基于AHP和ArcGIS的北京市农业节水区划研究

在总结国内外学者农业节水分区先进经验的基础上,结合北京市农业生态节水发展实际,充分考虑自然条件、水资源状况、工程管理和社会经济状况等,构建涵盖干旱指数、地下水超采、土壤类型、节水灌溉率、农民人均收入在内的北京市农业节水分区指标体系,分析各指标空间分布规律,界定各指标的分级标准,并划定相应分区。采用层次分析法(AHP)对各指标分级赋值,利用ArcGIS软件中的叠加分析功能将图层按权重叠加,对分区重分类并相应赋值,将各影响因素的分值和权重相乘并求和得到最终的评分结果,按照评分结果将北京市划分为农业节水优先发展区、农业节水适宜发展区和农业节水鼓励发展区,根据分区结果提出相应工程节水及农艺节水措施。     

酿酒酵母菌胞内海藻糖提取工艺参数的优化

建立了超声破碎酿酒酵母细胞和冷三氯乙酸化学浸提海藻糖的工艺，探索了离子色谱分析技术条件，采用响应曲面法（RSM），研究了液料比R、超声功率W、工作时间T1、超声总时间T2和浸提时间T3等5个试验关键因子对海藻糖提取的影响规律，并构建了动态控制的数学模型，得到了海藻糖提取最优工艺参数依次为：尺为7、W为698W、T1为4．9s、T2为7．3min、T3为9min。结果表明：模型极显著，具有可行性和有效性，超声功率、工作时间和超声总时间对海藻糖提取量的影响最大，为生产中的应用提供了科学依据。     

Characterization of humus-protease complexes extracted from soil

Pyrophosphate (140 mM, pH 7.1) extracts of two arable soils and one pasture soil were ultrafiltrated separating the extracted material into three fractions: A_I with nominal molecular weight (nmw) > 100 kD, A_II with nmw between 10 kD and 100 kD and R with nmw < 10 kD. Protease activity was determined in the fractions by using three different substrates: N-benzoyl-l-argininamide (BAA), specific for trypsin; N-benzyloxy-carbonyl-l-phenylalanyl l-leucine (ZPL), specific for carboxypeptidases; and casein, essentially a non-specific substrate. The derivative fractions were also analysed for their amino acid N and humic (HA) and fulvic (FA) acid contents. The organic matter of extracts and derivative fractions obtained from the pasture soil was analysed by isoelectric focusing (IEF) and that of fractions analysed by pyrolysis gas chromatography (Py-GC). Activities of the extract were monitored for their thermal stability and those of the extract and derivative fractions for their optimal pH.Due to the mechanical disintegrating action of sodium pyrophosphate over the humic substances during the fractionation process the amount of total organic C and FA in the fractions was ranked as R > A_II > A_I. The lowest amino acid N/organic C was found in the R fraction, whereas A_II fraction was rich in humic acids, carbohydrates and amino acid N and A_I fraction showed the lowest carbohydrate content. At least 70% of the total BAA- and ZPL-hydrolysing activity was associated to particles with nmw higher than 10 kD and at least 30% of these activities were present in particles with nmw higher 100 kD. Casein-hydrolysing activity was quite evenly distributed among the three fractions (A_I, A_II and R). The extracted protease-organic complexes were resistant to thermal denaturation and some of them showed optimal activity at pH values higher than 10 as a result of the polyanionic characteristics of the humic material surrounding enzyme molecules and of the presence of alkaline protease. Comparison of data obtained in Py-GC analyses and in protease activity suggests that BAA-hydrolysing activity was associated to a highly condensed humic matter and ZPL-hydrolysing activity to less resistant humic substances, while at least some of the extracted casein-hydrolysing activity was present as glyco-proteins not associated to humus. BAA-hydrolysing activity was probably inhibited by fresh organic matter of carbohydrate origin whereas lignin derived organic matter probably inhibited ZPL- and casein-hydrolysing activity.     

