In this paper,the load characteristics of shock wave,bubble pulsating water jet and cavitation closure are studied by carrying out underwater explosion experiments and numerical simulation of fixed square plates with ...In this paper,the load characteristics of shock wave,bubble pulsating water jet and cavitation closure are studied by carrying out underwater explosion experiments and numerical simulation of fixed square plates with 2.5,5 and 10 g trinitrotoluene.The results show that under the combined action of multiple loads,the impulse of bubble pulsation and water jet load plays a leading role in the process of underwater explosion,and the impulse of cavitation closure load is greater than that of shock wave.The damage to the structure cannot be ignored,and the pressure time-history curve presents a“multi-peak”state,and it is pointed out that the water jet is a concentrated load.Then,the dynamic response of the full-scale model of the ship under the combined action of multiple loads is studied,and the dynamic response of the ship under different cabin water depths and different explosion distances is discussed.The results show that when the ship is empty,the damage degree of the ship is the most serious,and the influence of cavitation effect on the half cabin is weaker than that of the empty cabin,so the damage degree is the second,and the damage degree is the smallest when the cabin is full.When the distance parameter is less than 0.68,the shock wave and the after flow play a leading role in the dynamic response of the ship.When the distance parameter is between 0.68 and 1.38,the combined action of the bubble pulsating water jet and the cavitation closure multi-load causes the main damage to the ship.When the distance parameter is greater than 1.38,the bubble pulsation and the cavitation closure load play a leading role.展开更多
Traditional seawater desalination requires high amounts of energy, with correspondingly high costs and limited benefits, hindering wider applications of the process. To further improve the comprehensive economic benef...Traditional seawater desalination requires high amounts of energy, with correspondingly high costs and limited benefits, hindering wider applications of the process. To further improve the comprehensive economic benefits of seawater desalination, the desalination load can be combined with renewable energy sources such as solar energy, wind energy, and ocean energy or with the power grid to ensure its effective regulation. Utilizing energy internet(EI) technology, energy balance demand of the regional power grid, and coordinated control between coastal multi-source multi-load and regional distribution network with desalination load is reviewed herein. Several key technologies, including coordinated control of coastal multi-source multi-load system with seawater desalination load, flexible interaction between seawater desalination and regional distribution network, and combined control of coastal multi-source multi-load storage system with seawater desalination load, are discussed in detail. Adoption of the flexible interaction between seawater desalination and regional distribution networks is beneficial for solving water resource problems, improving the ability to dissipate distributed renewable energy, balancing and increasing grid loads, improving the safety and economy of coastal power grids, and achieving coordinated and comprehensive application of power grids, renewable energy sources, and coastal loads.展开更多
The shakedown analysis of structures under variable multi-loadings is considered, and the corresponding simple shakedown condition is presented in this paper. Distribution of fixed stresses field is given, and the sel...The shakedown analysis of structures under variable multi-loadings is considered, and the corresponding simple shakedown condition is presented in this paper. Distribution of fixed stresses field is given, and the self-equilibrium of fixed stresses field is analyzed. Elastic shakedown and plastic shakedown conditions are presented based on the fixed stresses field. The theorem is convenient to evaluate the shakedown limit of structures under cyclical variable multiloadings through solving positive scalar fields and fixed stresses field factors at a series of dangerous positions of the structure, and tedious computations are avoided. Finally the theorem is applied to a thick-walled cylindrical tube under variable pressure and temperature, and the rolling contact problem. The results are in good agreement with some computational results.展开更多
目的针对飞机货舱配载方案评估中多属性决策的复杂性,以及现有评估方法在权重确定上过度依赖专家经验导致的主观偏差,或单纯依赖客观数据忽略决策者偏好的局限性,提出一种融合主观先验与客观数据驱动的混合赋权评估模型,以提供更为合理...目的针对飞机货舱配载方案评估中多属性决策的复杂性,以及现有评估方法在权重确定上过度依赖专家经验导致的主观偏差,或单纯依赖客观数据忽略决策者偏好的局限性,提出一种融合主观先验与客观数据驱动的混合赋权评估模型,以提供更为合理、可靠的配载方案择优决策支持。方法首先,引入大型语言模型(Large language model,LLM),构建“虚拟专家委员会”,通过精心设计的提示词工程,获取多维度、多情境下的主观权重。其次,针对传统熵权法对数据分布敏感、难以有效区分指标优劣等问题,提出一种改进的数据预处理熵权法(Improved data preprocessing entropy weighting method,IDPEW),该方法结合指标值的辨识度和信息熵的均衡性来确定客观权重。最后,将LLM生成的主观权重与IDPEW计算的客观权重进行加权组合,构建综合评价函数,对飞机货舱配载方案进行全面评估和排序。结果实验结果表明,LLM模拟专家意见时最关注“装载率”(主观权重0.2250),而IDPEW方法从数据中识别出“横向不平衡度”最具区分力(客观权重0.2481)。混合赋权模型(α=0.5)有效平衡了主客观偏好,在24个方案中精准识别出综合性能最优的方案,验证了模型在复杂情境下的稳定性。结论创新性地利用LLM低成本构建“虚拟专家”获取先验知识,并通过耦合指标辨识度与均衡性的IDPEW方法,提升了客观赋权精度。该模型克服了单一赋权的局限,为飞机货舱配载方案的科学评估提供了一种兼具可解释性和实用性的新范式。展开更多
Using an energy-based Hamiltonian function method,this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations.First,...Using an energy-based Hamiltonian function method,this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations.First,we complete the dissipative Hamiltonian realization of the power system and adjust its operating point by the means of pre-feedback control.Then,based on the obtained Hamiltonian realization,we discuss the robust excitation control of the power system and put forward an H1 excitation control strategy.Simulation results demonstrate the effectiveness of the control scheme.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12172178).
