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How tightly is the nuclear symmetry energy constrained by a unitary Fermi gas?

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Nuclear Science and Techniques 2017年第12期28卷 248-254页

作者： Nai-Bo Zhang bao-jun Cai bao-An Li William G.Newton jun Xu Department of Physics and Astronomy Texas A&M University-Commerce Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space Sciences Shandong University Department of Physics Shanghai University Department of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University Shanghai Institute of Applied Physics Chinese Academy of Sciences

We examine critically how tightly the density dependence of nuclear symmetry energy E_(sym)(q) is constrained by the universal equation of state of the unitary Fermi gas EUG(q) considering currently known uncertainties of higher order parameters describing the density dependence of the equation of state of isospin asymmetric nuclear matter. We found that E_(UG)(q) does provide a useful lower boundary for the E_(sym)(q). However, it doesnot tightly constrain the correlation between the magnitude E_(sym)(q_0) and slope L unless the curvature K_(sym)of the symmetry energy at saturation density q_0 is more precisely known. The large uncertainty in the skewness parameters affects the E_(sym)(q_0) versus L correlation by the same almost as significantly as the uncertainty in K_(sym).

关键词： Symmetry energy Unitary gas Equation of state Nuclear matter

A progressive framework for rotary motion deblurring

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Defence Technology（防务技术） 2024年第2期32卷 159-172页

作者： Jinhui Qin Yong Ma jun Huang fan fan You Du School of Electronic Information Wuhan UniversityWuhan430072China

The rotary motion deblurring is an inevitable procedure when the imaging seeker is mounted in the rotating *** rotary motion deblurring methods suffer from ringing artifacts and noise,especially for large blur *** solve the above problems,we propose a progressive rotary motion deblurring framework consisting of a coarse deblurring stage and a refinement *** the first stage,we design an adaptive blur extents factor(BE factor)to balance noise suppression and details *** a novel deconvolution model is proposed based on BE *** the second stage,a triplescale deformable module CNN(TDM-CNN)is designed to reduce the ringing artifacts,which can exploit the 2D information of an image and adaptively adjust spatial sampling *** establish a standard evaluation benchmark,a real-world rotary motion blur dataset is proposed and released,which includes rotary blurred images and corresponding ground truth images with different blur *** results demonstrate that the proposed method outperforms the state-of-the-art models on synthetic and real-world rotary motion blur *** code and dataset are available at https://***/JinhuiQin/RotaryDeblurring.

关键词： Rotary motion deblurring Progressive framework Blur extents factor TDM-CNN

基于自适应续流比的混合式步进电机转矩脉动抑制方法

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陕西科技大学学报 2025年第1期43卷 142-151,202页

作者：王焜刘宝泉刘艺张浩铭刘俊陕西科技大学电气与控制工程学院陕西西安710021 西安西电高压开关有限责任公司陕西西安710018

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前... 详细信息

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前时刻所需的续流模式.在快速续流模式下,实时监测电流指令与实际电流的差值Δi ref,通过自适应系数k动态调节续流时间,直至电机相电流快速下降至给定电流i ref后切换至缓慢续流模式.对续流时长与快速续流占总续流时间的比例自适应调节以适应不同工况下步进电机的平稳运行,有效降低了转矩脉动.最后,搭建MATLAB/Simulink仿真平台并进行实验验证,结果表明,与传统混合续流控制相比,所提方法能够有效减小步进电机的转矩脉动.

关键词：混合式步进电机自适应续流比电流纹波转矩脉动

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Enhanced photocatalytic activity of sponge-like ZnFe2O4 synthesized by solution combustion method

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Progress in Natural Science:Materials International 2012年第6期22卷 639-643页

作者： Song Sun Xiaoyan Yang Yi Zhang fan Zhang Jianjun Ding jun bao Chen Gao CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering.University of Science and Technology of ChinaHefei National Synchrotron Radiation Laboratory & School of Nuclear Science and Technology University of Science and Technology of China.Hefei CAS Key Laboratory of Materials for Energy Conversion Department of Materials Science and Engineering.University of Science and Technology of China.Hefei National Synchrotron Radiation Laboratory & School of Nuclear Science and Technology University of Science and Technology of ChinaHefei

A kind of cubic ZnFe2O4with spinel structure was synthesized by an improved solution combustion method via a facile and environmentally friendly pathway and their photocatalytic activity under visible light radiation was *** particle synthesized under the ignition temperature of 573 K has a pure *** a small amount impurities,α-Fe2O3and *** formed in the sample during the combustion process at higher ignition temperature of 623 *** synthesized ZnFe2O4has a sponge-like porous structure and wide absorption in the visible-light *** impuritiesα-Fe2O3and ZnO formed in the sample probably enhance the reduction and oxidation ability and promote the separation of photo-generated electrons and *** with ZnFe2O4synthesized by the conventional solid state reaction,the ZnFe2O4derived by solution combustion method showed the better photocatalytic activity under visible light radiation.

