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941.
Shear Viscosity to Non-Equilibrium Entropy Density Ratio of Hot Quark-Gluon Plasma at Finite Chemical Potential 总被引:1,自引:0,他引:1
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In the framework of irreversible thermodynamics, we study the transport properties of hot quark-gluon plasmas. The viscous entropy production at finite chemical potential as well as the shear viscosity to non-equilibrium entropy density ratio is investigated in weakly coupled limit by using kinetic theory. The results show that the chemical potential contributes positively to their ratio compared to the pure temperature case. The ratio exhibits two boundaries in the coupling strength in which a minimum value of 0.42 is found at αs=0.6. 相似文献
942.
A 2.048μm Tm,Ho:GdVO4 Laser Pumped Doubly Resonant Optical Parametric Oscillator Based on Periodically Poled Lithium LiNbO3
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A multi-grating periodically poled LiNb03 (PPLN) doubly resonant optical parametric oscillator (DROPO) pumped by a 2-ttm laser is demonstrated experimentally. Employing acousto-optically Q-switched Tm,Ho:GdV04 laser with pump pulse of 25ns and repetition rate of lOkHz as pump sources firstly, the noncritically quasi- phase-matched (QPM) tunable mid-IR output in 3.87-4.43 μm is produced. Wavelength tuning is achieved with crystal temperature tuning from 50-180^o C. When the incident average pump power is 3 W at 2.048μm, the total OPO output power of 195mW at wavelength 3.88μm is obtained, corresponding to optical-to-optical conversion efficiency up to 6.5%. 相似文献
943.
Existence and Stability of Compact-Like Discrete Breather in Discrete One-Dimensional Monatomic Chains
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Compact-like discrete breathers in discrete one-dimensional monatomic chains are investigated by discussing a generalized discrete one-dimensional monatomic model. It is proven that compact-like discrete breathers exist not only in soft Ф^4 potential but also in hard Ф^4 potential and K4 chains. The measurements of compact-like discrete breathers' core in soft and hard Ф^4 potential are determined by coupling parameter K4, while the measurements of compact-like discrete breathers' core in K4 chains are not related to coupling parameter K4. The stabilities of compact-like discrete breathers correlate closely to coupling parameter K4 and the boundary condition of lattice. 相似文献
944.
Using the technology of pressure jump, variations of temperature associated with pressure from 2.4 GPa to 4.6 GPa are measured for lead. The Grfuneisen parameter is calculated from the thermodynamic relation γ =(Ks/T)(aT/aP)s, in which substitution of △T/△P for aT/aP at median pressure is strictly justified. The correction of temperature change is carried out by analysing the experimental data, which makes the process more approaching to an adiabatic condition. The calculated values of △T/ △ P and γ gradually decrease with the increasing pressure. The decrease trend is consistent with the previous work. The γ values in the range of 2-3 GPa are averagely higher than the results of Ramakrishnan et al., indicating the effect of temperature correction. The improved method is promising for measurements of Grfineisen parameter to higher pressure range. 相似文献
945.
A dynamical equation for quantum information density (QID) in curved spacetime is presented. The related fluctuation of QID with quantum Einstein equation is also discussed, which reveals the measuring of the dynamical mutual information condition using a Gaussian quantum channel. 相似文献
946.
This paper proposes a scheme for entanglement concentration of unknown triparticle W class states with a certain probability. This protocol is mainly based on the coincidences of single-photon detectors and requires single-photon detectors and linear optical elements. The scheme is feasible within current technology. 相似文献
947.
We propose a simple scheme to generate an arbitrary photon-added coherent state of a travelling optical field by combining an array of degenerate parametric amplifiers and corresponding single-photon detectors. Particularly, when the single-photon-added coherent state is observed by developing the novel technique of Zavatta et al (2004 Science 306 660), we can simultar/eously obtain the generalized N-qubit W state. 相似文献
948.
Density functional theory study on LaNi4.5Al0.5 hydride phase: electronic properties and sites occupation*
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In this paper the crystal structure, electronic structure and hydrogen site occupation of LaNi4.5Al0.5Hy hydride phase (y = 5.0, 6.0) have been investigated by using full-potential linearized augmented plane wave method. The hydrogen atoms were found to prefer the 6m, 12o and 12n sites, while no 4h sites were occupied. A narrowed Ni-d band is found due to the lattice expansion, the total density of states at EF increases with y, which indicates that the compounds become less stable. The interaction between Al and Ni, H plays a dominant role in the stability of LaNi4.5Al0.5 hydride phase. The smaller the shift of EF towards the higher energy region, the more stable the compounds will be. The obtained results are compared with experimental data and discussed in the light of previous works. 相似文献
949.
950.
郑勇林 《原子与分子物理学报》2007,24(5):957-960
在晶格密度泛函理论(LDFT)的框架内研究了哈巴德(Hubbard)模型,当考虑晶格内位置的单粒子密度矩阵γij、自旋S时,这个模型的相互作用能w[γij,S]为密度矩阵γij、总自旋S的函数.且当所有最近邻的γij=γ12时,对环状系统的w[γij,S]可获得精确的数值计算结果;文中同时还讨论了w[γij,S]函数在弱电子关联(γ102)和强电子关联(γi∞j)以及在γ1∞2<γ12<γ012区域限制下的性质.以非关联能w0[γ0ij,S]为单位标度的w[γij,S]表明的赝普适行为与g12=(γ12-γ1∞2)/(γ012-γ1∞2)函数一样.另外,w[γij,S]函数对不同总自旋S有一定的依赖. 相似文献