文摘In this paper,the load characteristics of shock wave,bubble pulsating water jet and cavitation closure are studied by carrying out underwater explosion experiments and numerical simulation of fixed square plates with 2.5,5 and 10 g trinitrotoluene.The results show that under the combined action of multiple loads,the impulse of bubble pulsation and water jet load plays a leading role in the process of underwater explosion,and the impulse of cavitation closure load is greater than that of shock wave.The damage to the structure cannot be ignored,and the pressure time-history curve presents a“multi-peak”state,and it is pointed out that the water jet is a concentrated load.Then,the dynamic response of the full-scale model of the ship under the combined action of multiple loads is studied,and the dynamic response of the ship under different cabin water depths and different explosion distances is discussed.The results show that when the ship is empty,the damage degree of the ship is the most serious,and the influence of cavitation effect on the half cabin is weaker than that of the empty cabin,so the damage degree is the second,and the damage degree is the smallest when the cabin is full.When the distance parameter is less than 0.68,the shock wave and the after flow play a leading role in the dynamic response of the ship.When the distance parameter is between 0.68 and 1.38,the combined action of the bubble pulsating water jet and the cavitation closure multi-load causes the main damage to the ship.When the distance parameter is greater than 1.38,the bubble pulsation and the cavitation closure load play a leading role.
基金supported by the State Grid Science and Technology Project, “Study on Multi-source and Multiload Coordination and Optimization Technology Considering Desalination of Sea Water” (No. SGTJDK00DWJS1800011)
文摘Traditional seawater desalination requires high amounts of energy, with correspondingly high costs and limited benefits, hindering wider applications of the process. To further improve the comprehensive economic benefits of seawater desalination, the desalination load can be combined with renewable energy sources such as solar energy, wind energy, and ocean energy or with the power grid to ensure its effective regulation. Utilizing energy internet(EI) technology, energy balance demand of the regional power grid, and coordinated control between coastal multi-source multi-load and regional distribution network with desalination load is reviewed herein. Several key technologies, including coordinated control of coastal multi-source multi-load system with seawater desalination load, flexible interaction between seawater desalination and regional distribution network, and combined control of coastal multi-source multi-load storage system with seawater desalination load, are discussed in detail. Adoption of the flexible interaction between seawater desalination and regional distribution networks is beneficial for solving water resource problems, improving the ability to dissipate distributed renewable energy, balancing and increasing grid loads, improving the safety and economy of coastal power grids, and achieving coordinated and comprehensive application of power grids, renewable energy sources, and coastal loads.
文摘The shakedown analysis of structures under variable multi-loadings is considered, and the corresponding simple shakedown condition is presented in this paper. Distribution of fixed stresses field is given, and the self-equilibrium of fixed stresses field is analyzed. Elastic shakedown and plastic shakedown conditions are presented based on the fixed stresses field. The theorem is convenient to evaluate the shakedown limit of structures under cyclical variable multiloadings through solving positive scalar fields and fixed stresses field factors at a series of dangerous positions of the structure, and tedious computations are avoided. Finally the theorem is applied to a thick-walled cylindrical tube under variable pressure and temperature, and the rolling contact problem. The results are in good agreement with some computational results.
基金Supported by National Natural Science Foundation of China （60674039, 60704004） and Innovation Fund for Outstanding Scholar of Henan Province （084200510009 ）
文摘目的针对飞机货舱配载方案评估中多属性决策的复杂性,以及现有评估方法在权重确定上过度依赖专家经验导致的主观偏差,或单纯依赖客观数据忽略决策者偏好的局限性,提出一种融合主观先验与客观数据驱动的混合赋权评估模型,以提供更为合理、可靠的配载方案择优决策支持。方法首先,引入大型语言模型(Large language model,LLM),构建“虚拟专家委员会”,通过精心设计的提示词工程,获取多维度、多情境下的主观权重。其次,针对传统熵权法对数据分布敏感、难以有效区分指标优劣等问题,提出一种改进的数据预处理熵权法(Improved data preprocessing entropy weighting method,IDPEW),该方法结合指标值的辨识度和信息熵的均衡性来确定客观权重。最后,将LLM生成的主观权重与IDPEW计算的客观权重进行加权组合,构建综合评价函数,对飞机货舱配载方案进行全面评估和排序。结果实验结果表明,LLM模拟专家意见时最关注“装载率”(主观权重0.2250),而IDPEW方法从数据中识别出“横向不平衡度”最具区分力(客观权重0.2481)。混合赋权模型(α=0.5)有效平衡了主客观偏好,在24个方案中精准识别出综合性能最优的方案,验证了模型在复杂情境下的稳定性。结论创新性地利用LLM低成本构建“虚拟专家”获取先验知识,并通过耦合指标辨识度与均衡性的IDPEW方法,提升了客观赋权精度。该模型克服了单一赋权的局限,为飞机货舱配载方案的科学评估提供了一种兼具可解释性和实用性的新范式。
基金supported by the National Natural Science Foundation of China(Grant No.60974005)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20094101120008)the Nature Science Foundation of Henan Province(No.092300410201).
文摘Using an energy-based Hamiltonian function method,this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations.First,we complete the dissipative Hamiltonian realization of the power system and adjust its operating point by the means of pre-feedback control.Then,based on the obtained Hamiltonian realization,we discuss the robust excitation control of the power system and put forward an H1 excitation control strategy.Simulation results demonstrate the effectiveness of the control scheme.
