乙草胺,喹禾灵的同柱气相色谱分析

采用气相色谱法,氢焰离子化检测器,选择２．５％ＳＰ２４０１／ｃｈｒｏｍｏｓｏｒｂ Ｗ－ＨＰ（８０￣１００目）色谱柱,以乙二酸二正辛酯为内标,在相同的气相色谱条件下,完成乙草胺、喹禾灵的有效成分定量分析。     

废弃的植物培养基厌氧发酵产气潜力研究

[目的]弄清废弃植物培养基厌氧消化潜力与特性.[方法]以废弃的植物培养基为发酵原料,以沼气池底部的活性污泥为接种物,在常温条件下进行了批式厌氧消化试验,研究了废弃的植物培养基与接种污泥各处理厌氧消化的产气速率、潜力和产气量.[结果]常温条件下,混合培养基与接种污泥的TS比例为8∶1、浓度12％的处理,产气量最高,为10 391.3 ml,并且发酵天数为5d左右,发酵速度较快,产气效果最好;混合培养基与接种污泥的TS比例为6∶1、浓度8％的处理,原料产气率最高,为0.230 m3/kg,并且发酵天数为4d左右,说明原料被利用的水平高.[结论]该研究为植物组培工厂废弃物的处理和配套沼气工程的工艺设计提供了科学依据.     

Structural studies on soil nitrogen by Curie-point pyrolysis — gas chromatography/mass spectrometry with nitrogen-selective detection

Curie-point pyrolysis-gas chromatography mass spectrometry with N-selective detection was used to characterize the structure of organic N compounds in four mineral soils. The technique was found suitable for the fast, sensitive, and highly specific identification of N-containing pyrolysis products from whole soils with total N contents between 0.08 and 0.46%. In order to optimize the methodology, one agricultural soil was pyrolyzed at final temperatures of 573, 773, and 973 K. Almost no chemical alterations to identifiable pyrolysis products were observed when the final pyrolysis temperature was increased from 573 to 973 K. More than 50 N-containing pyrolysis products were identified, and were divided into compound classes chracterized by specific molecular-chemical structures. These included pyrroles, imidazoles, pyrazoles, pyridines, pyrimidines, pyrazines, indoles, quinolines, N derivatives of benzene, alkyl nitriles, and aliphatic amines. Three additional soil samples different in origin and N content were analyzed at 773 K and each showed a specific thermosensitive N-selective chromatogram. Many N-containing pyrolysis products were identified in all samples, which indicated general qualitative regularities in the thermal release of N-containing pyrolysis products from the four soils. In the pyrolyzates of the investigated soils a number of compounds were identified, which is usually not detectable in pyrolysis-gas chromatography spectrometry analyses with N-selective detection of plants and microorganisms. Among these were N derivatives of benzene and long-chain alkyl nitriles, which appear to be soil-specific and suggest significant transformations of organic N in soils. Thus, our results contribute to a better understanding of the molecular-chemical structure of unknown N.     

三种脱毒方法降低亚麻籽中氰化氢含量的效果比较

亚麻籽（flaxseed）富含α-亚麻酸、木脂素和其它营养成分。然而,由于生氰糖苷的存在限制了其在饲料和食品工业中的应用。本研究通过滴定测定加工过程中氢氰酸 (HCN生氰糖苷的转化产物）的去除量来确定溶剂提取、微波烘烤和水煮三种方法去除亚麻籽中生氰糖苷的效力。结果显示为：原料亚麻籽中HCN的测定值为157.68mg/kg,微波烘烤法对HCN的去除量为95.57%;溶剂提取法提取一次去除HCN量为52%,两次去除量为80%,三次去除量为89%;水煮法的去除量为88.12％。在这些方法中微波法对HCN的去除率最高;溶剂法相对于微波加工法更易实现规模化生产;蒸煮法和水煮法在特殊情况下才可考虑使用。     

油菜籽油分及脂肪酸同时测定的气相色谱快速方法

本文拟定了对菜籽油分与脂肪酸组分同时测定的气谱快速方法,基于使用氢氧化四甲铵为催化剂,酯交换在汽化室以热解方式进行,可使油分定量地转换成脂肪酸甲酯。甲酯总峰面积的大小,可作为含油量的量度,与外标作比较,求得菜籽的含油率;再对各脂肪酸甲酯的峰面积作归一化法处理,便可求得各脂肪酸的含量;与油重法和IUPAC庚烷法测定结果相比较,其相对误差分别为±3％和±3—10％,符合快速分析的要求。     

发酵与焙烤对可可豆香气影响的GC-MS分析

采用顶空固相微萃取（HS-SPME）和气-质联用仪（GC-MS）分析未发酵豆、发酵豆和焙烤豆的香气成分,并采用主成分分析法对可可豆香气的影响进行分析。结果表明：未发酵豆、发酵豆和焙烤豆香气差异明显。从未发酵豆和发酵豆中分别鉴定出30和62种挥发性成分,主要为醇类、酮类、烯烃类和醛类,发酵后可可豆香气物质增多。在105、125、145 ℃下焙烤的未发酵豆和发酵豆分别鉴定出47、59、84和71、68、83种,主要为醇类、酯类、醛类、烯烃和吡嗪类,低温焙烤和高温焙烤的可可豆香气差异明显;酮类集中于未发酵低温焙烤区,酸类、酯类和醇类偏向于发酵低温焙烤区,呋喃类和吡嗪类等杂环类化合物指向高温焙烤区。这些香气成分的差异,形成不同处理可可豆之间的风味差异,可可豆香气成分的主成分分析可以作为可可豆不同处理潜在的评价方法。     

Muffins with resistant starch: Baking performance in relation to the rheological properties of the batter

The effect on baked muffins of progressively replacing wheat flour with resistant starch (RS) was studied. Muffin volume and height and the number and area of gas cells decreased significantly when the RS level reached about 15% (by weight of total formulation) or higher. Rheological properties of the raw batters were studied: the mechanical spectra of batters at 25 °C, the evolution of the dynamic moduli (G′ and G″) with rising temperatures (from 25 to 85 °C) and the mechanical spectra at 85 °C were obtained from oscillatory rheological tests. The decrease in the viscosity and in the elastic properties of the muffin batter as the flour was increasingly replaced by RS was related to the baking performance of the final baked products.     

中部与东部经济水平差距衡量及其影响因素分析——以安徽与浙江为例

为寻找发达地区与非发达地区经济差距的原因,利用变形的柯布-道格拉斯生产函数对安徽、浙江的经济差距进行了衡量并对其原因进行了分析。研究结果表明,2省经济差距最重要的原因不是人们一直非常重视的投资,而是人力资本和以资本、劳动之外的影响因素为代表的交易费用。     

热聚乙烯钢丝索在管道跨越工程中的应用

针对忠武输气管道跨越工程跨度大、管径大、荷载大的特点，对跨越主索的选择进行了分析和比较，比较结果表明，热聚乙烯钢丝索在弹性模量、防腐性能、施工工艺和工程投资等方面具有明显优势，适于忠武输气管道跨越作用，介绍了这种钢丝索在马水河、蚂蝗溪、木龙河和大溪沟跨越工程中的设计与应用，认为其应用经验可为其它管道跨越工程提供借鉴。     

冀东地区植保技术在无公害蔬菜生产中的应用

随着人们生活条件的不断改善,人们越来越关注食品安全问题,无公害蔬菜生产显得非常重要。对无公害蔬菜生产中存在的问题进行了阐述,并针对存在问题提出了改进蔬菜病虫害防治、生产配套技术以及科学施肥等相关植保措施,确保生产出优质蔬菜。