夸克胶子物质内的qq-↑q→qq-↑q反应

夸克胶子物质内的从夸克-夸克-反夸克到夸克-夸克-反夸克的散射过程会影响夸克物质和反夸克物质的热平衡化，其散射振幅是研究热平衡化的一个基础．依据微扰QCD理论，编制Fortran程序，推导了αs^4阶的各个qq-↑q→qq-↑q散射费曼图的振幅平方和不同费曼图间的干涉项．     

近十年壮族民间信仰研究综述

就十年来壮族民间信仰的研究成果分别作简要的阐述。认为近十年来,随着广西政治、经济的发展,引起壮人文化的自觉,越来越多的壮学家将目光审视于自身的文化,以自然崇拜、“布洛陀”“姆六甲”始祖神崇拜、师公教信仰等为特征的壮族民间信仰研究取得长足进展。     

5G非正交多址系统中使用全双工基站干扰的安全传输方案

为了保证5G非正交多址(NOMA)系统中私密信息上行传输过程的信息安全,提出了一种基于全双工基站干扰的物理层安全传输方案。首先,分别使用二项式点过程和泊松点过程,对NOMA上行传输系统中用户设备和窃听者的空间位置分布进行刻画,建立NOMA上行传输系统模型;其次,为了使低硬件复杂度的用户设备付出较小的开销实现安全传输,全双工基站在接收信息的同时发送人工噪声干扰潜在窃听者;最后,基于全双工基站干扰方案,使用随机几何理论对系统的可靠性和安全性进行分析。理论和仿真结果表明:用户设备距离基站越近,全双工基站干扰方案对安全吞吐量的提升越明显;即使对于距基站最远的用户设备,在最优的噪声功率下,该方案仍可以使其安全吞吐量提高约41%。     

强子物质中的介子-介子散射(英文)

建立了一个夸克交换模型和提出了一个夸克-反夸克湮灭模型来研究介子-介子散射。从量子色动力学我们得到一个依赖于温度的夸克作用势。从微扰量子色动力学推导对应于夸克-反夸克湮灭和产生的跃迁势。模型给出基态介子质量的实验值,并且在玻恩近似下能说明真空中阈能附近的π-π弹性散射相移的实验值。从S矩阵元出发,推导散射的跃迁振幅和截面公式。计算出涉及π,ρ,K,K*的反应的非极化截面。发现这些截面具有强烈的温度依赖性。We have established a quark-interchange model and have proposed a quark-antiquark annihilation model to study meson-meson scattering. From QCD we obtain a temperature-dependent quark potential. The transition potential corresponding to quark-antiquark annihilation and creation is derived in perturbative QCD. The experimental ground-state meson masses are reproduced and the experimental data of elastic phase shifts for ππ scattering near the threshold energy in vacuum can be accounted for in the Born approximation. Starting from S-matrix element, we derive the transition amplitude and the cross section for the scattering. Unpolarised cross sections for reactions involving π, ρ, K and K* are calculated. Remarkable temperature dependence of the cross sections is found.     

Temperature-dependent cross sections for πφ and ρφ nonresonant reactions in hadronic matter

With a potential of which the large-distance part reflects lattice gauge results and of which the short-distance part is given by one gluon exchange plus perturbative one- and two-loop corrections, the Schrödinger equation brings about temperature dependence of meson masses and mesonic quark-antiquark relative-motion wave functions. The ground-state meson masses drop with increasing temperature. The transition amplitude calculated from the potential, the meson masses and the wave functions gives temperature-dependent cross sections for the five nonresonant reactions πφ→KK^* (or K^*K), πφ→K^*K^*,ρφ→KK,ρφ→KK^*(orK^*K) and ρφ→K^*K^*. The numerical temperature-dependent cross sections are parametrized. The peak cross section of either πφ→KK^* or πφ→K^*K^* increases from T=0 to T=0.75T_c and decreases with further increasing temperature. The cross section for ρφ→KK,ρφ→KK^* and ρφ→K^*K^* has a decreasing trend while the temperature increases from 0.75T_c.     

Cross sections for charmonia dissociation in collisions with pions, rhos and kaons

We calculate the unpolarized cross sections for dissociation reactions of charmonia in collisions with π, ρ and K in a potential that is derived from QCD. The reactions are governed by the quark-interchange processes. The mesonic quark-antiquark relative-motion wave functions are determined by the central spin-independent terms of the potential. The numerical wave functions and cross sections are parametrized. The difference of transition amplitudes in the prior form and in the post form is explored by deriving and examining the transition amplitudes of the one-gluon-exchange spin-spin term of the potential in the two forms. We find that the post-prior discrepancy in meson-meson elastic scattering that is governed by quark-interchange processes depends on the difference of quark or antiquark masses and of quark-antiquark spatial distributions of the two mesons.     

大专院校公体课排球专项考试内容及方法的探究

针对大专院校公体课教学计划的调整,排球专项学时的压缩,为探究排球专项考试内容及方法,对西安市部分大专院校排球专项课开设现状、考试内容及方法进行了抽样调查,在综合其他院校考试方法的基础上,根据陕西教育学院生源排球基础,经反复试验,初步对陕西教育学院构思了新的考试内容及方法,并对不宜采纳的其他方法进行了分析与评述。     

浅谈广告对品牌塑造的影响

在现代市场经济条件下,产品由卖方市场转变为买方市场,企业面临着日趋激烈的市场竞争,可谓是不见硝烟的商场逐鹿。制造和拥有品牌的过程是艰难的,更需要不断地进行品牌塑造。广告是品牌塑造的法宝之一,它是最常见的,也是最有效的。但任何事物都不是绝对的,广告犹如一把双刃剑,用得不好,也会伤害到自己。通过广告与品牌塑造关系的论述,得出品牌塑造离不开广告宣传,但又不只是广告宣传,而且品牌塑造是一项长期艰苦的、无止境的系统工程,同时也是一项回报性极高的投资的结论。     

核力的手征夸克-孤子模型理论

本文简短地描述了含单胶子交换的手征夸克孤粒子模型;将此孤粒子模型里所确定的夸克-胶子耦合常数及所解得的夸克波函数,输入到相对论的两夸克集团理论,研究了两核子系统问题.本文完整地考虑了夸克交换核中的动能和相对运动能量项,由此改进了~3S_1道和~1S_0道的相移.相移与Arndt等人的实验相移基本一致.计算结果表明,单胶子交换和夸克交换提供短程排斥势,手征场则提供了中、长程吸引势.