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41.
叶面积指数(Leaf Area Index,LAI)是描述植物冠层结构特征的重要参数,也是研究植物冠层表面物质和能量交换必不可少的参数。根据在塔里木河下游河岸林地利用LAI-2250实测的LAI数据,比较Landsat 8 OLI遥感数据提取的几种常规植被指数估算LAI的能力,建立LAI估算模型,并利用实测数据对模拟结果进行精度验证,生成塔里木河下游LAI分布图。结果表明:(1)各植被指数(Vegetation Indexes,VIs)与LAI均具有一定的相关性,对于不同的植被指数,二次多项式回归模型相关性均最高;(2)在不区分植被类型的样本分析中,大气阻抗植被指数(Atmospherically Resistant Vegetation Index,ARVI)与实测LAI具有最高的相关性;(3)分别针对柽柳林和胡杨林样本分析,判定系数R2和反演精度均具有不同程度的提高,对应的最适植被指数分别为归一化植被指数(Normalized Differential Vegetation Index,NDVI)和ARVI;(4)塔里木河下游河岸植被LAI有3个高值区:大西海子水库附近、下游中部和尾闾湖台特玛湖附近。全区LAI值主要分布在0~1.5之间,均值为0.361。该研究结果为遥感提取塔里木河下游河岸林带高空间分辨率的叶面积指数数据提供了数据支持和方法支撑。 相似文献
42.
西昆仑造山带中带上石炭统提热艾力组为一套浅变质碎屑岩沉积,四周被三叠纪岩浆岩所包围,研究其沉积环境及物源特征对揭示该区构造背景具有重要的意义。通过野外详细的剖面测制、沉积相标志的观察,结合室内岩矿鉴定和地球化学等综合分析,揭示该套碎屑岩具典型的鲍马序列结构特征,岩性成分成熟度低,主要为一套近物源的斜坡重力流沉积,其物源区较为复杂,主要为切割岩浆弧、过渡岩浆弧和再旋回造山带,源区构造环境为大陆岛弧及活动大陆边缘,表现出活动大陆边缘弧后盆地的沉积特点。 相似文献
43.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｏｔｅｓｔｔｈｅｌａｙｅｒｅｄｔｈｒｅｅ ｄｉｍｅｎｓｉｏｎａｌｎｏｎｌｉｎｅａｒｎｕｍｅｒｉｃａｌｍｏｄｅｌｐｒｅｓｅｎｔｅｄｉｎＰａｒｔＩ,ｉｔｗａｓａｐ ｐｌｉｅｄｔｏａｓｔｒａｔｉｆｉｅｄ ,ｒｅｃｔａｎｇｕｌａｒ,ａｎｄｔｗｏ ｌａｙｅｒｓｅａａｒｅａｗｉｔｈｓｔｅｐ ｌｉｋｅｔｏｐｏｇｒａｐｈｙｔｏｓｉｍｕｌａｔｅｔｈｅｇｅｎｅｒａｔｉｏｎａｎｄｐｒｏｐａｇａｔｉｏｎｏｆｉｎｔｅｒｎａｌｔｉｄｅｓ.Ｔｈｅｉｎｔｅｒｎａｌｔｉｄｅｖｅｌｏｃｉｔｉｅｓｏｆｔｈｅｕｐｐｅ… 相似文献
44.
在水温为２１．４℃—３１．２℃，盐度为２７．２‰—３６．３‰的环境条件下，进行了企鹅珍珠贝培育附壳珍珠的研究。经２８７天的育珠，成活率８７．５％。在收获的１５个母贝中，植入直径为７～１０ｍｍ的珠核４７粒，佛像模型２个；收获附壳珍珠４０颗，佛像２个，留核率达８５．７％。其中商品珠３５颗，商品珠率为８３．３％。在商品珠中，珠色为银白色的１６颗，占４５．７％；金黄色的１６颗（包括１佛像），占４５．７％；污斑珠３颗，占８．６％。珍珠直径超过１１ｍｍ的有５颗，１０．０～１０．９ｍｍ的有１９颗，９．０～９．９ｍｍ的有９颗，８．０～８．９ｍｍ的仅１颗。抽测珍珠５颗，珠层厚度最大者８６２．５μｍ，最薄者５６２．５μｍ。 相似文献
45.
