The paper is to study the TCF bleaching of high-yield chemical pulp of NS-AQ aspen(digester yield 63.7%, Kappa number 37.3, brightness 50.0%ISO, intrinsic viscosity 1,340ml/g). Under the suitable conditions(oxygen pre...The paper is to study the TCF bleaching of high-yield chemical pulp of NS-AQ aspen(digester yield 63.7%, Kappa number 37.3, brightness 50.0%ISO, intrinsic viscosity 1,340ml/g). Under the suitable conditions(oxygen pressure 0.6MPa, 85℃, 80min., NaOH 5%, MgSO4 0.3%, consistency 11%), oxygen delignification, can increase the brightness of pulp to 64.9%ISO, substantially decrease Kappa number to 9.11. Before the oxygen delignification pretreating pulp by acidic chelant(Qa)under conditions of pH 3.0, 30min, 40℃, DTPA 0.25%, consistency 15%, and after the Qa strengthening oxygen delignification by H2O2(Op, H2O2 2%)can increase the brightness of pulp to 77.1%ISO, decrease Kappa number and intrinsic viscosity to 6.36 and 984ml/g, respectively. After the Op, pretreat pulp by chelant once again(pH 6.0, 60℃, consistency 12%, other as the Qa), and following this pretreatment do bleach with 1% H2O2, namely using Qa-Op-Q-P bleaching sequence, resulting in the brightness 84.8%ISO, Kappa number 5.01, intrinsic viscosity 792ml/g, total bleaching loss 12.17% for bleached pulp.展开更多
Maize(Zea mays L.) stands prominently as one of the major cereal crops in China as well as in the rest of the world.Therefore,predicting the growth and yield of maize for large areas through yield components under hig...Maize(Zea mays L.) stands prominently as one of the major cereal crops in China as well as in the rest of the world.Therefore,predicting the growth and yield of maize for large areas through yield components under high-yielding environments will help in understanding the process of yield formation and yield potential under different environmental conditions.This accurate early assessment of yield requires accuracy in the formation process of yield components as well.In order to formulate the quantitative design for high yields of maize in China,yield performance parameters of quantitative design for high grain yields were evaluated in this study,by utilizing the yield performance equation with normalization of planting density.Planting density was evaluated by parameters including the maximum leaf area index and the maximum leaf area per plant.Results showed that the variation of the maximum leaf area per plant with varying plant density conformed to the Reciprocal Model,which proved to have excellent prediction with root mean square error(RMSE) value of 5.95%.Yield model estimation depicted that the best optimal maximum leaf area per plant was 0.63 times the potential maximum leaf area per plant of hybrids.Yield performance parameters for different yield levels were quantitatively designed based on the yield performance equation.Through validation of the yield performance model by simulating high yields of spring maize in the Inner Mongolia Autonomous Region and Jilin Province,China,and summer maize in Shandong Province,the yield performance equation showed excellent prediction with the satisfactory mean RMSE value(7.72%) of all the parameters.The present study provides theoretical support for the formulation of quantitative design for sustainable high yield of maize in China,through consideration of planting density normalization in the yield prediction process,providing there is no water and nutrient limitation.展开更多
文摘The paper is to study the TCF bleaching of high-yield chemical pulp of NS-AQ aspen(digester yield 63.7%, Kappa number 37.3, brightness 50.0%ISO, intrinsic viscosity 1,340ml/g). Under the suitable conditions(oxygen pressure 0.6MPa, 85℃, 80min., NaOH 5%, MgSO4 0.3%, consistency 11%), oxygen delignification, can increase the brightness of pulp to 64.9%ISO, substantially decrease Kappa number to 9.11. Before the oxygen delignification pretreating pulp by acidic chelant(Qa)under conditions of pH 3.0, 30min, 40℃, DTPA 0.25%, consistency 15%, and after the Qa strengthening oxygen delignification by H2O2(Op, H2O2 2%)can increase the brightness of pulp to 77.1%ISO, decrease Kappa number and intrinsic viscosity to 6.36 and 984ml/g, respectively. After the Op, pretreat pulp by chelant once again(pH 6.0, 60℃, consistency 12%, other as the Qa), and following this pretreatment do bleach with 1% H2O2, namely using Qa-Op-Q-P bleaching sequence, resulting in the brightness 84.8%ISO, Kappa number 5.01, intrinsic viscosity 792ml/g, total bleaching loss 12.17% for bleached pulp.
基金supported by the National Key Research and Development Program of China(2018YFD020060 and 2017YFD0301307)the National Natural Science Foundation of China(31971851)the earmarked fund for China Agriculture Research System(CARS-02-12)
文摘Maize(Zea mays L.) stands prominently as one of the major cereal crops in China as well as in the rest of the world.Therefore,predicting the growth and yield of maize for large areas through yield components under high-yielding environments will help in understanding the process of yield formation and yield potential under different environmental conditions.This accurate early assessment of yield requires accuracy in the formation process of yield components as well.In order to formulate the quantitative design for high yields of maize in China,yield performance parameters of quantitative design for high grain yields were evaluated in this study,by utilizing the yield performance equation with normalization of planting density.Planting density was evaluated by parameters including the maximum leaf area index and the maximum leaf area per plant.Results showed that the variation of the maximum leaf area per plant with varying plant density conformed to the Reciprocal Model,which proved to have excellent prediction with root mean square error(RMSE) value of 5.95%.Yield model estimation depicted that the best optimal maximum leaf area per plant was 0.63 times the potential maximum leaf area per plant of hybrids.Yield performance parameters for different yield levels were quantitatively designed based on the yield performance equation.Through validation of the yield performance model by simulating high yields of spring maize in the Inner Mongolia Autonomous Region and Jilin Province,China,and summer maize in Shandong Province,the yield performance equation showed excellent prediction with the satisfactory mean RMSE value(7.72%) of all the parameters.The present study provides theoretical support for the formulation of quantitative design for sustainable high yield of maize in China,through consideration of planting density normalization in the yield prediction process,providing there is no water and nutrient limitation.
