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P. M. Berry J. Spink M. Sterling A. A. Pickett 《Journal of Agronomy and Crop Science》2003,189(6):390-401
Lodging resistance ratings for winter wheat cultivars are frequently based upon observations of lodging. This is an unreliable method because of the frequent occurrence of years without significant lodging events. It also does not distinguish between stem and root lodging resistance. This paper describes the development and testing of instrumentation and procedures for two field‐based methods to rapidly assess stem and root lodging resistance. Both methods used a specifically designed instrument for measuring the resistance of shoots against rotational displacement. Stem lodging resistance was assessed when the soil was dry and strong, whereas resistance to root lodging was assessed after the soil had been weakened by irrigation. Tests were carried out on 14 winter wheat cultivars grown at two sites in the UK during 2002. Both methods were able to detect statistically significant differences between the cultivars for their resistance to stem and root lodging. A comparison of these results with observations of lodging in the field showed that the methods accounted for about 60 and 50 % of the stem and root lodging respectively. 相似文献
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Michel JB Shen YK Aiden AP Veres A Gray MK;Google Books Team Pickett JP Hoiberg D Clancy D Norvig P Orwant J Pinker S Nowak MA Aiden EL 《Science (New York, N.Y.)》2011,331(6014):176-182
We constructed a corpus of digitized texts containing about 4% of all books ever printed. Analysis of this corpus enables us to investigate cultural trends quantitatively. We survey the vast terrain of 'culturomics,' focusing on linguistic and cultural phenomena that were reflected in the English language between 1800 and 2000. We show how this approach can provide insights about fields as diverse as lexicography, the evolution of grammar, collective memory, the adoption of technology, the pursuit of fame, censorship, and historical epidemiology. Culturomics extends the boundaries of rigorous quantitative inquiry to a wide array of new phenomena spanning the social sciences and the humanities. 相似文献
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Profiles of stratospheric ozone and chlorine monoxide radical (C1O) have been obtained from balloon measurements of atmospheric limb thermal emission at millimeter wavelengths. The C1O measurements, important for assessing the predicted depletion of stratospheric ozone by chlorine from industrial sources, are in close agreement with present theory, The predicted decrease of C1O at sunset was measured. A tentative value for the stratospheric abundance of hydrogen peroxide was also determined. 相似文献
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