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超子耦合常数对混合星性质的影响 总被引:2,自引:0,他引:2
用相对论平均场理论描述强子物质, 用NJL模型描述夸克物质研究了超子耦合常数对混合星性质的影响. 结果表明, 随着超子耦合常数的增大, 强子-夸克相变密度变小, 混合相区域的状态方程变硬, 中子星的最大质量及对应的半径变大. 超子耦合常数由0.73增到1.0时, 混合星最大质量由1.68M⊙增至1.84M⊙, 相应的半径由11.4km变到12.5km. 该夸克模型下不同强子参数组对应的混合星性质也有较明显的差异. 可知, 其适合于描述大质量而小夸克核心的混合星. 相似文献
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用孤粒子袋模型计算强子的静态物理性质 总被引:1,自引:1,他引:0
本文在平均场近似下,对孤粒子袋模型作了较详细的数值解,计算了强子静态物理性质.特点是考虑了夸克质量和质心修正后,明显改善gA/gV值,并且,强子质量、均方根电荷半径和磁矩等均与实验值基本相符.初步导出d夸克和u夸克间的质量差. 相似文献
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Computer simulations and density functional theory results are reported for a Lennard-Jones liquid in a slit or pore formed by two parallel hard walls. Both density profiles and solvation forces are computed. Two classes of calculation are performed. In the first class, a high bulk density is selected and, starting from a high temperature, the temperature is reduced until the temperature corresponding to bulk liquid—vapour coexistence is reached. For small slit widths or exceedingly large widths, the density in the slit decreases continuously until the slit is virtually empty or ‘dry’. When the slit width is somewhat larger than a molecular diameter, but still finite, the density in the slit decreases continuously as the temperature is decreased until there is an abrupt change in the density in the slit. Below this temperature, the density is smaller. Further decreases in the temperature, result in a continuous decrease in the slit density until the slit is virtually empty. In the second class, the density and temperature for bulk coexistence are chosen and the bulk density is increased. At the temperature and bulk density for bulk coexistence, the slit is virtually empty and remains so for all widths that we consider. As the bulk density is increased at constant temperature, the slit remains empty as the width is increased until some specific width is reached and then starts to fill abruptly. The agreement of the density functional and simulation results is qualitative but good. 相似文献
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CHIRAL PHASE TRANSITION IN A MODEL WITH DYNAMICAL SPONTANEOUS-SYMMETRY-BREAKING AT FINITE TEMPERATURE AND DENSITY 下载免费PDF全文
The chiral-symmetry-restoring phase transition in a model with dynamical spontaneous-symmetry-breaking is discussed qualitatively,making use of an approximation method.The selfconsistency equation of the model is established.The condensation and mass of fermions as well as the temperature or density dependence of energy density and specific heat are obtained.It turns out that,in this approximation,the chiral-phase-transition is second order at zero chemical potential and finite temperature; and the transition is first order for both cases at finite temperature and density and at zero temperature and finite density,this moment.the transition temperature or density from broken phase to normal phase differs from that from normal phase to broken phase. 相似文献
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Microwave methods are used to obtain the periodic variations in time and space of some plasma parameters. The electron density is obtained using a time-display of the reflection coefficient due to a plasma-perturbed cavity, and the electron temperature from the noise signal of a Dicke radiometer gated periodically. Assuming simple one-dimensional sinusoidal variations of temperature and density, the fundamental convolution integrals relating the appropriate cavity parameters to the plasma properties are solved and formulas are obtained to calculate the real fluctuating quantities. Also in that case where the lenghth of the cavity field region equals the dimension of the variations the correct phase relation between electron temperature and density is obtained. The method is used for diagnostics of self exited moving striations in hydrogen. The striations (frequency 24 kHz, striation lenghts ~1 cm) move from cathode to anode and the sequence of the different maxima for an observer in rest is electron density, temperature and light-emission. The phase shift between density and temperature is about 90 degrees, the appropriate density variation is 10:1 and the temperature variation >2:1. 相似文献
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Jing-Lin Xiao 《Chinese Journal of Physics (Taipei)》2017,55(1):22-27
We change the ellipsoidal boundary in a quantum rod (QR) into a spherical one by a coordinate transformation, and then study the influences of the ellipsoid aspect ratio and polaron radius on the probability density (PD) and oscillation period (OP) of an electron with the variational method of Pekar type (VMPT). By employing the quantum statistics theory (QST), we investigate the temperature effects on the PD and the OP. Numerical results denote that the electron probability density and the oscillation period increase (decay) with raising temperature in lower (higher) temperature regime. The electron probability density increases (decreases) with increasing ellipsoid aspect ratio when the temperature is in lower (higher) regime. The electron probability density decays (enhances) with increasing polaron radius when the temperature is in lower (higher) temperature regime. The oscillation period is an increasing function of the ellipsoid aspect ratio, whereas it is a decreasing one of the polaron radius. 相似文献
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The temperature dependence of several thermodynamic properties of water is determined at atmospheric pressure by a set of computer simulations with a polarizable potential model. It is found that the maximum of the density occurs at the correct temperature, but the decrease in density with increasing temperature is more rapid than expected for real water. Consequently, the temperature dependence of other quantities, especially that of the thermal expansion coefficient, is reproduced with some inaccuracies. The model, however, turns out to be a definitive improvement over similar non-polarizable ones, for which the density maximum is either missing or found to be shifted considerably with temperature. 相似文献
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利用发射光谱法,研究了圆柱型空心阴极放电条纹的特性.测量了条纹区的发射光谱,在此基础E计算得到r电子激发温度、相对电子密度和电子平均能量的空间分布特性.结果表明条纹区的光强、电子激发温度和电子密度均呈非等幅的周期性变化.与暗纹中心处相比,明纹中心具有较高的电子激发温度和较低的电子密度.由阴极向阳极,明纹中心处的电子激发温度幅值逐渐减小.此外,条纹区的电子激发温度随着电流的增加而增加. 相似文献
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Y.G. Ma Q.M. Su W.Q. Shen J.S. Wang D.Q. Fang X.Z. Cai H.Y. Zhang D.D. Han 《The European Physical Journal A - Hadrons and Nuclei》1999,4(3):217-220
Thermodynamical features of Xe system is investigated as functions of temperature and freeze-out density in the frame of
lattice gas model. The calculation shows different temperature dependence of physical observables at different freeze-out
density. In this case, the critical temperature when the phase transition takes place depends on the freeze-out density. However,
a unique critical excitation energy %and the same excitation reveals regardless of freeze-out density when the excitation
energy is used as a variable instead of temperature. Moreover, the different behavior of other physical observables with temperature
due to different ρf vanishes when excitation energy replaces temperature. It indicates that the excitation energy can be seen as a more basic
quantity to control nuclear disassembly.
Received: 25 November 1998 /Revised version: 20 January 1999 相似文献
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在包含三体核力的有限温度Brueckner-Hartree-Fock理论方法基础上, 利用质量算子的空穴线展开, 研究了热核物质中基态关联所导致的对单核子势的重排修正项的密度和温度依赖性, 并讨论了三体核力对重排项的影响. 结果表明:单核子势的重排项贡献具有较强的密度和温度相关性, 重排项贡献随密度增加而增强并随温度升高而减弱. 在计算中引入三体核力会在一定程度上抑制基态空穴关联
效应, 从而导致单核子势的重排项贡献减小, 而且三体核力对重排项贡献的影响随密度增大而增强. 相似文献