基于叶绿体DNA单倍型的银杏遗传多样性格局研究

对中国7个潜在野生银杏（GinkgobilabaL．）种群的叶绿体DNAmatK基因区进行测序,得到总长度为1588bp的碱基序列,共出现3个多态位点,物种水平的核苷酸多态性很低（0．136％）;3种单倍型（HI,HII,HIII）,出现频率分别为92％、2％、6％．总体遗传多样性格局为：祖先单倍型H1分布范围广泛;而另外两种单倍型分别局限在天目山种群和金佛山种群．金佛山种群有一半以上个体为同一特有单倍型,揭示了该银杏群体在遗传资源方面应该优先保护,同时也为该地区是银杏冰期避难所之一提供了有力证据．     

爱玉ISSR反应体系的建立与优化

通过单因子试验和正交设计,对影响爱玉ISSR-PCR扩增效果的因素,如模板DNA用量、Taq酶用量、dNTPs浓度、引物浓度、延伸时间和循环次数等指标进行优化.实验确立了可用于爱玉ISSR-PCR分析最适宜的反应体系：20 μL反应体积中含1 ng模板DNA、1.0 U Taq酶、0.4 μmol/L引物和0.18 mmol/L dNTPs;PCR扩增程序为94 ℃预变性4 min;94 ℃变性45 s,53 ℃退火45 s,72 ℃延伸2.5 min,共35个循环;72 ℃延伸7min,4 ℃保存.应用该体系对14份爱玉种质进行扩增,证实了该体系的适用性和稳定性.     

一类重尾分布族的若干性质

得到了若干个i．i．d．的正格子点上一类重尾分布族y族随机变量的和也是属于该族,因此正格子点上y族对卷积封闭．     

参薯色素的稳定性研究

研究了pH值、温度、光照、金属离子、几种食品添加剂和氧化还原剂等对紫色参薯色素稳定性的影响.结果表明,色素颜色随着溶液的pH值改变而变化;温度、蔗糖、苯甲酸钠、维生素C、Na+、Cu2+、Ca2+、Zn2+对色素影响很小,而光照、H2O2、SO32-对色素有影响.     

Isolation and characterization of a new species of Vibrio-Vibrio olivaceus sp.nov. from diseased flounder （Paralichthys olivaceus temminck et schlegel）

One kind of pathogenic bacteria was isolated from diseased (or dead) flounder (Paralichthys olivaceus L.) which expressed bacterial septicaemia. The phenotyic information of the 10 pure cultures was studied extensively, including morphological characteristics, colony characteristics in different media, physiological and biochemical characteristics, and the mol%G C ratio of the DNA for representative strain. The results showed that the isolates belonged to a new species of Vibrio. In addition, the representative strains have been re-checked by China Center for Type Culture Collection (CCTCC), the results were the same as ours, the examined strains were also regarded as a new species of Vibrio, and designated as Vibrio olivaceus sp.nov. by its isolated fish (Paralichthys olivaceus) based on its biological properties following Rules of International Code of Nomenclature of Bacteria. In the same time, we conducted studies on the serum homology of isolates, pathogenicity of isolates by experimental infection. The results showed that all the isolates were of serologic similarity and the isolates have strong pathogenicity to flounder. Inspection to pure cultures and isolates from liver of moribund fish from infection experiment by fluorescent antibody technique showed the feasibility of fluorescent antibody technique as an auxiliary method of examination.     

基于MPLS的VPDN网络研究与实现

虚拟拨号专用网络(VPDN:Virtual Private Dialup Network)是VPN(Virtual Private Network)应用扩展.为有效地降低封装开销,在简要介绍了VPDN第2层实现的基本原理基础上,对VPDN关键技术进行了分析,比较了PPTP(Point to Point Tunneling Protocol)和L2TP(Layer 2 Tunneling Protocol)隧道协议封装形式以及IPSec的安全特点.提出了第3层基于MPLS(Multi Protocol Label Switch)实现VPDN的设计方法以及VPDN需要进一步研究的问题.该方案可降低封装开销约5.8%,为第3层VPDN研究提供了一个有益的设计思路.     

基于FPGA的L波段卫星数字信标机

描述了一种新型的零中频L波段卫星信标接收机。本接收机同时运用了零中频和数字信号处理技术。使用Matlab软件辅助设计数字滤波器,结果表明当滤波带宽越窄,信噪比越高。当输入测试信号频率为950.5 MHz,-80 dBm时,接收机输出-1 dBm,信噪比为30 dBm;当输入信号为-100 dBm时,接收机输出为-20 dBm,信噪比为15 dBm。     

考研数学中的等价无穷小替换

不定式（待定型）极限运算是历年来考研数学必考的题目,罗比达法则是解决这类极限运算的有效工具．但罗比达法则也有它的局限性．如果把等价无穷小替换和罗比达法则结合起来用,不仅可以达到事半功倍的效果,而且有时还可以解决罗比达法则不适用的情形．     

中国薹草属(莎草科)植物资料增补Ⅱ

作为中国薹草属Carex植物资料的补充,该文继续报道在查阅、整理和鉴定国内外5个植物标本馆中采自中国的薹草属标本时,发现的12个省级分布新纪录种.其中复序薹草亚属Subg.Vigneastra和二柱薹草亚属Subg.Vignea各有1种,薹草亚属Subg.Carex10种;湖南新记录种有广西薹草C.kwangsiensis、长穗薹草C.dolichostachya、长安薹草C.heudesii、根花薹草C.radiciflora4种,云南新纪录种有广西薹草、丝叶薹草C.capilliformis、武都薹草C.wutuensis、锐果薹草C.tatsutakensis、似舌叶薹草C.pseudoligulata和密苞叶薹草C.phyllocephala6种,白里薹草C.blinii在湖北为新纪录,显舌薹草C.macroglossa为贵州新纪录,筛草C.kobomugi在福建为新纪录种.     

一类多种群系统的伴随方程L~∞解的连续性

本文研究了一类多种群系统的伴随方程及其L∞解的估计.我们讨论了多种群情形下一般化的伴随方程,得到了这个伴随方程解的L∞估计.