XML签名技术研究及其应用

介绍了XML数字签名的原理及其签名和验证过程。保证基于XML的信息的机密性、可靠性、完整性和不可抵赖性。保证了其应用的安全。     

Genetic analysis of fruit shape traits at different maturation stages in sponge gourd

The fruit shape is important quantitative trait closely related to the fruit quality. However, the genetic model of fruit shapes has not been proposed. Therefore, in the present study, analysis of genetic effects for fruit shape traits （fruit length and fruit perimeter） in sponge gourd was conducted by employing a developmental genetic model including fruit direct effects and maternal effects. Analysis approaches of unconditional and conditional variances were applied to evaluate the genetic behavior of fruit shape traits at economical and physiological maturation times. The results of variance analysis indicated that fruit length and fruit perimeter were simultaneously affected by fruit direct genetic effects and maternal effects. Fruit direct genetic effects were relatively more important for fruit shape traits at whole developmental period. The gene expression was most active at the economical maturation stage （1-12 d after flowering） for two shape traits, and the activation of gene was mostly due to direct dominance effects at physiological maturation stage （13-60 datter flowering）. The coefficients due to different genetic effects, as well as the phenotypic correlation coefficients, varied significantly between fruit shape traits themselves at various maturation stages. The results showed that it was relatively easy to improve fruit shape traits for industrial purpose by carefully selecting the parents at economical maturation stage instead of that at physiological maturation stage.     

QTL analysis for some quantitative traits in bread wheat

Quantitative trait loci (QTL) analysis was conducted in bread wheat for 14 important traits utilizing data from four different mapping populations involving different approaches of QTL analysis. Analysis for grain protein content (GPC) sug- gested that the major part of genetic variation for this trait is due to environmental interactions. In contrast, pre-harvest sprouting tolerance (PHST) was controlled mainly by main effect QTL (M-QTL) with very little genetic variation due to environmental interactions; a major QTL for PHST was detected on chromosome arm 3AL. For grain weight, one QTL each was detected on chromosome arms 1AS, 2BS and 7AS. QTL for 4 growth related traits taken together detected by different methods ranged from 37 to 40; nine QTL that were detected by single-locus as well as two-locus analyses were all M-QTL. Similarly, single-locus and two-locus QTL analyses for seven yield and yield contributing traits in two populations respectively allowed detection of 25 and 50 QTL by composite interval mapping (CIM), 16 and 25 QTL by multiple-trait composite interval mapping (MCIM) and 38 and 37 QTL by two-locus analyses. These studies should prove useful in QTL cloning and wheat improvement through marker aided selection.     

有关DNA复制的题组分析

<正>"DNA分子的复制"在各省的考试大纲和考试说明要求中均属"理解"层次,即能理解"DNA分子的复制"与其他相关知识的联系和区别,并能在较复杂的情境中综合运用其进行分析、判断、推理和评价,现将与DNA复制有关的考题进行集中分析。1 DNA复制与细胞分裂细胞分裂间期要进行染色体(质)复制,包括     

例析限制酶切割难题现象

<正>近年来,选择合适限制酶对目的基因和质粒进行切割似乎成为高考的一个热点,如江苏、天津等地的高考试题中,多次涉及限制酶切割目的基因和质粒的问题。由于考生对限制酶识别序列及切割点产生的黏性末端认识不清,导致该类试题时常成为难题。这类试题考查的能力主要包括以下几个方面。     

利用乘法定律解决多对性状组合问题

多对性状的遗传分析计算,往往是遗传学的难点之一,如果不能准确把握分析和计算的思路,往往会发生配子、基因型、表现型种类和数目计算的遗漏、混乱或错误,而在解决这些诸多问题的时候,乘法定律的灵活使用,会帮助解决多对性状的组合问题。     

《太平经》中的“平”和“行”——答连登岗教授

本文回复连登岗教授就《太平经》中＂平＂、＂行＂释义所提出的批评,论文从语篇出发,通过全面的材料分析,论证它们是话语标记,而不是言说动词。     

中国英语学习者书面语中推导性话语标记语使用情况调查——一项基于语料库的研究

通过语料库文本分析的方式,把中国英语学习者（英语专业学生）书面语中推导性话语标记语的使用情况和英语本族语者使用情况进行对比。结果显示,（1）中国英语学习者书面语中推导性话语标记语的使用存在严重的过多和过少使用并存现象,且呈简单化、口语化倾向;（2）推导性标记语使用水平会随着学习者语言水平的提高而有所提高,但个别推导性标记语的使用具有语用＂石化＂特征。     

日语中的语用缓和策略分析

在日语中,语用缓和策略的使用远远多于其他语言。日本人在谈话时喜欢采取前置表现、间接表达、缓和标记语等语用缓和策略削弱或消除话语的负面因素,降低面子威胁程度,建立良好的人际关系。本文探讨日语中的语用缓和策略的使用及其社会和文化心理成因。     

陆地棉F2代单株选择的主成分分析

以抗虫棉品种和非抗虫棉杂交,在选择的条件下对F2代单株性状采用主成分分析的方法,就综合农艺性状对产量性状的影响进行了研究.结果表明:前5个主成分因子累积方差贡献率达74.95％,基本反映遗传信息.各主成分分析结果依次为:结铃性因子、形态因子、铃重因子、衣分因子、营养生长因子.依据主成分评价,较为理想的杂交F2代抗虫棉单...