Xi'an (Xi'an Chi Xan) is a fictional character created by Marvel Comics for their Marvel 2099 imprint. In the title X-Men 2099, he was the founder, leader, and enemy of the team of X-Men who was always haunted by his past.

Multivariate Analysis of Heavy Metal Contamination in Urban Dusts of Xi'an, Central China
Characterization and source apportionment of atmospheric organic and elemental carbon during fall and winter of 2003 in Xi'an, China
CHARACTERIZATION AND SOURCE APPORTIONMENT OF ATMOSPHERIC ORGANIC AND ELEMENTAL CARBON DURING FALL AND WINTER OF 2003 IN XI'AN,CHINA
Impact of land tenure transformation on physical development of Drum-Tower Muslim District, Xi'an China
Investigation of BMD in 1478 cases in Xi'an
The Spatial Structure of Regional Tourism System: Its Model and Optimization--A Case Study of Xi'an
Ionic composition of TSP and PM 2.5 during dust storms and air pollution episodes at Xi'an, China
Water-soluble ions in atmospheric aerosols measured in Xi'an, China: Seasonal variations and sources
Comparative Study on Citizens' Sports Consumption inEastern and Western Cities in China -Exampled by Shanghai and Xi'an City
Spatial Structure of Tourist Flow in Xi'an Tourism Region