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171.
We review various exact results concerning the presence of algebraic tails in three-dimensional quantum plasmas. First, we present a solvable model of two quantum charges immersed in a classical plasma. The effective potential between the quantum charges is shown to decay as 1/r 6 at large distances r. Then, we mention semiclassical expansions of the particle correlations for charged systems with Maxwell-Boltzmann statistics and short-ranged regularization of the Coulomb potential. The quantum corrections to the classical quantities, from orderh 4 on, also decay as 1/r 6. We also give the result of an analysis of the charge correlation for the one-component plasma in the framework of the usual many-body perturbation theory; some Feynman graphs beyond the random phase approximation display algebraic tails. Finally, we sketch a diagrammatic study of the correlations for the full many-body problem with quantum statistics and pure 1/r interactions. The particle correlations are found to decay as 1/r 6, while the charge correlation decays faster, as 1/r 10. The coefficients of these tails can be exactly computed in the low-density limit. The absence of exponential screening arises from the quantum fluctuations of partially screened dipolar interactions.  相似文献   
172.
Formally exact theories of tagged particle motion in liquids are developed, based upon kinetic theory for hard spheres and mode coupling for smooth potentials. It is shown that the resulting equations are tractable in the long time and Brownian limits. The coefficient of the long time tail of the velocity correlation function is seen to differ from its low-density form by only the replacement of the low-density viscosity and diffusion constant by the true viscosity and diffusion constant. In the Brownian limit, the slip Stokes-Einstein law is obtained, with the true viscosity. The relation to other work is discussed.Supported by NSF Grant No. CHE81-11422 and by a Dreyfus Teacher-Scholar grant to TK.  相似文献   
173.
铝的激发光谱的测量   总被引:1,自引:1,他引:0  
用120keV的Al+离子与10μg/cm2的碳箔相互作用,研究AlⅠ、AlⅡ和AlⅢ的激发光谱,其结果与其它实验进行了比较。  相似文献   
174.
We present, in an expository way, an elementary rigorous proof (patterned after an argument of Kirsch-Martinelli) that the Anderson model has Lifschitz tails in very great generality.Research partially supported by USNSF Grant No. MCS-81-20833.  相似文献   
175.
D Syam 《Pramana》1984,22(1):31-41
The mass spectrum of dimuons produced from the matter in the central region of rapidity in ultra-relativistic heavy-ion collisions is calculated in accordance with Bjorken’s recently proposed model for relativistic heavy-ion collisions. The matter in this central region is assumed to consist of a deconfined quark-gluon plasma phase and a pionized phase. Distinct enhancements of the dimuon mass spectrum below 500 MeV, due to the quark-gluon phase, are predicted for a deconfinement phase-transition temperatureT c<200 MeV.  相似文献   
176.
Let {Xn; n ≥ 1} be a stationary sequenceof non-negative random variables with heavy tails. Under mixing conditions, we study logarithmic asymptotics for the disp(Sn > nx) ≈ n-αx+1 for appropriate values of x, where α is a specific parameter. The related conjecture proposed by Gantert is investigated. As a by-product, the so-called supremum large deviations principle is also studied.  相似文献   
177.
微波消解系统处理秦巴山区各县区娑罗子样品,火焰原子吸收光谱法测定娑罗子中Ca、Mn、Cu、Zn、Fe、Mg6种微量元素的含量,石墨炉和氢化物法测定As、Pb和Cd3种重金属元素的含量。采用此方法回收率在97.06%—102.52%之间,相对标准偏差(RSD)小于1.76%。在秦巴山区10个采样点的娑罗子中均含有丰富的人体必需微量元素,比较各种元素含量,不同来源的样品存在差异。  相似文献   
178.
In this work we study internal band edges localization of acoustic waves in 2-dimensional space obtained by random perturbation of some periodic media. Our results rely on the study of Lifshitz tails for the integrated density of states for random acoustic operators of the form . Localization is then deduced by the standard multiscale argument.  相似文献   
179.
This paper describes the development and validation of a sequential injection (SI) anodic stripping voltammetry (ASV) method using the hanging mercury drop electrode for accumulation of the heavy metal cations Cu(II), Pb(II) and Cd(II). The method was applied to wastewater samples after proper acid digestion in open vessels to eliminate matrix effects. For a deposition time of 90 s at the flow rate of 10 μl s−1, the detection limits of the method were 0.06, 0.09 and 0.16 μmol L−1 for Cd, Pb and Cu, respectively. Under these conditions the linear dynamic range was between 0.20 and 9.0 μmol L−1 and the sampling frequency was 30 analyses per hour. The relative standard deviation of the method was 3%(n=7) at the concentration level of 2.0 μmol L−1. The accuracy of the method was evaluated by spiking the samples with known amounts of the metal cations, and by comparison with an independent analytical technique, the inductively coupled plasma atomic emission spectroscopy (ICP-AES). Average recoveries were around of 84%, and the results showed no evidence of systematic errors in comparison to the ICP-AES.  相似文献   
180.
We study the mechanism and probability of in-medium hadronization in the deconfined medium produced in heavy-ion collisions at RHIC and LHC. We show the likelihood of color-neutral objects to be formed inside the partonic fireball and the probability of these states to escape the medium with reduced interaction strength and energy loss. We will suggest specific measurements that are sensitive to the early degrees of freedom and show predictions for these measurements at RHIC and the LHC.  相似文献   
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