THE GENERALIZED NEWTON ITERATIVE PROCEDURE

We suggest a class of generalized Newton method in this paper. As special exampls, it contains the usual Chebyshev method, tangent-hypobolic method and steepest descent method.     

3种椰子基因组DNA提取方法的比较

旨在得到一套快速提取椰子DNA的方法。采用CTAB小样法、SDS-CTAB法以及PVP法提取椰子组织的DNA,并通过后续的PCR扩增和酶切等实验比较了3种方法所提取的DNA质量的优劣。将CTAB小样法提取的DNA与SDS-CTAB法和PVP法提取的DNA进行了比较,CTAB小样法提取的DNA的OD260/OD280(1.839)较另外2种方法SDS-CTAB法(1.709)和PVP法(1.613)的值更高,CTAB小样法提取的DNA适合于PCR扩增,扩增的条带清晰,且特异性好。此外,CTAB小样法提取的DNA,酶切也较为均匀。CTAB小样法能高效地提取椰子的DNA,并且能一次提取大量的高质量DNA样品,因而能满足高通量的实验要求,同提取DNA能较好地满足下游的分子生物学研究。     

Research on Shoelast CAD/CAM Technology

Some new developments of boundary contour method have been presented in this paper. The developments include the boundary contour method based on equivalent boundary integral equations, the traction boundary contour method as well as the application of the boundary contour method to crack problems and elastic thin plate bending problems.     

双波长分光光度法测定土壤硝态氮的可行性研究

为了探寻简单、快速的土壤硝态氮测定方法,以指导农业生产氮肥施用,对双波长长法测定土壤硝态氮的方法进行了探讨,并与广泛应用的反射仪法和流动分析仪测定方法进行了比较,结果表明双波长分光光度法与反射仪测定和流动分析仪测定方法高度相关,操作简便、准确,可用于土壤硝态氮的测定。     

基于数字照片解析的黄瓜叶片面积测定及效果分析

为快速测定黄瓜叶片面积,开发了基于数字照片解析技术的叶片面积测定法,通过与坐标纸法、复印比重法对比,分析数字照片解析法的准确性与稳定性。结果表明：数字照片解析法与坐标纸法测定的结果无显著差异（配对检验P(p＞|t|)=0.872＞0.05）,复印比重法测定的结果较坐标纸法显著偏高。数字照片解析法较坐标纸法更为便捷、准确,可作为一种新的叶面积测定法推广使用。     

鲜米糠中蛋白质的提取工艺研究

以新鲜米糠为原料,采用碱法、酸法、盐法分步对米糠蛋白进行复合提取。在提取过程中,以蛋白质提取率为指标,确定料液比、pH值、温度、时间对米糠蛋白提取率的影响,通过正交试验确定这3种方法各自提取蛋白的最佳工艺,最后依次采用碱提、酸提、盐提的最佳工艺条件分步对米糠蛋白进行提取。结果表明,碱法提取新鲜米糠蛋白最佳工艺条件:时间2.5 h,pH值12,温度30℃,料液比1∶11,提取率为34.49%;酸法提取新鲜米糠最佳工艺条件:时间3 h,pH值0.05,温度35℃,料液比1∶11,提取率为25.88%;盐法提取新鲜米糠蛋白最佳工艺条件:NaCl浓度0.6 mol/L,温度35℃,料液比1∶11,提取率为15.66%。复合法提取新鲜米糠蛋白总提取率达60.12%。     

三角褐指藻细胞破碎方法的研究

三角褐指藻是一种含有较高多不饱和脂肪酸的海洋单胞藻。为了从细胞中提取不饱和脂肪酸,采用反复冻融法、超声波破碎法和匀浆法分别对三角褐指藻细胞进行破碎,并测定油脂提取率。结果表明,超声波破碎法、反复冻融法和匀浆法的最大细胞破碎率分别为91.5%,56.7%和81.2%;油脂提取率分别为18.1%,13%和13.4%。从操作的简捷性和经济效益来看,超声波破碎法优于反复冻融法和匀浆法。     

有机农业生产中的有害生物管理技术

综合介绍了有机生产中控制有害生物的技术措施,主要有:生态学技术措施、农业措施、物理措施以及生物药剂防治措施等,为有机农业生产中有害生物的管理提供了思路和方法。     

不同尺度农田水分利用效率测定方法评述

摘要：水分利用效率是反映作物物质生产与水分消耗之间关系的指标,在不同的学科存在不同的理解,在不同尺度有不同的计算方法。本文评述了收获法、红外气体分析法、涡度相关法、稳定同位素法测定水分利用效率的优缺点及其适用的尺度。     

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.     

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.     

魔芋叶片中4种总RNA提取方法的比较

本研究分别利用TRIzol法、异硫氰酸胍法、改良的CTAB法及试剂盒这4种方法提取魔芋叶片的总RNA,并用紫外光谱和琼脂糖凝胶电泳对各个提取效果进行鉴定。反复试验的结果表明:TRIzol法难以提取魔芋叶片总RNA,异硫氰酸胍法提取的总RNA浓度低、杂质较多且有部分降解,这两种方法不适宜用于魔芋叶片总RNA提取;试剂盒方法提取的总RNA产率和纯度较高,但稳定性差、成功率低且成本较高;改良的CTAB法利用PVP和β-巯基乙醇去除酚类物质,水饱和酚-氯仿去除蛋白质,醋酸钾去除多糖,该方法提取得到的总RNA的纯度较高,OD260/OD280值为1.893,而且效果稳定,有良好的可重复性。因此,我们认为改良的CTAB法是一种简便、快速且经济的提取魔芋叶片总RNA的方法。     

