Professors

Li Xie

Key Laboratory of Mechanics on Western Disaster and Environment, College of Civil Engineering and Mechanics, Lanzhou University, South Tianshui Road 222, Lanzhou, Gansu Province, P.R. China, 730000
 
 
 
EDUCATION
Ph.D., Solid Mechanics      College of Physical Engineering and Technology, Lanzhou University, P. R. China, 2005
B. S., Theoretical and Applied Mechanics
Department of Mechanics, Lanzhou University, P.R. China. 2000
PROFESSIONAL EXPERIENCE
2015.5-present: Professor, College of Civil Engineering and Mechanics of Lanzhou University, P.R. China.
2013.8-2014.6: Visiting Scholar, Department of Chemical Engineering of Case Western Reserve University, USA.
2007.4-2015.4: Associate Professor, College of Civil Engineering and Mechanics of Lanzhou University, P.R. China.
2005.7-2007.4: Lecturer, College of Civil Engineering and Mechanics of Lanzhou University, P.R. China.
 
RESEARCH AREAS
Transportation model of wind-blown sand movement.
Contact electrification in particle system.
Computational electromagnetics in particle systems.
PROFESSIONAL ACTIVITIES
Secretary general of Chinese Association of Environmental Mechanics (2015-2019)
Member of Gansu Society of Theoretical and Applied Mechanics (2015-2019)
Member of Gansu Society of Theoretical and Applied Mechanics (2011-2014)
 
FUNDINGS
Grant of the National Natural Science Foundations of China (No11472122), ¥960 000, Jan/01/2015-Dec/31/2018.
Grant of the National Natural Science Foundations of China (No11072096), ¥350 000, Jan/01/2011-Dec/31/2013.
Grant of the National Natural Science Foundations of China (No10601022), ¥310 000, Jan/01/2007-Dec/31/2009.
 
My Research Summary
My research focuses on the start of single sand particle, formation process of wind ripple and sand dune, mechanism of wind-blown sand transport, prediction of wind erosion, statistical results of saltating sand particles and analysis of measurement precision of experimental results. We establish the statistical particle-bed collision model, which is a foundation to study a mechanism of wind-blown sand movement.  
Another project is on the Laboratory measurement of saltating sand particles’ angular velocities and simulation of its effect on saltation trajectory. We observed the spin attitudes and angular velocity of sand particle in detail in wind tunnel and show their effect on the trajectory of sand particle. In the simulations of the sand particle’s trajectory or the mass flux profile, it is necessary to take account of all spin components. Electrostatics of particles in particle system, e.g., wind sand flux, is very common phenomenon, and moving particles in these systems usually can carry an amount of net charges. Due to the charges carried by particles, the electrostatics force that will be produced acts upon the particles and affect the movement of particles. In addition, charges carried by particles have a certain extent of the effect on the scattering of electromagnetic wave, therefore the measurement to particle systems based on the scattering of electromagnetic wave need to be assessed. According to that, we are conducting two projects, one of which is evaluation of the effect of particle's net surface charge on optical measurement instruments. The other is mainly intended to find the mechanism, to establish essential models of electrification in moving particle system.
 
