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Bayesian inference of neutron-skin thickness and neutron-star observables based on effective nuclear interactions

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 97-105页

作者： Jia Zhou jun xu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China School of Physics Science and Engineering Tongji UniversityShanghai 200092China

We have obtained the constraints on the density dependence of the symmetry energy from neutron-skin thickness data by parityviolating electron scatterings and neutron-star observables using a Bayesian approach,based on the standard Skyrme-HartreeFock(SHF)model and its extension as well as the relativistic mean-field(RMF)*** the neutron-skin thickness data(neutron-star observables)mostly constrain the symmetry energy at subsaturation(suprasaturation)densities,they may more or less constrain the behavior of the symmetry energy at suprasaturation(subsaturation)densities,depending on the energy-density functional *** showing the final posterior density dependence of the symmetry energy,we also compare the slope parameters of the symmetry energy at 0.10 fm-3as well as the values of the symmetry energy at twice saturation density from three effective nuclear *** present work serves as a comparison study based on relativistic and non-relativistic energy-density functionals,for constraining the nuclear symmetry energy from low to high densities using a Bayesian approach.

关键词： symmetry energy neutron skin neutron star

A novel weighting scheme for random k-SAT

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Science China(Information Sciences) 2016年第9期59卷 5-10页

作者： jun LIU Ke xu State Key Laboratory of Software Development Environment Beihang University

Consider a random k-conjunctive normal form F;（n, rn） with n variables and rn clauses. We prove that if the probability that the formula Fk（n, rn） is satisfiable tends to 0 as n →∞, then r≥2.83, 8.09, 18.91,40.... 详细信息

关键词： computational complexity satisfiability phase transition second moment method weighting scheme

Damage evolution and crack propagation in rocks with dual elliptic flaws in compression

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Acta Mechanica Solida Sinica 2017年第6期30卷 573-582页

作者： jun xu Zhaoxia Li Department of Engineering Mechanics Southeast University Nanjing 210096 China Jiangsu Key Laboratory of Engineering Mechanics Southeast University Nanjing 210096 China

To give an insight into the understanding of damage evolution and crack propagation in rocks,a series of uniaxial and biaxial compression numerical tests are carried *** investigations show that damage evolution occurs firstly in the weak rock,the area around the flaw and the area between the flaw and the neighboring rock *** mostly generate as tensile cracks under uniaxial compression and shear cracks under biaxial *** patterns are classified and *** relationship between the accumulated lateral displacement and the short radius（b）is fitted,and the equation of crack path is also established.

关键词： Damage evolution Crack propagation Elliptic flaw

Induced neural stem cells regulate microglial activation through Akt-mediated upregulation of CXCR4 and Crry in a mouse model of closed head injury

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Neural Regeneration Research 2025年第5期20卷 1416-1430页

作者： Mou Gao Qin Dong Dan Zou Zhijun Yang Lili Guo Ruxiang xu Department of Neurosurgery Sichuan Academy of Medical Sciences and Sichuan Provincial People’s HospitalSchool of MedicineUniversity of Electronic Science and Technology of ChinaChengduSichuan ProvinceChina Department of Neurosurgery Chinese PLA General HospitalBeijingChina Department of Neurology Fu Xing HospitalCapital Medical UniversityBeijingChina

Microglial activation that occurs rapidly after closed head injury may play important and complex roles in neuroinflammation-associated neuronal damage and *** previously reported that induced neural stem cells can modulate the behavior of activated microglia via CXCL12/CXCR4 signaling,influencing their activation such that they can promote neurological ***,the mechanism of CXCR4 upregulation in induced neural stem cells remains *** this study,we found that nuclear factor-κB activation induced by closed head injury mouse serum in microglia promoted CXCL12 and tumor necrosis factor-αexpression but suppressed insulin-like growth factor-1 ***,recombinant complement receptor 2-conjugated Crry(CR2-Crry)reduced the effects of closed head injury mouse serum-induced nuclear factor-κB activation in microglia and the levels of activated microglia,CXCL12,and tumor necrosis factor-α.Additionally,we observed that,in response to stimulation(including stimulation by CXCL12 secreted by activated microglia),CXCR4 and Crry levels can be upregulated in induced neural stem cells via the interplay among CXCL12/CXCR4,Crry,and Akt signaling to modulate microglial *** agreement with these in vitro experimental results,we found that Akt activation enhanced the immunoregulatory effects of induced neural stem cell grafts on microglial activation,leading to the promotion of neurological recovery via insulin-like growth factor-1 secretion and the neuroprotective effects of induced neural stem cell grafts through CXCR4 and Crry upregulation in the injured cortices of closed head injury ***,these beneficial effects of Akt activation in induced neural stem cells were positively correlated with the therapeutic effects of induced neural stem cells on neuronal injury,cerebral edema,and neurological disorders post–closed head *** conclusion,our findings reveal that Akt activation may enhance the immunoregulatory effects of induced neura

