检索结果-南通市图书馆

redback/Black Widow systems as progenitors of the highest neutron star masses and low-mass Black holes

在线全文

学校读者我要写书评

暂无评论

science China(physics,Mechanics & Astronomy) 2020年第12期63卷 115-116页

作者： J.E.horvath A.Bernardo L.s.rocha r.Valentim p.h.r.s.moraes M.G.B.de Avellar Universidade de sao paulo Department of Astronomy IAG-USP.R.do Matao 122605508-090Cidade UniversitariaSao Paulo SPBrazil Departamento de Física Instituto de Ciências AmbientaisQuímicas e Farmacêuticas(ICAQF)R.Sao Nicolau 21009913-030Diadema SPBrazil

The long-standing problem of the maximum mass that can be achieved by the compact objects,with clear implications for the equation of state of matter above the nuclear saturation density(see ref.[1]and references therein),is receiving a new twist with the latest data from binary systems and Ns-Ns merging *** ago,double neutron stars systems(DNs)data installed the idea of a"canonical"mass of^1.4 M_⊙,but later work provided evidence for heavier objects with increasing degree of confidence,and it became clear that at least a second"mass scale"had to be present[2].

关键词： mass canonical saturation

Fast radio Bursts as Crustal Dynamical Events Induced by Magnetic Field Evolution in Young Magnetars

在线全文

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2022年第3期22卷 39-46页

作者： J.E.horvath p.h.r.s.moraes M.G.B.de Avellar L.s.rocha Universidade de são paulo(Usp) Instituto de AstronomiaGeofísica e Ciências AtmosféricasRua do Matão 1226Cidade Universitária05508-090 São PauloSPBrazil Universidade Federal de são paulo(UNIFEsp) Instituto de Ciências AmbientaisQuímicas e FarmacêuticasRua São Nicolau 21009913-030 DiademaSPBrazil Universidade Federal do ABC(UFABC) Centro de Ciências Naturais e Humanas(CCNH)Avenida dos Estados 500109210-580Santo AndréSPBrazil

We revisit in this work a model for repeating Fast radio Bursts based of the release of energy provoked by the magnetic field dynamics affecting a magnetar’s *** address the basics of such a model by solving the propagation of the perturbation approximately,and quantify the energetics and the radiation by bunches of charges in the so-called charge starved region in the ***(almost)simultaneous emission of newly detected X-rays from sGr 1935+2154 is tentatively associated with a reconnection behind the *** strength of f-mode gravitational radiation excited by the event is quantified,and more detailed studies of the nonlinear(spiky)soliton solutions are suggested.

关键词： stars:magnetars relativistic processes radiation mechanisms:non-thermal

Fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

在线全文

学校读者我要写书评

暂无评论

Matter and radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.X.Wang X.L.Zhu s.M.Weng p.Li X.F.Li h.Ai h.r.pan Z.M.sheng Key Laboratory for Laser plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFsA Shanghai Jiao Tong UniversityShanghai 200240China research Center of Laser Fusion of China Academy of Engineering physics MianyangSichuan 621900China state key Laboratory of high Field Laser physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-Ir)to terahertz(Thz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-Ir or Thz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-Ir or Thz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength Ir and Thz spectral ranges.

关键词： laser ultrashort photon

holographic dark energy in non-conserved gravity theory

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

Communications in Theoretical physics 2024年第4期76卷 126-133页

作者： h r Fazlollahi Institute of Gravitation and Cosmology Peoples Friendship University of Russia(RUDN University)6 Miklukho-Maklaya StMoscow117198Russia

recently, reconsidering the rastall idea T_(μ;νν)^(v)=α_(,μ) through relativistic thermodynamics gives a new form for the scalar field α which led us to construct modern modified theory of gravity debugged ‘non-conserved gravity theory’ Fazlollahi 2023 Euro. phys. J. C 83 923. This theory unlike other modified theories of gravity cannot directly explain the current acceleration expansion in the absence of the cosmological constant and or existence of other forms of dark energy. hence, in this study we have reinvestigated holographic dark energy Ρ_(X)~h^(2) in the non-conserved theory of gravity. In this context, the density and pressure of dark energy depend on the non-conserved term and density of the dust matter field. As shown, due to non-conservation effects on large-scale structures, unlike the original holographic model, our model onsets an acceleration epoch for the current Universe satisfies observations. Moreover, the interaction and viscous scenarios are studied for this model.