关键词： Zinc ferrite Photocatalysis Solution combustion Infrared thermal image

A MICROMECHANICAL FRAMEWORK WITH AGGREGATE-MASTIC INTERFACE EFFECT FOR PREDICTING UNIAXIAL COMPRESSION CREEP OF ASPHALT MIXTURE

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Acta Mechanica Solida Sinica 2014年第3期27卷 306-314页

作者： jun Wu Xinhua Yang fan Bai Department of Mechanics Huazhong University of Science and Technology

According to the elastic-viscoelastic correspondence principle, an elastic microme- chanical framework taking the inclusion-matrix interface effect into account is extended for predicting viscoelastic properties of asphalt mixture, which is simply treated as elastic coarse aggregate inclusions periodically and isotropically embedded in a viscoelastic asphalt mastic matrix. The Burgers model is adopted for characterizing the matrix mechanical behavior, so that the homogenized relaxation modulus of asphalt mixture in compression creep is derived. After a series of uniaxial compression creep tests are performed on asphalt mastic in different temperature and stress conditions in order to determine the matrix constitutive parameters, the framework presented is validated by comparison with the experiment, and then some predictions of uniaxial compression creep behavior of asphalt mixture in different temperature and stress conditions are given.

关键词： asphalt mixture micromechanics elastic-viscoelastic correspondence principle compression creep

Constraints on the skewness coefficient of symmetric nuclear matter within the nonlinear relativistic mean field model

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Nuclear Science and Techniques 2017年第12期28卷 279-287页

作者： bao-jun Cai Lie-Wen Chen School of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong UniversityShanghai 200240China

Within the nonlinear relativistic mean field(NLRMF) model, we show that both the pressure of symmetric nuclear matter at supra-saturation densities and the maximum mass of neutron stars are sensitive to the skewness coefficient, J_0, of symmetric nuclear matter. Using experimental constraints on the pressure of symmetric nuclear matter at supra-saturation densities from flow data in heavy-ion collisions and the astrophysical observation of a large mass neutron star PSR J0348+0432, with the former favoring a smaller J_0 while the latter favors a larger J_0, we extract a constraint of -494 MeV≤J_0≤-10 MeV based on the NL-RMF model. This constraint is compared with the results obtained in other analyses.

关键词： Equation of state of nuclear matter Heavy-ion collisions Neutron stars

The energy release rate for hygrothermal coupling elastic materials

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Acta Mechanica Sinica 2006年第1期22卷 28-33页

作者： fan Yang jun Wang Dapeng Chen Institute of Computational Engineering and Science Southwest Jiaotong UniversityChengdu 610031 China Department of Material Science Fudan UniversityShanjzhai 200433. China

In the fracture problems of hydrophilic elastic materials under coupling effects of heat conduction, moisture diffusion and mechanical deformation, the conventional J-integral is no longer path independent. The value of J is unequal to the energy release rate in hygrothermal coupling cases. In the present paper, we derived a general form of the energy release rate for hygrothermal fracture problems of the hydrophilic elastic materials on the basis of energy balance equation in cracked areas. By introducing the constitutive relations and the essential equations of irreversible thermodynamics, a specific expression of the energy release rate was obtained, and the expression can be reformmulated as path independent integrals, which is equivalent to the energy release rate of the fracture body. The path independence of the integrals is then verified numerically.

关键词： Fracture Energy release rate J-integral Hygrothermal coupling problems

Thermodynamic Properties of Carbon and Manganese in Mn-C and Mn-Fe-C Melts

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Journal of Iron and Steel Research International 2008年第5期15卷 13-18页

作者： CHEN Er-bao WANG Shi-jun School of Metallurgy and Resources Anhui University of Technology Ma＇anshan 243002 Anhui China

Carbon solubility in Mn Fe melts （xMn =0. 083-0. 706, XFe =0. 034-0. 715） was measured experimentally at various temperatures. By thermodynamic derivation and calculation, the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained. Using Gibbs-Duhem relationship, the experimental results of this study, and experimental data obtained by strict thermodynamic derivation and calculation in references, the relationships between other thermodynamic properties （εCC, εCCC, εCFe, εCCFe, and εCFeFe） in Mn-Fe-C system and temperature were obtained.

关键词： Mn-Fe-C melt activity interaction parameter thermodynamic property carbon manganese

Thermodynamic Properties of Mn-C Melts

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Journal of Iron and Steel Research International 2008年第2期15卷 1-6页

作者： CHEN Er-bao WANG Shi-jun School of Metallurgy and Resources Anhui University of Technology Ma＇anshan 243002 Anhui China

Carbon solubility in Mn-Fe melts（xMn=0.161-0.706,xFe=0.034-0.633）was measured experimentally at various *** thermodynamic derivation and calculation,the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was *** Gibbs-Duhem relationship,the experimental results of this study,and experimental data reported in references,the relationship between other thermodynamic properties in Mn-C system and temperature were obtained by thermodynamic derivation and calculation.

关键词： Mn-C melt activity interaction coefficient thermodynamic property carbon manganese