Determining earth pressure on jacked pipes is essential for ensuring lining safety and calculating jacking force,especially for deep-buried pipes.To better reflect the soil arching effect resulting from the excavation...Determining earth pressure on jacked pipes is essential for ensuring lining safety and calculating jacking force,especially for deep-buried pipes.To better reflect the soil arching effect resulting from the excavation of rectangular jacked pipes and the distribution of the earth pressure on jacked pipes,we present an analytical solution for predicting the vertical earth pressure on deep-buried rectangular pipe jacking tunnels,incorporating the tunnelling-induced ground loss distribution.Our proposed analytical model consists of the upper multi-layer parabolic soil arch and the lower friction arch.The key parameters(i.e.,width and height of friction arch B and height of parabolic soil arch H 1)are determined according to the existing research,and an analytical solution for K l is derived based on the distribution characteristics of the principal stress rotation angle.With consideration for the transition effect of the mechanical characteristics of the parabolic arch zone,an analytical solution for soil load transfer is derived.The prediction results of our analytical solution are compared with tests and simulation results to validate the effectiveness of the proposed analytical solution.Finally,the effects of different parameters on the soil pressure are discussed.展开更多
Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which sa...Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which satisfy the stiffimss and rotational speed required to the spindle. A general full factorial design method was used to verify some factors that affect the natural frequency of a spindle. It is verified that the shorter shaft length and bearing span length represent the higher natural frequency, and there are some effects according to the change in the levels of factors. The detailed spindle dimension is determined by applying an EVD method, which can define the optimal bearing position through considering the limiting condition. Based on the estimated regression model, the optimal spindle size and bearing distance that can improve the primary natural frequency are obtained, and the influence of design factors on the natural frequency is also analyzed.展开更多
A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevaryin...A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.展开更多
The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricatin...The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricating high-performance and large-area organic solar cells(OSCs).This method allows for the independent dissolution and deposition of donor and acceptor materials,enabling precise morphology control.In this review,we provide a comprehensive overview of the LBL processing technique,focusing on the morphology of the active layer.The swelling intercalation phase-separation(SIPS)model is introduced as the mainstream theory of morphology evolution,with a detailed discussion on vertical phase separation.We summarize recent strategies for morphology optimization.Additionally,we review the progress in LBL-based large-area device and module fabrication,as well as green processing approaches.Finally,we highlight current challenges and future prospects,paving the way for the commercialization of LBL-processed OSCs.展开更多
针对城市场景下载人电动垂直起降飞行器(electric vertical takeoff and landing,eVTOL)路径规划问题进行了研究。首先,使用危险度栅格法进行三维城市空间建模,对选定型号的eVTOL飞行器,以航程、运行风险和高度变化为目标函数,结合飞行...针对城市场景下载人电动垂直起降飞行器(electric vertical takeoff and landing,eVTOL)路径规划问题进行了研究。首先,使用危险度栅格法进行三维城市空间建模,对选定型号的eVTOL飞行器,以航程、运行风险和高度变化为目标函数,结合飞行器自身特性及环境限制,构建了多约束条件的载人eVTOL路径规划模型。然后,设计了一种改进人工电场算法(im-proved artificial electric field algorithm,IAEFA),在传统人工电场算法(artificial electric field algorithm,AEFA)的基础上增加了自适应库伦参数,并在库伦常数的计算中引入递减系数,以此进行仿真求解。实验结果显示,所构建的模型可以达到预期效果。使用改进算法进行路径规划的求解效果更优,相较传统粒子群算法和人工电场法,航程更短,高度变化更小且运行更为安全。最后,根据对照实验确定递减系数的取值,当递减系数取值为1.5时,改进算法的求解效果最优。展开更多
基金Project(2022YJS073)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2024YFE0198500)supported by the National Key Research and Development Program of China:Intergovernmental International Science and Technology Innovation CooperationProject(U2469207)supported by the National Natural Science Foundation Railway Innovation and Development Joint Fund Project,China。
文摘Determining earth pressure on jacked pipes is essential for ensuring lining safety and calculating jacking force,especially for deep-buried pipes.To better reflect the soil arching effect resulting from the excavation of rectangular jacked pipes and the distribution of the earth pressure on jacked pipes,we present an analytical solution for predicting the vertical earth pressure on deep-buried rectangular pipe jacking tunnels,incorporating the tunnelling-induced ground loss distribution.Our proposed analytical model consists of the upper multi-layer parabolic soil arch and the lower friction arch.The key parameters(i.e.,width and height of friction arch B and height of parabolic soil arch H 1)are determined according to the existing research,and an analytical solution for K l is derived based on the distribution characteristics of the principal stress rotation angle.With consideration for the transition effect of the mechanical characteristics of the parabolic arch zone,an analytical solution for soil load transfer is derived.The prediction results of our analytical solution are compared with tests and simulation results to validate the effectiveness of the proposed analytical solution.Finally,the effects of different parameters on the soil pressure are discussed.
基金Project(RTI04-01-03) supported by the Regional Technology Innovation Program of the Ministry of Knowledge Economy (MKE) of Korea
文摘Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which satisfy the stiffimss and rotational speed required to the spindle. A general full factorial design method was used to verify some factors that affect the natural frequency of a spindle. It is verified that the shorter shaft length and bearing span length represent the higher natural frequency, and there are some effects according to the change in the levels of factors. The detailed spindle dimension is determined by applying an EVD method, which can define the optimal bearing position through considering the limiting condition. Based on the estimated regression model, the optimal spindle size and bearing distance that can improve the primary natural frequency are obtained, and the influence of design factors on the natural frequency is also analyzed.
基金supported in part by the Nation Natural Science Foundation of China under Grant No.52175099China Postdoctoral Science Foundation under Grant No.2020M671494Jiangsu Planned Projects for Postdoctoral Research Funds under Grant No.2020Z179。
文摘A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.
基金Project(22408404)supported by the National Natural Science Foundation of China。
文摘The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricating high-performance and large-area organic solar cells(OSCs).This method allows for the independent dissolution and deposition of donor and acceptor materials,enabling precise morphology control.In this review,we provide a comprehensive overview of the LBL processing technique,focusing on the morphology of the active layer.The swelling intercalation phase-separation(SIPS)model is introduced as the mainstream theory of morphology evolution,with a detailed discussion on vertical phase separation.We summarize recent strategies for morphology optimization.Additionally,we review the progress in LBL-based large-area device and module fabrication,as well as green processing approaches.Finally,we highlight current challenges and future prospects,paving the way for the commercialization of LBL-processed OSCs.
文摘针对城市场景下载人电动垂直起降飞行器(electric vertical takeoff and landing,eVTOL)路径规划问题进行了研究。首先,使用危险度栅格法进行三维城市空间建模,对选定型号的eVTOL飞行器,以航程、运行风险和高度变化为目标函数,结合飞行器自身特性及环境限制,构建了多约束条件的载人eVTOL路径规划模型。然后,设计了一种改进人工电场算法(im-proved artificial electric field algorithm,IAEFA),在传统人工电场算法(artificial electric field algorithm,AEFA)的基础上增加了自适应库伦参数,并在库伦常数的计算中引入递减系数,以此进行仿真求解。实验结果显示,所构建的模型可以达到预期效果。使用改进算法进行路径规划的求解效果更优,相较传统粒子群算法和人工电场法,航程更短,高度变化更小且运行更为安全。最后,根据对照实验确定递减系数的取值,当递减系数取值为1.5时,改进算法的求解效果最优。
