本项目包括两部分内容，拟利用最新观测数据对类星体光变的物理性质开展研究，并利用近红外光谱观测对高红移类星体的黑洞质量进行研究。1）将利用SDSS、WISE、中美南银冠U波段巡天（SCUSS）观测数据对大样本类星体光学、红外波段光变的物理性质进行系统性的研究，仔细考查吸积盘、宽发射线区、尘埃环等对类星体光变的贡献，研究射电强类星体、射电宁静类星体和宽吸收线类星体光变性质及其物理机制的异同。2）基于我们获得的30多个高红移类星体的近红外JHK波段光谱，利用红移至近红外波段的Hbeta和MgII发射线性质对这些类星体中心黑洞质量及吸积率进行研究。将结果与利用光学光谱中CIV发射线性质得到的结果相比较，研究不同方法估算黑洞质量的系统性差异，研究获得高红移类星体黑洞质量的最可靠方法。通过比较高、低红移类星体样本所得到的结果了解宇宙中黑洞增长的物理过程。

This project includes two parts, one is to study the physics properties of quasar variability using the recently released data, another is to study the black hole masses of high redshift quasars using near-IR spectroscopy. 1)Using the data from SDSS, WISE and SCUSS on large samples of quasars, we will present a detailed study on the optical and IR variability properties, investigate the contributions from accretion disk, broad line region and dust torus to the quasar variability and the similarity and difference in the variability properties and physics mechanisms among radio-loud, radio-quiet and broad absorption quasars. 2)Using the near-IR JHK spectra we got recently for more than 30 high redshift quasars with several telescopes in the US, we will study their black hole masses and accretion rates based on the properties of Hbeta and MgII emission lines.Compared with the results obtained from CIV lines in their SDSS optical spectra, we will investigate the systematic differences in black hole mass estimations and find the best method for high redshift quasars. The comparisons of our results with those of low redshift quasars will also help us to understand the black hole growing process in the universe.