[Objectives] This study was conducted to explore the effects of different N application rates and densities on the growth and development of direct-seeding rape as well as on its yield.[Methods] A field experiment was...[Objectives] This study was conducted to explore the effects of different N application rates and densities on the growth and development of direct-seeding rape as well as on its yield.[Methods] A field experiment was carried out by setting five N fertilizer treatments and three density levels.[Results] Increasing seeding density and N application rate could improve the seed yield of rape. The suitable N application rate for the three densities were calculated using the fitted fertilizer efficiency models, respectively, to be 186.77, 221.35 and 236.14 kg/hm^2, at which the yields were the highest. The results showed that in this area, the seeding density of direct-seeding rape could be selected in the range of 6.0×10^5-7.5×10^5 plants/hm^2, and the suitable N application rate could be in the range of 221.35-236.14 kg/hm^2.[Conclusions] This study provides a theoretical basis for the maximization of spatial resource and efficient utilization of fertilizer.展开更多
The failure of electrical equipment directly or indirectly caused by overheating has become one of the main reasons for equipment accidents.The real-time condition monitoring method of electrical equipment based on di...The failure of electrical equipment directly or indirectly caused by overheating has become one of the main reasons for equipment accidents.The real-time condition monitoring method of electrical equipment based on digital twin(DT)has received extensive attention and is considered as a technology with great engineering values and excellent application prospects.However,the current calculation of DT mostly relies on the traditional finite element method(CFEM).This method becomes less computationally efficient as the size of the DT increases,especially for electrical equipment with high complexity.It is difficult to meet the requirements real-time calculation in DT.Therefore,starting from the algorithm optimization and parallel architecture,based on the weighted residual method and stabilised conforming nodal integration,a novel discrete method of electrothermal coupling equation is proposed and the data storage structure of the algorithm from the bottom layer is redesigned,and the corresponding GPU and multi-core CPU parallel framework are proposed.Finally,taking the high voltage bushing as an example,the correctness of the method in this paper is verified by the CFEM code and commercial software ABAQUS.Under the same grid and accuracy requirement,the calculation time is shortened by at least five times than ABAQUS.And the method is easy to extend to other types of multi-physics calculations.展开更多
The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic f...The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic fields at a few mega-Gauss are generated due to nonvanishing cross product ▽(n/) × p. Excited in an inhomogeneous plasma of decreasing density, the quasi-static magnetic field structure is shown to drift quickly both in lateral and longitudinal directions. When two parallel-propagating laser pulses with close focal spot separation are used, such field drifts can develop into magnetic reconnection(annihilation) in their overlapping region, resulting in the conversion of magnetic energy to kinetic energy of particles. The reconnection rate is found to be much higher than the value obtained in the Hall magnetic reconnection model. Our work proposes a potential way to study magnetic reconnection-related physics with short-pulse lasers of terawatt peak power only.展开更多
文摘[Objectives] This study was conducted to explore the effects of different N application rates and densities on the growth and development of direct-seeding rape as well as on its yield.[Methods] A field experiment was carried out by setting five N fertilizer treatments and three density levels.[Results] Increasing seeding density and N application rate could improve the seed yield of rape. The suitable N application rate for the three densities were calculated using the fitted fertilizer efficiency models, respectively, to be 186.77, 221.35 and 236.14 kg/hm^2, at which the yields were the highest. The results showed that in this area, the seeding density of direct-seeding rape could be selected in the range of 6.0×10^5-7.5×10^5 plants/hm^2, and the suitable N application rate could be in the range of 221.35-236.14 kg/hm^2.[Conclusions] This study provides a theoretical basis for the maximization of spatial resource and efficient utilization of fertilizer.
基金State Grid Corporation of China,Grant/Award Number:5500-202099280A-0-0-00。
文摘The failure of electrical equipment directly or indirectly caused by overheating has become one of the main reasons for equipment accidents.The real-time condition monitoring method of electrical equipment based on digital twin(DT)has received extensive attention and is considered as a technology with great engineering values and excellent application prospects.However,the current calculation of DT mostly relies on the traditional finite element method(CFEM).This method becomes less computationally efficient as the size of the DT increases,especially for electrical equipment with high complexity.It is difficult to meet the requirements real-time calculation in DT.Therefore,starting from the algorithm optimization and parallel architecture,based on the weighted residual method and stabilised conforming nodal integration,a novel discrete method of electrothermal coupling equation is proposed and the data storage structure of the algorithm from the bottom layer is redesigned,and the corresponding GPU and multi-core CPU parallel framework are proposed.Finally,taking the high voltage bushing as an example,the correctness of the method in this paper is verified by the CFEM code and commercial software ABAQUS.Under the same grid and accuracy requirement,the calculation time is shortened by at least five times than ABAQUS.And the method is easy to extend to other types of multi-physics calculations.
基金supported by the National Basic Research Program of China(Grant No.2013CBA01500)the National Natural Science Foundation of China(Grant Nos.11421064,and 11220101002)a Leverhulme Trust Research Project Grant at University of Strathclyde
文摘The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic fields at a few mega-Gauss are generated due to nonvanishing cross product ▽(n/) × p. Excited in an inhomogeneous plasma of decreasing density, the quasi-static magnetic field structure is shown to drift quickly both in lateral and longitudinal directions. When two parallel-propagating laser pulses with close focal spot separation are used, such field drifts can develop into magnetic reconnection(annihilation) in their overlapping region, resulting in the conversion of magnetic energy to kinetic energy of particles. The reconnection rate is found to be much higher than the value obtained in the Hall magnetic reconnection model. Our work proposes a potential way to study magnetic reconnection-related physics with short-pulse lasers of terawatt peak power only.
