This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic ...This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic agricultural soils with p H 4.03-6.02 in Yunnan Province, Southern China. The accumulation of15 N-NO3-and nitrification rates decreased with the addition of biochar at the end of incubation, suggesting that biochar could be a nitrification inhibitor in acidic fertilized soil. Nitrification rates in soil with p H 4.03 were evidently lower than those in soil with p H 4.81-6.02 with or without biochar. Decreased nitrification rates were detected in the acidic soils with biochar. Soil p H controlled nitrification more than biochar in certain strongly acidic soils.展开更多
Time-dependent characteristics(TDCs)have been neglected in most previous studies investigating the deviation mechanisms of bridge pile foundations and evaluating the effectiveness of preventive measures.In this study,...Time-dependent characteristics(TDCs)have been neglected in most previous studies investigating the deviation mechanisms of bridge pile foundations and evaluating the effectiveness of preventive measures.In this study,the stress-strain-time characteristics of soft soils were illustrated by consolidation-creep tests based on a typical engineering case.An extended Koppejan model was developed and then embedded in a finite element(FE)model via a user-material subroutine(UMAT).Based on the validated FE model,the time-dependent deformation mechanism of the pile foundation was revealed,and the preventive effect of applying micropiles and stress-release holes to control the deviation was investigated.The results show that the calculated maximum lateral displacement of the cap differs from the measured one by 6.5%,indicating that the derived extended Koppejan model reproduced the deviation process of the bridge cap-pile foundation with time.The additional load acting on the pile side caused by soil lateral deformation was mainly concentrated within the soft soil layer and increased with the increase in load duration.Compared with t=3 d(where t is surcharge time),the maximum lateral additional pressure acting on Pile 2#increased by approximately 47.0%at t=224 d.For bridge pile foundation deviation in deep soft soils,stress-release holes can provide better prevention compared to micropiles and are therefore recommended.展开更多
Agricultural productivity is crucial to the economy.The output and quality of crops have a direct impact on people’s daily lives and a country’s food and clothing.Therefore,harvesting high-quality crops efficiently ...Agricultural productivity is crucial to the economy.The output and quality of crops have a direct impact on people’s daily lives and a country’s food and clothing.Therefore,harvesting high-quality crops efficiently and maximizing yield per unit area are the most important goals pursued by farmers.As an important parameter of plant growth,light intensity is one of the important factors that affects plant growth and development,morphological establishment and accumulation of functional chemical substances.When light intensity cannot meet the plant’s needs,the optimal light intensity or uneven light distribution will have a greater impact on plant growth and development.This paper aims to address the optimal plant light intensity problem.The paper presents an expert system technology database storing the empirical value of real-time light intensity values and compares it with a parallel particle swarm optimization algorithm to identify the optimal locations where LED lights need to be turned on and where drive circuit lit LED arrays need to be situated,to identify the number of LED fill lights and to solve light intensity optimization problems.展开更多
基金Supported by National Natural Science Foundation of China(31201688)Yunnan University’s Research Innovation Fund for Graduate Students
文摘This study was conducted to investigate the effects of mixed biochar on the nitrification rate in acidic soils. A15 N tracer experiment with(15 NH4)2 SO4 was conducted to determine the nitrification rates of 4 acidic agricultural soils with p H 4.03-6.02 in Yunnan Province, Southern China. The accumulation of15 N-NO3-and nitrification rates decreased with the addition of biochar at the end of incubation, suggesting that biochar could be a nitrification inhibitor in acidic fertilized soil. Nitrification rates in soil with p H 4.03 were evidently lower than those in soil with p H 4.81-6.02 with or without biochar. Decreased nitrification rates were detected in the acidic soils with biochar. Soil p H controlled nitrification more than biochar in certain strongly acidic soils.
基金supported by the Science and Technology Research Project of Jiangxi Education Department(Nos.GJJ2201509,GJJ2201501)the National Natural Science Foundation of China(Nos.51878671,51969018,52378344)+1 种基金the Natural Science Foundation of Jiangxi Province(No.20224BAB204076)the Young Scientific and Technological Talents Sponsorship Project in Ganpo Juncai Support Program(No.2023QT08).
文摘Time-dependent characteristics(TDCs)have been neglected in most previous studies investigating the deviation mechanisms of bridge pile foundations and evaluating the effectiveness of preventive measures.In this study,the stress-strain-time characteristics of soft soils were illustrated by consolidation-creep tests based on a typical engineering case.An extended Koppejan model was developed and then embedded in a finite element(FE)model via a user-material subroutine(UMAT).Based on the validated FE model,the time-dependent deformation mechanism of the pile foundation was revealed,and the preventive effect of applying micropiles and stress-release holes to control the deviation was investigated.The results show that the calculated maximum lateral displacement of the cap differs from the measured one by 6.5%,indicating that the derived extended Koppejan model reproduced the deviation process of the bridge cap-pile foundation with time.The additional load acting on the pile side caused by soil lateral deformation was mainly concentrated within the soft soil layer and increased with the increase in load duration.Compared with t=3 d(where t is surcharge time),the maximum lateral additional pressure acting on Pile 2#increased by approximately 47.0%at t=224 d.For bridge pile foundation deviation in deep soft soils,stress-release holes can provide better prevention compared to micropiles and are therefore recommended.
基金support from the Top-notch talent plan program of higher education in Hebei(BJ2017036)Natural Science Foundation of Hebei Province(No.C2015204043)Key Research and Development Program of Hebei Province(18227209D,18227209D-1).
文摘Agricultural productivity is crucial to the economy.The output and quality of crops have a direct impact on people’s daily lives and a country’s food and clothing.Therefore,harvesting high-quality crops efficiently and maximizing yield per unit area are the most important goals pursued by farmers.As an important parameter of plant growth,light intensity is one of the important factors that affects plant growth and development,morphological establishment and accumulation of functional chemical substances.When light intensity cannot meet the plant’s needs,the optimal light intensity or uneven light distribution will have a greater impact on plant growth and development.This paper aims to address the optimal plant light intensity problem.The paper presents an expert system technology database storing the empirical value of real-time light intensity values and compares it with a parallel particle swarm optimization algorithm to identify the optimal locations where LED lights need to be turned on and where drive circuit lit LED arrays need to be situated,to identify the number of LED fill lights and to solve light intensity optimization problems.
