研究有限温、有限密QCD相结构与相变及其在相对论重离子碰撞中的实现已成为当代物理学中最激动人心的研究领域之一。关注的中心课题是可能的新的物质形态QGP的性质及其在实验室中的产生，QCD对称性的自发破缺及其恢复，强相互作用物质的相变等。这将检验和改进我们对强相互作用物质性质和QCD低能行为的了解。由于相变是非微扰行为，需要发展有效的非微扰QCD方法。本项目拟将一种重要的连续时空的非微扰QCD方法-QCD的Dyson-Schwinger方程-应用到有限温特别是有限密强相互作用系统中去，建立具有较好QCD基础的物态方程并由此研究强相互作用物质的热力学性质，包括剪切粘滞系数和体粘滞系数，研究QCD相图及CEP(critical end point)。此外，我们还将紧密结合我国兰州重离子加速器CSR能区的特点，研究π介子，Ｋ介子的有效质量，衰变常数与介质密度的关系。

The study of QCD phase structure and phase transition at.finite temperature and density and its realization in relativistic heavy ion collisions has been one of the most exciting realms of contemporary physics. The.central focus is the properties of a possible new state of matter QGP and its production in laboratories, spontaneous breaking of QCD symmetries and its realization, phase transition of strongly interacting matter. This will test and improve our understanding of properties of strongly matter and low energy behavior of QCD. Because phase transition is nonperturbative behavior, one needs to develop effective nonperturbative QCD methods. This item tries to apply one important continuum nonperturbative QCD method-Dyson-Schwinger equation of QCD- - to.strongly interacting systems at finite temperature (especially at finite density),.establish equation of state with better QCD foundation and from this study thermodynamical properties of strongly interacting matter, including shear viscosity and bulk viscosity, and study QCD phase diagram and CEP (critical end point). In addition, we will closely combine the features of energy range of Lanzhou heavy ion accelerator CSR to study the relation of effective mass, decay constant of pion and kaon with the medium density.