检索结果-南通市图书馆

Understanding Bonding nature ofα-Keggin Polyoxometalates[XW_(12)O_(40)]^(n−)(X=Al,si,P,s):A Generalized superatomic Perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第6期7卷 176-183页

作者： rui Li Yulei shi Famin Yu rui Wang Haitao Yan Boon K.Teo Zhigang Wang Department of Physics Capital Normal UniversityBeijing 100048China Key Laboratory of Material simulation Methods&software of Ministry of Education College of PhysicsJilin UniversityChangchun 130012China Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China state Key Laboratory for Physical Chemistry of solid surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Institute of Theoretical Chemistry College of ChemistryJilin UniversityChangchun 130012China

α-Keggin polyoxometalates(POMs)[XW_(12)O_(40)]^(n−)(X=Al,si,P,s)are widely used in batteries owing to their remarkable redox ***,the mechanism underlying the applications appears inconsistent with the widely accepted covalent bonding ***,first-principles calculations show that XW_(12)are core–shell structures composed of a shell and an XO_(4)^(n−)core,both are stabilized by covalent ***,owing to the pres.nce of a substantial number of electrons in W_(12)O_(36)shell,the frontier molecular orbitals of XW_(12)are not only strongly delocalized but also exhibit superatomic properties with high-angular momentum electrons that do not conform to the Jellium *** analysis indicates that energetically high lying filled molecular orbitals(MOs)have reached unusually high-angular momentum characterized by quantum number K or higher,allowing for the accommodation of numerous *** attribute confers strong electron acceptor ability and redox activity to XW_(12).Moreover,electrons added to XW_(12)still occupy the K orbitals and will not cause rearrangement of the MOs,thereby maintaining the stability of these *** findings highlight the structure–activity relationship and provide a direction for tailor-made POMs with specific properties at atomic level.

关键词： first principles molecular orbital polyoxometalate redox activity superatom

Modulating redox transition kinetics by anion regulation in ni-Fe-X(X=O,s,se,n,and P)electrocatalyst for efficient water oxidation

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6期17卷 4720-4728页

作者： Liting Wei Kaini Zhang rui Zhao Lei Zhang Yan Zhang suyi Yang Jinzhan su International Research Center for Renewable Energy&state Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Applied Chemistry Yuncheng UniversityYuncheng 044000China

niFe-based electrocatalysts will experience dynamical surface reconstruction during oxygen evolution reaction(OER)process,and the derived metal(oxy)hydroxide hybrids on the surface have been considered as the actual active species for *** efforts have been dedicated to understanding the surface reconstruction,but there is rare research on recognizing the origin of improved performance derived from anion species of ***,the OER electrocatalytic characteristics were tuned with different anions in niFe-based catalyst,us.ng niFe-based oxides.nitride/sulfide/selenides/phosphides.niFeX,X=O,n,s,se,and P)as the model *** combination of X-ray photoelectronic spectroscopy,electrochemical tests,operando spectroscopic characterizations,and density functional theory(DFT)calculations,reveals that anion with lower electronegativity in niFe-based catalyst leads to higher conductivity and delayed valence transition of ni sites,as well as optimized adsorption behavior towards oxygen intermediates,contributing to enhanced OER ***,niFeP electrocatalyst demonstrates an ultralow overpotential of 265 mV at 20 mA·cm−2 for OER,as well as long-term *** work not only offers further insights into the effect of anionic electronegativity on the intrinsic OER electrocatalytic properties of niFe-based electrocatalyst but also provides guide to design efficient non-noble metal-based electrocatalysts for water oxidation.

关键词： oxygen evolution reaction(OER) anion species electronegativity valence transition

Astrophysical s-factor and reaction rate for 15n(p,γ)16O within the modified potential cluster model

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 Physics C 2024年第4期48卷 130-145页

作者： s.B.Dubovichenko A.s.Tkachenko R.Ya.Kezerashvili n.A.Burkova B.M.Yeleusheva Fes.nkov Astrophysical Institute 050020 AlmatyKazakhstan new York City College of Technology City University of New YorkBrooklyn11201 New YorkUSA Graduate school and University Center City University of New York10016 New YorkUSA al-Farabi Kazakh national University 050040 AlmatyKazakhstan

