一种改良的快速大量提取禾谷类作物成熟籽粒总RNA的方法

禾谷类作物成熟籽粒富含多糖、蛋白质和脂类等成分,传统的提取方法所得的RNA大多不能满足下游操作的需求。此实验利用一种改良的CTAB法对小麦、水稻、玉米成熟籽粒总RNA进行提取,实验步骤简单。RNA得率高,完整性好,电泳条带清晰,OD260/OD280值在1.6~1.8之间。RT-PCR和Northern印迹分析显示该法所提RNA能够满足下游实验操作的要求。进一步分析发现,这种改良的CTAB法对玉米籽粒RNA的提取效果优于小麦和水稻,更适于玉米籽粒RNA的提取。     

花生总RNA提取方法比较研究

通过对2种RNA提取方法（改良CTAB法和Trizol法）和2种RNA提取试剂盒（AXYGEN总RNA提取试剂盒和TIANDZ总RNA提取试剂盒）进行比较研究,以期获得质量较好的花生不同器官的总RNA,为后续分子生物学实验奠定基础。实验结果表明,与TRIZOL法及2种RNA提取试剂盒相比,改良CTAB法提取的花生总RNA完整性好,得率高,稳定性好,并且无DNA污染,可以进一步满足半定量RT-PCR等实验需要。     

大豆成株期抗旱性鉴定评价方法研究

以我国不同地区育成的77个大豆品种(系)为供试材料、以晋豆21为对照, 在年降雨量不足40 mm的甘肃敦煌市, 设干旱胁迫和正常灌水2个处理, 考察与产量相关的8个农艺性状, 应用简单相关、等级相关等统计学方法, 筛选优异的抗旱种质资源, 旨在明确大豆成株期抗旱性鉴定指标和评价方法。9种抗旱性评价方法比较结果表明, 基于抗旱系数法、伤害指数和敏感指数对供试材料的抗旱性评价结果完全一致, 基于生物产量、单株粒数和单株荚数的综合评价方法与基于产量的直接评价方法比并无优势。经典的抗旱系数法适宜于筛选抗旱资源, 但不一定能筛选出正常条件下的丰产资源, 而本文提出的改进抗旱指数法可筛选到抗旱性和丰产性兼备的品种, 为抗旱育种和生产应用服务;通过划分不同品种熟期组, 筛选到不同熟期类型的抗旱、丰产品种。本研究为制订“大豆抗旱性鉴定评价技术规范”提供了理论依据, 对大豆资源的抗旱性鉴定和抗旱性育种具有重要的意义。     

五味子的DNA提取及RAPD鉴定研究

采用CTAB、SDS、改良CTAB法对五味子总DNA提取进行研究,并对总DNA进行电泳分析和含量测定,结果表明以改良CTAB法提取五味子叶片DNA纯度最好,以此DNA为模板可获得条带清晰、重复性好的RAPD扩增结果。从14条重复性好的引物中共扩增出67条带,平均每个引物4.8个片段,多态性位点数为58,比例为86.6%。UPGMA聚类分析的结果与五味子形态学分类结果相似,10份五味子优系在遗传相似系数0.69处可划分为3个类群,该RAPD技术体系可以很好地用于10份五味子种质资源的鉴定。     

An Accurate Expansion Method for Modes Based on the Improved First-Order Perturbation

The premise for improved first-order perturbation is that all original modes of structure have been known. It will take much error for modes if the conventional method of truncated higher frequency modes is used. Taking higher frequency modes into account, an accurate expansion method based on the improved first-order perturbation is put forward, which can improve the precise of modes obviously.     

Synthetic Assessment of Power Transformer Condition Based on Matter-element Theory

Condition assessment on power transformer is an important approach to improve reliability of transformer and provide proper decision-making for condition-based maintenance. For long, static assessment method used in the past has already not adapted to the development of modem electricity transmission and distribution technology. So based on the deficiency of fuzzy synthetic assessment method, matter-element synthetic assessment method is introduced. The method can evaluate transformer condition not only in quality but also in quantity. Because each index weight can be given fairly and fast through improved analytic hierarchy process, which need not carry on consistency chec accuracy of assessment can be improved. Examples analysis has proved that assessment method of power transformer condition based on matter-element theory is rational and effective.     

Parameter optimized Morlet wavelet de noising method based on cross validation method

A new de noising method based on parameter optimized Morlet wavelet is put forward. The Morlet wavelet is chosen as the mother wavelet because its shape is similar to the mechanical shock signals. The mother Morlet wavelet is improved by adding two parameters which decide the shape of the mother wavelet in time domain. The added parameters and the appropriate scale parameter for the wavelet transformation are designed by the cross validation method. Finally, the useful components of the signal can be obtained by the improved Morlet wavelet de noising method. The gear fault diagnosis experimental result shows that the proposed method has a good de nosing performance and it is effective in fault feature extraction.     