初探土壤有机质测定方法的改进

基于榆林乃至黄土高原地区土壤有机质含量水平普遍偏低的现状,采用经典土壤有机质测定方法,滴定所用的硫酸亚铁（铵）消耗量很大,甚至与空白接近,耗时又消耗化学试剂。笔者选取69个有机质含量在2.0~30 g/kg的土样,采用经典土壤有机质测定方法和减半使用K₂Cr₂O₇-H₂SO₄溶液的情况下测定有机质含量,其他条件不变,进行对比。结果表明,经典方法与改进方法,当有机质含量≤8.7 g/kg时,100%的数据符合平行测定允许差;随着土壤有机质含量增加,2种方法测定土壤有机质含量差异越来越大,当有机质含量＞15.2 g/kg时,修订方法的测定结果均低于经典方法的测定结果,且只有27%的数据能满足平行测定允许差,不宜采用上述测定方法。该有机质测定改进方法,特别是当有机质含量≤8.7 g/kg时,既节约了化学试剂,又节省了配置试剂和滴定所用的时间,提高了工作效率也不影响测定结果的准确性。     

食品中乳酸菌含量倾注法与涂布法结果差异性研究

选取不同品种含有乳酸菌的样品,分别使用倾注法和涂布法进行检测,比较所得结果有无差异性。同时分析了倾注法和涂布法的优缺点。     

Study on Analysis Methods for Rock Slope FoundationStability of the Highrise Building

Based on the practical project a study on analysis methods for rock slope foundation stability of highrise-building project criterion transfer coefficient method, rotation limit equilibrium method (Sweden slices method) and finite element method was carried out.The authors found that safety factor of criterion transfer coefficient method is larger than that of rotation limit equilibrium method, but is similar to the results of finite element method. So, when rockslope foundation stability of highrise building is to be analysed,the rotation limit equilibrium method is suggested to use.     

AN IMPROVED MIXED FINITE ELEMENT METHOD OF ANALYZING THREE-DIMENSIONAL ELASTIC CONTACT PROBLEMS

This paper presents an improved mixed finite element method of analyzing elastic contact problems, in which a new numerical algorithm is developed to calculate the flexibility matrix of the contact region. With this method the contact problem of two teeth-engaging is initially solved as a three-dimensional elastic finite element analgsis, In comparison with mixed fimte element method, the improved mixed finite element method is much more efficiency in solving contact problems.     

澳洲坚果叶面积测定方法比较

为确定不同品种澳洲坚果叶面积测定的最佳方法,找出系数回归法测量澳洲坚果叶面积的最佳参数,对3种叶面积测量方法进行比较,对不同叶片参数与叶面积间的关系进行回归分析。结果表明,同一品种经方格法、画纸称重法、图像处理法测定的叶面积均无显著性差异,3种方法测定结果的相关系数都在0.999以上,说明3种方法均可作为澳洲坚果叶面积测定的可靠方法;不同品种的各叶片参数与叶面积间的回归系数并不相同,在利用系数回归法测量澳洲坚果叶面积时,叶长宽积是最能反映实际叶面积的叶片参数。本研究可为澳洲坚果的生理研究和生产实践提供重要参考。     

Indirect Regulation Pricing Methods of Public Utility

The author analyses the advantages and disadvantages of common indirect regulation pricing methods of public utility goods. It is pointed out that it results in high trade-cost and A-J effect binging in an excess of investment when capital yield method be used. It is not reasonable enough in setting PRI-X of PRI-X pricing method. An integrated indirect regulation pricing method is put forward which is to form a two-tier incentive mechanics both in expanding producing ability and improving efficiency. In initial stages of new public project, capital yield method should be used in order to activate investment motive. Upper-limit pricing method should be used in anaphase in order to improve the producing efficiency.     

AN OPTIMIZATION METHOD FOR SOLVING THE BOUNDARY WALUE QUESTION OF DIFFERENTIAL EQUATIONS

This paper presents an optimization method for solving the boundary value question of a differential equation on the basis of the trial-and-error method and the optimization method. As compared with the differential method, this method has some advantages such as quiker velocity at count, higher precision(especially at the boundary points) and can be widely used.     

紫黑色作物花色苷实验室定量检测方法研究

为了寻求快速、经济地测定自然界中紫黑色作物总花色苷含量的方法,利用酸性乙醇对黑元麦、茄子、葡萄3种不同作物进行花色苷提取,并采用pH示差法和差减法2种不同的实验室方法对3种样品总花色苷含量进行留样分析再测定。结果表明,黑元麦、葡萄采用pH示差法和差减法这2种测定方法的结果精确度和准确性没有显著性差异,且样品进行留样再检测时发现,2种样品测定结果之差的绝对值均小于测定结果质量不确定度,可以说明黑元麦、葡萄花色苷实验室定量检测pH示差法和差减法均适用。茄子采用pH示差法测定值相对标准偏差为2.20%,精确度明显好于差减法;从质控图看,茄子检出值出现1次连续4个点上升的情况,说明茄子皮利用差减法测定结果准确性差;从留样再检测结果可以看出,利用差减法测定2次结果之差的绝对值为0.023 mg/g,小于测定结果质量不确定度0.011 mg/g,说明茄子花色苷pH示差法检测结果可信赖,差减法检测存在问题。