检索结果-南通市图书馆

Three-dimensional fracture of UO2 ceramic pellets by phase field modeling

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 169-180页

作者： Wei Xiong Xuan Ye Hongzhang Cheng Xiaoming Liu institute of nuclear and New Energy technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University state key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences School of Engineering Science University of Chinese Academy of Sciences

Fracture is the primary failure type for the UO2ceramic pellets,which are operated under irradiation and thermal processes,and physically confined by the *** this work,by combining closely coupled physical processes of heat conduction,heat transfer,and mechanical deformation with the cohesive phase field framework,we proposed a high-precision modeling of quasistatic cracking of three-dimensional （3D） UO2ceramic fuel pellets under high temperature and *** simulation results agree well with the experimental results,indicating that the proposed method has the potential to capture 3D crack modes in the interested time ***,we studied the relation of the 3D fracture patterns of fuel pellets with the peak power *** was found that the power level plays a critical role in determining the competition between radial and circumferential cracks,as well as transverse penetrating cracks.

关键词： phase field method nuclear fuel pellet coupled thermo-mechanical model thermal fracture

Particle-number conserving analysis for the 2-quasiparticle and high-K multi-quasiparticle states in doubly-odd ^(174,176)Lu

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 physics C 2013年第1期37卷 36-43页

作者：李冰桓张振华雷奕安 state key Lab of nuclear physics and technology School of PhysicsPeking University state key laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of Sciences

Two-quasiparticle bands and low-lying excited high-K four-, six-, and eight-quasiparticle bands in the doubly-odd 174, 176Lu are analyzed by using the cranked shell model （CSM） with the pairing correlations treated by a particle-number conserving （PNC） method, in which the blocking effects are taken into account exactly. The proton and neutron Nilsson level schemes for 174, 176Lu are taken from the adjacent odd-A Lu and Hf isotopes, which are adopted to reproduce the experimental bandhead energies of the one-quasiproton and one-quasineutron bands of these odd-A Lu and Hf nuclei, respectively. Once the quasiparticle configurations are determined, the experimental bandhead energies and the moments of inertia of these two- and multi-quasiparticle bands are well reproduced by PNC-CSM calculations. The Coriolis mixing of the low-K （K=｜Ω1-Ω2｜） two-quasiparticle band of the Gallagher-Moszkowski doublet with one nucleon in the Ω = 1/2 orbital is analyzed.

关键词： doubly-odd nucleus moment of inertia particle-number conserving method

theoretical study of fusion reactions ^(32)S + ^(94,96)Zr and ^(40)Ca + ^(94,96)Zr and quadrupole deformation of ^(94)Zr

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2016年第4期59卷 58-65页

作者： Bing Wang WeiJuan Zhao EnGuang Zhao ShanGui Zhou Department of physics Zhengzhou University state key laboratory of theoretical physics Institute of Theoretical Physics Chinese Academy of Sciences Center of theoretical nuclear physics National Laboratory of Heavy Ion Accelerator

The dynamic coupling effects on fusion cross sections for reactions^(32)S + ^(94,96)Zr and ^(40)Ca + ^(94,96)Zr are studied with the universal fusion function formalism and an empirical coupled channel(ECC) model. An examination of the reduced fusion functions shows that the total effect of couplings to inelastic excitations and neutron transfer channels on fusion in ^(32)S +^(94)Zr(^(40)Ca +^(94)Zr) is almost the same as that in ^(32)S +^(96)Zr(^(40)Ca +^(96)Zr). The enhancements of the fusion cross section at sub-barrier energies due to inelastic channel coupling and neutron transfer channel coupling are evaluated separately by using the ECC model. The results show that effect of couplings to inelastic excitations channels in the reactions with94 Zr as target should be similar as that in the reactions with ^(96) Zr as target. This implies that the quadrupole deformation parameters β_2of ^(94)Zr and^(96) Zr should be similar to each ***, β_2 's predicted from the finite-range droplet model, which are used in the ECC model, are quite different. Experiments on^(48) Ca +^(94)Zr or^(36) S +^(94)Zr are suggested to solve the puzzling issue concerning β_2for^(94)Zr.

