目的对纸质食品包装材料中松香酸抽提方案进行优化。方法分别采用超声萃取法、微波萃取法、索氏萃取法、Na OH/尿素/硫脲混合碱溶液溶解-超声提取法对纸质食品包装材料中的松香酸进行提取,并对提取产物进行了高效液相色谱法分析,比较4...目的对纸质食品包装材料中松香酸抽提方案进行优化。方法分别采用超声萃取法、微波萃取法、索氏萃取法、Na OH/尿素/硫脲混合碱溶液溶解-超声提取法对纸质食品包装材料中的松香酸进行提取,并对提取产物进行了高效液相色谱法分析,比较4种提取方法的提取效果,并对经4种提取方法提取后的样品进行了电子显微镜分析,观察提取后的样品中松香的残留情况。结果经混合碱溶液-超声提取法处理的样品,松香酸含量测定值明显高于其他三种方法。经超声萃取法、微波萃取法和索氏萃取法处理的样品中均残留有松香,而经混合碱溶液-超声提取法处理的样品中未观察到松香残留,与高效液相色谱分析的结果一致。结论 Na OH/尿素/硫脲混合碱溶液溶解-超声提取法可以完全提取样品中的松香酸。展开更多
[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different f...[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.展开更多
使用氢氧化钠-硫脲-尿素-水溶液预处理漂白阔叶木化学热磨机械浆,促进纤维之间的结合及纤维表面淀粉的留着以提高纸张强度。通过单因素实验,评估淀粉用量、纸浆浓度、用碱量、冷冻时间对纸张强度的影响情况并探究最佳工艺条件。当淀粉...使用氢氧化钠-硫脲-尿素-水溶液预处理漂白阔叶木化学热磨机械浆,促进纤维之间的结合及纤维表面淀粉的留着以提高纸张强度。通过单因素实验,评估淀粉用量、纸浆浓度、用碱量、冷冻时间对纸张强度的影响情况并探究最佳工艺条件。当淀粉用量为15%、纸浆浓度为15%、用碱量为7%、冷冻时间为45m i n时,该化机浆的增强效果最明显,在打浆度相当的前提下,成纸抗张指数、耐破指数都均较大提升,但耐折度没有明显变化。展开更多
文摘目的对纸质食品包装材料中松香酸抽提方案进行优化。方法分别采用超声萃取法、微波萃取法、索氏萃取法、Na OH/尿素/硫脲混合碱溶液溶解-超声提取法对纸质食品包装材料中的松香酸进行提取,并对提取产物进行了高效液相色谱法分析,比较4种提取方法的提取效果,并对经4种提取方法提取后的样品进行了电子显微镜分析,观察提取后的样品中松香的残留情况。结果经混合碱溶液-超声提取法处理的样品,松香酸含量测定值明显高于其他三种方法。经超声萃取法、微波萃取法和索氏萃取法处理的样品中均残留有松香,而经混合碱溶液-超声提取法处理的样品中未观察到松香残留,与高效液相色谱分析的结果一致。结论 Na OH/尿素/硫脲混合碱溶液溶解-超声提取法可以完全提取样品中的松香酸。
基金Supported by Construction Project of Maize Industry Technology System of Modern Agriculture in Yunnan Province(Yunnong(ke)2009-53Yunnongcai(2009-171))~~
文摘[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.
文摘使用氢氧化钠-硫脲-尿素-水溶液预处理漂白阔叶木化学热磨机械浆,促进纤维之间的结合及纤维表面淀粉的留着以提高纸张强度。通过单因素实验,评估淀粉用量、纸浆浓度、用碱量、冷冻时间对纸张强度的影响情况并探究最佳工艺条件。当淀粉用量为15%、纸浆浓度为15%、用碱量为7%、冷冻时间为45m i n时,该化机浆的增强效果最明显,在打浆度相当的前提下,成纸抗张指数、耐破指数都均较大提升,但耐折度没有明显变化。
