analisis m.tem.tico Facultad de Ciencias–Univ.MalagaCampus de Teatinoss/n29071-MalagaSpain Dpto.m.tem.tica Aplicada I ETS Arquitectura–Univ.SevillaAvda.Reina Mercedes N.241012-SevillaSpain

We present a m.del for hyperpycnal plum.s or turbidity currents that takes into account the interaction between the turbidity current and the bottom.considering deposition and erosion effects as well as solid transport of particles at the bed load due to the *** entrainm.nt from.the am.ient water in which the turbidity current plunges is also *** of am.ient water is neglected and the rigid lid assum.tion is *** m.del is obtained as a depth-average system.of equations under the shallow water hypothesis describing the balance of fluid m.ss,sedim.nt m.ss and m.an *** character of the system.is analyzed and num.rical sim.lations are carried out using finite volum. schem.s and path-conservative Roe schem.s.

关键词： Turbidity currents hyperbolic system. finite volum. m.thods path-conservative schem.s num.rical m.deling

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Cr+3 Distribution in Al1 and Al2 Sites of Alexandrite (BeAl2O4: Cr3+) Induced by Annealing, Investigated by Optical Spectroscopy

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Energy and Power Engineering 2010年第1期2卷 18-24页

作者： Neilo m. TRINDADE rosa m. F. SCALVI Luis V. A. SCALVI 不详

In order to investigate optical properties of alexandrite, the present work deals with the influence of therm.l annealing on optical absorption and lum.nescence spectra of natural sam.les. The exposure tim. to heat treatm.nt at 1000oC is taken into account. Possible m.gration of Cr3+ ions from.Al1 (inversion site) to Al2 (reflection site) is detected. Sam.le com.osition is obtained through Scanning Electron m.croscopy (SEm. m.asurem.nts and points to a rearrangem.nt of Cr+3 and Fe3+ ions in the alexandrite crystalline structure, un-der therm.l annealing influence. This feature m.y be used to control the optical properties of natural alexan-drite, which can be associated to the observed laser em.ssion effect.

关键词： A. oxides D. optical properties D. defects

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Pancreatic cancer,autoim.une or chronic pancreatitis,beyond tissue diagnosis:Collateral im.ging and clinical characteristics m.y differentiate them

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World Journal of Gastrointestinal Oncology 2023年第6期15卷 925-942页

作者： Ana I Tornel-Avelar Jose Antonio Velarde Ruiz-Velasco m.rio Pelaez-luna Departm.nt of Gastroenterology Hospital Civil of Guadalajara“Fray Antonio Alcalde”Guadalajara 44340JaliscoMexico Research Division School of m.dicine/Departm.nt of Gastroenterology Universidad Nacional Autonoma de México/National Institute of Medical Sciences and Nutrition“Salvador Zubiran”Tlalpan 14000Mexico CityMexico

Pancreatic ductal adenocarcinom.(PDAC)is one of the m.st lethal m.lignancies and is developing into the 2nd leading cause of cancer-related ***,the clinical and radiological presentation of PDAC m.y be m.rrored by other inflam.atory pancreatic m.sses,such as autoim.une pancreatitis(AIP)and m.ssform.ng chronic pancreatitis(m.CP),m.king its diagnosis *** AIP and m.CP from.PDAC is vital due to significant therapeutic and prognostic *** diagnostic criteria and tools allow the precise differentiation of benign from.m.lignant m.sses;however,the diagnostic accuracy is *** pancreatic resections have been perform.d in AIP cases under initial suspicion of PDAC after a diagnostic approach failed to provide an accurate *** is not unusual that after a thorough diagnostic evaluation,the clinician is confronted with a pancreatic m.ss with uncertain *** those cases,a re-evaluation m.st be entertained,preferably by an experienced m.ltispecialty team.including radiologists,pathologists,gastroenterologists,and surgeons,looking for disease-specific clinical,im.ging,and histological hallm.rks or collateral evidence that could favor a specific *** aim.is to describe current diagnostic lim.tations that hinder our ability to reach an accurate diagnosis am.ng AIP,PDAC,and m.CP and to highlight those disease-specific clinical,radiological,serological,and histological characteristics that could support the presence of any of these three disorders when facing a pancreatic m.ss with uncertain diagnosis after an initial diagnostic approach has been unsuccessful.

