In addition, adopting the four step rule annunciated by American Academy of Science ( AAS), the residual aluminum ions of the tap water in Xi'an City were studied for the Chemical health and harm risk assessment. 此外,论文采用美国科学院(NAS)公布的四步法,对西安市自来水中残余铝离子进行了化学物质的健康危害风险评价。
Xi'an Forest of Steles, one of the important cultural heritages in the old city area of Xi'an, is the largest stone sculpture museum in china, which was annunciated as the first batch cultural preservation units in the whole country. 西安碑林是西安明城内一处重要的文化遗产,中国最大的石刻艺术馆,1961年被确定为全国第一批文物保护单位。