INTRODUCTIONAsoneofthemethodsenablingnumericalsolutionofdifferentialequations,thefinite differ encemethodiswidelyacceptedinthestudyofphysicaloceanography.Afinite differenceschememusthavepropertiesofconvergence ,consistencyandstabilitytoyieldusefulapproximatesolutionoftherelevantdifferentialequations.However,thepropertiesneednotbeverifiedonebyonebecausethewell knownLaxLawassuresthattheconvergenceisequivalenttothestabilityforafinitediffer enceschemewithconsistence .Twomainmethodsforstudyin… 相似文献
47.
潮成内波在物理海洋和相关学科中的影响 总被引：2，自引：1，他引：2
潮成海洋内波作为物理海洋学中的一个研究内容，虽然对海洋中的能量分配过程起着相当重要的作用，但其作用和影响却不仅仅限于此范畴之内。在许多相关学科的研究中，如水声学、地学(物质输运、地形地貌、深水沉积、地壳液体流动)、海洋工程(海洋资源的勘探、开发和保护等)、海洋生态环境，海水养殖、渔业捕捞，航道淤积以及观测仪器、卫星海洋学等，都存在潮成内波的作用。文章分析了线性或弱非线性潮成内波(常称为内潮波)和强非线性潮成内波(常称为内孤立波)可能的作用方式，对其在物理海洋学及各相关学科中的作用作了简单介绍。 相似文献
48.
通过对TOGA-COARE期间的一组锚系仪器阵列资料的分析得出:在赤道西太平洋1°45′S,156°E.海域存在显著的半日潮频内波,它的水平波数(波长)、垂向波数、水平传播速度和垂向传播速度分别约为:3.3×10-2 km-1 (210 km),-1.6×10-3 m-1,2.0 m/s,-3.8 cm/s.波形向斜下方传播,亦即波能向斜上方传输.它在观测点西南方生成后,向东北方向传播,到达观测海区.流速矢量旋转谱水平随深度的变化呈马鞍形,低谷及深处的峰所在深度分别与南赤道流及赤道潜流的南边界所在深度大体一致.旋转椭圆主轴方位角随深度变化,在浅层(40 m处)为北偏东30°,到深处(324 m)转为东偏南14°.总体上呈东北方向,表明波来自西南方向. 相似文献
49.
A distinct type of nonlinear internal-wave packet, with the largest internal solitary wave in the middle of the packet, was regularly observed in the South China Sea during the Asian Seas International Acoustics Experiment in 2001. Data analysis shows that the occurrence of the distinct internal wave packet is closely related with the occurrence of lower-high internal tides; the internal tides are mixed in the experimental area and, thus, there is diurnal inequality between the heights of two neighboring internal tides. Modeling of internal tides and internal solitary waves in a shoaling situation suggests that this type of wave packet can be generated in the South China Sea by the large shoaling of internal solitary waves and internal tides. Both the internal solitary waves and the internal tides come from the direction of Luzon Strait. The initial large internal solitary waves contribute to the occurrence of the largest internal solitary wave in the middle of the packet and the waves behind the largest internal solitary wave, while the shoaling internal tides bring about the nonlinear internal waves in front of the largest internal solitary wave via interaction with the local shelf topography. 相似文献
50.
A distinct type of nonlinear internal-wave packet, with the largest internal solitary wave in the middle of the packet, was
regularly observed in the South China Sea during the Asian Seas International Acoustics Experiment in 2001. Data analysis
shows that the occurrence of the distinct internal wave packet is closely related with the occurrence of lower-high internal
tides; the internal tides are mixed in the experimental area and, thus, there is diurnal inequality between the heights of
two neighboring internal tides. Modeling of internal tides and internal solitary waves in a shoaling situation suggests that
this type of wave packet can be generated in the South China Sea by the large shoaling of internal solitary waves and internal
tides. Both the internal solitary waves and the internal tides come from the direction of Luzon Strait. The initial large
internal solitary waves contribute to the occurrence of the largest internal solitary wave in the middle of the packet and
the waves behind the largest internal solitary wave, while the shoaling internal tides bring about the nonlinear internal
waves in front of the largest internal solitary wave via interaction with the local shelf topography. 相似文献