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61.
为深入挖掘川楝药材中的微生物资源,研究分析了川渝地区川楝内生放线菌的多样性和群落结构.运用PCR-DGGE技术对重庆万州、四川资阳、四川遂宁三个地区采集的川楝样品进行分析.DGGE图谱显示不同地区相同部位的样品以及相同地区的不同部位之间川楝内生放线菌都存在多样性差异,这种差异来自于地域环境和自身代谢水平的不同.不同部位总体上呈现树皮的多样性最丰富,而果实的多样性最差.对DGGE条带进行回收测序,共获得24条序列,归于11个属,链霉菌属(Streptomyces)为优势菌属占25%,其余的川楝内生放线菌归于为芽球菌属(Blastococcus)、气微菌属(Aeromicrobium)、中村氏菌属(Nakamurella)、分枝杆菌属(Mycobacterium)、棒杆菌属(Corynebacterium)、红球菌属(Rhodococcus)、冷杆菌属(Cryobacterium)、微杆菌属(Microbacterium)、诺卡氏菌属(Nocardioides)、利夫森氏菌属(Leifsonia)等稀有放线菌属,占总数的75%.结果表明分布于不同地域的川楝各组织内生放线菌多样性及群落结构存在差异,蕴藏着丰富的放线菌资源.  相似文献   
62.
长白山自然保护区蝴蝶多样性研究   总被引:4,自引:0,他引:4  
2003~2006年对长白山保护区蝴蝶种类进行了调查研究,共采集蝴蝶121种,隶属7科63属,以蛱蝶科为主要科,各林带均有分布共有19种.在不同生境中,随着海拔的升高蝴蝶的多样性有较明显的变化,其中红松阔叶林带蝴蝶的物种数、多样性指数、均匀度最高,苔原带最低.  相似文献   
63.
张薇 《科技信息》2009,(33):37-38
基于Alamouti提出的BPSK调制下空时分组码在Rayleigh衰落信道中的码性能原理,推导出高阶调制方式下Nakagami衰落信道中空时分组码的符号差错率的最小距离球界,仿真分析了两信道下引入空时分组码的多天线系统中发射和接收天线分集增益,发射天线数量的“地板效应”.  相似文献   
64.
Existing human rights doctrine and enforcement structures often fail to protect human welfare. The new agora project (Jenlink and Banathy 2002) offers a structure to democratically re-build human rights. To examine the role of new agoras in re-crafting old institutions, I begin by identifying the context of human rights: globalization, diverse identities, and democracy. After analyzing the impact of diversity on democratic structures, I introduce human rights as conceived by Banathy’s (2000) Third Generation. With this in mind, I am prepared to examine the challenges and opportunities for shaping a new operationalization of human rights using the new agora structure.
Keri E. Iyall SmithEmail:
  相似文献   
65.
西藏色季拉山野生花卉植物资源的研究   总被引:1,自引:0,他引:1  
李文博 《科技信息》2009,(25):I0119-I0120,I0103
西藏色季拉山区有丰富野生花卉植物资源,具有较高的开发利用价值,是西藏花卉资源最丰富的地区之一。该文在广泛深入地调查、采集、整理和鉴定的基础上,研究了色季拉山花卉资源的多样性性质。该区有较高观赏价值的花卉达79科161属340余种,具有种类丰富,名花众多;花色结构和花期呈多样性;植物区系成分复杂,特有植物多;垂直分布明显;形态各异,色彩绚丽等特点。根据本区野生花卉植物资源的种类、区系成分和特征、开发和保护现状,对本区野生花卉植物资源的开发利用进行了探讨,旨在为其选育与开发利用提供理论依据。  相似文献   
66.
The concept of interactional expertise – characterized by sociologists Harry Collins and Robert Evans as the ability to speak the language of a discipline without the corresponding ability to practice – can serve as a powerful way of breaking down expert/non-expert dichotomies and providing a role for new voices in specialist communities. However, in spite of the vast uptake of this concept and its potential to fruitfully address many important issues related to scientific expertise, there has been surprisingly little critical analysis of it. We seek to remedy this situation by considering potential benefits of interactional expertise and the ways in which the current conception can – and cannot – realize those benefits. In particular, we argue that interactional expertise hasn't reached its full potential for addressing who ought to be involved in scientific research and decision-making, largely owing to an unnecessarily restrictive way of operationalizing the concept. In its place, we offer a broader, more pluralistic account of interactional expertise – one that is in line with the original spirit of the concept, but also captures the diversity that we see as being an important aspect of interactional experts and the value they can bring to the table.  相似文献   
67.
空时分组码 (STBC)利用多输入 多输出 (MIMO)无线通信系统的本质特性 ,通过提供发射天线分集和接收端的信号处理 ,从本质上提高了无线通信系统的容量 ,并以其编译码算法简单的特点获得了广泛关注和应用。在介绍了空时码和多输入 多输出无线通信系统的系统模型后 ,以基本的两天线空时分组码C2 为例给出了其编码和解码算法 ,并基于此提出了适于高速无线通信系统的空时分组编码结合正交调制 (QAM)的通信方案。最后给出了该方案在 16 QAM调制条件下几种典型空时分组码的误符率和误码率的性能仿真结果。结果表明 ,该方案是一种适于高速无线通信系统的优选方案  相似文献   
68.
An updated list of over 200 species of corals from Cosmoledo and Aldabra atolls is presented, which more than doubles previously known species diversity, and establishes these atolls as amongst the most species-rich in the Western Indian Ocean. However, partly this is an artefact of a new method of recording with digital cameras, described here, which greatly improves recording efficiency. This is the first underwater study of Cosmoledo, and the first for Aldabra outside the expedition reports cited. The survey extended to >30 m depth, and comes after the 1998 massive coral mortality. Coral cover was virtually eliminated at that time to about 8-10 m depth in Cosmoledo on seaward slopes, below which coral mortality was only about 50%. Mortality was selective regarding different species, genera and families. Cosmoledo's lagoon of >150 km2 is shallower than the 'critical depth' of 8-10 m, resulting in an almost complete elimination of corals. To compare these atolls with other reefs in the region, critical depths are summarized for over 25 Indian Ocean locations. New coral recruits are abundant in the shallows of Cosmoledo and Aldabra 4 years later, though cover remains very low. Much bare rock remains (with turf algae) and some genera such as Acropora, previously apparently abundant, remain relatively very scarce. Apart from Porites, whose higher survival is now well documented, the best survivors from the 1998 mortality, and the most successful recruitment of new corals, are of faviids. Soft corals remain extremely scarce in all locations examined above the 'critical depth'. It is predicted that there may be a shift in the identity of the main species of corals in these atolls for many years.  相似文献   
69.
椒江河口生态环境质量评价   总被引:6,自引:0,他引:6  
根据2003年8月调查资料,对椒江河口的生态环境质量进行评价.结果表明:椒江河口水体的DIN、DIP、Hg、Pb、DO、COD等6项属重污染,水体富营养化指数0.67~1237,均值288;表层沉积物的单项标准指数均小于1;河口水域底栖生物种类6种,多样性指数H'为0~1.92;潮间带共鉴定大型潮间带生物38种,H'为1.03~2.40之间,种类多样性差,丰度低,个体分布不均匀,生态环境脆弱.  相似文献   
70.
1994—1995年,在武夷山保护区内,我们选择枯叶蛾昆虫作为研究对象,设置样点,对枯叶蛾昆虫的分布规律、优势种类、多样性指数、均匀性指数、区系类似度、种群数量等方面做了一些研究工作。结果表明:枯叶蛾科昆虫在武夷山保护区的多样性指数是较高的。  相似文献   
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