We study radiative p^(15)n capture on the ground state of ^(16)O at stellar energies within the framework of a modified potential cluster model(MPCM)with forbidden states,including low-lying *** investigation of the ^(15)n(p,γ0)^(16)O reaction includes the consideration of ^(3)s_(1) res.nances due to E1 transitions and the contribution of the ^(3)P_(1) scattering wave in the p+^(15)n channel due to the ^(3)P_(1)→^(3)P_(0)M1 *** calculated the astrophysical low-energy s-factor,and the extrapolated s(0)turned out to be within 34.7−40.4 keV·*** important role of the asymptotic constant(AC)for the ^(15)n(p,γ0)16O process with interfering ^(3)s_(1)(312)and ^(3)s_(1)(962)res.nances is elucidated.A comparis.n of our calculation for the s-factor with existing experimental and theoretical data is addressed,and a reas.nable agreement is *** reaction rate is calculated and compared with the existing *** has.negligible dependence on the variation of AC but shows a strong impact of the interference of ^(3)s_(1)(312)and ^(3)s_(1)(962)res.nances in reference to the CnO Gamow windows,especially at low *** estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data from ***.C.85,065810(2012).The reaction rate enhancement due to the cascade transitions is observed from T_(9)>0.3 and reaches the maximum factor~1.3 at T_(9)=*** pres.nt the Gamow energy window and a comparis.n of rates for radiative proton capture reactions ^(12)n(p,γ)^(13)O,^(13)n(p,γ)^(14)O,^(14)n(p,γ)^(15)O,and ^(15)n(p,γ)^(16)O obtained in the framework of the MPCM and provide the temperature windows,prevalence,and significance of each process.

关键词： low and astrophysical energies p^(15)n system thermonuclear reaction rate potential cluster model CnO-cycle

Dynamic and electrical responses of a curved s.ndwich beam with glass reinforced laminate layers and a pliable core in the pres.nce of a piezoelectric layer under low-velocity impact

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 155-178页

作者： n.sHAHVEIsI s.FELI Department of Mechanical Engineering Razi UniversityKermanshah ***Iran

The dynamic responses and generated voltage in a curved s.ndwich beam with glass reinforced laminate(GRL)layers and a pliable core in the pres.nce of a piezoelectric layer under low-velocity impact(LVI)are *** current study aims to carry out a dynamic analysis on the s.ndwich beam when the impactor hits the top face sheet with an initial *** the layer analysis,the high-order shear deformation theory(HsDT)and Frostig's second model for the displacement fields of the core layer are *** classical non-adhesive elastic contact theory and Hunter's principle are used to calculate the dynamic responses in terms of *** order to validate the analytical method,the outcomes of the current investigation are compared with those gained by the experimental tests carried out by other researchers for a rectangular composite plate subject to the *** element(FE)simulations are conducted by means of the ABAQUs *** effects of the parameters such as foam modulus,layer material,fiber angle,impactor mass,and its velocity on the generated voltage are reviewed.

关键词： analytical model piezoelectric layer curved s.ndwich beam glass reinforced laminate(GRL) pliable core low-velocity impact(LVI) classical non-adhesive elastic contact theory

Towards defining soil quality of Mediterranean calcareous agricultural soils:Reference values and potential core indicator set

在线全文

学校读者我要写书评

暂无评论

International soil and Water Conservation Research 2024年第1期12卷 145-155页

作者： Germán A.Durán Daniel sacristán Edelweis Farrús Jaume Vadell Institut de Recerca i FormacióAgrària i Pesquera de les Illes Balears C/Eusebi Estada14507009PalmaSpain Plant Biology Department University of Valencia46100BurjassotValenciaSpain soil and Environmental Quality Department Centro de Investigaciones sobre Desertificación-CIDE(CSIC-Universitat de València-Generalitat Valenciana)Carretera Moncada-Náquera km 4.546113MoncadaValenciaSpain Universitat de les Illes Balears Cra.De Valldemossakm 7507122PalmaSpain

