应用核磁共振技术测定油菜籽含油量的方法研究

本文建立了系统的应用核磁共振技术测定油菜种子含油量的方法。首次报道了样品前处理，最适工作参数选择和校正方法的系统研究结果。 50份不同含油量的种子样品用于核磁共振法与经典索氏抽提法比较试验，两方法相关系数r=0.9823。核磁共振仪对纯菜籽油的线性响应r=0.9994。最少种子需要量为0.5克。测定环境温度和种子样     

不同茶叶中咖啡因的提取

采用索氏抽提法提取茶叶中的咖啡因,以95%乙醇为提取剂,利用生石灰中和乙醇提取液中含有的单宁酸,使咖啡因从提取液中游离出来,然后采用升华法使咖啡因结晶,对提取出的咖啡因样品用红外光谱进行结构鉴定,确定其成分。主要测定了市售各类不同产地茶叶中咖啡因含量,并对其中一种茶叶——铁观音不同加工方法 (以其价位或等级作为参考)的咖啡因含量进行粗略评价。在试验过程中,对相关试验条件(如提取剂体积、升华时间等)作了初步探讨。     

进口大豆粉碎细度对索氏抽提法测粗脂肪含量的影响

以进口大豆为研究对象,采用高效粉碎机和脂肪测定仪进行粉碎和抽提,研究其粉碎细度对索氏抽提法测粗脂肪含量的影响。结果表明,大豆粉碎细度越小,其粗脂肪含量测得越高。     

不同提取方法对灵芝孢子油的影响

以破壁的灵芝孢子为原料,研究了超临界CO_2萃取法、索氏抽提法和水酶法对提取灵芝孢子油的影响。结果表明,索氏抽提法提油率最高,超临界CO_2萃取法次之,水酶法最低,但提取的灵芝孢子油中三萜类含量反之,分别为24.45%,25.12%和28.96%。通过正交试验优化得到超临界CO_2萃取灵芝孢子油的最佳条件为萃取压力30 MPa,萃取温度45℃,萃取时间3 h,CO_2流量20 L/h,灵芝孢子油的提取率可达到24.63%。同时,对3种提取方法得到的灵芝孢子油的脂肪酸组成分析,结果显示3种提取方法得到的灵芝孢子油脂肪酸组成无显著差异,不饱和脂肪酸含量均超过80%。     

娑罗子中脂肪酸成分分析

采用乙醚索氏抽提法提取婆罗子中的脂肪油.经BF3-CH3-OH甲酯化处理,用气相色谱-质谱连用法(GC-MS)测定脂肪酸的组成.婆罗子出油率为30.2%,试验共分出57个峰,首次确定52种脂肪酸成分.其中主要的脂肪酸是亚油酸(41.29%)、棕榈酸(17.81%)、油酸(14.08%)、硬脂酸(3.19%)和15-二十四碳烯酸(2.16%),不饱和脂肪酸总含量高达73.256%.     

烟蚜茧蜂畸形细胞对寄主生理代谢的调控

【研究目的】研究畸形细胞对寄主蚜虫的生理生化的影响及其自身的发展变化。【方法】分别采用Folin-酚法、SDS聚丙烯酰胺凝胶电泳法、薄层层析法和索氏抽提法测定寄生和未寄生寄主血淋巴的蛋白质含量、蛋白质组成、糖类含量和脂肪含量变化。【结果】寄生寄主与未寄生寄主相比,生理代谢受到抑制。血淋巴蛋白和甘油酯含量随日龄逐渐增加到第3天达最大后下降,而糖含量逐渐降低,分析是畸形细胞分泌和合成的结果。同时,经SDS-PAGE电泳显示,血淋巴中新出现15.9kDa和51.1kDa两种特异的蛋白质。【结论】通过对寄主血淋巴主要成分的分析,烟蚜茧蜂畸形细胞对寄主的发育起着重要的调控作用。     

鸡肉汤中滋味呈味前体物质的提取方法研究

以120日龄的武隆黑鸡为研究对象,以提取液总氮含量、游离氨基酸含量、无机离子含量为评价指标,评价热水抽提法、冷水抽提法、冷水-乙醇抽提法等3种方法对滋味物质的提取效果。结果表明,就总氮抽提率而言,冷水抽提法的总氮抽提率为17.83%,冷水-乙醇抽提法的抽提率为10.31%,而热水抽提法提取率为9.06%。就抽提液游离氨基酸的抽提效果而言,热水抽提法效果最好,抽提液游离氨基酸总含量为309.15 mg/L;冷水-乙醇抽提法的效果次之,抽提液游离氨基酸总含量为282.06 mg/L;冷水抽提法的抽提效果最差,抽提液游离氨基酸总含量为258.02 mg/L。就无机离子抽提效果而言,热水抽提的效果最好,抽提液无机离子总含量为998.54 mg/L;冷水抽提法次之,抽提液无机离子总含量为752.69 mg/L;冷水-乙醇抽提法的效果最差为474.08 mg/L。综上所述,热水抽提法可以作为滋味呈味物质提取的有效方法。     

油料中含油率测定方法研究

青海省粮油检测防治所依据固-液萃取的基本原理,遵循物质在其间的扩散规律,充分考虑影响固-液萃取的因素,在对比目前索氏抽提法及相关改进方法的基础上提出了蒸煮与喷淋相结合的方法,原方法使用过程中主要存在以下不足：（1）以浸泡为主,提取时间长;（2）试剂用量大,蒸发损失多;（3）仪器虹吸管等附件易损坏;（4）试剂回收难.喷淋式固液萃取以喷淋为主,克服了上述不足.     