作物覆盖度的近地面测量方法综述

作物覆盖度是农业生态学、作物栽培学和水土保持学等学科中的重要研究参数,因此如何快速和准确地地获得覆盖度数据对相关科技工作者具有实用价值。本文综述了国内外的作物覆盖度的近地面观测方法,将其归纳为三大类：地面实测类、动态模型类和遥感类,提出并评估了利用叶面积指数推导作物覆盖度的模型法。同时,在分析各种方法的特点和优势的基础上,对不同情形下的覆盖度方法的使用提出建议,最后对作物覆盖度测量方法可能的发展与研究方向作出了展望。以期为相关研究人员快速获得适宜的观测方法和方案提供参考。     

3种常用农业气象干旱指标及其在实际应用中的修订

不可能存在一个适用于各种情况的通用的农业气象干旱指标,在实际应用中,由于各干旱指标均具有一定的局限性,一些研究者会在原有指标的基础上,针对要解决的具体问题对指标进行改良和修订。本研究在介绍降水距平百分率、帕尔默干旱指数、CI干旱指数这3个常用农业气象干旱指标的基本原理及优缺点的基础上,对应用者对这3个指标的修订进展进行了综述,为使用者了解要更准确使用这些指标进行农业干旱监测评估提供基本思路。     

野生香蕉叶片总RNA提取方法研究

采用TRIZOL试剂盒法、RNAsio试剂法和改良CTAB法提取香蕉叶片总RNA,并通过凝胶电泳、紫外分光光度法检测提取的RNA样品的质量。研究结果表明：改良CTAB法提取的RNA具有28SrRNA和18SrRNA两条清晰的条带,OD260／OD280在1.80-1.95之间,OD260／OD230在1.75-2.10之间,具有较高的纯度;其它两种方法获得的RNA纯度不够,降解严重。将提取的RNA分别逆转录成cDNA,经RT-PCR扩增,只有改良CTAB法出现清晰的条带,进一步证明改良CTAB法提取的RNA具有很高的纯度,可以满足进一步分子生物学研究的要求。     

随机森林方法在玉米-大豆精细识别中的应用

研究基于遥感影像的作物精确识别技术方法, 对获取作物分布信息具有重要意义。随机森林分类(random forest classification, RFC)是机器学习的一种, 本文使用Landsat-8 OLI卫星影像数据, 针对研究区内的大豆、玉米和其他地物等3种主要作物类型, 系统比较了该方法与较为成熟的最大似然分类(maximum likelihood classification, MLC)、支持向量机分类(support vector machine, SVM)方法的分类精度。结果表明, MLC、SVM、RFC的总体分类精度分别为91.68%、91.49%、94.32%, Kappa系数分别为0.87、0.87、0.91, RFC方法作物识别精度比MLC和SVM分类显著提升。对原始7波段影像进行主成分变换(principal component analysis, PCA), 提取前4个主成分分量, 同时计算归一化植被指数(normalized difference vegetation index, NDVI)和归一化水体指数(normalized difference water index, NDWI), 将6个额外辅助特征波段叠加到原始7个波段影像上进行再次分类, MLC和SVM方法作物识别精度未有提升, RFC方法总体精度提高了1.49个百分点, Kappa系数提高0.03, 精度提升幅度有限, 主要原因是6个辅助波段在类型识别中作用较小。在分类耗时上, MLC、SVM、RFC分别为145 s、11 000 s、1800 s, 表明随机森林分类具有最好的分类精度和适中的耗时。综合评价后, 随机森林分类方法在进行大豆-玉米精细识别中具有较大优势, 具有业务应用的潜力。     

基于决策树方法的淡水沼泽湿地信息提取——以扎龙湿地为例

为了及时准确地获取湿地基础信息,对湿地进行动态监测和保护。以扎龙湿地为研究区,以区域湿地遥感信息提取为目标,采用TM影像数据、DEM数据、归一化植被指数、纹理信息等复合识别指标构建决策树模型,对研究区不同地类进行分类。然后与传统的最大监督分类法所得到的结果进行对比。结果表明,采用基于指数的决策树分类方法对扎龙湿地类型进行分类,较传统的最大似然监督分类精度提高了14.6%;总体Kappa系数提高了0.1751,分类精度较监督分类有明显的提高,证明基于多源数据决策树分类方法是内陆淡水沼泽湿地信息提取的有效手段。     

Improved Modal Capacity Spectrum Method for Estimating Seismic Performance of Structures

Performance-based seismic design involves how to confirm inelastic displacement demand of structures under earthquake in concise and reasonable way. Two shortages need to improve in analyzing the elastic-plastic seismic responses of structures if the traditional capacity methods are employed. The shortages are the uncertainty of equivalent high damp of elastic-plastic structures and the limitation of the higher order vibration mode effect being not taken into account. To solve these problems, the authors propose the concept and analyzing process of improved capacity spectrum method based on modal pushover analysis and the elastic seismic responses spectrum modified by strength reduction coefficient and ductile coefficient. The example of analyzing the performance of frame structure is shown which may be a simple and effective method used in engineering. This method has application potential in Performance-based seismic design.     