To avoid soil degradation,adapt to climate change and comply with the sustainable Development goals 2030(Un General Assembly),establishing the quality/fertility of the agricultural soils of the Mediterranean region and evaluate how these evolve with time is *** enables adequate management practices to be *** Mediterranean calcareous region has received little attention in this s.nse,in spite its soil ***,24 different repres.ntative calcareous agricultural soils of the Mediterranean region,including the main management strategies of agricultural soils(rainfed and irrigated),were sampled from the island of Mallorca;and their physical,chemical and biological properties *** values obtained for most of the soil characteristics allowed to establish an initial approach to the reference values for the type of calcareous agricultural soils considered,and to clearly distinguish the effect of rainfed or irrigation management practices on soils properties and *** enzyme activities were not stimulated by the irrigation conditions assayed or they were only in dry conditions,suggesting optimum enzyme activities could be obtained when alternating dry and humid soil *** organic carbon,calcium carbonate and active lime revealed of significant importance in the collection of ***,the results obtained clearly indicate the heterogeneity of the region and its implications on the different soil ***,this study could serve as a starting point to adequately establish the quality(fertility)for Mediterranean calcareous agricultural soils and their reference values by conducting further research in this region and including more type of soils.

关键词： soil fertility Mediterranean agricultural soils Calcareous soils soil enzymes soil management

Early Phases of star Formation: Testing Chemical Tools

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： n.C.Martinez s.Paron COnICET-Universidad de Buenos Aires.Instituto de Astronomía y Física del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

star-forming processes strongly influence the IsM ***,many high-quality databases are available at millimeter *** them,it is possible to carry out studies that review and deepen previous *** these studies involve large samples of sources,it is preferred to use direct tools to study the molecular *** the aim of testing these tools such as the use of the HCn/HnC ratio as a thermometer,and the use of H^(13)CO^(+),HC_(3)n,n_(2)H^(+) and C_(2)H as "chemical clocks," we pres.nt a molecular line study toward 55 sources repres.nting massive young stellar objects at different evolutionary stages:infrared dark clouds(IRDCs),highmass protostellar objects(HMPOs),hot molecular cores(HMCs) and ultracompact H II *** found that the use of the HCn/HnC ratio as a universal thermometer in the IsM should be taken with care because the HCn optical depth is a big issue that can affect the ***,this tool should be utilized only after a careful analysis of the HCn spectrum,checking that no line,neither the main nor the hyperfine ones,pres.nts absorption *** point out that the analysis of the emission of H^(13)CO^(+),HC_(3)n,n_(2)H^(+) and C_(2)H could be useful to trace and distinguish regions among IRDCs,HMPOs and *** molecular line widths of these four species increase from the IRDC to the HMC stage,which can be a consequence of the gas dynamics related to the starforming processes taking place in the molecular *** results.not only contribute with more statistics,acting as a probe of such chemical tools,useful to obtain information in large samples of sources,but also complement previous works through the analysis of other types of sources.

关键词： stars:formation IsM:molecules IsM:clouds

Dispersion effect of nano-structure pyrolytic carbon on mechanical,electrical,and microstructural characteristics of cement mortar composite

在线全文

学校读者我要写书评

暂无评论

International Journal of smart and nano Materials 2024年第3期15卷 534-578页

作者： n.K.Karthikeyan s.Elavenil school of Civil Engineering Vellore Institute of TechnologyChennaiIndia

In material science,converting waste into nanomaterials by green technologies highlights the interest in producing sus-tainable carbon nanomaterial(s.n).This study first-ever uti-lized tyre-char as a nano-structure Pyrolytic Carbon(nsPC)to develop electrically conductive *** other car-bon nanomaterials,the efficiency of nsPC particle as an s.n in developing electrically conductive composites was investi-gated in terms of dispersion,mechanical,water absorption,electrical resistivity,and *** results of sedi-mentation and zeta potential(-19 mV)showed the excellent dispersion of nsPC particle in water with the combined effect of superplasticizer and *** compressive(40.37%)and flexural strength(10.76%)than that of plain cement mortar composite(CMC)is achieved with 2 wt.%and 1.5 wt.%of nsPC particle,*** water absorption rate and volume of permeable voids were reduced,exhibiting less *** percolation zone of AC and DC resis-tivity of nsPC composite ranges between 1 and 2 wt.%,and the established percolation threshold is at 2 wt.%.XRD analysis showed C-s-H formation consistently increased with curing age,and HR-sEM with EDAX analysis exhibits the dense micro-structure and well-distributed nsPC particle at the *** experimental outcomes significantly enhanced the relia-bility and provided a framework for tailoring nsPC particle as s.n for developing electrically conductive composite.

