Based upon the toms long - time series data products , total ozone amount and its variations with season and yearly differences over china are analyzed . it was found that yearly differences of the total ozone amount are observed in some years , and seasonal changes are clearly observed 本文还利用常规观测资料和六年的toms臭氧反演产品(月平均产品)资料，分析了我国上空1997 - 2002年间大气臭氧总量的分布和季节变化。
The fourth part introduce how to display data product and implement display function . display program divide product into some category . it display product by product category and display information , so this system can display some product which unknown but in these category 第四部分介绍了数据产品的显示方法和显示的实现过程，显示程序把产品分为几个种类，按照种类显示产品，从而使系统拥有显示相同种类未知产品的能力。
The arable land classification system can be subdivided tree models : the arable land classification subsystem , the query and analysis subsystem and the dynamic update subsystem . in the first part the author discusses how to construct the arable land classification information system , which emphasizes the formation and the function of the system . the second part is the concrete example of the appliance in the arable land classification system where the process of the arable land classification , the classification data products and its analysis are introduced explicitly 全文分为三部分：第一部分为农用地分等信息系统的构建，着重论述了分等信息系统的构成、功能，可以分为分等子系统、查询分析子系统和动态更新子系统三个功能模块；第二部分为实例分析，重点论述了分等子系统在农用地分等工作中的应用、数据成果及其分析；第三部分为农用地分等信息系统的特点及其展望，分析了该系统的特点和不足，提出发展的方向。