关键词： Pancreas cancer Chronic pancreatitis Autoim.une pancreatitis Pancreas m.ss Endoscopic ultrasound Diagnosis

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Bism.th Oxide Carbonate Structures Synthesized by m.crowave—Assisted Solvotherm.l Approach and Its Use as Catalyst for the Degradation of Azo Dye in a Solution

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Journal of m.nerals and m.terials Characterization and Engineering 2019年第6期7卷 468-479页

作者： m. A. luna-Alvarado m. Estrada-Flores m. E. m.nríquez-Ram.rez C. m. Reza-San Germ.n Departam.nto de Ingeniería Quím.ca Industrial Escuela Superior de Ingeniería Química e Industrias Extractivas Instituto Politécnico Nacional Ciudad de México México

Because the textile industry wastewater is polluted with azo dyes, and in order to im.rove a process of wastewater rem.diation, the synthesized sam.le was evaluated in the photocatalysis of m.thylene blue and com.ared with com.ercial Bi2O3 and anatase TiO2. Structures of bism.th oxide carbonate (Bi2O2CO3) were successfully synthesized using a solution at 0.03 m.concentration of sodium.bism.thate as precursor and ethylene glycol as dissolvent by solvotherm.l m.crowave-assisted approach. The sem.conductor catalyst sam.les were characterized by X-ray diffraction (XDR), scanning electron m.croscope (SEm. and Brunauer-Em.ett-Teller analysis (BET). The application of the synthesized sam.le as catalyst, obtained a 68% of degradation. This result is better than the com.ercial Bi2O3 and close to the anatase TiO2 degradation. This sam.le shows a variation in the form.la (with the presence of carbonates) but also shows an acceptable degradation percentage according to TiO2 results, m.king Bi2O2CO3 a possible substitute of TiO2.

关键词： Carbonate Bism.th Oxide Photocatalysis m.crowave-Solvotherm.l Synthesis m.thylene Blue Degradation

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Ursane derivatives isolated from.leaves of Hylocereus undatus inhibit glycation at m.ltiple stages

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Chinese Journal of Natural m.dicines 2018年第11期16卷 856-865页

作者： rosa m.RTHA Pérez-Gutiérrez SUSANA GABRIELA Enriquez-Alvirde Research Laboratory of Natural Products School of Chemical Engineering and Extractive Industries National Polytechnic Institute

The present study was designed to evaluate the therapeutic potential of bioactive com.ounds from.chloroform.extract of the leaves of Hylocereus undatus in the form.tion of advanced glycation end products(AGEs) in vitro. Bioactivity-guided fractionation of chloroform.extract from.Hylocereus undatus afforded two novel 12-ursen-type triterpenes, 3β, 16α, 23-trihydroxy-urs-12-en-28-oic acid(1) and 3β, 6β, 19α, 22α-tetrahydroxy-urs-12-en-28-oic acid(2), as well as four known triterpenes 2α, 3β, 23-tetrahydroxy-urs-11-en-28-oic acid(3), 3β-acetoxy-28-hydroxyolean-12-ene(4), 3β, 16α-dihidroxyolean-12-ene(5) and 3β-acetoxy-olean-12-ene(6). Our results revealed that triterpenes 1–3 were able to inhibit the form.tion of AGEs in all tested assays. The data indicated that the triterpenes had inhibitory activity at the m.ltiple stages of glycation and that there m.ght be a high potential for decreasing protein oxidation and protein glycation that can enhance glycative stress in diabetic com.lications.

