检索结果-南通市图书馆

Classical model for diffusion and thermalization of heavy quarks in a hot medium: memory and out-of-equilibrium effects

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2019年第9期43卷 90-100页

作者： marco ruggieri marco Frasca Santosh Kumar Das School of Nuclear Science and Technology Lanzhou University222 South Tianshui RoadLanzhou 730000China Via Erasmo Gattamelata Rome 00176Italy School of Physical Science Indian Institute of Technology GoaPonda-403401GoaIndia

We consider a simple model for the diffusion of heavy quarks in a hot bath,modeling the latter by an ensemble of oscillators distributed according to either a thermal distribution or to an out-of-equilibrium distribution with a saturation *** this model it is easy to introduce memory effects by changing the distribution of oscillators:we model them by introducing a Gaussian distribution,dN/dω,which can be deformed continuously from aδ?function,giving a Markov dissipation,to a broad kernel with *** the equation of motion of the heavy quark in the bath,we remark how dissipation comes out naturally as an effect of the back-reaction of the oscillators on the ***,the exact solution of this equation allows to define the thermalization time as the time necessary to remove any memory of the initial *** find that the broadening of the dissipative kernel,while keeping the coupling fixed,lowers the thermalization *** also derive the fluctuation-dissipation theorem for the bath,and use it to estimate the kinematic regime in which momentum diffusion of the heavy quark dominates over *** find that diffusion is more important as long as K0/E is small,where K0 and E denote the initial energy of the heavy quark and the average energy of the bath,respectively.

关键词： relativistic heavy ion collisions heavy quarks Brownian motion memory effect quark-gluon plasma

Quark mass scaling and properties of light-quark matter

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2016年第6期27卷 43-48页

作者： Zhen-Yan Lu Guang-Xiong Peng Shi-Peng Zhang marco ruggieri Vincenzo Greco School of Physical Sciences University of Chinese Academyof SciencesBeijing 100049China Theoretical Physics Center for Science Facilities Institute of High Energy PhysicsBeijing 100049China Synergefic Innovation Center for Quantum Effects and Application Hunan Normal UniversityChangsha 410081China Department of Physics and Astronomy University of CataniaVia S.Sofia 6495125 CataniaItaly Laboratori Nazionali del Sud INFN-LNSVia S.Sofia 6295123 CataniaItaly

We study the properties of two-flavor quark matter in the equivparticle model.A new quark mass scaling at finite temperature is proposed and applied to the thermodynamics of two-flavor quark *** is found that the perturbative interaction has strong effect on quark matter properties at finite temperature and high *** pressure at the minimum free energy per baryon is exactly *** increasing temperature,the energy per baryon increases,while the free energy per baryon decreases.

关键词：物质性质夸克质量轻夸克标度最小自由能有限温度夸克物质相互作用

Landau quantization and spin polarization of cold magnetized quark matter

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第6期46卷 164-173页

作者： Zhen-Yan Lu Jian-Feng Xu Xin-Jian Wen Guang-Xiong Peng marco ruggieri Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials School of Physics and ElectronicsHunan University of Science and TechnologyXiangtan 411201China School of Physics and Electrical Engineering Anyang Normal UniversityAnyang 455000China Departrnent of Physics and Institute of Theoretical Physics Shanxi UniversityTaiyuan 030006China School ofNuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China School ofNuclear Science and Technology Lanzhou UniversityLanzhou 730000China

The magnetic field and density behaviors of various thermodynamic quantities of strange quark matter under compact star conditions are investigated in the framework of the thermodynamically self-consistent quasiparticle *** individual species,a larger number density n_(i) leads to a larger magnetic field strength threshold that aligns all particles parallel or antiparallel to the magnetic ***,in contrast to the finite baryon density effect which reduces the spin polarization of magnetized strange quark matter,the magnetic field effect leads to an enhancement of *** also compute the sound velocity as a function of the baryon density and find the sound velocity shows an obvious oscillation with increasing *** for the oscillation,the sound velocity grows with increasing density,similar to the zero-magnetic field case,and approaches the conformal limit V_(s)^(2)=1/3 at high densities from below.