关键词： empirical coupled channel model barrier distribution universal fusion function neutron transfer

Cosmic Constraints to the wCDM Model from Strong Gravitational Lensing

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2016年第7期33卷 191-195页

作者：安洁常葆荣徐立昕 institute of theoretical physics School of Physics and Optoelectronic TechnologyDalian University of Technology state key laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of Sciences

We study the cosmic constraint to the wCDM （cold dark matter with a constant equation of state w） model via 118 strong gravitational lensing systems which are compiled from SLA CS, BELLS, LSD and SL2S surveys, where the ratio between two angular diameter distances Dobs =DA（Zl, Zs ） / D A （ O, Zs ） is taken as a cosmic observable. To obtain this ratio, we adopt two strong tensing models： one is the singular isothermal sphere model （SIS） and the other one is the power-law density profile （PLP） model. Via the Markov chain Monte Carlo method, the posterior distribution of the cosmological model parameters space is obtained. The results show that the cosmological model parameters are not sensitive to the parameterized forms of the power-law index γ. Furthermore, the PLP model gives a relatively tighter constraint to the cosmological parameters than that of the SIS model. The predicted value of Ωm = 0.31＋0.44 -0.24 by the SIS model is compatible with that obtained by P1anck2015： Ωm = 0.313 ± 0.013. However, the value of Ωm =0.15＋0.13 -0.11 based on the PLP model is smaller and has 1.25σ tension with that obtained by Planck2015.

关键词： of on it from Cosmic Constraints to the wCDM Model from Strong Gravitational Lensing SIS is PLP that Planck into been

Chiral Magnetic Effect and Chiral Phase Transition

在线全文

学校读者我要写书评

暂无评论

Communications in theoretical physics 2011年第1期55卷 123-127页

作者：付伟杰刘玉鑫吴岳良 Kavli institute for theoretical physics China(KITPC) Key Laboratory of Frontiers in Theoretical PhysicsInstitute of Theoretical PhysicsChinese Academy of Science Department of physics and state key laboratory of nuclear physics and technology Peking University Center of theoretical nuclear physics National Laboratory of Heavy Ion Accelerator

We study the influence of the chiral phase transition on the chiral magnetic effect. The azimuthal charge-particle correlations as functions of the temperature are calculated. It is found that there is a pronounced cusp in the correlations as the temperature reaches its critical value for the QCD phase transition. It is predicted that there will be a drastic suppression of the charge-particle correlations as the collision energy in RHIC decreases to below a critical value. We show then the azimuthal charge-particle correlations can be the signal to identify the occurrence of the QCD phase transitions in RHIC energy scan experiments.

关键词： QCD phase transitions chiral symmetry chiral magnetic effect

Plasma parameter diagnosis using hydrogen emission spectra of a quartz-chamber 2.45 GHz ECRIS at Peking University

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2018年第4期61卷 69-74页

作者： WenBin Wu HaiTao Ren ShiXiang Peng Yuan Xu JiaMei Wen Tao Zhang JingFeng Zhang AiLin Zhang Jiang Sun ZhiYu Guo JiaEr Chen state key laboratory of nuclear physics and technology & institute of Heavy Ion physics Peking University

A quartz-chamber 2.45 GHz electron cyclotron resonance ion source(ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 m A hydrogen ion beam at 50 k V with a duty factor of 10%. The root-mean-square(RMS) emittance of this beam is less than 0.12π mm mrad. In our initial work,the electron temperature and electron density inside the plasma chamber had been measured with the line intensity ratio of noble gases. Based on these results, the atomic and molecular emission spectra of hydrogen were applied to determine the dissociation degree of hydrogen and the vibrational temperature of hydrogen molecules in the ground state, respectively. Measurements were performed at gas pressures from 4×10^(-4) to 1×10^(-3) Pa and at input peak RF power ranging from 1000 to 1800 W. The dissociation degree of hydrogen in the range of 0.5%-10% and the vibrational temperature of hydrogen molecules in the ground state in the range of 3500-8500 K were obtained. The plasma processes inside this ECRIS chamber were discussed based on these results.

