云南植物区系新资料(二)

报道了云南新记录种4个和新变种1个,其中新变种为悦人杜鹃兰。引证标本均保存于国家林业局云南珍稀濒特森林植物保护与繁育实验室标本馆(YCP)。     

园林树木的分类方法及观赏特性评价

以人为分类法为主论述了园林树木的分类方法,继而在阐述园林树木观赏特性评价指标的基础上,分析比较了几种园林树木观赏特性的评价方法,据此提出了今后相关的研究方向。     

天目木兰的挥发性化学成分

用水浴加热一反相柱吸附提取天目木兰(Magnolia amoena Cheng)的挥发性物质,用GC-MS对其化学成分和相对含量进行了系统分析,得到27个组分,鉴定出23种化合物,其中主要成分为α-蒎烯、β-蒎烯、莰烯、β-月桂烯、D-柠檬烯、鞋葑酮、十八烷等.     

Analyze the Present Status in the Calculation Methods of Lightning Protection Performance for Transmission Line

Lightning is the main reason that endangers transmission line working safety and reliabilty today. The theory and characteristic of methods that not only estimate the lightning performance for back strike such as standard method, traveling wave method, Monte Carlo technique, treeing fault method, EMTP and so on but also for the shielding failure such as standard method, EGM, leader progression model and so on are summarized. The criterion of flashover for insulators is referred simply, furthermore, it gives the opinion that the development of research for the future.     

Lightning Shielding Simulation Model of Transmission Line

Transmission lines are easily hit by lightning, and lightning shielding failure is an important reason of lightning accidents of transmission line. So researches on lightning shielding of transmission line should be strengthened. On the basis of the abundant understand to known lightning shielding models of transmission line, a new lightning shielding simulation model of transmission line is presented in the paper. In this model, the effect of attracting lightning of upward leader is considered reasonably, and the method of variable descending step is adopted to simulate the descending process of lightning leader. The simulation calculating results show that the model is in good agreement with field experience of transmission line. It can guide lightning shielding design of transmission line and estimate the performance of lightning shielding of transmission line.     

Lightning Protection Performance of Transmission Line with High Tower and Great Span

This paper studies lightning protection performance of transmission line with high tower and great span, and puts forward the lightning shielding model of transmission line with high tower and great span. The model simulates the developing process of lightning downward leader, and take the effect of upward leader to downward leader into account. Moreover, the model consider backward lightning , that is even downward leader have developed lower than transmission line, Which will be occur lightning line. Aim at a certain sea transmission line with great span, its lightning performance is calculated with regular method, EGM and the model. The results have been analysed and compared. Because of thinking over backward lightning , the model can be used for calculating lightning shield performance of all kinds of transmission lines.     

性别效应对家蚕茧质性状QTL定位的影响

家蚕茧质性状的性别效应十分明显。分别以性别效应调整前和调整后的家蚕全茧量、茧层量、茧层率和蛹体质量等数量性状值为基础,对性别效应调整前后的茧质性状作数量性状基因座(QTL)定位比较分析,以探讨性别效应对家蚕QTL定位的影响。结果显示,检测出的控制各性状的上位性位点数、QTL总数以及效应显著的QTL数等,都表现为调整前比调整后要多,有效QTL在连锁群上的分布也表现一定的差异。此结果说明由于性别效应的影响可能会导致检测出控制家蚕茧质性状的上位性位点数和QTL总数的增加及其分布的不同,从而引起QTL分析结果的偏差。     

桑蚕种品种纯度抽样检验方案设计

桑蚕一代杂交种杂交率检验是一种形态检验的方法,准确性和时效性差。提出了使用DNA检验方法进行品种纯度检验,研究设计了适合的抽样检验方案。该方案保证了目前行业标准检验方法的可靠性和精确度。使用该方案,在蚕种纯度很高的情况下,只需检验很小,的样本就能通过,非常适合个体检验准确而成本相对较高的DNA检测方法。     

大气苯酚对蓖麻蚕的影响及其对策

蓖麻接触15ul/L大气苯酚2-10h后叶片出现伤斑、失绿、枯焦卷曲等受害症状，接触6h后株高、条重、产叶量以及叶绿素、粗蛋白和可溶性糖含量分别下降9.9%、11.8%、9.5%、34.7%、3.8%和42.8%。全龄蓖麻蚕接触1ul/L大气苯酚或食下苯酚含量7-21mg/kg的污染叶后均影响其虫蛹率、产孵量及孵化率；接触8ul/L以上的大气苯酚或食下苯酚含量45-70mg/kg的污染叶后吞生长发育变慢，生命力和生殖能力下降，茧丝性状刀明显不良，大气苯酚在这些方面的影响比苯酚污染叶大，蓖麻蚕对大气苯酚的抵抗力随龄期增大而显著增强。用5%石灰水浸渍苯酚污染叶后喂蚕，或将苯酚污染叶与蛎污染叶交替喂蚕，可减轻苯酚对蚕的毒害。     

Lightning Proof Performance of 500 kV Transmission Line in Chongqing Area

Considering the importance of 500 kV line and taking 500 kV transmission line in Chongqing as an example, the authors calculate lightning strike outage rate (including return stroke and lightning shielding failure) using regulation method, outage rate of return stroke using travelling wave method, and outage rate of lightning shielding failure using EGM. By comparing and analysing the calculating fesults, weakness of insulation and the area of easy to striking are found out, and corresponding improving measure is brought forward. The results show bigger gradient of lightning higher return stroke tripping, and in regulations result of accounting return stroke tripping is more closed to practical experience, accounting shielding failure rate exists obviously defect, and in EGM accounting shielding failure rate have take much factor, result is more close to practical experience.