关键词： non-conserved gravity covariant form of thermodynamics holographic dark energy

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第2期33卷 108-114页

作者： U.s.Mahabaleshwar G.p.Vanitha L.M.pérez Emad h.Aly I.pop Department of studies in Mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of Mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in h_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/h_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/h_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

MgO-attached graphene nanosheet(MgO@GNs)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2062-2076页

作者： s.Abazari A.shamsipur h.r.Bakhsheshi-rad M.s.soheilirad F.Khorashadizade s.s.Mirhosseini Department of Materials and Metallurgical Engineering Amirkabir University of TechnologyTehran ***Iran Iranian National standards Organization of hormozgan HormozganIran Advanced Materials research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of Materials and Metallurgical Engineering Iran University of Science and TechnologyTehranIran

Magnesium(Mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and ***,they suffer from low corrosion resistance and antibacterial *** this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(MgO@GNs/Mg)composite to improve mechanical,corrosion and cytocompatibility *** have revealed that the incorporation of MgO@GNs nanohybrids into Mg-based composite enhanced microhardness and compressive *** vitro,osteoblast cell culture tests show that using MgO@GNs nanohybrid fillers enhances osteoblast adhesion and apatite *** presence of MgO@GNs nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the *** demonstrated that the MgO@GNs/Mg composite possesses excellent antibacterial properties because of the combination of the release of MgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid ***,the MgO@GNs/Mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a promising material for load-bearing implant applications.

关键词： metal matrix composites MgO@GNs nanohybrid strengthening mechanisms antibacterial activity biocompatibility

Enhanced entropy generation and heat transfer characteristics of magnetic nano-encapsulated phase change materials in latent heat thermal energy storage systems

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6期45卷 1051-1070页

作者： p.s.rEDDY p.srEEDEVI Department of Mathematics Rajeev Gandhi Memorial College of Engineering and TechnologyNandyal 518501India

The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEpCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing *** effects of various parameters,including the viscosity parameter,ranging from 1 to 3,the thermal conductivity parameter,ranging from 1 to 3,the rayleigh parameter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temperature,ranging from 1.0 to 1.2,the volume fraction of NEpCMs,ranging from 2%to 6%,the stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility parameter,ranging from 0.1 to 0.5,are examined in detail on the temperature contours,isentropic lines,heat capacity ratio,and velocity ***,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented *** results indicate that the time taken by the NEpCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temperatureθf ***,the contours of the heat capacity ratio Cr decrease with the increase in the stefan number ste.

关键词： volume fraction of nano-encapsulated phase change material(NEpCM) radiation stefan number heat capacity ratio entropy generation

Cr-induced fusion reactions to synthesize superheavy elements

在线全文

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2024年第5期35卷 122-130页

作者： s.Madhu h.C.Manjunatha N.sowmya B.M.rajesh L.seenappa r.s.susheela Department of physics R V College of EngineeringBangalore 560074India Visvesvaraya Technological University BelagaviKarnataka 590018India Department of physics Government First Grade CollegeSrinivasapurKarnataka 563135India Department of physics Government First Grade CollegeDevanahallyKarnataka 562110India Department of physics Government First Grade CollegeMulbagalKarnataka 563131India Department of physics Government First Grade collegeNanjangudOoty RoadMysore 571301India

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 *** cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior *** estimated cross sections from this analysis are consistent with the findings of prior *** the current study,the predicted cross section was found to be 42fb at 236 MeV for ^(53)Cr+^(243)Am,23.2 fb at 236 MeV for ^(54)Cr+^(247)Cm,95.6 fb at 240 MeV for ^(53)Cr+248Bk,and 1.33 fb at 242 MeV for ^(53)Cr+***,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.

关键词： Fusion cross sections Compound nucleus formation probability survival probability Evaporation residue cross sections

A concise review on surface and structural modification of porous zeolite scaffold for enhanced hydrogen storage

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 33-53页

作者： B.A.Abdulkadir r.s.r.Mohd Zaki A.T.Abd Wahab s.N.Miskan Anh-Tam Nguyen Dai-Viet N.Vo h.D.setiabudi Centre for research in Advanced Fluid&processes Universiti Malaysia Pahang Al-Sultan AbdullahLebuh Persiaran Tun Khalil YaakobGambangPahang 26300Malaysia Faculty of Chemical&process Engineering Technology Universiti Malaysia Pahang Al-Sultan AbdullahLebuh Persiaran Tun Khalil YaakobGambangPahang 26300Malaysia Center of Excellence for Green Energy and Environmental Nanomaterials(CE@GrEEN) Nguyen Tat Thanh University300A Nguyen Tat ThanhDistrict 4Ho Chi Minh City 755414Viet Nam

Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical ***,the storage capacity of the unmodified zeolites has been rather unsatisfactory(0.224%-1.082%(mass))compared to its modified ***,the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites,with studies exploring surface modifications through physical and chemical treatments,as well as the integration of various active *** enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals,resulting in increased storage capacity through interactions with the charge density of these ***,there is a great demand to critically review their role such as well-defined topology,pore structure,good thermal stability,and tunable hydrophilicity in enhanced hydrogen *** article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen *** of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent,like pressure,structure,and morphology were studied,and ***,future perspectives,recommendations,and directions for modified zeolites were discussed.

关键词： Zeolites hydrogen storage surface modification Adsorption Active metal