关键词： Akt signaling cerebral edema closed head injury Crry CXCR4 induced neural stem cell microglia neuroinflammation

Samarium doped apatite-type orange-red emitting phosphor Ca5（PO4）2SiO4 with satisfactory thermal properties for n-UV w-LEDs

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Journal of Rare Earths 2019年第9期37卷 949-954,I0002页

作者： ze Zhang Jialiang Niu Wei Zhou Dingdian xu Huanhuan Du Department of Chemistry School of ScienceBeijing Technology and Business University

A novel single-phase Sm^3+activated Ca5(PO4)2SiO4 phosphor was successfully fabricated via a conventional solid-state method,which can be e fficie ntly excited by near ultraviolet(n-UV)light-emitting *** crystal structure and luminescence properties were characterized and analyzed systematically by using relevant *** Ca5(PO4)2SiO4:Sm^3+phosphor shows an orange-red emission peaking at600 nm under the excitation of 403 nm and the optimal doping concentration of Sm^3+is determined to be 0.08,The critical distance of Ca5(PO4)2SiO4:0.08 Sm^3+is calculated to be 1.849 nm and concentration quenching mechanism of the Sm^3+in Ca5(PO4)2SiO4 host is ascribed to energy transfer between nearestneighbor *** decay time of Ca5(PO4)2 SiO4:0,08 Sm^3+is determined to be 1.1957 *** addition,the effect of temperature on the emission intensity was also studied,72.4%of the initial intensity is still preserved at 250℃,better thermal stability compared to commercial phosphor YAG:Ce^3+indicates that Ca5(PO4)2SiO4:0.08 Sm^3+has excellent thermal stability and active energy is deduced to be 0.130 *** the results demonstrate that orange-red emitting Ca5(PO4)2SiO4:0.08 Sm3+phosphor exhibits good luminescent *** to the excellent thermal quenching luminescence property,Ca5(PO4)2SiO4:0.08 Sm^3+phosphor can be applied in n-UV white light emitting diodes and serve as the warm part of white light.

关键词： Phosphors Ca5(PO4)2SiO4:Sm^3+ Luminescence Orange-red phosphor Rare earths

Precipitation behavior and martensite lath coarsening during tempering of T/P92 ferritic heat-resistant steel

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International Journal of Minerals,Metallurgy and Materials 2014年第5期21卷 438-447页

作者： Lin-qing xu Dan-tian Zhang Yong-chang Liu Bao-qun Ning Zhi-xia Qiao ze-sheng Yan Hui-jun Li State Key Lab of Hydaulic Engineering Simulation and Safety School of Material Science and EngineeringTianjin University School of Materials Science and Engineering Tianjin University of Technology School of Mechanical Engineering Tianjin University of Commerce

Tempering is an important process for T/P92 ferritic heat-resistant steel from the viewpoint of microstructure control, as it facili- tates the formation of final tempered martensite under serving conditions. In this study, we have gained deeper insights on the mechanism underlying the microstructural evolution during tempering treatment, including the precipitation of carbides and the coarsening of martensite laths, as systematically analyzed by optical microscopy, transmission electron microscopy, and high-resolution transmission electron mi- croscopy. The chemical composition of the precipitates was analyzed using energy dispersive X-ray spectroscopy. Results indicate the for- mation of M3C （cementite） precipitates under normalized conditions. However, they tend to dissolve within a short time of tempering, owing to their low thermal stability. This phenomenon was substantiated by X-ray diffraction analysis. Besides, we could observe the precipitation of fine carbonitrides （MX） along the dislocations. The mechanism of carbon diffusion controlled growth of M23C6 can be expressed by the zener＇s equation. The movement of Y-junctions was determined to be the fundamental mechanism underlying the martensite lath coarsening process. Vickers hardness was estimated to determine their mechanical properties. Based on the comprehensive analysis of both the micro- structural evolution and hardness variation, the process of tempering can be separated into three steps.

