核磁共振技术在竹木材研究中的应用

核磁共振技术在竹木研究相关领域起到了重要的作用,以其它方法无法比拟的优势越来越多的应用于竹木材研究之中。文章在阅读文献的基础上,结合实验数据,阐述了核磁共振技术在研究竹木材高分子组成、抽提物以及胶粘剂化学结构方面的应用。     

基于Hyperion光谱信息的鲁西北盐碱地特性探析

利用Hyperion影像及盐碱地分布端元提取了鲁西北典型盐碱地光谱数据并对其特性进行了探析,以证实光谱信息对于该区盐碱地研究的可用性。利用生成的原始及包络线去除的光谱曲线,分别从土壤电导率、土壤盐分含量及一系列诊断性指标入手,借助诊断性吸收波段对本区盐碱地特性进行了分析。结果表明：该区盐碱地兼具其他地点盐碱地光谱吸收共性及自身特性,证实了基于遥感光谱信息的盐碱地特性分析是可行的,可用于区域盐碱地遥感监测。     

蜀柏毒蛾核型多角体病毒的研究

蜀柏毒蛾Parocneria orienta Chao是柏木的一种重要害虫。1988年笔者在福建南平室内饲养和野外调查时,发现蜀柏毒蛾幼虫自然罹病死亡,经鉴定其病原为一种核型多角体病毒。该病毒尚未见报道,现将其分离、电镜观察、生物活性测定等报道如下。     

鼠、兔核质杂交及早期胚胎发育的研究

以2~8细胞期鼠胚细胞为供体核,选用注射hCG后15h、17h的兔卵母细胞为受体胞质,施加1.6 kv/cm、160、两次脉冲的电场条件,间隔20min,融合液为含Ca、Mg的0.3mol/L甘露醇,适于鼠、兔种间EOBC的融合激活。小鼠2—细胞、4—细胞期胚细胞与兔去核卵母细胞融合率高于8—细胞期胚细胞,分别为83%、80%及62.5%,桑囊胚发育率差异不显著。体细胞共同培养系统和Taurine能显著提高鼠、兔核质杂交胚的体外发育能力。     

发动机异响的判断与排除

本文介绍了发动机故障检测与诊断基本方法,并结合实际工作中积累的经验,通过案例形式,说明用经验法进行发动机异响判断与排除的方法,力求在发动机机械故障检测维修中具有借鉴意义。     

对我国核农学发展规律的探讨

本文对我国核农学研究与应用的现状和存在问题进行了初步分析 ;认为造成我国核农学现状的主要原因在于人才因素、学科之间的影响和发展的不平衡性、核农学自身特点及其对市场经济体制的适应性等。国内外核农学的发展状况表明 :市场经济体制或计划经济体制不是影响核农学发展的关键因素     

Characterization of organic phosphorus in leachate from a grassland soil

The degree of eutrophication in fresh water ecosystems may be influenced by the forms of phosphorus (P) leached from agricultural systems. Physico-chemical fractionation of P in leachate from a grassland soil carried out over a two year period indicated that the majority of the P loss from the Lismore soil occurred in unreactive particulate (55-76%) P forms. ³¹P nuclear magnetic resonance analysis of a selected leachate sample indicated that unreactive P was mainly comprised of monoester and diester forms of organic P. The presence of phosphomonoesterase (20-200 μg p nitrophenol l⁻¹ h⁻¹) and phosphodiesterase (68 μg bis-p nitrophenol l⁻¹ h⁻¹) activity in leachate resulted in hydrolysis of 10-21% of total unreactive P (TUP), indicating that some of the monoesters and diesters can be eventually hydrolyzed into inorganic P forms during P transport. Enzyme hydrolysis showed that 23% of the TUP was present as labile monoester P (LMP), followed by 20% as inositol hexakisphosphate (IHP) and 14% as diesters (phospholipids and nucleic acids). The findings of this study suggest that LMP, IHP and diesters are an important component of organic P leaching from the grassland soil.     

“中国春”小麦不同缺体的RAPD分析

利用ＰＣＲ－９０Ａ型ＤＮＡ扩增仪，对７个中国春小麦缺体核ＤＮＡ进行了扩增。结果显示，中国春小麦缺体核ＤＮＡ的ＲＡＰＤ产物可分为二种类型：（１）所有供试材料均能扩增出的片段，代表了核ＤＮＡ在进化上的保守性。有一个引物检测到这类片段。（２）全部供试材料间存在的差异片段，这类片段是用来基因定位的主要依据。另外，建立中国春小麦缺体系统的ＲＡＰＤ指纹图谱对研究小麦的系统进化也将有重要意义     

Phylogenetic relationships in the North African genus <Emphasis Type="Italic">Hedysarum</Emphasis> as inferred from ITS sequences of nuclear ribosomal DNA

Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were analysed to precise their length (637–643 bp) and resolve phylogenetic relationships among eight Mediterranean species of the genus Hedysarum (Fabaceae). The infra-specific variability levels of the ITS sequences of spontaneous population of H. coronarium proved a lack of polymorphism both in the length and in the sequences examined in this species. Hence, a consensus ITS sequence characterising each Hedysarum species has been investigated for analysis of inter-specific polymorphisms. The level of variation of ITS sequence was high enough to make the ITS1 and ITS2 a useful tool for phylogenetic reconstruction. However, ITS2 seems to be relatively more polymorphic and more informative than ITS1 regarding length or GC percent. The phylogenic relationships in the genus Hedysarum based on ITS1 and ITS2 sequences taken independently or together, are discussed in the context of current work in molecular biosystematics. Results exhibited the distinctiveness of the two H. spinosissimum subspecies (i.e. H. spinosissimum ssp. capitatum and H. spinosissimum ssp. spinosissimum). In addition, the great similarity of the ITS sequences between H. coronarium (the only cultivated species of the genus) and H. carnosum suggests the usefulness of the latter in selection programmes to improve pastoral production in semi-arid areas.