PUBLICATIONS
1.   Li Xie,Xiao-jing Zheng and You-he Zhou, A theoretical study of the distribution of the initial velocity of saltation sand particles by collision. Key engineering materials2003,243-244: 613-618.
2.   Zheng Xiaojing, Xie Li and Zhou Youhe. Exploration of probability distribution of velocities of saltating sand grains based on the stochastic grain-bed collisions. Physics letters A.2005,334107-118.
3.   Li XIE, Zhibao Dong and Xiao Jing Zheng. Experimental analysis of sand particles’ lift-off and incident velocities in wind-blown sand flux. Acta Mechanica Sinica. 2005,21564-573.
4.   Xiaojing Zheng, Li Xie and Zou Xue-Yong. Theoretical prediction of liftoff angular velocity distributions of sand particles in wind-blown sand flux. Journal of Geophysical research, 2006, 111, doi:10.1029/2005jd6164.
5.   Bo Tianli, Xie Li, and Zheng Xiaojing. Simulation of wind ripples, International Journal of Nonlinear Sciences and Numerical Simulation.2007, 7:223-228.
6.   Xie Li, Ling Yuquan, and Zheng Xiaojing, Laboratory measurement of saltating sand particles’ angular velocities and simulation of its effect on saltation trajectory, Journal of Geophysical Research, 2007, 112, doi:10.1029/2006jd008254
7.   Xie Li and Zheng Xiaojing, Probability of rebound and eject of sand particle in wind-blown sand movement. Acta mechianica sinica, 2007, 23471-475doi:10.1007/s10409-007-0103-4
8.   Xiaojing Zheng, Tianli Bo and Li Xie, DPTM simulation of Aeolian sand ripple, Science in China Series G: Physics, Mechanics & Astronomy, 2008, 51:328-336. 
9.   Xiaojing Zheng, Ning Cheng, Li XieA three-dimensional analysis on lift-off velocities of sand grains in wind-blown sand flux, Earth surface landforms and processes, 2008, 331824-1838.
10. Zheng Xiaojing, Zhu Wei and XIE Li, A probability density function of liftoff velocities in mixed-size wind sand flux, Science in China Series G: Physics, Mechanics & Astronomy, 2009, 52976-985
11. Li Xie, Xingcai Li and Xiaojing Zheng, Attenuation of electromagnetic wave by charged dust particles in sandstorm, Applied Optics, 2010,49:6756-6761
12. Jun Zhou and Li Xie, Effect of net surface charge on particle sizing and material recognition by using PDA, Applied Optics, 2011, 50:379-386
13. Xingcai Li, Li Xie and Xiaojing Zheng, The comparison between Mie theory and the Rayleigh approximation to calculate the EM scattering by partially charged sand, Journal of Quantitative Spectroscopy and Radiative Transfer, 2012, 113:251-258
14. Li Xie and Kui Han, Influence of relative humidity on the aeolian electric field, Aeolian Research, 2012, 7:45-50
15. Wenwen Hu, Li Xie, Xiaojing Zheng, Simulation of the electrification of wind-blown sand, EPJ E-Soft Matter & Biological Physics, 2012, 35:22 DOI: 10.1140/epje/i2012-12022-1
16. Shaozhen Duan, Ning Cheng, Li Xie, A new statistical model for threshold friction velocity of sand particle motion, Catena, 2012, 104: 32-38, doi:10.1016/j.catena.2012.04.009
17. Wenwen Hu, Li Xie, Xiaojing Zheng, 2012, Contact charging of silica glass particles in a single collision, Applied Physics Letters, 101, 114107-114105. 
18. L. Xie, G. Li, N. Bao, and Jun Zhou, Contact electrification by collision of homogenous particles, Journal of Applied Physics, 2013, 113, 184908 (2013); doi: 10.1063/1.4804331
19. Li Xie, Kui Han, Yanping Ma and Jun Zhou, An electrifiacation mechanism of sand grains based on the diffuse double layer and Hertz contact theory, Applied Physics Letters, 103, 104103 (2013), doi:10.1063/1.4819948
20. L. Xie, P. F. He, Jun Zhou and D. J. Lacks, Correlation of contact deformation with contact electrification of identical materials, Journal of Physics D: Applied Physics, 2014, 47(21):215501. 
21. Qin Jianhu and Li XIE, Scattering phase function  charged spherical particle, Applied optics, 2015, 54(28), 8439-8443 (2015)
22. L. Xie, N. Bao, Y. Jiang, K. Han, J. Zhou, An instrument for charge measurement due to a single collision between two spherical particles, Rev Sci Instrum. 2016 Jan;87(1):014705. doi: 10.1063/1.4939727.
23.  L Xie, N. Bao, Y. Jiang, J. Zhou, Effect of humidity on contact electrification due to collision between spherical particles, AIP Advance, 2016, 6(3):50
24. Li XIE, Xuqiang Dou and Jun Zhou, Sizing charged particles by Phase Doppler Anemometry, Applied Optics, 20165512):3279-3286
25.25.J. Qin, L. XIE, Charge estimation of particles based on the electromagnetic scattering signals, Europhysics Letters, 2016, 115:54007
26. Xuqiang Dou, Li XIE, Electromagnetic Wave Attenuation due to theCharged Particles inDust&Sand(DUSA) Storms, Journal of Quantitative Spectroscopy and Radiative Transfer, 2017, 196:169-175
27. Haichao Zhong, Jun Zhou1, Li Xie, Experimental Measurement of Electromagnetic Waves Depolarization in S and C Band due to Sand and Dust, IEEE Antennas and Wireless Propagation Letters, 2017, 16:2345-2348 
28. Hongxiang Yu, Li’an Mu, Li Xie, Numerical Simulation of Particle Size Effects on Contact Electrification in Granular Systems, Journal of Electrostatics, 2017, 90: 113-122
29. Jùn Zhou, X. Dou and Li XIE, Scattering and Attenuation of Electromagnetic Waves by Partly Charged Particles, Journal of Quantitative Spectroscopy and Radiative Transfer, 2018, 206: 55-62
30. Hichao Zhong, Jun Zhou, Zhixin Du, Li XIE, An experimental study on laser    
   attenuation coefficient by dust/sand storms under controlled laboratory
   conditions, Journal of , 2018, in press
31. Xie Li, Zheng Xiaojing, Impact action of soil particles on crust in wind erosion, Proceeding of International Conference on Science and Technology for Desertification Control, 2007, 1:63-72. 
32. Yan, J. Xie, L., Effect of charged sand/dust particles on signal of electromagnetic wave, Mechanic Automation and Control Engineering (MACE), 2010 International Conference on26-28 June 2010, 4520 – 4523, Wuhan, China
33.  Li Xie, Dewen Sun and Jun Zhou, Electrification of glass by fracture. 13th International Conference on Fracture (ICF13), 2013.
34.  L. Xie, Y. Jiang, N. Bao, K. Han, and Jun Zhou, An Experiment Investigation On Electrification By Collision Between Chemically Identical Glass Particles, AIP Conf. Proc. 1542 , 859 (2013)
35. Li XIE and J. ZHOU, Contact electrification of particles considering effect of relative, Proc. 2017 Annual Meeting of the Electrostatics of America, 1
36. Tianli Bo, Xiaohui Lü, Li Xie and Xiaojing Zheng, A Field Measurement of Structure and Saturation of Wind Ripple, Benjamin Veress and Jozsi Szigethy, Horizons in Earth Science Research, 2009 Nova Science Publishers, Inc. Chapter 23.