<正>比较了不同Z-艺、参数条件下合成改性脲醛树脂性能指标的变化趋势，以及不同工艺参数对改性树脂胶合性能的影响。结果表明：加成反应阶段，pH的降低对改性脲醛树脂各项性能的提高有利；升高反应温度可以改善改性脲醛树脂的综合性能，适中的加成反应时间有助于改性脲醛树脂的各项性能的改善；缩聚反应阶段，pH的降『氐不利y-储存期的延长，但对改性脲醛树脂其他性能的提高均有较好影响，缩聚反应的温度过_高或过低均不利于改性脲醛树脂综合性能的提高；初摩尔比明显地影响储存期，初摩尔比高则储存期长；甲醛释放量随初摩尔比降低呈升高趋势。

By means ot" analyzing many soil sample’s physical and chemical characteristic such as soil bulk density, non-capillary porosity,infiltration capability, soil organic matter, soil pH value and so on in different Quercus variabitis forest soil profiles, the results showed that they have obvious roomage variability. And this roomage variability in vertical is more than that in horizontal. Therefore, we must base on the deviation theory to confirm the soil sample in different soil depth. And this is the only way to ensure the results to be correct and comparability. The results also showed it is needed to sampling decades samples even more than 100 when analyzing infiltration capability, but less than 20 samples when analyzing other soil characteristic.