检索结果-南通市图书馆

Nonlinear corrections for the nuclear gluon distribution in eA processes

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第3期48卷 52-64页

作者： G.r.boroun b.rezaei f.Abdi department of Physics Razi UniversityKermanshah 67149Iran.

An analytical study with respect to the nonlinear corrections for the nuclear gluon distribution function in the next-to-leading order approximation at small x is *** consider the nonlinear corrections to the nuclear gluon distribution functions at low values of x and Q^(2) using the parametrization f_(2)(x,Q^(2))and the nuclear modification factors obtained from the Khanpour-Soleymaninia-Atashbar-Spiesberger-Guzey *** CT18 gluon distribution is used for the baseline proton gluon density at Q^(2)_(0)=*** discuss the behavior of the gluon densities in the next-to-leading order and the next-to-next-to-leading order approximations at the initial scale Q^(2)_(0),as well as the modifications due to the nonlinear *** find that the QCD nonlinear corrections are more significant for the next-to-leading order accuracy than the next-to-next-to-leading order for light and heavy *** results of the nonlinear GLr-MQ evolution equation are similar to those obtained with the rausch-Guzey-Klasen gluon upward and downward evolutions within the *** magnitude of the gluon distribution with the nonlinear corrections increases with a decrease in x and an increase in atomic number A.

关键词： gluon distribution nonlinear corrections light and heavy nuclei low x physics

Tribologically induced nanostructural evolution of carbon materials: A new perspective

在线全文

学校读者我要写书评

暂无评论

friction 2024年第1期12卷 144-163页

作者： Guilherme Oliveira NEVES Nicolás ArAYA Diego berti SALVArO Thiago de souza LAMIM renan Oss GIACOMELLI Cristiano bINder Aloisio Nelmo KLEIN JoséDaniel biasoli de MELLO Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil departamento de Ingeniería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile SENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes *** the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem *** a recently developed advanced raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon *** addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application *** of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

关键词： carbon nanostructures tribology raman spectroscopy defects quantification tribolayer solid lubrication

Inflow and outflow permeability tests in a very soft clay under low stresses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： J.W.S.Vargas f.A.b.Danziger f.r.Lopes T.Lunne federal University of rio de Janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the bAT probe at SarapuíII soft clay test site are presented.A description of the bAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay bAT probe Inflow and outflow tests

radiative capture of proton through the ^(14)N(p,γ)^(15)O reaction at low energy

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 183-192页

作者： b.f.Irgaziev Abdul Kabir Jameel-Un Nabi National University of Uzbekistan Tashkent 100174Uzbekistan Space and Astrophysics research lab National Centre of GIS and Space ApplicationsDepartment of Space ScienceInstitute of Space TechnologyIslamabad 44000Pakistan University of Wah Quaid AvenueWah Cantt 47040PunjabPakistan

The CNO cycle is the main source of energy in stars more massive than our *** process defines the energy production,the duration of which can be used to determine the lifetime of massive *** cycle is an important tool for determining the age of globular *** proton capture via p+^(14)N→^(15)O+γ,at energies of astrophysical interest,is an important process in the CNO *** this project,we apply a potential model to describe both non-resonant and resonant reactions in the channels where radiative capture occurs through electric E1 *** employed the r-matrix method to describe the ongoing reactions via M1 resonant transitions,when it was not possible to correctly reproduce the experimental data using the potential *** partial components of the astrophysical S-factor are calculated for all possible electric and magnetic dipole transitions in ^(15)*** linear extrapolated S-factor at zero energy(S(0))agrees well with earlier reported values for all transition types considered in this *** on the value of the total astrophysical S-factor,depending on the collision energy,we calculate the nuclear reaction rates for p+^(14)N→^(15)O+γ.The computed rates agree well with the results reported in the NACrE II Collaboration and most recent existing measurements.

关键词： CNO cycle potential model r-matrix method cross-section astrophysical S-factor nuclear rates.

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.b.Zhang S.J.Song f.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPfE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).by detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

Quantum-mechanical effects in photoluminescence from thin crystalline gold films

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第4期13卷 783-794页

作者： Alan r.bowman Alvaro rodríguez Echarri fatemeh Kiani fadil Iyikanat Ted V.Tsoulos Joel D.Cox ravishankar Sundararaman f.Javier García de Abajo Giulia Tagliabue Laboratory of Nanoscience for Energy Technologies(LNET) STIÉcole Polytechnique Fédérale de Lausanne(EPFL)LausanneSwitzerland ICfO–Institut de Ciencies fotoniques The Barcelona Institute of Science and TechnologyCastelldefels(Barcelona)Spain. MbI–Max-born-Institut BerlinGermany. POLIMA–Center for Polariton-driven Light–Matter Interactions University of Southern DenmarkOdense MDenmark. Danish Institute for Advanced Study University of Southern DenmarkOdense MDenmark. department of Materials Science&Engineering Rensselaer Polytechnic InstituteTroyNYUSA. department of Physics Applied Physicsand AstronomyRensselaer Polytechnic InstituteTroyNYUSA. ICrEA–Institucio Catalana de recerca i Estudis Avancats BarcelonaSpain