关键词： Landau levels quark matter spin polarization strong magnetic field

Role of copper chelating agents: between old applications and new perspectives in neuroscience

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第3期20卷 751-762页

作者： Rosalba Leuci Leonardo Brunetti Vincenzo Tufarelli marco Cerini marco Paparella Nikola Puvača Luca Piemontese Department of Pharmacy-Pharmaceutical Science University of Bari Aldo MoroBariItaly Department of Precision and Regenerative Medicine and Jonian Area(DiMePRe-J) Section of Veterinary Science and Animal ProductionUniversity of Bari Aldo MoroBariItaly Department of Engineering Management in Biotechnology Faculty of Economics and Engineering Management in Novi SadUniversity Business Academy in Novi SadNovi SadSerbia

The role of copper element has been an increasingly relevant topic in recent years in the fields of human and animal health, for both the study of new drugs and innovative food and feed supplements. This metal plays an important role in the central nervous system, where it is associated with glutamatergic signaling, and it is widely involved in inflammatory processes. Thus, diseases involving copper(Ⅱ) dyshomeostasis often have neurological symptoms, as exemplified by Alzheimer's and other diseases(such as Parkinson's and Wilson's diseases). Moreover, imbalanced copper ion concentrations have also been associated with diabetes and certain types of cancer, including glioma. In this paper, we propose a comprehensive overview of recent results that show the importance of these metal ions in several pathologies, mainly Alzheimer's disease, through the lens of the development and use of copper chelators as research compounds and potential therapeutics if included in multi-target hybrid drugs. Seeing how copper homeostasis is important for the well-being of animals as well as humans, we shortly describe the state of the art regarding the effects of copper and its chelators in agriculture, livestock rearing, and aquaculture, as ingredients for the formulation of feed supplements as well as to prevent the effects of pollution on animal productions.

关键词： agriculture Alzheimer's disease chelators copper feed supplements multi-target

From mice to humans:a need for comparable results in mammalian neuroplasticity

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 464-466页

作者： marco Ghibaudi Enrica Boda Luca Bonfanti Neuroscience Institute Cavalieri Ottolenghi OrbassanoItaly Department of Veterinary Sciences University of TurinTurinItaly Department of Neuroscience Rita Levi-Montalcini University of TurinTurinItaly

Brain plasticity-A universal tool with many variations:The study of brain plasticity has been gaining interest since almost a century and has now reached a huge amount of information(>80,000 results in PubMed).Overall,different types of plasticity,including stem cell-driven genesis of new neurons(adult neurogenesis),cells in arrested maturation(dormant neurons),neuro-glial and synaptic plasticity,can coexist and contribute to grant plastic changes in the brain,from a cellular to system level(Benedetti and Couillard-Despres,2022;Bonfanti et al.,2023).

关键词： plasticity al. arrest

Novel Methodologies for Preventing Crack Propagation in Steel Gas Pipelines Considering the Temperature Effect

在线全文

学校读者我要写书评

暂无评论

Structural Durability & Health Monitoring 2025年第1期19卷 1-23页

作者： Nurlan Zhangabay Ulzhan Ibraimova marco Bonopera Ulanbator Suleimenov Konstantin Avramov Maryna Chernobryvko Aigerim Yessengali Department of Architecture and Urban Planning Mukhtar Auezov South Kazakhstan UniversityShymkent160012Kazakhstan Department of Industrial Civil and Road Construction Mukhtar Auezov South Kazakhstan UniversityShymkent160012Kazakhstan Mechanics Sound&Vibration LaboratoryDepartment of Civil EngineeringCollege of EngineeringNational Taiwan UniversityTaipei10617Taiwan Department of Reability&Dynamic Strength A.Pidhornyi Institute of Mechanical Engineering Problems of National Academy of Sciences of UkraineKharkiv61046Ukraine

Using the software ANSYS-19.2/Explicit Dynamics,this study performedﬁnite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire *** effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also *** results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum *** analysis of the inﬂuence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire *** increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the inﬂuence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline *** analysis of the temperature effect on the pipeline material,within a range from-40℃ to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length *** such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃ and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline signiﬁcantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of *** work integrated the existing methods for crack localization along steel gas pipelines.

