筛部
Although the sieve tubes are not cut off directly during tapping, the outer part of the sieve tube layer at/ near the tapping cut will be collapsed as a result of the damaging effect from tapping.
虽然割胶时不直接切断筛管,但是在割口及其附近,筛管层外层的筛管在伤害的影响下毁坏。
First, turpentine was inverted to high-yied dipentene and part terpinolene using 13X molecular sieve as catalyst.
第一步催化是松节油在13X钠型分子筛的催化下,获得较高收率的双戊烯和部分异松油烯;
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