检索结果-南通市图书馆

Injection of a Self-propelled Polymer into a Small Circular Cavity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-Li Zhou Xiao Yang Fan Wu Meng-Bo Luo department of physics Taizhou UniversityTaizhou318000China department of physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第6期67卷 127-136页

作者： Rui Chen Shun-Qing Shen department of physics The University of Hong KongHong Kong 999077China department of physics Hubei UniversityWuhan 430062China

In topological insulators,massive surface states resulting from local symmetry breaking were thought to exhibit a half-quantized Hall conductance,obtained from the low-energy effective model in an infinite Brillouin *** a lattice model,the surface band is composed of a combination of surface states and bulk *** massive surface states alone may not be enough to support an exact one-half quantized surface Hall conductance in a finite Brillouin zone and the whole surface band always gives an integer quantized Hall conductance as enforced by the TKNN *** explore this,we investigate the band structures of a lattice model describing the magnetic topological insulator film that supports the axion insulator,Chern insulator,and semi-magnetic topological insulator *** reveal that the gapped and gapless surface bands in the three phases are characterized by an integer-quantized Hall conductance and a half-quantized Hall conductance,*** propose an effective model to describe the three phases and show that the low-energy dispersion of the surface bands inherits from the surface Dirac *** gapped surface band manifests a nearly half-quantized Hall conductance at low energy near the center of Brillouin zone,but is compensated by another nearly half-quantized Hall conductance at high energy near the boundary of Brillouin zone because a single band can only have an integer-quantized Hall *** gapless band hosts a zero Hall conductance at low energy but is compensated by another half-quantized Hall conductance at high energy,and thus the half-quantized Hall conductance can only originate from the gapless ***,we calculate the layer-resolved Hall conductance of the *** conclusion suggests that the individual gapped surface band alone does not support the half-quantized surface Hall effect in a lattice model.

关键词： magnetic topological insulator Dirac equation half-quantized Hall conductance

同方期刊数据库

Tidal effects based on a GUP-induced effective metric

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第9期76卷 65-74页

作者： Soon-Tae Hong Yong-Wan Kim Young-Jai Park Center for Quantum Spacetime and department of physics Sogang University department of physics and Research Institute of physics and Chemistry Jeonbuk National University department of physics Sogang University

In this paper, we study tidal forces in the Schwarzschild black hole, whose metric explicitly includes a generalized uncertainty principle(GUP) effect. We also investigate interesting features of the geodesic equations and tidal effects that are dependent on the GUP parameter αrelated to a minimum length. Then, by solving the geodesic deviation equations explicitly with appropriate boundary conditions, we show that α in the effective metric affects both the radial and angular components of the geodesic equation, particularly near the singularities.

关键词： effective metric generalized uncertainty principle geodesic deviation equation

Tuning structural,electrical,dielectric and magnetic properties of Mg-Cu-Co ferrites via dysprosium(Dy^(3+))doping

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 137-146,I0005页

作者： Maria Akhtar M.S.Hasan Nasir Amin N.A.Morley Muhammad Imran Arshad department of physics Government College UniversityFaisalabad38000Pakistan department of physics The University of Lahore53700Pakistan department of Materials Science and Engineering The University of SheffieldS13JDUK department of physics&Astronomy University College LondonUK

In current research work,Dy3+substituted Mg0.5Cu0.25Co0.25Fe2-xDyxO4(0.0≤x≤0.04 with the step interval of 0.01)soft ferrites were synthesized by the sol-gel auto combustion *** prepared samples were characterized by the techniques using X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared(FTIR)spectroscopy,curre nt-voltage(Ⅰ-Ⅴ)measurement,LCR meter,vibrating sample magnetometer(VSM)and *** data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x=*** non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX *** DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in ***,the high resistivity is observed with the order of 1010Ω·cm,and the activation energy is 0.944 eV for samples x=*** dielectric parameters including dielectric constant,dielectric losses,and impedance gradually decrease with the increase in frequency from 8 Hz to 8 *** minimum dielectric loss at high frequency is found for sample x=*** coercivity(Hc)and saturation magnetization(Ms)are found in the ranges of 520.82-544.02 Oe and 20.5841-21.1473 emu/g,*** observations confirm that dysprosium(x=0.03)doped MCC-soft ferrites may be applicable in transformer cores,microwave absorbance,and telecommunication devices.

关键词： Soft ferrites DC resistivity Dielectric loss Impedance Coercivity Rare earths

Consistency between domain wall oscillation modes and spin wave modes in nanostrips

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第6期33卷 511-516页

作者：董新伟吴振江 department of physics and Institute of Theoretical physics and Astrophysics Xiamen UniversityXiamen 361005China

Investigations on domain wall(DW) and spin wave(SW) modes in a series of nanostrips with different widths and thicknesses have been carried out using micromagnetic simulation. The simulation results show that the frequencies of SW modes and the corresponding DW modes are consistent with each other if they have the same node number along the width direction. This consistency is more pronounced in wide and thin nanostrips, favoring the DW motion driven by *** analysis of the moving behavior of a DW driven by SWs is also carried out. The average DW speed can reach a larger value of ~ 140 m/s under two different SW sources. We argue that this study is very meaningful for the potential application of DW motion driven by SWs.

