科研工作:

2004年至今在西北工业大学应用数学系工作，曾访问德国University of Giessen, 美国University of Oklahoma等大学。 科研项目国家自然科学基金:群对称条件下奇异临界椭圆方程的可解性，2011.01-2013.12。在包括J. Differential Equations等著名期刊上发表SCI论文十余篇。Publications:l 2007[1].   Qianqiao Guo, Pengcheng Niu, Existence of a fixed point for a semicontinuous operator and its application, Nonlinear Analysis 66 (2007) 1141-1144. l 2008[1].   Qianqiao Guo, Pengcheng Niu, Jingbo Dou, Multiplicity of solutions for singular semilinear elliptic equations with critical Hardy-Sobolev exponents, Appl. Anal. Discrete Math. 2 (2008) 158-174.[2].   Qianqiao Guo, Pengcheng Niu, Nodal and positive solutions for singular semilinear elliptic equations with critical exponents in symmetric domains, J. Differential Equations 245 (2008) 3974-3985.[3].   王彦林, 郭千桥, 一类非迷向Heisenberg 群上凸函数的两类比较原理, 纺织高校基础科学学报21(2) (2008) 171-175.l 2009[1].   Qianqiao Guo, Pengcheng Niu, Yongzhong Wang, Global compactness results for singular quasilinear elliptic problems with critical Sobolev exponents and applications, Nonlinear Analysis 71 (2009) 2944-2963.[2].   Qianqiao Guo, Pengcheng Niu, Some theorems on existence and uniqueness of fixed points for decreasing operators, Computers and Mathematics with Applications 57 (2009) 1515-1521. [3].   Qianqiao Guo, Xuewei Cui, Positive solutions for semilinear elliptic equations with critical Sobolev exponents, Journal of the Graduate School of the Chinese Academy of Sciences 26(2) (2009) 158-166. [4].   窦井波, 郭千桥, Heisenberg 群上无穷远处的集中列紧原理和具有Sobolev临界指数的p-次 Laplace 方程多解的存在性, 数学物理学报 29 (2009) 1033-1043. [5].   Wenbai Li, Mingyong Liu, Qianqiao Guo, Underwater localization for multiple AUVs based on bearing and range measurements, Journal of China Ordnance(兵工学报) 5(4) (2009) 267-272. l 2010[1].   Qianqiao Guo, Pengcheng Niu, Xuewei Cui, Existence of sign-changing solutions for semilinear singular elliptic equations with critical Sobolev exponents, J. Math. Anal. Appl. 361 (2010) 543-557. [2].   Jingbo Dou, Qianqiao Guo, Pengcheng Niu, Hardy inequalities with remainder terms for the generalized Baouendi-Grushin vector fields, Math. Inequal. Appl. 13 (3) (2010) 555-570. [3].   Yongzhong Wang, Qianqiao Guo, Nonexistence of nontrivial supersolution of higher-order evolution equation, Mathematica Applicata (应用数学) 1(2010) 145-149.[4].   Yongzhong Wang, Qianqiao Guo, Global positive supersolution of quasilinear elliptic equation with Hardy potential, Proceedings of the Ninth International Conference on Information and Management, Urumchi, China, August, 11-19, 2010, pp. 495-498.l 2011[1].   Yuanyuan Li, Qianqiao Guo, Pengcheng Niu, Global compactness results for quasilinear elliptic problems with combined critical Sobolev-Hardy terms, Nonlinear Analysis 74 (2011) 1445-1464. [2].   Xiaojing Feng, Pengcheng Niu, Qianqiao Guo, Multiple solutions of some boundary value problems with parameters, Nonlinear Analysis 74 (2011) 1119–1131.[3].   Xiaojing Feng, Pengcheng Niu, Qianqiao Guo, Existence of solutions for 2mth-order periodic boundary value problems, Applied Mathematics and Computation 218 (2011) 2343–2352.l 2012[1].   Yuanyuan Li, Qianqiao Guo, Pengcheng Niu, The existence of solutions for quasilinear elliptic problems with combined critical Sobolev-Hardy terms, J. Math. Anal. Appl. 388 (2012) 525–538. [2].   Jingbo Dou, Qianqiao Guo, Solutions for polyharmonic elliptic problems with critical nonlinearities in symmetric domains, Communications on Pure and Applied Analysis 11(2012)453-464. [3].   Qianqiao Guo, Junqiang Han, Pengcheng Niu, Existence and multiplicity of solutions for critical elliptic equations with multi-polar potentials in symmetric domains, Nonlinear Analysis 75 (2012) 5765–5786.l 2013[1].   Yuanyuan Li , Bernhard Ruf, Qianqiao Guo, Pengcheng Niu, Quasilinear elliptic problems with combined critical Sobolev-Hardy terms, Annali di Matematica, 192 (1)(2013) 93-113. l 2014[1].   Yuanyuan Li, Bernhard Ruf, Qianqiao Guo, Pengcheng Niu，Positive solutions for singular elliptic equations with mixed Dirichlet-Neumann boundary conditions，Math. Nachr. 287, No. 4, 374–397 (2014).l 2015[1].   Junqiang Han, Qianqiao Guo, Nonlinear degenerate parabolic equations with time-dependent singular potentials for Baouendi-Grushin vector fields, Acta Mathematica Sinica, English Series, 31,1, 123-139 (2015).