NH5110核磁共振含油量测定仪应用试验

前言利用核磁共振技术测定油料种子的含油率,是国际上六十年代初开始采用的一项新技术,国外已广泛地应用并扩展到许多领域,但在我国还刚刚开始,由于该法与现行使用的索氏抽提法(或改良直滴式抽提法)相比,具有快速、安全无毒、操作方便、不破坏油料种子等优点。因此,对从事粮油检化验人员具有很大吸引力。但该仪器的准确度和     

王瓜不同部位营养成分的分析

采用凯氏定氮法、酸碱滴定法、索氏抽提法、蒽酮比色法等方法,对野生植物王瓜果实、种子和根的主要成分进行分析。结果表明,王瓜种子的脂肪含量达29.93 g/100 g,蛋白含量达31.75 g/100 g;王瓜果实的蛋白含量达40.21 g/100 g;王瓜根的黄酮含量达156.58 mg/100 g,多酚含量达113.035 mg/100 g,说明王瓜具有较高的营养价值。通过显著性分析发现,王瓜各部位营养成分的含量差异显著(p0.05)。野生王瓜有望成为新型物质生产原料,可促进功能食品的发展。     

小麦新陈快速鉴别方法的研究

对小麦的新陈快速鉴别方法进行了研究。研究结果表明,愈创木酚法在小麦收获后的前两个月用于现场收购当年产的新麦,有较高的准确度;酸度指示法在一定程度上可以快速判断小麦的新鲜程度,适用于异地调运新麦。     

THE REANALYSIS THEORY OF COUHLED METHOD OF FINITE ELEMENT AND BOUNDARY ELEMENT METHOD WITH VARIATION OF BOUNDARY

The coupled element of finite element and boundary element theory has been used to carry out the reanalysis of structures with geomeotric variation based on the varitional principle. It will not only reduce the amount of analyser' work,save the memory of computer,but also enhance the accuracy of reanalysis. So it will effectively make the reanalysis of large structures easy.     

ANALYSIS OF NONLINEAR PROBLEMS OF LAMINATED PLATES BY USE OF PERTURBATION AND WEIGHTEDRESIDUAL METHOD

This paper solves the geometrically nonlinear problems of symmetric, cross-ply laminated anisotropic rectangular plates subjected to uniformly distributed load by the higher-order shear deformation theory and taking an advantage of the perturbation and the weightedresidual method. First, with the help of the perturbation, the nonlinear partial equations have been changed into linear ones. This paper can solve these linear ones by the weighted-residual method. The combination of quintic B-spline functions are chosen as the basis of trial function and Dirac delta functtion, the weighted function. The method used in this paper is simple, direct and efficient. The numerical results show a good convergence and they are in good agreement with the available data.     

AREA-VECTOR METHOD CALCULATJJNG THE DISPLACEMENTS OF BEAMS AND FRAMES

A new method with which to calculat the displacements of beams and frames is presented. The areas of tending moment diagram of beam or frame and the slope at the origin of the elastic curve are treated as some rotatable vectors with this method. Angular displacement and in-line displacement can be calculated by using the projection and moment of these vectors. This method can be used to calculate displacement of the bar and the bar syttem ( including three dimensional forms. ) , which made from linear or ncnlinear elastic materials. The cross section of the bar is changeable.     

THE METHOD AND ITS APPLICATION FOR COUPLED ANALYSING PLASTIC DEFORMATION OF ROLLING WORKPIECE AND ELASTIC DEFORMATION OF ROLLS

A method for coupled analysing plastic deformation of rolling workpiece and elastic de'formaticn of rolls is developed. The interaction of plastic defo rmation of rolling workpice and elastic deformation of rolls is considered. The couple is formulated by setting up force equilibrium equation at the interface of the rolling workpiece and tne rolls. The plastic deformation of rolling workpiece is treated by the rigid plastic finite element method and the elastic deformation of rolls is treated by the boundary element method. The rolling presure, perunit. forward slip, neutral from angle obtained from coupled analysis are lower than those obta-ined rigid rolls. The results obtained from analysis show that the analytical accuracy can be heightened using the coupled ana-ytical methcd dveeloped for treatng rolling3proccss.     

ANALYSIS OF THE TIME HISTORY RESPONSE FOR LARGE STRUCTURE UNDER THE ACTION OF IMPULSIVE LOADING USING STEP-BY-STEP REDUCED DYNAMIC-STIFFNESS COMPOSITION METHOD

In this paper, a dynamic substructure method for analysing the transient response of the large structure is proposed. The method is based or, the combination of the reduced dynamic-stiffness composition method and the step-by-stop integration method. Its main feature is that the computational effort may be reduced significantly. Several examples are given to prove its reliability, effectiveness and accuracy.     

谷物不溶性膳食纤维测定方法研究

修改采用AACC32-20(1999)<不溶性膳食纤维测定方法>,对原国家标准GB/T9822-1988<谷物不溶性膳食纤维测定方法>进行了研究和讨论分析.结果表明,纤维测定仪器可以作为谷物不溶性膳食纤维的测定仪器,样品的粉碎粒度为20-30目,α-淀粉酶浓度为2.5%(W/V),取消了试剂中的十氢萘,样品不溶性膳食纤维测定值的相对误差小于10%.     

THE APPLICATIONS OF GRAPH THEORY IN STRUCTURE MECHANICS

This paper presents some ideas of graph theory which are led int(?) structural matrix analysis. The main contents of this paper are the principal points of the graph theory, the computative principles of the node method and the mesh method.