关键词： electron cyclotron resonance ion source(ECRIS) hydrogen plasma optical emission spectroscopy dissociation degree of hydrogen vibrational temperature

Effect of order–disorder transition on thermodynamic and electronic properties of σ and χ phases in W–Re alloy: the first-principles calculation

在线全文

学校读者我要写书评

暂无评论

Tungsten 2025年第1期 195-213页

作者： Zhi-Peng Zhu Dian Jia William Yi Wang Jun-Lei Yin Xing-Yu Gao Shu-Feng Yang Hai-Feng Song Jin-Shan Li state key laboratory of Solidification Processing Northwestern Polytechnical University laboratory of Computational physics Institute of Applied Physics and Computational Mathematics School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The Tungsten-Rhenium(W-Re) alloys,celebrated for their high melting point,strength at elevated temperatures,electrical resistivity,and radiation resistance,have been widely utilized in high-temperature components,aerospace,electronics,and nuclear *** constituents of the topologically close-packed(TCP) phases,the sigma phase(σ) and chi phase(χ) formed within W-Re alloys wield considerable influence on the mechanical properties and the stability of the *** calculations were utilized in the present work to explore the structural,thermodynamic,and electronic properties of both ordered and disordered configurations within the σ and χ phases,culminating in a systematic elucidation of the higher phase stability exhibited by the ordered *** is found that the bulk modulus of these two phases is directly proportional to the concentration of Re in the alloy,while the equilibrium volume is inversely *** thermodynamic parameters of the σ and χ phases are calculated via the mean-field potential *** similar trends observed in the isobaric heat capacity,enthalpy increment,and entropy change curves for these two phases suggest they possess comparable thermodynamic *** is noteworthy that the contribution of ionic vibrations predominantly affects the isobaric heat capacity,while the contribution of thermal electronic excitations increases linearly with *** the structure and thermodynamic properties of TCP phases in W-Re alloys at low temperatures has profound significance for optimizing material performance,microstructures features,establishing theoretical foundations,and predicting material behavior.

关键词：

Mixing of two-quasineutron and two-quasiproton K~π=6^+ configurations in the vicinity of ^(174)Yb

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 physics C 2013年第3期37卷 41-44页

作者：焦长峰董国香许甫荣 state key laboratory of nuclear physics and technology School of PhysicsPeking University Center for theoretical nuclear physics National Laboratory for Heavy Ion Physics

In the framework of the projected shell model, we investigate the competition between the two-quasineutron and two-quasiproton K~π=6~＋ states in the ytterbium isotopes and N =104 isotones adjacent to ^（174）Yb. The ^（174）Yb results are compared with the experimental *** K~π =6~＋ isomer observed in ^（174） Yb is assigned as an admixture of the ν7/2^-[514] ν5/2^-[512] and π7/2~＋ [404]π5/2~＋ [402] intrinsic structure, which explains the experimental ｜g K-g R ｜ value. Similar mixing would appear in ^（174） Yb, ^（176） Hf,and ^（178） W. The low-lying K~π=6~＋ states are also predicted in ^（170-178） Yb.

关键词： Kisomers projected shell model rotational band,factor

Triaxiality of High-K Isomers in A - 130 Region

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2008年第5期25卷 1621-1624页

作者：刘红亮许甫荣 School of physics and state key laboratory of nuclear physics and technology Peking University Beijing 100871 Center for theoretical nuclear physics National Laboratory for Heavy Ion Physics Lanzhou 730000

Remarkable triaxiality is found in the high-K isomeric states of A-130 nuclei using the configuration-constrained calculations of potential-energy surfaces. The triaxiality gives the further understanding of the decay properties of the isomers. The calculation with triaxiality can well explain the measured quadrupole moment of the K^z=7^- isomer in ^130Ce.

关键词： supernova explosion proto-neutron star shock wave