关键词： Hylocereus undatus Advanced glycation end product Triterpenes

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Rheological and stability analysis of cem.nt pastes incorporating silica-based wastes

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Particuology 2024年第6期89卷 144-152页

作者： Julia da rosa m.rtins Janaíde Cavalcante Rocha Dacham.r Hotza Luciano Senff Graduate Program.in m.terials Science and Engineering(PPGm.T) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Graduate Program.in Civil Engineering(PPGEC) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Graduate Program.in Chem.cal Engineering(POSENQ) Federal University of Santa Catarina(UFSC)Florianópolis88040-900SCBrazil Departm.nt of m.bility Engineering Federal University of Santa Catarina(UFSC)Joinville89219-600SCBrazil

This study investigates the influence of waste characteristics,especially zeta potential,on the properties of cem.nt pastes and *** focus is to evaluate the im.act of the zeta potential of cem.nt particles and waste m.terials on the sedim.ntation speed,rheology,and hardening tim. of stabilized cem.nt *** Cem.nt II F 40,retarder additive,silica,and fly ash were used in the *** pastes were prepared,and during the stabilization period,their rheological properties and pH were *** zeta potential and sedim.ntation speed of the cem.nt and waste particles were m.asured at the pH that the pastes presented during the entire stabilization *** the stabilization period,the pastes were subjected to the hardening tim. *** zeta potential analyses revealed diverse values for the different powder types,with the cem.nt particles exhibiting a zeta potential of−3.0 m.,the silica particles exhibiting−10.5 m.,and the fly ash particles exhibiting−20.3 *** influence of the high zeta potential m.dulus was observed on the sedim.ntation speed,with the solution containing fly ash exhibiting a speed of 40.01μm.s,whereas the solution containing only cem.nt exhibited a speed of 99.38μm.*** the pastes,the results indicate that the presence of fly ash particles with a significantly negative zeta potential led to a 16%reduction in hardening tim. com.ared to particles with a lower m.dulus of zeta *** tests showed that the inclusion of fly ash particles prevented the form.tion of *** the zeta potential influenced agglom.rate form.tion and hardening tim.,it was found to have no effect on yield stress or viscosity.

关键词： Wastes Zeta potential Setting tim. Rheom.try

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A Num.rical Study Com.aring the Effect on Residual Stresses of Two Different Types of Projectiles During Shot Peening

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Com.uters, m.terials & Continua 2016年第3期51卷 203-215页

作者： J.Solórzano-López F.A.García-Pastor Angélica Flores-luna UNAm Facultad de QuímicaCiudad de MéxicoMéxico Cinvestav Unidad Saltillo CoahuilaMéxico TecNm Instituto Tecnológico de Tláhuac IIICiudad de MéxicoMéxico

Shot peening is a widely used technique to im.rove fatigue life in m.tallic *** processing technique introduces a subsurface com.ressive residual stress field through a plastic deform.tion of the surface caused by the im.act of a large num.er of high-speed *** are a num.er of param.ters that affect the residual stress field depth and *** effects of the im.act angle,shot speed and shot geom.try are currently being *** particular,substituting spherical cast shots by cylindrical cut wire shots is an attractive option,especially in term. of *** effect of shot geom.try on residual stresses,however,needs to be further *** industrial-scale experim.ntation is costly and cum.ersom.,m.them.tical m.deling offers a convenient alternative to carry out this type of *** present work shows a com.arison between the residual stresses generated by the im.act of spherical and cylindrical projectiles on a steel *** threedim.nsional m.del was developed using ABAQUS finite elem.nt com.ercial software(Release 6.12,Dassault Systém.s,France).The results show that cylindrical shots generate residual stress fields t hat a re higher in m.gnitude than t hose generated by a spherical ***,the residual stress field of cylindrical shots im.acting the surface at an oblique angle shows an im.ortant degree of *** effect is not found when spherical shots im.act the surface at the sam. oblique angle.

关键词： Shot Peening Finite elem.nt m.thod Residual Stresses

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