Responses of Seed Yield and Economic Benefit of Winter Oilseed Rape(Brassica napus L.) to Different NPK Ratio and Dose

Field experiments were conducted during 2008-2010 to investigate the effects of NPK fertilization on seed yield and economic benefit of a new hybrid cultivar of winter oilseed rape(Brassica napus L.)- Xiangzayou763,and to determine the optimum NPK ratio and dose in Hunan,China.The results showed that NPK ratio(1:0.50:0.50) with 180 kg/hm2 N,90 kg/hm^2 P_2O_5 and 90 kg/hm^2 K_2O was the optimum combination for the highest seed yield(2 231.13 kg/hm2) and economic benefit(9 816.97 Yuan/hm^2),of which 1 641.23 Yuan/hm^2 being set for fertilizer investment(VCR=4.11).Besides,the effects of N,P and K fertilizers on seed yield and oil production of winter oilseed rape were not identical.N had the greatest effect on plant growth of winter oilseed rape,followed by P and K.Total leaf number,green leaf number,leaf length and width,rhizome diameter,branch number,dry weight per plant and other agronomic characters in high N treatments were higher than those in low N treatments.By correlation and path analysis of yield components,the contribution rate to seed yield was found:effective silique number per plant>seed number per silique>1 000-seed weight.

Evaluation of semivariogram features for objectbased image classification

Inclusion of textures in image classification has been shown beneficial.This paper studies an efficient use of semivariogram features for object-based high-resolution image classification.First,an input image is divided into segments,for each of which a semivariogram is then calculated.Second,candidate features are extracted as a number of key locations of the semivariogram functions.Then we use an improved Relief algorithm and the principal component analysis to select independent and significant features.Then the selected prominent semivariogram features and the conventional spectral features are combined to constitute a feature vector for a support vector machine classifier.The effect of such selected semivariogram features is compared with those of the gray-level co-occurrence matrix(GLCM)features and window-based semivariogram texture features(STFs).Tests with aerial and satellite images show that such selected semivariogram features are of a more beneficial supplement to spectral features.The described method in this paper yields a higher classification accuracy than the combination of spectral and GLCM features or STFs.

非国有股东治理、参与方式与国有企业创新

随着中国国有企业混合所有制改革的不断深入,非国有股东治理及其参与方式发挥愈发重要的作用。研究以2008-2020年沪深主板国有上市公司为样本,分别从股权治理、高层治理和委员会治理三个层面实证检验了非国有股东参与方式对国有企业创新的影响。研究发现,在股权治理层面,非国有股东对国有企业创新能力的提升作用有限;但在更深层次的高层治理和委员会治理层面,非国有股东可以有效提高国有企业的创新能力,委员会治理是非国有股东高层治理促进国有企业创新的路径。区分政府控制层级和混合所有制改革政策推进力度的进一步研究发现,非国有股东对创新能力的正面促进作用主要集中在地方国有企业和深化混合所有制改革后。研究不仅在理论层面上有助于厘清非国有股东参与国有企业内部治理的具体路径,而且在实践层面上对国有企业在深化改革过程中如何提升创新能力具有现实指导意义。