丝瓜藤和叶中齐墩果酸的提取与含量分析

采用超声波辅助提取法优选提取工艺、比色法测定齐墩果酸的含量.通过单因素和正交试验设计法考察了乙醇体积分数、固液比、提取温度和提取时间对丝瓜叶中齐墩果酸提取率的影响.优化得到的提取工艺为：乙醇体积分数75％,固液比（g/mL）1∶40,提取温度70℃,提取时间70 min.齐墩果酸在3.3 μg/mL∽20.0 μg/mL （r=0.997 9,n=6）范围内浓度与吸光度呈良好的线性关系.丝瓜藤和丝瓜叶中齐墩果酸的含量分别是3.82 mg/g,3.24 mg/g.丝瓜藤中齐墩果酸含量高于丝瓜叶中的含量.所优化的工艺稳定、可行,该法测定齐墩果酸的含量,重复性较好.     

Leaf movement simulation

This paper presents a method for the animation of leaf movement.Leaves are classified into two classes:moveable and non-moveable.For moveable leaves,their movements consist of two parts:leafstalk rotation and leaf surface rotation.For each rotation,a movement model was constructed and the movement was computed based on each model,respectively.The final leaf movements were obtained by superposition of these two rotations.The method‘s principle is simple and easy to use.     

Selenium Speciation Studies from Soan-Sakesar Valley,Salt Range,Pakistan

Abstract

A regional study of Selenium (Se) speciation in surface waters, groundwaters, and saturation extracts from Soan-Sakesar valley Salt-Range, Pakistan was started in March 1994 and completed in October 1996. Groundwaters, streams, and springs had median concentrations of: total Se 48, 404.5, and 82 μg/l; Se^+VI 40, 350 and 51 μg/l; Se^+IV 8, 48 and 29 μg/l; Se^-II 0, 6.5 and 2.0 μg/l, respectively. The concentration of Se exceeded the recommended water quality guidelines for drinking and irrigation water of 10 and 20 μg/l, respectively. In saturation extracts, median total Se, Se^+VI, Se^+IV and Se^-II were 190, 146, 37 and 7.0 μg/l, respectively. Uchhali, Khabbaki and Jahlar lake water samples had the mean concentration of: total Se 2103, 670 and 297 μg/l; Se^+VI 1777, 470, and 233 μg/l; Se^+IV 291, 166 and 39 μg/l; Se^-II 35, 34 and 25 μg/l, respectively. The Sakesar limestone Formation of Eocene age rich in shales and fossils (median Se concentration 7.2 μg/kg) are considered to be the source of selenium that have enriched soils of Soan-Sakesar valley. Selenim speciation results show the abundance of selenate in all the environmental samples. A linear relationship between Se^+VI and pH (R²= 0.84, 0.58, 0.88, 0.82, and 0.91; significant at the 0.05 level) for groundwater, saturation extract, stream, spring, and lake waters were noted, suggesting that the Se^+VI in the samples is highly associated with pH. Linear relationships were established between Se^+VI and Mg, NO₃, and SO₄ for groundwater (R²= 0.24, 0.16, and 0.64; significant at the 0.01 level) and surface water (R²= 0.96, 0.14, and 0.91; significant at the 0.001 level). This suggests the high concentrations of Mg, NO₃ and SO₄, which strongly adsorb and compete with selenium for surface site, increases the Se^+VI fraction. The results show that the higher percentage of selenate on other species in the analyzed samples is favored by higher pH and oxidizing environments of the valley.     

嵌入式植物叶面积测量装置的研制

针对叶面积测量方法大多依赖计算机做图像处理,研制了一种嵌入式植物叶面积测量装置,以CycloneⅡ系列EP2C70F896C6为核心器件,用硬件描述语言Verilog设计叶片图像采集单元、图像存储单元、图像处理单元,内嵌NiosⅡ软核处理器完成叶面积计算。设计的关键在于解决了叶片图像实时高速采集问题,并且实现脱机运行。实验结果表明:测量装置能够测量离体叶片叶面积,适当改进,可以应用于测量叶片其他参数。     

烤烟硅肥肥效及施用量的研究

本文以省内８个产烟县统一硅肥肥效试验结果中的产量及产值为依据，分别进行了各点试验及其同质检验试验的变量分析，其中多数试验的处理Ｆ值都达到显著标准。硅肥对烤烟增产增值是有效的，可信的，应注意因地制宜施用具佳施硅量。硅肥增产增值原因在于促进烤烟生长，增加叶面积及其指数，以及缓解烤烟病害，特别是炭疽病害，因而提高了烤烟中上等烟的比例。     

桑叶天然染料的萃取和稳定性研究

采用正交实验法及单因子实验法，有效地萃取桑叶染液并对其稳定性进行了研究和探讨。发现桑叶的水萃取液和盐酸萃取液的光吸收曲线相似。桑叶天然染料萃取的最大影响因子是萃取剂的种类，有效的萃取剂在本试验中是氢氧化钠，其萃取液的色浓度、光密度值大，氢氧化钠最佳浓度为20％。三种萃取液的光稳定性和抗还原性能均较好，其中H2O和HCl萃取液的抗氧化性能较弱，而NaOH萃取液的稳定性则较好，并且均可在一定的条件下保存几天，因此一次萃取一定量的桑叶染液可供给几天染色用，减少了提取桑叶染液的次数，节约了时间、劳力及能耗，有利于桑叶染料实用化的进程。     

螺旋桨桨叶计算机实体造型方法研究

提出了一种螺旋桨桨叶造型的新方法——采用UG软件对螺旋桨桨叶进行精确实体缝合造型法，充分利用Matlab与UG的接口技术。对桨叶截面曲线的形成进行了优化，提高了造型精度，得到了光顺的螺旋桨桨叶的三雏实体模型，为螺旋桨的性能优化及数控精加工创造了条件。     

菠菜叶片线粒体DNA的提取及RAPD分析

以菠菜叶片为实验材料,采用差速离心法、DNaseI处理得到无核污染的线粒体、以SDS法去除蛋白,消化RNA得到单纯的菠菜叶片mtDNA,通过对mtDNA纯度的测定,从而建立了菠菜叶mtDNA快速、高效的提取技术体系;同时选取30个引物对三种菠菜mtDNA进行RAPD扩增,对提取的mtDNA体系进行了RAPD分析,结果表明,由引物S7、S16、S21、S24扩增出的条带清晰、多态性较好,片段大小在200~2000 bp之间,表明菠菜各品种的mtDNA各碱基序列上的多态性,是各品种之间进化凸现的原因之一。本研究建立的试验方法耗时短、对离心机的要求不高,并且提取的mtDNA产率高、结构也比较完整。     

基于多分类SVM的石榴叶片病害检测方法

石榴是陕西临潼广泛种植的水果作物之一。石榴的生产力由于其果实、茎和叶中各种类型的疾病引起的感染而降低,叶片病害主要由细菌、真菌、病毒等引起。疾病是限制水果生产的一个主要因素,疾病往往难以控制,如果没有准确的疾病诊断,就不能在适当的时间采取适当的控制行动。图像处理技术是植物叶片病害检测和分类中广泛应用的技术之一,旨在利用支持向量机分类技术对石榴叶片病害进行检测和分类。首先用K均值聚类法分割出病变区域,然后提取颜色和纹理特征,最后采用LSVM（线性支持向量机）分类技术对叶片病害类型进行检测。所提出的系统可以成功地检测和分类所检查的疾病,准确率为89.55%。