[Objectives] This study was conducted to use the feeding value of wolfberry branches and to provide a basis for the rational use of its active ingredients and nutrients and the development of new feed resources. [Meth...[Objectives] This study was conducted to use the feeding value of wolfberry branches and to provide a basis for the rational use of its active ingredients and nutrients and the development of new feed resources. [Methods] Wolfberry branches and whole-plant corn were used to make mixed silage of wolfberry branches, which replaced different proportions of whole-plant corn silage for feeding hybrid mutton sheep, and the feeding effect of the mixed silage of wolfberry branches on hybrid mutton sheep was analyzed, which provides a technical basis for rational utilization of mulberry resources to ruminants. A single factor feeding comparison experiment was carried out. 32 hybrid mutton sheep of 8 months old with conform gender, age, body weight, physiological state and feeding management level were selected and divided into two groups, 16 in each group. [Results] The gross output value of weight gain of the experimental group was 18.06 yuan, which was higher than the CK(12.97 yuan) by 5.09 yuan. [Conclusions] The addition of the mixed silage of wolfberry branches to the diet had a positive effect on the increase of the weight gain of the hybrid mutton sheep and the reduction of the feed conversion ratio compared with the single whole-plant corn silage.展开更多
[Objectives] This study was conducted to investigate the effect of mixed silage of mulberry branches and leaves on the production performance of Tan Han hybrid mutton sheep and explore the feasibility in production. [...[Objectives] This study was conducted to investigate the effect of mixed silage of mulberry branches and leaves on the production performance of Tan Han hybrid mutton sheep and explore the feasibility in production. [Methods] Twenty-six Tan Han hybrid mutton sheep were selected and divided into two groups, 13 in each group. The experimental group was fed with the mixed silage and the control group(CK) was fed with whole-plant corn silage. [Results] The average daily weight gain per sheep of the experimental group was 9.2% higher than that of the CK(P<0.05), and the feed conversion ratio was decreased by 6.98%(P<0.05). The average daily weight gain per sheep in the 30 d improved the gross profit by 7.75 yuan, which meant an increase of 16.32%. [Conclusions] The mulberry mixed silage is feasible in the production, and it could significantly improve the production performance of the hybrid mutton sheep.展开更多
Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with...Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with actuation redundancy in parallel mechanism. Branched chains with actuation redundancy are synthesized for eliminating interior singularity of 3-translational and 1-rotational（3T1R） parallel mechanisms. Guided by the discriminance method of hybrid screw group according to Grassmann line geometry, all the possibilities are listed for the occurrence of interior singularities in 3T1R parallel mechanism. Based on the linear relevance of screw system and the principles of eliminating parallel mechanism singularity with actuation redundancy, different types of branched chains with actuation redundancy are synthesized systematically to indicate the layout and the number of the branched chainsinterior with actuation redundancy. A general method is proposed for the configuration synthesis of the branched chains with actuation redundancy of the redundant parallel mechanism, and it builds a solid foundation for the subsequent performance optimization of the redundant actuation parallel mechanism.展开更多
It is shown that when backorders, setup times and dynamic demand are included in capacitated lot sizing problem, the resulting classical formulation and one of the transportation formulations of the problem (referred ...It is shown that when backorders, setup times and dynamic demand are included in capacitated lot sizing problem, the resulting classical formulation and one of the transportation formulations of the problem (referred to as CLSP_BS) are equivalent. And it is shown that both the formulations are “weak” formulations (as opposed to “strong” formulation). The other transportation version is a strong formulation of CLSP_BS. Extensive computational studies are presented for medium and large sized problems. In case of medium-sized problems, strong formulation produces better LP bounds, and takes lesser number of branch-and-bound (B&B) nodes and less CPU time to solve the problem optimally. However for large-sized problems strong formulation takes more time to solve the problem optimally, defeating the benefit of strength of bounds. This essentially is because of excessive increase in the number of constraints for the large sized problems. Hybrid formulations are proposed where only few most promising strong constraints are added to the weak formulation. Hybrid formulation emerges as the best performer against the strong and weak formulations. This concept of hybrid formulation can efficiently solve a variety of complex real life large-sized problems.展开更多
直流断路器作为柔性直流电网的关键设备,对直流输配电网的安全、稳定运行有着重要的意义。针对带限流能力的直流断路器存在的造价偏高、故障清除速度慢等问题,提出了一种带自充电支路的改进型混合直流断路器(improved hybrid DC circuit...直流断路器作为柔性直流电网的关键设备,对直流输配电网的安全、稳定运行有着重要的意义。针对带限流能力的直流断路器存在的造价偏高、故障清除速度慢等问题,提出了一种带自充电支路的改进型混合直流断路器(improved hybrid DC circuit breaker with self-charging branch,SCB-IHDCCB)拓扑,设置限流电感旁路和接地旁路,优化自充电支路路线,将泄能支路与自充电支路结合使用,在保证断路器性能的前提下,减少了支路数量,大大降低了晶闸管等元器件数量,从而大大降低其造价。对所提拓扑在单端系统中的工况进行了理论推导与分析,基于所提拓扑设计了500kV的单端直流系统,在PSCAD/EMTDC中建立模型进行了仿真验证,并与其他拓扑方案的性能、元器件数量进行比较。仿真结果表明,SCB-IHDCCB的性能和造价都得到较大优化,具有良好的经济性和应用前景。展开更多
基金Supported by Ningxia Key R&D Program(2019BBF02016)Special Fund for Agricultural Science and Technology Independent Innovation of Ningxia Academy of Agriculture and Forestry Sciences
文摘[Objectives] This study was conducted to use the feeding value of wolfberry branches and to provide a basis for the rational use of its active ingredients and nutrients and the development of new feed resources. [Methods] Wolfberry branches and whole-plant corn were used to make mixed silage of wolfberry branches, which replaced different proportions of whole-plant corn silage for feeding hybrid mutton sheep, and the feeding effect of the mixed silage of wolfberry branches on hybrid mutton sheep was analyzed, which provides a technical basis for rational utilization of mulberry resources to ruminants. A single factor feeding comparison experiment was carried out. 32 hybrid mutton sheep of 8 months old with conform gender, age, body weight, physiological state and feeding management level were selected and divided into two groups, 16 in each group. [Results] The gross output value of weight gain of the experimental group was 18.06 yuan, which was higher than the CK(12.97 yuan) by 5.09 yuan. [Conclusions] The addition of the mixed silage of wolfberry branches to the diet had a positive effect on the increase of the weight gain of the hybrid mutton sheep and the reduction of the feed conversion ratio compared with the single whole-plant corn silage.
