查询词典 Shannon

It is essentially the study of Shannon theorem which states that "it is possible to transmit information through a noisy channel at any rate less than channel capacity with an arbitrarily small probability of error" This course is intented to introduces the basic information theory.

资讯理论尝试建立一个通讯系统的数学模型，基本上是在探讨Shannon的定理：「在有杂讯的通道中，只要传送率低於通道容量，则存在一种编码方法，使得解码错误的机率趋近於零。

The main topics include entropy and mutual information, data compression, noiseless coding, Shannon theorem, noiseless coding, Shannon Theorem, linear codes, cyclic codes.

本课程宗旨是简介基础的资讯理论，主要课程含嫡及相互信息、资料压缩、无杂讯编码及Shannon定理、线性码、循环码等。

The topics covered include the basic concepts of information theory--entropy, mutual information, channel capacity, information rate, Shannon's noiseless coding theorem and Shannon's fundamental coding theorem; modeling of information sources--zero-memory and Markov models; modeling of information channels--BSC and BEC channels, additivity of information and cascaded channels; construction of compact source codes--Kraft inequality, compact codes, Huffman and LZW compression codes; and analysis and design of error-control channel codes--Hamming distance, binary linear codes and the parity-check matrix, Hamming codes, checksum codes, cyclic codes and the generator polynomial and CRC codes.

课程的内容包括：信息论的基本概念（熵、交互信息、信道容量、信息率、 Shannon无噪声编码定理和Shannon基本编码定理）、信源模型（无记忆模型和Markov模型）、信息信道模型（BSC 和 BEC模型、信息的可加性和级联信道），紧致信源编码设计（Kraft不等式，紧致编码，Huffman 和LZW压缩编码）以及差错控制信道码的设计与分析（海明距离，二元线性码，奇偶校验矩阵，海明码，校验和，循环码，生成多项式和CRC码）。

Based on RAPD data, Nei's gene diversity index averaged 0.2523 and Shannon's information index averaged 0.3730, while Nei's gene diversity index averaged 0. 252 3 and Shannon's informative index averaged 0.3958 based on DOGE data.

结果表明：RAPD分子标记显示不同浓度废水驯化的细菌群落的Nei's指数平均为0.252 3，Shannon's信息指数平均为0.373 0；而采用DGGE技术得到不同浓度废水驯化的细菌群落的h平均为0.252 3，I平均为

Across the altitudinal gradient, a total of 12635 individuals belonging to 6 phyla, 15 classes and 33 orders were collected. With increasing altitude, the density of soil fauna decreased, but the group number was less affected. There was a higher co-occurrence of soil faunal communities along the altitudinal gradient, and Nematoda, Acarina, and Collembola were the dominant groups. Below the altitude 370 m, the Shannon-Wiener index, Pielou index, and Margalef abundance index increased with increasing altitude; while above the altitude 370 m, the Shannon-Wiener index and Pielou index decreased but the abundance index increased after an initial slight decrease.

结果表明：土壤动物密度随海拔升高而下降，类群数受海拔影响较小，各海拔群落的共有度较高，优势类群基本均为线虫、蜱螨目和弹尾目；Shannon-Wiener指数、Pielou均匀度指数及Margalef丰富度指数仅在海拔370 m以下随海拔升高而增加，而在海拔370 m以上，Shannon-Wiener指数与Pielou均匀度指数下降，丰富度指数在略有下降后再次上升。

Prattii- Ailanthus altissima deciduous broad-leaved forest community and Cerasus trichostorna-Cerasus dielsiana-Acer caudatum deciduous broadleaved forest community , had lower total richness and Shannon-Wiener index .

3人工林群落与次生林群落相比，人工林群落具有较低的物种丰富度指数和Shannon-Wiener多样性指数以及较高的优势度指数，次生林具有较高的物种丰富度指数和Shannon-Wiener多样性指数以及较低的优势度指数。

Between shrub and herb layers ,the difference of each index was not significant The total richness index and Shannon-Wiener index of Phellodendron amurense plantation community were all the highest than those of the other communities.(2) The total richness index of Machilus pingii- Quercus oxyodon evergreen broad-leaved forest community, Alnus cremastogyne-Betula luminifera-Quercus oxyodon evergreen-deciduous broad-leaved forest community and Rhus potaninii- Juglans sigillata- Quercus oxyodon evergreen-deciduous broad-leaved forest community all exceeded 31 .These communities , the dominance species in their shrub layers is Fargesia rufa ,such as Betula luminifera-Rhus chinensis-Quercus oxyodon evergreen-deciduous broad-leaved forest community, Quercus oxyodon-Litsea pungens-Cornus macrophylla evergreen-deciduous broad-leaved forest community, Cornus macrophylla- Acer caudatum var.

