梁子湖湿地植物多样性现状与评价

根据1999~2001年的野外调查数据,研究了湖北梁子湖湿地浮游藻类和高等植物多样性资源.结果表明,该湿地常见浮游藻类73种,隶属于7门58属(绿藻28种,硅藻19种,蓝藻14种,金藻4种,裸藻3种,甲藻3种,隐藻2种);高等植物282种,隶属于72科183属(苔藓8种,蕨类9种,裸子植物3种,被子植物262种),其中国家重点保护野生植物5种.浮游藻类密度和生物量均值分别为(1163.79913.51)104cell/L和6.1342.737mg/L,叶绿素a含量12.754.98mg/L,浮游藻类表层日

Satellite Constellation Design for Complex Coverage

Most traditional satellite constellation design methods are associated with a simple zonal or global, continuous or discontinuous coverage connected with a visibility of points on the Earth's surface. A new geometric approach for more complex coverage of a geographic region is proposed. Full and partial coverage of regions is considered. It implies that, at any time, the region is completely or partially within the instantaneous access area of a satellite of the constellation. The key idea of the method is a two-dimensional space application for maps of the satellite constellation and coverage requirements. The space dimensions are right ascension of ascending node and argument of latitude. Visibility requirements of each region can be presented as a polygon and satellite constellation as a uniform moving grid. At any time, at least one grid vertex must belong to the polygon. The optimal configuration of the satellite constellation corresponds to the maximum sparse grid. The method is suitable for continuous and discontinuous coverage. In the last case, a vertex belonging to the polygon should be examined with a revisit time. Examples of continuous coverage for a space communication network and of the United States are considered. Examples of discontinuous coverage are also presented.

区域资源环境系统物质流动模式

IEECAS SKLLQG

Microwave-assisted preparation of 2-methallyloxyphenol

Catechol reacted with beta-methallyl chloride in the presence of base and phase transfer catalyst under microwave irradiation and gave 2-methallyloxyphenol within 1 similar to 2 minutes. The yield of 2-methallyloxyphenol varied from 64%similar to 68%.

新疆博格达山地面生苔藓植物物种多样性研究

采用相似性系数和物种多样性指数对新疆博格达山地面生苔藓植物的物种多样性进行了研究 .结果表明 ,博格达山地区苔藓植物区系具有丰富性和复杂性的特点 ,共有地面生苔藓植物 32科 73属 186种 (含变种、变型 ) ;山地荒漠带和山地草原带苔藓植物物种相似性最高 ,为 0 .6 80 9,山地森林带和高山垫状植被带相似性最低 ,仅为 0 .1342 ;山地森林带苔藓植物在整个博格达山地面生苔藓植物群落中占据优势地位 ;山地森林带苔藓植物物种多样性最为丰富 ,为该山地苔藓植物多样性的分布中心 ,是苔藓植物多样性保护的关键地区

模型药物毒性血清1H NMR谱代谢组学的Fisher判别分析研究

基于核磁共振技术的代谢组学是近年发展起来的一种新的组学技术,主要利用生物体液的核磁共振谱提供生物体内全部小分子代谢物的丰富信息。然而,噪声的存在影响了模式识别方法分析的准确度。近年来小波变换以其多分辨率分析的特性、方法简单、快速等优点成为一种有效的去除分析信号噪声的方法。本实验通过运用小波变换去除噪声、校正基线后,再进行Fisher判别分析,得到了较传统分析更为清晰的代谢标识物,建立了良好的代谢模型

Organic template-directed crystallization of the complex fluoride NH4MnF3 with perovskite structure

(100)-oriented NH4MnF3 perovskite with different morphologies have been obtained in situ via an organic template; experimental results can be rationalized in terms of electrostatic interactions and lattice matching between the organic template and the ions undergoing nucleation.

皮状丝孢酵母发酵大米草水解液生产微生物油脂

大米草是一种外来引种植物，本来引进的目的是为了保滩护岸、促淤造陆。然而大米草过度繁殖，侵袭海洋沿岸滩涂，所以综合开发大米草有着重要的经济意义和生态意义。本实验研究着力于将大米草水解液通过皮状丝孢酵母发酵而制取生物油脂。并且随着近年来石油价格的攀升和对于汽车尾气对环境造成的日趋严重的污染，生物柴油的开发受到高度重视。微生物油脂则是生物柴油生产的很好的原料，因为它无需占用耕地，而能够把农业加工剩余物或是其它的含纤维素的生物质转化为油脂。 本实验采用产油酵母菌皮状丝孢酵母（Trichosporon cutaneum）直接发酵经过简单脱毒处理的大米草水解液生产微生物油脂。在122℃，固—液比为10%（w/v），分别用1%、2%、4%和6%稀硫酸水解大米草，结果表明在6%的酸浓度下水解40 min后还原糖含量最高，达到22.8 g/L。而同时以1%稀硫酸在140℃下水解大米草，2.8h后，水解液中葡萄糖产量达到最高14.2g/L。确定了摇瓶发酵最适工艺条件：摇床转速200 rpm，接种量10%（v/v），装液量为200 mL (1000-mL三角瓶)。在此基础上，确定了水解液最适浓缩倍数和pH值，水解液浓缩倍数为4.0时产油量高达6.0 g/L，产油率为46.3%。本文为高效利用大米草提供了新的途径。 关键词:皮状丝孢酵母,大米草,水解,发酵,微生物油脂

The effect of land management on plant community composition, species diversity, and productivity of alpine Kobersia steppe meadow

Grassland degradation is widespread and severe on the Tibet Plateau. To explore management approaches for sustainable development of degraded and restored ecosystems, we studied the effect of land degradation on species composition, species diversity, and vegetation productivity, and examined the relative influence of various rehabilitation practices (two seeding treatments and a non-seeded natural recovery treatment) on community structure and vegetation productivity in early secondary succession. The results showed: (1) All sedge and grass species of the natural steppe meadow had disappeared from the severely degraded land. The above-ground and root biomass of severely degraded land were only 38 and 14.7%, respectively, of those of the control. So, the original ecosystem has been dramatically altered by land degradation on alpine steppe meadow. (2) Seeding measures may promote above-ground biomass, particularly grass biomass, and ground cover. Except for the grasses seeded, however, other grass and sedge species did not occur after seeding treatments in the sixth year of seeding. Establishment of grasses during natural recovery treatment progressed slowly compared with during seeding treatments. Many annual forbs invaded and established during the 6 years of natural recovery. In addition, there was greater diversity after natural recovery treatment than after seeding treatments. (3) The above-ground biomass after seeding treatment and natural recovery treatment were 114 and 55%, respectively, of that of the control. No significant differences in root biomass occurred among the natural recovery and seeded treatments. Root biomass after rehabilitation treatment was 23-31% that of the control.