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The performance of electronic nose (E-nose) for Chinese Cymbidium scent profiling has been evaluated. Changes in scent profiles of two Cymbidium ensifolium cultivars have been monitored at different flowering stages (initial flowering, full flowering, and terminal flowering) and different times combined with two gas collecting devices. Samples were collected by static headspace (SHS) method. How E-nose can be used for pattern recognition and for studying the releasing of flower scent were proposed. Data obtained were subjected to principal component analysis (PCA) and discriminant function analysis (DFA). PCA was performed on the initially instrumental data to explore the structure of each data set and such result showed that the sensory data contained information related to the cultivar and to time spots. DFA was performed to improve the results, leading to clear separations between the sample groups. Gas collecting device did not seriously affect the result of PCA and DFA. Relative aroma intensity (RAI) was proposed as an alternative concept to compare scent intensity between samples on different time points. These results demonstrate the potential application of the E-nose to evaluate the scent profile of flower. 相似文献
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不同生境中沙地柏根面积分布特征 总被引:17,自引:0,他引:17
本文利用挖掘法和渐近方程y=1-β^d(β为深度系数,d为土壤深度(cm),y为地表到土层d的根面积比例(0~1)揭示半干旱毛乌素沙地不同生境中常绿灌木沙地柏根面积分布特征。结果表明:(1)根面积指数(根面积/地表面积)随土壤水分可利用性降低而减小,这种格局有利于减缓植株地下部分对水分的竞争,从而经济、长时间地利用有限水分资源;(2)深度系数(β)、最大根系深度(Rmax)、含50%总根面积的根系深度(R50)和含90%总根面积的根系深度(R90)均随水分可利用性降低而增大,这表明沙地柏可通过增大根系深度以补偿土壤水分的降低;(3)根面积分布特征既可能记载了生境中水分状况的变化,又可在一定程度上为群落动态提供证据。 相似文献
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AbstractTo investigate the effect of some biological and chemical fertilizers on the root physiological and growth indexes and also Sorghum grain yield, this study was carried out in randomized complete block design with three replicates. The treatments of the study included (1) arbuscular mycorrhizal fungus Glomus mosseae?+?vermicompost, (2) mycorrhiza fungus?+?Nitroxin, (3) mycorrhiza fungus+ Rhizobium sp., (4) mycorrhiza fungus?+?NPK chemical fertilizer (40-40-20), (5) mycorrhiza fungus, and (6) control treatment. The highest root colonization rate and specific root length were observed in the co-inoculation with mycorrhiza?+?Nitroxin treatment. The other root growth parameters were observed at the mycorrhiza?+?vermicompost treatment. Also the highest rate of Sorghum physiological growth indexes root such as root area index and net assimilation rate were belonged to the co-inoculation of mycorrhiza?+?Nitroxin treatment. The highest root growth rate and root relative growth rate were obtained in the mycorrhiza?+?vermicompost treatment. So it can be concluded that biological fertilizers can be used as an appropriate alternative for chemical fertilizers in sustainable agriculture system. 相似文献
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