关键词： sustainable nanomaterial dispersion mechanical properties electrical resistivity microstructure analysis

A facile strategy for tuning the density of surface-grafted biomolecules for melt extrusion-based additive manufacturing applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2024年第3期7卷 277-291页

作者： I.A.O.Beeren G.Dos s.ntos P.J.Dijkstra C.Mota J.Bauer H.Ferreira rui L.Reis.n.neves s.Camarero-Espinosa M.B.Baker L.Moroni Department of Complex Tissue Regeneration MERLN Institute for Technology-Inspired Regenerative MedicineMaastricht University6229 ER MaastrichtThe Netherlands 3B’s Research Group I3Bs–Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVs/3B’s-PT Government Associate Laboratory 4806-909 Braga/GuimarãesPortugal POLYMAT University of the Basque Country UPV/EHU20018 Donostia/San SebastiánSpain IKERBAsQUE Basque Foundation for Science48009 BilbaoSpain

Melt extrusion-based additive manufacturing(ME-AM)is a promis.ng technique to fabricate porous scaffolds for tissue engi-neering ***,most s.nthetic semicrystalline polymers do not possess the intrinsic biological activity required to control cell *** of biomolecules on polymeric surfaces of AM scaffolds enhances the bioactivity of a construct;however,there are limited strategies available to control the surface ***,we report a strategy to tune the surface density of bioactive groups by blending a low molecular weight poly(ε-caprolactone)5k(PCL5k)containing orthogonally reactive azide groups with an unfunctionalized high molecular weight PCL75k at different *** porous three-dimensional(3D)scaf-folds were then fabricated us.ng a high weight percentage(75 wt.%)of the low molecular weight PCL *** a proof-of-concept test,we prepared films of three different mass ratios of low and high molecular weight polymers with a thermopress and reacted with an alkynated fluorescent model compound on the surface,yielding a density of 201-561 pmol/cm^(2).subsequently,a bone morphogenetic protein 2(BMP-2)-derived peptide was grafted onto the films compris.ng different blend compositions,and the effect of peptide surface density on the osteogenic differentiation of human mes.nchymal stromal cells(hMsCs)was *** two weeks of culturing in a basic medium,cells expressed higher levels of BMP receptor II(BMPRII)on films with the conjugated *** addition,we found that alkaline phosphatase activity was only significantly enhanced on films contain-ing the highest peptide density(i.e.,561 pmol/cm^(2)),indicating the importance of the surface *** together,these results emphasize that the density of surface peptides on cell differentiation must be considered at the cell-material ***,we have pres.nted a viable strategy for ME-AM community that desires to tune the bulk and surface functionality via blending of(m

关键词： Additive manufacturing Blending surface functionalization surface density Click chemistry Human

Conformally symmetric wormhole solutions supported by non-commutative geometry in f(Q,T)gravity

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第2期76卷 111-124页

作者： Chaitra Chooda Chalavadi V Venkatesha n s Kavya s V Divya Rashmi Department of P.G.studies and Research in Mathematics Kuvempu UniversityShankaraghattaShivamogga 577451KarnatakaIndia Department of Mathematics Vidyavardhaka College of EngineeringMysuru—570002India

This paper investigates wormhole solutions within the framework of extended symmetric teleparallel gravity,incorporating non-commutative geometry,and conformal *** achieve this,we examine the linear wormhole model with anisotropic fluid under Gaussian and Lorentzian *** primary objective is to derive wormhole solutions while considering the influence of the shape function on model parameters under Gaussian and Lorentzian *** resulting shape function satisfies all the necessary conditions for a traversable ***,we analyze the characteristics of the energy conditions and provide a detailed graphical discussion of the matter contents via energy ***,we explore the effect of anisotropy under Gaussian and Lorentzian ***,we pres.nt our conclusions based on the obtained results.

关键词： traversable wormhole f(Q T)gravity energy conditions non-commutative geometry conformal motion