关键词： ferritic steel heat resisting tempering precipitation martensite coarsening

Shear viscosity of nuclear matter

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Nuclear Science and Techniques 2013年第5期24卷 71-75页

作者： xu jun Shanghai Institute of Applied Physics Chinese Academy of SciencesJiading Campus Department of Physics and Astronomy Texas A & M University-CommerceCommerce

This paper reports my recent study[1]on the shear viscosity of neutron-rich nuclear matter from a relaxation time *** isospin- and momentum-dependent interaction is used in the *** of density,temperature,and isospin asymmetry of nuclear matter on its shear viscosity have been *** to the symmetry energy,the symmetry shear viscosity is defined and its density and temperature dependence are studied.

关键词：剪切粘度核物质不对称弛豫时间相互作用同位旋依赖性丰中子

Oxygen transfer characteristics of bubbly jet in regular waves

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Journal of Hydrodynamics 2020年第5期32卷 879-887页

作者： ze-gao Yin De-chun Liu Yuan Li Yan-xu Wang College of Engineering Ocean University of ChinaQingdao 266100China

The dissolved oxygen level is an important index of the water environment,and in this paper,the oxygen transfer of the bubbly jet in regular waves is investigated numerically and *** Reynolds-averaged Navier-Stokes equations,the re-normalisation group k-e equations,and the volume of fluid(VOF)technique are used along with a 2-D CFD model to simulate the wave and bubble motions as well as the turbulence,and a dissolved oxygen transport equation is used to model the oxygen transfer behavior both through the bubbly interface and the wave surface.A series of experiments are conducted to validate the mathematical model,with good *** addition,a group of dimensionless parameters are defined from the wave parameter and the aeration parameter,and their relationships with the total oxygen transfer coefficient are ***,the dimensional analysis and the least squares methods are used to derive simple prediction formulas for the total oxygen transfer coefficient,and they are validated with the related experimental data.

关键词： Bubbly jet regular wave mathematical model total oxygen transfer coefficient

Synthesis and characterization of two-dimensional lead-free(K, Na)NbO3 micro/nano piezoelectric structures

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Journal of Advanced Ceramics 2020年第1期9卷 27-34页

作者： Li-Qian CHENG Mei FENG Yiwen SUN Zhen ZHOU ze xu State Key Laboratory of Coal Resources and Safe Mining Department of Materials Science and EngineeringChina University of Mining&Technology(Beijing)Beijing 100083China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Two-dimensional(2 D)lead-free(K,Na)Nb O3(KNN)micro/nano structures with controllable K/Na ratio were successfully fabricated via a two-step molten salt synthesis(MSS).In this work,the reaction factors,including the proportion of molten salts,the types of carbonates,the sintering temperature,and the sintering time,were discussed in detail and the optimized condition was *** microstructure of KNN was confirmed by confocal Raman spectroscopy,while piezoresponse force microscopy(PFM)was applied to measure three-dimensional(3 D)morphology and piezoelectric properties of KNN *** as-synthesized KNN platelets apparently possess anisotropic morphology and uniform structure,the size of which reaches 5–20μm in length/width and 0.5–1μm in *** should be noted that the K/Na ratios of the KNN crystals are basically consistent while the proportion of salts changes within a certain *** enrichment of Na element in the products is also observed,which owes to the smaller ionic radius of Na+comparing to that of K+.This result provides a reference for the further preparation of textured ceramics and flexible piezoelectric generators.

关键词： (K,Na)NbO3(KNN) lead-free two-dimensional(2D)structure piezoelectric property