关键词： micromagnetic simulation domain wall spin wave

An improved bound on accelerated light dark matter

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第2期67卷 105-118页

作者： Liangliang Su Lei Wu Bin Zhu department of physics and Institute of Theoretical physics Nanjing Normal UniversityNanjing 210023China School of physics Yantai UniversityYantai 264005China

Light(sub-GeV)dark matter has gained increasing interest in terms of direct *** dark matter is a promising candidate that can generate detectable nuclear recoil energy within the sub-GeV *** of the large kinetic energy,its interactions with the nucleus are predominantly governed by inelastic scattering,including quasi-elastic and deep inelastic *** this work,we calculated the inelastic effects in dark matter-Earth scattering mediated by a vector *** analysis revealed that the impact of inelastic scattering relies on the mediator mass and the kinetic energy spectrum of dark *** results exhibited considerable disparity:the upper bounds of the exclusion limit for the spin-independent cross-section between accelerated dark matter and nuclei via a heavy mediator differ by several tens of times when inelastic scattering is considered.

关键词： accelerated dark matter inelastic scattering direct detection experiment

Molecular Chaperone-Dependent Polymer Translocation through Nanopores: The Effects of Chaperone Concentration and Chaperone-Polymer Interaction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第1期42卷 125-132,I0011页

作者： Chang-Sheng Zuo Kang Wang Li-Zhen Sun Ting-Ting Sun department of physics Zhejiang University of Science and TechnologyHangzhou 310023China department of Applied physics Zhejiang University of TechnologyHangzhou 310014China

The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to its significance in biological systems and technological applications. In this work, we mainly focus on the effects of chaperone concentration and chaperone-polymer interaction on the polymer translocation. By assuming the polymer translocation to be a quasi-equilibrium process, the free energy F of the polymer can be estimated by Rosenbluth-Rosenbluth method and then the translocation time τ can be calculated by Fokker-Plank equation based on the obtained free energy landscape. Our calculation results show that the translocation time can be controlled by independently tuning the chaperone concentration and chaperone-polymer interaction at the cis side or the trans side. There exists a critical chaperone-polymer attraction ε~*=-0.2 at which the volume exclusion and interaction effects of the chaperone can balance each other. Additionally, we also find that at large chaperone-polymer attraction, the translocation time is mainly governed by the diffusion coefficient of the polymer.

关键词： Polymer translocation Rosenbluth-Rosenbluth method Fokker-Plank equation Free energy landscapes

Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3（001） via metallic δ-doping

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 119-127页

作者： Xiaotong Jiao Wenfeng Dong Mingxia Shi Heng Wang Cui Ding Zhongxu Wei Guanming Gong Yanan Li Yuanzhao Li Binjie Zuo Jian Wang Ding Zhang Minghu Pan Lili Wang Qi-Kun Xue State Key Laboratory of Low-Dimensional Quantum physics Department of Physics Tsinghua University School of physics&Information Technology Shaanxi Normal University Beijing Academy of Quantum Information Sciences department of physics Southern University of Science and Technology International Center for Quantum Materials School of Physics Peking University department of physics The Pennsylvania State University Collaborative Innovation Center of Quantum Matter Hefei National Laboratory

Superconductivity transition temperature（Tc） marks the inception of a macroscopic quantum phase-coherent paired state in fermionic systems. For 2D superconductivity, the paired electrons condense into a coherent superfluid state at Tc, which is usually lower than the pairing temperature, between which intrinsic physics including Berezinskii–Kosterlitz–Thouless transition and pseudogap state are hotly debated. In the case of monolayer FeSe superconducting films on SrTiO3（001）, although the pairing temperature（Tp） is revealed to be 65–83 K by using spectroscopy characterization, the measured zero-resistance temperature（Tc0） is limited to 20 K. Here, we report significantly enhanced superconductivity in monolayer FeSe films by δ-doping of Eu or Al on SrTiO3（001） surface, in which Tc0is enhanced by 12 K with a narrowed transition width ΔTc～8 K, compared with non-doped samples. Using scanning tunneling microscopy/spectroscopy measurements, we demonstrate lowered work function of the δ-doped SrTiO3（001） surface and enlarged superconducting gaps in the monolayer FeSe with improved morphology/electronic homogeneity. Our work provides a practical route to enhance 2D superconductivity by using interface engineering.

关键词： monolayer FeSe interface superconductivity δ-doping zero-resistance temperature superconductivity transition temperature

Nonlocal coherence harvesting from quantum vacuum

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第7期76卷 46-53页

作者： Rui-Di Wang Shu-Min Wu Xiao-Li Huang department of physics Liaoning Normal University

It is well known that nonlocal coherence reflects nonclassical correlations better than quantum entanglement. Here, we analyze nonlocal coherence harvesting from the quantum vacuum to particle detectors adiabatically interacting with a quantum scalar field in Minkowski *** find that the harvesting-achievable separation range of nonlocal coherence is larger than that of quantum entanglement. As the energy gap grows sufficiently large, the detectors harvest less quantum coherence, while the detectors could extract more quantum entanglement from the vacuum state. Compared with the linear configuration and the scalene configuration, we should choose the model of equilateral triangle configuration to harvest tripartite coherence from the vacuum. Finally, we find a monogamous relationship, which means that tripartite l1-norm of coherence is essentially bipartite types.

关键词： monogamous relationship nonlocal coherence quantum vacuum