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101.
棉花高光谱及其红边特征(I) 总被引:3,自引:0,他引:3
通过大田和室内试验,测定了2个品种的棉花冠层、完全展开倒1、3叶在不同时期的高光谱反射率及对应叶片的叶绿素、类胡萝卜素含量。结果表明:随发育期推移,棉花冠层光谱反射率在可见光范围降低,在近红外区域增高;叶片背面光谱反射率略高于正面,透射率小于反射率;叶面积指数、鲜叶重和干叶重与冠层反射光谱变量ρ800 ρ550、ρ800 ρ680、ρ680 ρ570之间存在显著相关;叶片叶绿素和类胡萝卜素浓度与其反射光谱变量ρ680 ρ570、ρ673 ρ640、ρ680 ρ550、PSSRa、PSNDa、RCh之间也呈显著相关。 相似文献
102.
103.
浅析南方丘陵地区土地平整中的表土问题及对策 总被引:3,自引:0,他引:3
土地平整工程是土地整理项目的核心内容,但是,南方丘陵地区土地平整中出现不科学的工程措施导致的表土破坏的潜在问题却一直没有引起重视。在此,针对南方丘陵地区土地整理中土地平整工程的特点及现状,总结土地平整从规划设计到项目实施表土保护问题并进行分析,提出加强表土保护的相应措施。 相似文献
104.
The prediction of grain and stover quality parameters in maize {Zea mays L.) by near infra-red reflectance spectroscopy (NIRS) was studied. A total of 110 grain and 135 stover samples originating from different genotypes and environments were assayed. Calibration equations for content of crude protein (CP), crude fat (CF), starch (ST), and water soluble carbohydrates (WSC) in grain were obtained by multiple linear regression of known manual values on NIRS data from the odd numbered samples. Calibrations for CP, acid detergent fibre (ADF), in vitro digestible organic matter according to the Tilley & Terry (IVDOM-T & T) and the gas production (IVDOM-Gp) method, respectively, and metabolizable energy (ME) in stover were developed analogously. Equations were validated with the evennumbered .samples and for ME additionally with the 1584 stover samples from an experiment with 66 F1 hybrids tested in six environments. The coefficients of multiple determination (R2) of the prediction equations ranged from 0.80 for IVDOM-Gp and ME in stover to 0.94 for CP in grain. Standard errors of calibration (SEC) and prediction (SEP) were in most cases not higher than commonly reported for conventional manual assays. With regard to the correct ranking of hybrids, prediction equations for ME applied well to stover samples from other environments with one exception. We concluded that NIRS can evaluate the quality traits investigated to a similar degree to that of conventional methods of analysis. Since NIRS is simple and safe to operate and allows rapid screening of several quality traits simultaneously, it should be particularly attractive for breeding purposes. 相似文献
105.
棉花高光谱及其红边特征(Ⅱ) 总被引:6,自引:4,他引:6
通过大田和室内试验,测定了2个棉花品种的冠层、完全展开倒1、3叶在不同时期的高光谱反射率及对应叶片的叶绿素、类胡萝卜素含量。结果表明:棉花冠层光谱红边具有“双峰”和“红边平台”现象,且红边位置λ_(red)位于695~720nm之间,红边幅值Dλ_(red)和红边面积S_(red)有“红移”和“蓝移”现象;叶面积指数、鲜叶重和干叶重与冠层光谱红边参数λ_(red)、Dλ(red)、S_(red)之间存在显著相关,叶片叶绿素和类胡萝卜素含量与其反射光谱的λ_(red)、Dλ(red)、S_(red)也有显著相关。 相似文献
106.
小麦叶片氮含量与冠层反射光谱指数的定量关系 总被引:15,自引:0,他引:15
本文以3种蛋白质类型的小麦品种在不同施氮水平下的3年田间试验为基础,研究了小麦叶片氮含量与冠层反射光谱的定量关系。结果显示,不同试验中拔节后叶片氮含量均随施氮水平呈上升趋势,同时冠层光谱反射率在不同施氮水平下存在明显差异。对于低、中、高籽粒蛋白质含量的品种,叶片氮含量与冠层反射光谱的归一化植被指数NDVI (1 220, 710)和红边位置均有密切的定量关系,决定系数在0.80左右。对于不同品质类型小麦品种,均可利用统一的回归方程描述其叶片氮含量随反射光谱参数的变化,对于低蛋白类型品种,采用单独的回归系数即可提高叶片氮含量估测的准确性。本研究确立的小麦叶片氮含量与冠层反射光谱的定量关系可用于不同的小麦品种、生育时期和施氮水平,为小麦氮素营养的监测诊断与精确施肥等提供理论依据和技术途径。 相似文献
107.
It has been argued that the wide-scale provision of artificial surface water in semi-arid savannas may result in homogenisation of foraging regimes, compromising biodiversity and ecosystem resilience. This is the first landscape-scale study investigating to what degree artificial waterholes and natural rivers influence the distribution of large herbivores, and hence foraging patterns, in the Kruger National Park, South Africa. This is explored by examining consistencies within and differences between distribution patterns of herbivore feeding groups on different geologies. Seven years of dry season aerial census data of thirteen large herbivores were analysed in a GIS. It was found that different herbivores exhibit different distribution patterns around rivers and waterholes. It was found that most grazer species were associated with artificial waterholes, whereas browsers and mixed feeders were indifferent to waterholes and were associated with the main rivers. This has important management implications for artificial water provision in the KNP and potentially for other semi-arid African savanna conservation areas. Man-made waterholes are therefore features in the landscape that can change the distribution of herbivores, even in a landscape where natural water is available, transforming patterns of landscape use. Furthermore, it was also found that the underlying geology interacts with water distribution in shaping herbivore distributions, with artificial waterholes and rivers acting as stronger nodes of herbivore activity on nutrient-rich basaltic soils than nutrient-poor granitic soils. The results from this paper may be useful for designing surface water policies and management plans for Kruger and other savanna reserves in Africa in order to maximise biodiversity conservation. 相似文献
108.
109.
用于重组竹地板底漆的热熔漆漆膜性能研究 总被引:1,自引:0,他引:1
对以热熔漆为底漆涂饰的重组竹地板及其对照组地板进行紫外光/冷凝耐老化试验,分析耐老化试验前后地板的漆膜性能,结果表明:耐老化试验前后热熔漆涂饰重组竹地板和对照组地板的各项性能均达到GB/T20240-2006《竹地板》中的规定,热熔漆漆膜性能表现更好。采用体式显微镜观察漆膜表面情况,采用裂纹条数、裂纹长度、裂纹面积比描述漆膜开裂情况,结果表明:耐老化试验后热熔漆涂饰重组竹地板的裂纹条数、裂纹长度、裂纹面积比相比于使用传统底漆涂饰重组竹地板分别下降了89.6%、62.5%和35.1%。热熔漆相比于传统底漆具有更好的抑制重组竹地板漆膜开裂的作用。 相似文献
110.