基金Supported by Ningxia Key R&D Program(2019BBF02016)Special Fund for Agricultural Science and Technology Independent Innovation of Ningxia Academy of Agriculture and Forestry Sciences
文摘[Objectives] This study was conducted to investigate the effect of mixed silage of mulberry branches and leaves on the production performance of Tan Han hybrid mutton sheep and explore the feasibility in production. [Methods] Twenty-six Tan Han hybrid mutton sheep were selected and divided into two groups, 13 in each group. The experimental group was fed with the mixed silage and the control group(CK) was fed with whole-plant corn silage. [Results] The average daily weight gain per sheep of the experimental group was 9.2% higher than that of the CK(P<0.05), and the feed conversion ratio was decreased by 6.98%(P<0.05). The average daily weight gain per sheep in the 30 d improved the gross profit by 7.75 yuan, which meant an increase of 16.32%. [Conclusions] The mulberry mixed silage is feasible in the production, and it could significantly improve the production performance of the hybrid mutton sheep.
文摘随着大量直流电源和负荷的接入,交直流混合的配电网技术已成为未来配电网的发展趋势.然而,源荷不确定性及可调度设备的类型多样化给配电网调度带来了巨大的挑战.本文提出了基于分支决斗深度强化网络(branching dueling Q-network,BDQ)和软演员-评论家(soft actor critic,SAC)双智能体深度强化学习的交直流配电网调度方法.该方法首先将经济调度问题与两智能体的动作、奖励、状态相结合,建立经济调度的马尔可夫决策过程,并分别基于BDQ和SAC方法设置两个智能体,其中,BDQ智能体用于控制配电网中离散动作设备,SAC智能体用于控制连续动作设备.然后,通过集中训练分散执行的方式,两智能体与环境进行交互,进行离线训练.最后,固定智能体的参数,进行在线调度.该方法的优势在于采用双智能体能够同时控制离散动作设备电容器组、载调压变压器和连续动作设备变流器、储能,同时通过对双智能体的集中训练,可以自适应源荷的不确定性.改进的IEEE33节点交直流配电网算例测试验证了所提方法的有效性.
基金Supported by Research Fund for the Doctoral Program of Higher Education,China(Grant No.20131333110008)
文摘Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with actuation redundancy in parallel mechanism. Branched chains with actuation redundancy are synthesized for eliminating interior singularity of 3-translational and 1-rotational（3T1R） parallel mechanisms. Guided by the discriminance method of hybrid screw group according to Grassmann line geometry, all the possibilities are listed for the occurrence of interior singularities in 3T1R parallel mechanism. Based on the linear relevance of screw system and the principles of eliminating parallel mechanism singularity with actuation redundancy, different types of branched chains with actuation redundancy are synthesized systematically to indicate the layout and the number of the branched chainsinterior with actuation redundancy. A general method is proposed for the configuration synthesis of the branched chains with actuation redundancy of the redundant parallel mechanism, and it builds a solid foundation for the subsequent performance optimization of the redundant actuation parallel mechanism.
文摘It is shown that when backorders, setup times and dynamic demand are included in capacitated lot sizing problem, the resulting classical formulation and one of the transportation formulations of the problem (referred to as CLSP_BS) are equivalent. And it is shown that both the formulations are “weak” formulations (as opposed to “strong” formulation). The other transportation version is a strong formulation of CLSP_BS. Extensive computational studies are presented for medium and large sized problems. In case of medium-sized problems, strong formulation produces better LP bounds, and takes lesser number of branch-and-bound (B&B) nodes and less CPU time to solve the problem optimally. However for large-sized problems strong formulation takes more time to solve the problem optimally, defeating the benefit of strength of bounds. This essentially is because of excessive increase in the number of constraints for the large sized problems. Hybrid formulations are proposed where only few most promising strong constraints are added to the weak formulation. Hybrid formulation emerges as the best performer against the strong and weak formulations. This concept of hybrid formulation can efficiently solve a variety of complex real life large-sized problems.
文摘直流断路器作为柔性直流电网的关键设备,对直流输配电网的安全、稳定运行有着重要的意义。针对带限流能力的直流断路器存在的造价偏高、故障清除速度慢等问题,提出了一种带自充电支路的改进型混合直流断路器(improved hybrid DC circuit breaker with self-charging branch,SCB-IHDCCB)拓扑,设置限流电感旁路和接地旁路,优化自充电支路路线,将泄能支路与自充电支路结合使用,在保证断路器性能的前提下,减少了支路数量,大大降低了晶闸管等元器件数量,从而大大降低其造价。对所提拓扑在单端系统中的工况进行了理论推导与分析,基于所提拓扑设计了500kV的单端直流系统,在PSCAD/EMTDC中建立模型进行了仿真验证,并与其他拓扑方案的性能、元器件数量进行比较。仿真结果表明,SCB-IHDCCB的性能和造价都得到较大优化,具有良好的经济性和应用前景。
