短語詞組短語retention n curve 記憶力曲線soil water retention characteristic curve 持水曲線soil water retention curve 土壤持水曲線equation of retention curve 特征曲線方程the water retention curve 土水特征曲線soil moisture retention curve 土壤水分特征曲線soil water retention curve fitting 水分特征曲線擬郃soil water retention curve model 土壤水分特征曲線模型 返回 retention curve