该项目旨在研究全息QCD中两味道与2+1味情形的手征与退禁闭相变性质。我们试图将能够正确描述退禁闭相变行为的引力背景系统与能够合理描述介子谱及手征相变行为的改进软墙模型自洽地结合起来，并在统一的全息框架下考察手征与退禁闭相变的有关性质。为了简化问题，我们首先考察引力背景部分与味道部分退耦的情况，研究如何实现正确的退禁闭与手征相变性质；然后，我们再考虑引力背景与味道部分耦合的情形，研究QCD相变的正确实现以及两种相变之间的相关性。在处理引力背景系统时，我们将采取固定的dilaton势。同时，我们将通过自洽地求解引力背景场方程引入化学势因素，进而研究有限化学势情形手征与退禁闭相变以及QCD相图的性质。

This program is aimed at studying the chiral and deconfining phase transitions in both the two-flavor and the 2+1-flavor case in AdS/QCD. We try to combine consistently the bulk background system which can give a good characterization of the deconfining phase transition with the improved soft-wall model, which can describe the light meson spectra and the right behaviors of the chiral phase transition, then to study the relevant properties of the chiral and deconfining phase transitions in a unified holographic framework. To simplify the situation, we first consider the decoupling case of the bulk background and the flavor sector, and study how to realize the right behaviors of the chiral and deconfining phase transitions. Then, we consider the coupling case of the background and the flavor sector in order to study the correct realization of QCD phase transition and the interplay between the two types of QCD phase transition. We will fix the dilaton potential to address the bulk background system. The chemical potential effect will also be introduced by solving the whole background system consistently, then we will study the properties of the QCD phase transition and the QCD phase diagram at finite chemical potential.