遗传物质稳定性的辩证理解--谈DNA的稳定性与可变性

DNA在生物界中,堪称生物大分子中最重要者,主宰一切生物体维持其生命的各种机能的正常运行及每个物种一代一代繁衍于世,其结构是相对稳定的.     

黄皮尖椒品种比较试验

对引进 9个黄皮尖椒品种的植物学性状、商品性状、抗病性及丰产性进行了比较试验 .结果表明 :苗丰 2 2号植株长势旺 ,产量高 (2 0 6 5 1kg·hm- 2 ) ,抗病性强 ,果实商品性好 ;9919较耐高温 ,商品外观好 ,果较长 ,产量较高 (2 0 0 87kg·hm- 2 ) ;优美 5号产量中等 ,但果色黄绿 ,果形美观 ,易为市场接受 ;茂椒 4号果色黄绿 ,果形美观 ,单果重达 4 5 .0 0g ,极具市场竞争力 .认为这 4个品种可作为海南冬季主栽辣椒品种并加以推广 .     

Genetic Diversity of Three Aristichthys nobilis Populations and One Inbreeding Stock

Genetic diversity of three Aristichthys nobilis populations and one inbreeding stock was studied using random amplified polymorphic DNA(RAPD)method. Materials of natural populations were collected from two counties of Guangxi Province, Hengxian (NH) and Shanglin (NS) and one city of Hubei Province, Wuhan city.(NW). Shanglin and Hengxian's river system respectively belongs to Qianjiang and Yujiang River, two tributaries confluencing to Xunjiang River, main tributary of Xijiang River, which is the biggest tributary of the Zhujiang River system, and Wuhan's water system belongs to the Yangtse River system. The inbreeding stock (RS) was the more than 10 generation descendant by brother-sister mating system whose parents were collected from Shanglin. The results showed that the genetic variety of individuals of RS was very low (0.105 4), whereas that of natural populations was relatively high,which from high to low was 0.158 1 (NW), 0.132 0 (NH) and 0.110 5 (NS). As an index for genetic distance pair-wise populations, the genetic variety between populations was studied, which characterized the genetic distance between populations. The genetic distance of NW and NH, NW and NS, NW and RS were respectively high, whereas that of NH and NS, NS and RS, NH and RS was low. Chi-test(χ2) and the analysis of the genetic variety pair-wise populations was taken as efficient approach for studying population difference.     

北疆复种油葵品种特性的初步研究

通过对 5个油葵品种特性不同侧面的量化分析 ,筛选并确定SF1 87和EX399,因其产量高 ,生育期短 ,含油量高 ,株型紧凑 ,便于机械收获 ,可作为北疆地区理想的复播油葵品种     

李莎如图形轨迹变化的规律

用几何画板描绘了各种情形下的李莎如图形,归纳总结出李莎如图形的轨迹形状不仅与两振动的圆频率比及初相差有关,还与初相φ1 和φ2 有关,并得到轨迹变化的规律.     

多元智力理论对新课程评价改革的影响

加德纳的多元智力理论是对传统评价理论的多方面突破，是一次对传统智力理论的革命。它不仅为世界范围内的教育评价改革提供了思维框架，也对我国新一轮课程评价的改革起到积极的影响。研究加德纳的多元智力理论，并将其运用于课程改革评价体系的构建中，对于完善新课程评价的标准、原则和方法，具有现实意义。     

优良草坪草在孝感地区适应性引种简报

对国内外20余种优良草坪草，在孝感市进行了为期5年的适应性研究。结果表明，结缕草类、高羊茅、野牛草和改良的狗牙根等在本地表现较好，这为孝感市园林绿化中选择适宜的草坪草种发展草坪业提供了科学的依据。     

完善信息管理系统功能必须广泛应用网络技术

针对我国现行信息管理系统的不足，提出了增强和完善应用网络技术的功能及措施。     

Features of Black English:Towards a Comprehensive Perspective

In the past,Black English was stigmatized as"bad English".People looked down upon Black English.As the development ofBlack English and the mixture with Standard English,Black English has attracted more and more attention from the world.Its status has beenimproved.Black English,as a kind of ethnic dialect,is finally accepted.People have realized that Black English is just a kind of language vari-ety with its own characters.This article mainly talks about the unique features of Black English from a comprehensive point of view.     

如何上好《中国革命史》之我见

在中国革命史教学过程中，通过师生之间建立副洽的情感关系、教学内容专题化、教学形式与手段多样化.才能提高学生的兴趣，达到最好的教学效果。