Luminescence constitutes a unique source of insight into hot carrier processes in metals,including those in plasmonic nanostructures used for sensing and energy ***,being weak in nature,metal luminescence remains poorly understood,its microscopic origin strongly debated,and its potential for unraveling nanoscale carrier dynamics largely ***,we reveal quantum-mechanical effects in the luminescence emanating from thin monocrystalline gold ***,we present experimental evidence,supported by first-principles simulations,to demonstrate its photoluminescence origin(i.e.,radiative emission from electron/hole recombination)when exciting in the interband *** model allows us to identify changes to the measured gold luminescence due to quantum-mechanical effects as the gold film thickness is ***,such effects are observable in the luminescence signal from flakes up to 40 nm in thickness,associated with the out-of-plane discreteness of the electronic band structure near the fermi *** qualitatively reproduce the observations with first-principles modeling,thus establishing a unified description of luminescence in gold monocrystalline flakes and enabling its widespread application as a probe of carrier dynamics and light-matter interactions in this *** study paves the way for future explorations of hot carriers and charge-transfer dynamics in a multitude of material systems.

关键词： luminescence quantum crystalline

The magnetosheath at high spectral resolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： K.D.Küntz D.Koutroumpa W.r.Dunn A.foster f.S.Porter D.G.Sibeck b.Walsh The Henry A.rowland department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

rPLP0/TbP are the most stable reference genes for human dental pulp stem cells under osteogenic differentiation

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2024年第6期16卷 656-669页

作者： Daniel b ferreira Leticia M Gasparoni Cristiane f bronzeri Katiucia b S Paiva Laboratory of Extracellular Matrix biology and Cellular Interaction Department of AnatomyInstitute of Biomedical SciencesUniversity of São PauloSão Paulo 05508-000São PauloBrazil

bACKGrOUND Validation of the reference gene(rG)stability during experimental analyses is essential for correct quantitative real-time polymerase chain reaction(rT-qPCr)data ***,in an unreliable way,several studies use genes involved in essential cellular functions[glyceraldehyde-3-phosphate dehydro-genase(GAPDH),18S rrNA,andβ-actin]without paying attention to whether they are suitable for such experimental conditions or the reason for choosing such ***,such studies use only one gene when Minimum Information for Publication of Quantitative real-Time PCr Experiments guidelines recom-mend two or more *** impacts the credibility of these studies and causes dis-tortions in the gene expression *** tissue engineering,the accuracy of gene expression drives the best experimental or therapeutical *** cultivated DPSCs under two conditions:Undifferentiated and osteogenic dif-ferentiation,both for 35 *** evaluated the gene expression of 10 candidates for rGs[ribosomal protein,large,P0(rPLP0),TATA-binding protein(TbP),GAPDH,actin beta(ACTb),tubulin(TUb),aminolevulinic acid synthase 1(ALAS1),tyro-sine 3-monooxygenase/tryptophan 5-monooxygenase activation protein,zeta(YWHAZ),eukaryotic translational elongation factor 1 alpha(Ef1a),succinate dehydrogenase complex,subunit A,flavoprotein(SDHA),and beta-2-micro-globulin(b2M)]every 7 d(1,7,14,21,28,and 35 d)by *** data were analysed by the four main algorithms,ΔCt method,geNorm,Normfinder,and bestKeeper and ranked by the reffinder *** subdivided the samples into eight *** All of the data sets from clonogenic and osteogenic samples were analysed using the reffinder *** final ranking showed rPLP0/TbP as the two most stable rGs and TUb/b2M as the two least stable *** theΔCt method or Normfinder analysis showed TbP/rPLP0 as the two most stable ***,geNorm analysis showed rPLP0/Ef1αin the first *** algorithms’two least stab

关键词： dental pulp stem cells reference gene Housekeeping gene Endogenous gene Osteogenic differentiation reffinder

Carbon Monoxide as C1 building block in fine Chemical 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

Chinese Journal of Chemistry 2024年第2期42卷 199-221页

作者： rui M.b.Carrilho Mario J.f.Calvete Gabor Mikle Laszlo Kollar Mariette M.Pereira University of Coimbra Coimbra Chemistry CentreDepartment of ChemistryRua Larga3004-535 CoimbraPortugal department of General and Inorganic Chemistry and ELKH-PTE research Groupfor Selective Chemical Syntheses University of PecsIfjusag utja 6H-7624 PecsHungary

Carbon monoxide(CO)has become one of the most relevant and versatile renewable C1 building blocks for chemical synthesis,especially in the fine chemicals industry,due to the development of efficient and selective catalysts for its *** this review,we present a comprehensive critical analysis of the last 10 years literature on the use of CO as a renewable feedstock for fine chemicals *** review is organized by type of catalytic reaction,namely alkene and alkyne carbonylation,hydroformylation,carbonylation of aryl halides,carbonylative cross-coupling and C-H *** examples of the synthesis of relevant building blocks and/or known pharmaceuticals are *** is placed on examples of utilizing CO as the C1 building block in one or more catalytic *** catalyst used and the reaction conditions are consistently presented throughout all of the examples.

关键词： Carbon monoxide fine chemicals Carbonylation Hydroformylation C-H functionalization