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以Landsat5 TM1、TM2、TM3、TM4、TM5和TM7等图像数据,经预处理后进行植被指数提取和主成分分析,生成13个波段数据集;并用最优指数法(OIF)选取目视解译波段,运用最大似然法(MLC)和线性光谱分解法(LSU)对华北平原农区河北省文安县2007年5月的杨树林地面积信息作了应用分析.结果表明:(1)... 相似文献
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DNA barcode assessment of Ceramiales (Rhodophyta) in the intertidal zone of the northwestern Yellow Sea 总被引：1，自引：0，他引：1
A total of 142 specimens of Ceramiales(Rhodophyta) were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species,14 genera,and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers,namely,partial large subunit r RNA gene(LSU),universal plastid amplicon(UPA),and partial mitochondrial cytochrome c oxidase subunit I gene(COI). No intraspecific divergence was found in our collection for these markers,except for a 1–3 bp divergence in the COI of Ceramium kondoi,Symphyocladia latiuscula,and Neosiphonia japonica. Because short DNA markers were used,the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in Gen Bank or BOLD(Barcode of Life Data) Systems. Three specimens were presumed as H eterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification,which was the first record in the investigated area,implying that it might be a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers,H eterosiphonia japonica converged with D asya spp. and was distant from the other Heterosiphonia spp.,implying that H. japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species,but the COI had a higher ability to discriminate between species. 相似文献
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《International Journal of Digital Earth》2013,6(6):487-504
This paper is an attempt to introduce the role of earth observation technology and a type of digital earth processing in mineral resources exploration and assessment. The sub-pixel distribution and quantity of alteration minerals were mapped using linear spectral unmixing (LSU) and mixture tuned matched filtering (MTMF) algorithms in the Sarduiyeh area, SE Kerman, Iran, using the visible-near infrared (VNIR) and short wave infrared (SWIR) bands of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument and the results were compared to evaluate the efficiency of methods. Three groups of alteration minerals were identified: (1) pyrophylite-alunite (2) sericite-kaolinite, and (3) chlorite-calcite-epidote. Results showed that high abundances within pixels were successfully corresponded to the alteration zones. In addition, a number of unreported altered areas were identified. Field observations and X-ray diffraction (XRD) analysis of field samples confirmed the dominant mineral phases identified remotely. Results of LSU and MTMF were generally similar with overall accuracy of 82.9 and 90.24%, respectively. It is concluded that LSU and MTMF are suitable for sub-pixel mapping of alteration minerals and when the purpose is identification of particular targets, rather than all the elements in the scene, the MTMF algorithm could be proposed. 相似文献
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赤潮异弯藻和海洋原甲藻LSU Rdna扩增及序列分析 总被引：1，自引：1，他引：1
利用引物D1R和D2C扩增并测定了赤潮异弯藻(Heterosigma akashiwo Hada)和海洋原甲藻(Prorocentrum micans Ehrenberg)的LSU rDNA D1与D2序列,并与GenBank中相关序列进行比较分析.结果表明:在种内水平,所测的H.akashiwo 6个株系之间共有5个变异位点,序列H.k与H.k-2,H.k-4均存在碱基替换;原甲藻属不同种内各株系之间的遗传距离为0.002～0.023之间,所测序列P.mi与P.micans其他株系之间均存在碱基替换.在种间水平上,原甲藻属不同种之间的遗传距离在0.045～0.139之间,大于种内遗传距离,每个种都具有特定的保守序列.根据序列间的遗传变异,可设计特异性的探针对不同株系和物种进行检测和计数. 相似文献
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藻类鉴定被广泛应用于藻类遗传学、生理学、生态学和应用藻类学,尤其是藻类调查和评估.然而,基于形态学的鉴定往往因为分类特征未出现或不典型、设备限制和人员经验欠缺等原因带来较大误差.随着测序技术的不断发展,分子标记已成为藻类鉴定的一个通用工具.由于藻类类群众多且差异很大,分子标记的选择成为藻类鉴定的关键.本文综述了蓝藻、硅藻、绿藻、甲藻、裸藻、隐藻、金藻、黄藻、红藻和褐藻等主要门类分子标记的选择及应用进展,包括分子标记选择原则、常用标记和相应序列数据库,以及各个分子标记在不同类群应用中的优缺点等.藻类分子鉴定源于编码核糖体RNA的基因（rDNA）,发展于细胞核、线粒体、叶绿体DNA等.然而,当前藻类分子鉴定逐渐细化和完善,单一的核糖体DNA、内转录间隔区（ITS）和保守蛋白编码基因等短序列分子标记已经很难满足藻类鉴定的需求,多标记组合成为一种必然选择.同时,线粒体基因组、叶绿体基因组、核基因组、转录组和宏基因组等提供了更多遗传进化信息,弥补了短序列分子标记在系统分类应用中的不足.对于藻类鉴定,单纯依赖分子标记或形态学都不足以保证鉴定的准确性,采用将分子生物学、形态学、生理生化学等结合的多相学方法,才能准确地完成鉴定工作.此外,藻类分子数据库的建立和完善是未来分子鉴定的重要工作,快速鉴定方法也必将在未来获得广泛的应用和发展. 相似文献
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线性光谱分离技术可以有效地提取像元水平上植被或其他端元(影像中的地物)的相对百分比,但是目前该技术在多光谱宽波段影像数据应用中,由于波段数量、波段宽度等的限制,估算精度离定量研究的水平仍有一定差距。鉴于此,本文提出了一种改进的线性光谱分离方法,该方法在对影像进行土地覆盖分类基础上进行分离,一方面同类土地覆盖类型内同种地物的光谱变异相对较小,更有利于端元选取;另一方面,分影像的地物种类数量明显少于整幅影像,更容易满足模型的适用条件,从而突破了波段数量限制,同时使地物光谱分离更具针对性,经过验证,该方法较传统分离方法相比植被覆盖度的反演精度可提高6.4%,用该方法实现了研究区的植被覆盖度的定量反演并对研究区植被覆盖度的空间结构进行了分析。 相似文献
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