section grading

基本解释

Timber structures-Strength graded structural timber with rectangular cross section-Part 3: Machine grading;
木结构按强度分类的矩形截面承重木料第3部分：机械分选；
Based on analysis of heavy minerals, paleocurrent and clastic particles grading, the sediment of Yanchang section in Ordos Basin comes from two types of parent rock.
根据重矿物组合、古流向和碎屑颗粒粒度等资料，对鄂尔多斯盆地上三叠统延长组物源区的母岩性质、物源方向及演变特征等进行了分析。
This research selects factors according to the demand of urban land grading and section otherness in research area and sets up factors system effecting urban-grade between cities;
根据城镇土地分等的要求和研究区的地域差异性选择因素因子，从而建立影响城镇间土地等的因素因子体系；