土壤重金属污染评价方法进展

【研究目的】土壤重金属污染是当今环境污染中污染面积最广、危害最大的环境问题之一,受到人们的广泛关注,因此国内外提出了众多的重金属污染评价方法,笔者将其进行系统的总结与归纳,为以后土壤重金属污染评价研究奠定基础;【方法】笔者综述了单因子指数评价法、内梅罗综合污染指数法、几何均值综合评价模式、污染负荷指数法、地积累指数法、沉积物富集系数法、潜在生态危害指数法,模糊数学法、灰色聚类法、基于GIS的地统计学评价法、健康风险评价方法、环境风险指数法等国内外典型的土壤重金属污染评价方法及模型,分析了各种方法的优劣之处和适用范围;【结论】通过分析表明各种评价方法都有一定的局限和不足之处,在评价中要对实测数据样本点进行充分分析,反复试验比较,结合评价的目的和侧重点选择较优的方法。最后提出根据实际的情况采用多种方法结合,同时,应该从重金属污染生态效应着手,开发生物评价法。     

改进遗传算法在饲料配方设计中的应用

针对现有饲料配方软件的局限性,以白绒山羊饲料配方为例,提出一种基于改进遗传算法的求解方法。与标准遗传算法相比,采用随机联赛选择替代轮盘赌模型,优化了选择策略;采用不同的随机数交叉和高斯变异,改进了交叉算子与变异算子。测试结果表明,该方法具有良好的运算效率,拓宽了搜索空间,提高了对重点区域的搜索能力,降低了成本,为复杂问题的优化提供了一种新的思路。     

哈大高速公路景观质量评价

构建高速公路景观评价体系和评价模型,探讨高速公路的景观评价方法。以哈大高速公路为例,从公路自身景观、公路沿线人文景观和公路两侧本底自然景观3方面进行评价、选取15个二级指标,55个三级指标的景观综合评价体系。参考有关的标准和研究资料制定二级指标的评价标准,利用层次分析法确定权重。采取景观综合指数法和模糊数学评价法对哈大高速公路总体景观质量进行了定量和定性评价。结果显示：哈大高速公路总体景观多数路段分数在6~7分之间,并且靠近哈尔滨和大庆2个城市路段分值高于中间路段,这可能与公路中间路段两侧的绿化和护理不到位有关。根据模糊评价法最大隶属度原则,哈大高速公路总体景观质量为“一般”等级,2种评价方法结果一致。鉴于各种评价方法的优点和缺点,采用基于AHP的综合指数法和模糊数学法适合高速公路景观质量的评价。     

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%。     

Comparative study on the identification of structural modal parameter using different methods

Chongqing Chaotianmen Yangtze River Bridge is the world's longest-span arch bridge. The node connections on its main truss’s lower chords are to bear millions of large-amplitude stress cycles caused by automobile and light-rail train loads. However, there exists no referential designing and testing experience in such detailing on long-span steel bridges at home and abroad as yet. High-cycle fatigue behavior testing on a detailing model has been conducted to study the fatigue reliability of the bridge’s critical node connections. The testing cycling load on the model is determined according to conventional specifications and the expected traffic flow on the Bridge. The 1/2-scale detailing model is carefully fabricated to simulate the node prototype and undergo the 2 million-cycle testing with the design load. Through testing, fatigue reliability of Chaotianmen Yangtze River Bridge’s main-truss lower-chord node connections during the design service life is verified. In addition, static test data are compared with those calculated by finite element analysis to prove the validity of the node model. In the end, fatigue destruction test of the model was carried out to get the fatigue failure law of the node connection and provide necessary parameters and reference for designing and monitoring of this bridge in the future.     

Application of Improved Hierarchic Genetic Algorithm to Damage Detection of the Main Girder for Cable-stayed Bridge

In the process of damage identification for high-order nonlinear structure such as cable-stayed bridges by the standard genetic algorithm, premature convergence would appear. In order to avoid this, an improved hierarchic genetic algorithm was proposed. The cable force change was used to establish the optimization function and threetypes of standard genetic algorithm were combined with variable fine-tuning and hierarchic strategy.To establish a hierarchical genetic algorithm with catastrophe characteristics A single-tower cable-stayed bridge model was used in the numerical simulation and the result showed that the probability of premature convergence was reduced in the improved hierarchic genetic algorithm and and the cable-stayed bridge damage was identified effectively. The anti-noise performance was better.