petroleum ether extracts 第1页

studies on the Chemical Constituents of Notopterygium incisium Ting Ⅲ Chemical Constituents Isolated and Identified from Petroleum Etber Extracts of N. incisium Ting STUDIES ON SPATIAL VARIABILITY OF CONTENTS OF PETROLEUM ETHER EXTRACTS FROM FLUE-CURED TOBACCO LEAVES AND SOIL FERTILITY FACTORS IN TOBACCO PLANNING FIELDS IN CENTRAL HENAN PROVINCE