关键词： Crack propagation ﬁnite-element internal pressure prestressing steel gas pipeline temperature effect

Measurement of vibration frequencies of ties in masonry arches by means of a robotic total station

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2022年第2期21卷 489-500页

作者： marco Gatti Dipartimento di Ingegneria University of Ferraravia Saragat 144123 FerraraItaly

Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is *** instrument made continuous recordings(up to ten per second)of the three-dimensional positions of a reflector situated at 1/2 or 1/4 of the length of the tie during vertical oscillation induced by an impulsive *** recording slips,vibration amplitudes(and their accuracy),hourly diagram and experimental spectra of vibrations,and the corresponding frequencies were *** results were verified by comparing them with the vibration frequencies and indirectly the tension and fixed support constraint calculated from accelerometric *** study provides interesting information on the accuracies of the reflector′s three-dimensional coordinates,but highlighted certain limits in the application of robotized total stations for measuring vibration frequencies of ties in masonry arches.

关键词： RTS frequency vibrations ties arches

σ-Phase in Lean Duplex Stainless Steel Sheets

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2015年第3期28卷 331-337页

作者： marco Breda Massimo Pellizzari marco Frigo Industrial Engineering Department(DII) University of PadovaVia Marzolo 9Int.435131 PaduaItaly Industrial Engineering Department(DII) University of TrentoVia Mesiano 7738123 TrentoItaly Outokumpu S.p.A. Piazza Piccapietra 916121 GenoaItaly

The precipitation kinetics of secondary phases in two austeno-ferritic lean duplex stainless steels（lean DSS）were examined after aging the materials at 800 ℃.Owing to the instability of ferrite,all DSS are known to be sensitive to solid-state phase transformations in the critical temperature range 600-1,000 ℃ and different secondary phases may form,depending on composition and *** performed thermodynamic simulations revealed the proneness to the precipitation of such phases also have been done in lean DSS,but only information on the equilibrium microstructures were ***,the materials were aged at various times,in order to verify the simulations and determine the precipitation *** occurred structural modifications were observed and quantified by scanning electron microscope and X-ray diffraction measurements,determining phase type,composition and volumetric *** 800 ℃,grade 2101 was found to be only affected by Cr_2N nitrides precipitation,whereas a significant amount of σ-phase was found to form in LDX 2404 for treatment longer than 1 h,almost totally replacing ferrite after 50 *** to now,the intermetallic σ-phase has been observed only in the high alloyed DSS,and the unexpected precipitation in grade 2404 highlighted that the increased content of molybdenum in this steel might be considered as determinant for the formation.

关键词： Lean duplex stainless steels Isothermal heat treatments σ-Phase Chromium nitrides Precipitation kinetics

Elastic period of vibration calculated experimentally in buildings hosting permanent GPS stations

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2018年第3期17卷 607-625页

作者： marco Gatti Department of Engineering University of Ferrara

During the earthquake in Emilia（Italy） of 2012,ca.30 permanent GPS stations were in operation within a radius of about 100 km from the epicenter,each equipped with an antenna rigidly fixed to the host building and sampling the GPS signal at a high rate（〉 1 Hz）.From the recording of the GPS measurements,the instantaneous displacements s（t） in the NorthSouth and East-West directions of the phase centers of the single GPS antennas at each permanent station during the most important seismic sequences were calculated in kinematic ***,for each of the two displacements considered as two distinct external forces,the elastic response spectra of the building were determined and from them the two periods of vibration T along two orthogonal directions coinciding with the walls of the building were *** experimentally obtained periods of vibration were compared with those inferable from the technical *** this way,a sufficiently large sample was obtained per building type,geometry（square,rectangular,regular or irregular planimetry）,height（from a minimum of 4 to a maximum of 20 m） and materials（masonry,reinforced concrete,etc.）.From the computational point of view,the study confirmed that GPS is an emerging tool for monitoring dynamic displacements and the experimentally estimated value of T is always lower than the one estimated with the formulae reported in the *** limitations of the study lie in the impossibility to choose a priori the geometry and/or structural type of the building hosting the GPS station.

关键词： permanent GPS stations Emilia-Romagna Italy earthquake period vibrations dynamic structure