细胞转化牛膝的质量分析

本研究用薄层扫描法和原子吸收分光光度法对细胞转化牛膝和天然怀牛膝进行了齐墩果酸和微量元素分析。结果表明，与天然怀牛膝相比，细胞转化牛膝的齐墩果酸含量略低(1．43％)，钙、镁、铜、铁、锌含量明显偏低，而锰含量偏高。     

桃多酚氧化酶的纯化及其特性

为延长桃果实货架寿命及提高贮藏保鲜技术,以5年生早花露桃果实为试材,对桃多酚氧化酶的纯化及其特性进行了研究,结果表明采用疏水柱层析,透析与PEG浓缩,纯化了早花露桃的多酚氧化酶.所得的酶液经薄层聚丙烯酰胺凝胶等电聚焦电泳,显示单一条带,等电点为3.0.经SDS-PAGE分析,它由2条主要多肽(相对分子质量(MW)分别为3.98×104,6.59×104)和2条含量较少的多肽(MW为6.67×104,6.76×104)所组成.纯化酶液的最高吸收峰在波长272.5nm处,300nm以上几乎无吸收.该酶对邻位二元酚有较高亲和力,几乎不能催化一元酚和三元酚的氧化.以儿茶酚为底物,其最适pH为7.0,最适反应温度20℃.在果实生长发育过程中,多酚氧化酶活性呈下降趋势,中期有一活性相对较小的峰,同时,多酚氧化酶疏水特性增强.     

液液萃取-QuEChERS净化-高效液相色谱-串联质谱法测定饲料添加剂可溶性粉中五氯酚酸钠含量

建立液液萃取-QuEChERS净化-高效液相色谱-串联质谱法测定可溶性粉中五氯酚酸钠含量的新方法。 可溶性粉先用水溶解后加入1moL/L 盐酸1mL调pH至4左右,加入乙醚液液萃取到乙醚层,蒸干乙醚,乙腈复溶,QuEChERS净化管净化后高效液相色谱-串联质谱测定,标准曲线外标法定量。 五氯酚酸钠在0.50~100μg/L质量范围内线性关系良好,相关系数为0.9994,检出限0.5μg/kg,定量限1.0μg/kg,可溶性粉剂中五氯酚酸钠添加量为1.0、5.0、10.0μg/kg时,五氯酚酸钠的平均回收率为80.2%~94.0%,相对标准偏差小于7%。 该方法快速、高效且价格低廉,适用于饲料添加剂可溶性粉中五氯酚酸钠的快速筛查分析测定。     

超临界CO2萃取南烛叶有效成分的色谱分析

用超临界ＣＯ２对南烛叶冻干粉进行萃取,并对萃取物进行气相、高效液相色谱分析。结果表明,南烛叶中含有Ｃ０１６（棕榈酸）、Ｃ０１８（硬脂酸）、Ｃ１１８（油酸）、Ｃ２１８（亚油酸）、Ｃ３１８（α－亚麻酸）和Ｃ０２０（花生酸）等６种脂肪酸,其中Ｃ３１８（α－亚麻酸）含量最高,达３６．４％;南烛叶还含有槲皮素和其它黄酮类化合物,槲皮素在萃取物中占３．５２％,黄酮总量占１１．６４％。     

丸粒化玉米种子的薄层干燥试验研究

利用丸粒化玉米种子干燥试验装置，研究了风温、风速、加热时间对丸粒化玉米种子干燥速率的影响。同时，采用正交试验方法，对丸粒化玉米种子进行了三因素三水平干燥试验，并建立了干燥特性曲线，分析了各试验因素对干燥特性的影响。结果表明：风温越高，风速越大，加热时间越长，干燥速度越快。     

绿黄隆在土壤中的迁移特性

应用土壤薄层层析（ＴＬＣ）法测定了１４Ｃ－绿黄隆在１０种土壤中的移动率，其Ｒｆ值为０．６５～１．０，表明绿黄隆在供试土壤中分别属可移动性和极易移动性。用大面积土柱淋溶法测得３种土壤柱在模拟降雨下的淋溶动态及其参数，经计算，在黄潮土、黄棕壤和红壤中，使１４Ｃ－绿黄隆垂直移动透过１０ｃｍ土层所需连续降水量分别为７５，８０和９４ｍｍ。绿黄隆在土壤中的迁移性与土壤ＰＨ值密切相关，随ｐＨ值增高其移动性和淋溶性增大。绿黄隆随水迁移性较强，它有可能对农业生态环境产生不良影响。     

葛根淀粉组份的亲和层析分离

本文应用交联明胶柱层析方法分离葛根淀粉，得到级份Ａ和级份Ｂ两组分。高碘酸氧化、蓝值及β－淀粉酶水解证明级份Ａ为支链淀粉，级份Ｂ为直链淀粉。葛根淀粉含１８．１％的直链淀粉。葛根支链淀粉平均８．６个（１→４）连接的已糖单位有一（１→６）连接的分支。