2润楠-曼椆常绿阔叶林、桤木-亮叶桦-曼椆常绿落叶阔叶混交林、青麸杨-野核桃-曼椆常绿落叶阔叶混交林群落的总体丰富度指数均大于31；在灌木层以青川箭竹为主的群落(亮叶桦-盐肤木-曼椆常绿落叶阔叶混交林、曼椆-木姜子-梾木常绿落叶阔叶混交林、梾木-川滇长尾槭-落叶阔叶林、川西樱桃-尾叶樱-川滇长尾槭落叶阔叶林)中，各群落总体丰富度指数和Shannon-Wiener多样性指数较小，总体优势度指数较大；8种次生林群落灌木层丰富度指数均高于乔木层，乔-灌层间丰富度指数差异性检验达显著水平；乔-草层间的丰富度指数差异性检验达极显著水平，Shannon-Wiener多样性指数差异达显著水平；灌-草层间的多样性指数和优势度指数差异性检验均达显著水平。

Bieti lost its habitat continuously in recently decades associated with the extension of rangelands and farmlands, as well as firewood collection etc. The monkey live mainly in primary fir forest and the mixed conifer forest, to evaluate the status of the monkeys' habitat, we employed GIS and RS software to identify the habitat types with five Landsat TM/ETM+ satellite imagery in winter of 1986, 1992, 1997, 2001 and 2006 years respectively. The work resulted in: 1 the size of summer grazing lands, farmlands, and fir forest was 13 100 hm2, 6 400 hm2, and 30 500 hm2 in 2006 respectively; 2 during the past 20 years (1986-2006), the size of fir forest (including primary fir forest and the mixed conifer forest) decreased by 14.6%(5 200 hm2), summer grazing lands and farmlands increased by 47.2%(4 200 hm2) and 14.3％(800 hm2) respectively; and 3, during the past 20 years, the number of firry forest patches increased by 68.4%, the mean size of firry forest patches decreased by 49.3%(from 15.1 to7.6 hm2), the largest patch index of firry forest decreased 54.9%; the patch richness had no change, but the Shannon's diversity index and the Shannon's evenness index increased by 2.7% respectively.

为了评估该物种的栖息地现状和变化情况，我们通过野外调查工作，应用GIS和RS技术，分别解译了1986年、1992年、1997年、2001年和2006年的Landsat TM/ETM+冬季卫星影像，并对解译结果进行了计算和分析，得到了以下西藏种群栖息地的主要结果：1）现有暗针叶林（包括原始针叶林和针阔混交林）面积是30 500 hm2，夏季牧场面积是13 100 hm2，农田面积是6 400 hm2；2）在过去20年间（1986-2006年），暗针叶林面积减少了14.6％（5 200 hm2），夏季牧场面积增加了47.2％（4 200 hm2），农田面积增加了14.3％（800 hm2）；3）在过去20年间，暗针叶林的斑块数量增加了68.4％，平均斑块面积下降了49.3％（从1986年的15.1 hm2下降到2006年的7.6 hm2），最大的斑块指数下降了54.9％；景观丰富度并没有变化，但Shannon多样性指数和Shannon均匀度指数分别增加了2.7％。

Dactylon, M. triquetra. At tillering, species richness, Simpon index and Shannon-Wiener index are higher while Pielou index is lower in SF than in CK. From booting to ripening, weed species richness, Simpon index and Shannon-Wiener index are lower while Pielou index is significantly higher in SF than in CK.

研究还表明，规模稻鸭生态种养水稻分蘖期物种丰富度、Simpon指数、Shannon-Wiener指数略高于水稻单一种植，Pielou指数低于水稻单一种植；孕穗期到成熟期物种丰富度、Simpon指数、Shannon-Wiener指数低于水稻单一种植，Pielou指数显著高于水稻单一种植。

Comparing with traditional cultivation system (two seasons planting cucumber with fallowing in summer), planting leafy vegetable anti garlic in summer increased the yields of the two crops anti the soil microbial biomass carbon content, total microbial population, and sucrase activity, decreased the amounts of soil nematode and root-knot nematode, and maintained a relative high Shannon-Weaver index. Planting crown daisy, garlic, and spinach in summer increased soil sucrase activity by 8.9%, 89.5%, and 36.9%, and the planting of crown daisy and garlic also increased the Shannon-Weaver index by 7.7% and 9.4%, respectively.

结果表明：夏茬休闲期种植速生叶菜和青蒜增加了土壤微生物量碳含量、微生物总量和蔗糖酶活性，维持了较高的Shannon-Weaver指数，减少了线虫和根结线虫的数量，增加了各茬作物产量，夏茬种植茼蒿、菠菜、青蒜后土壤蔗糖酶活性分别增加了8.9%、36.9%和89.5%，夏茬种植茼蒿和青蒜后Shannon-Weaver指数分别提高了7.7%和9.4%。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。