Using the data obtained from sample plots of Phyllostachys pubescens, the dynamic model of energy flow of Phyllostachys pubescens ecosystem was built in this paper.Based on the model,the analysis of energy flow was co...Using the data obtained from sample plots of Phyllostachys pubescens, the dynamic model of energy flow of Phyllostachys pubescens ecosystem was built in this paper.Based on the model,the analysis of energy flow was combined organically with the methods of economical threshold, the concept of economical threshold of energy flow of Phyllostachys pubescen ecosystem (EET) was put forward,and the effect of compensation and super compensation were discussed furthermore.The results showed that the economical threshold of energy flow of Phyllostachys pubescens ecosystem were: EET leaf =0.3133· x 3,EET branch =0.2440· x 1 (where x 1 and x 3 represent energy of leave and branches respectively) ;the effect of compensation and super compensation existed in Phyllostachys pubescens, and the compensation point and super compensation point of Phyllostachys pubescens were 31.33%,13.61% (expressed in defoliation rate)and 24.40%,11.94% (expressed in branch cut rate)respectively.Therefor,this paper will not only enrich the study of energy ecology in the Phyllostachys pubescens ecosystem,but also provide a scientific basis for the management of Phyllostachys pubescens.展开更多
This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current(DC) ...This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current(DC) micromotors. The open-loop and closed-loop approaches described here add the capability for net sidewise displacements of the microrobotic platform. A displacement is achieved by the execution of a number of repeating steps that depend on the desired displacement, the speed of the micromotors, and the elapsed time. Simulation and experimental results verified the performance of the proposed methodologies.展开更多
Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this pape...Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this paper,unbalanced output of conventional forward and reverse traveling wave differential currents under normal operating conditions and external faults was analyzed.A new type of traveling wave differential current was defined by combining forward and reverse traveling wave differential currents.Expressions of the defined differential current when internal and external faults occur were deduced.On this basis,a new principle of traveling wave module differential protection on series-capacitor-compensated lines was proposed,and characteristics of module differential current under different faults were analyzed.The priniciple is immune to line distributed capacity,series capacitor positions,and presence or absence of MOV breakovers.The validity of this scheme was verified by PSACD simulations.展开更多
文摘Using the data obtained from sample plots of Phyllostachys pubescens, the dynamic model of energy flow of Phyllostachys pubescens ecosystem was built in this paper.Based on the model,the analysis of energy flow was combined organically with the methods of economical threshold, the concept of economical threshold of energy flow of Phyllostachys pubescen ecosystem (EET) was put forward,and the effect of compensation and super compensation were discussed furthermore.The results showed that the economical threshold of energy flow of Phyllostachys pubescens ecosystem were: EET leaf =0.3133· x 3,EET branch =0.2440· x 1 (where x 1 and x 3 represent energy of leave and branches respectively) ;the effect of compensation and super compensation existed in Phyllostachys pubescens, and the compensation point and super compensation point of Phyllostachys pubescens were 31.33%,13.61% (expressed in defoliation rate)and 24.40%,11.94% (expressed in branch cut rate)respectively.Therefor,this paper will not only enrich the study of energy ecology in the Phyllostachys pubescens ecosystem,but also provide a scientific basis for the management of Phyllostachys pubescens.
基金supported in part by the National Science Foundation(IIS1318638 and IIS1426752)the Shenzhen Science and Technology Project(ZDSY20120617113312191)
文摘This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current(DC) micromotors. The open-loop and closed-loop approaches described here add the capability for net sidewise displacements of the microrobotic platform. A displacement is achieved by the execution of a number of repeating steps that depend on the desired displacement, the speed of the micromotors, and the elapsed time. Simulation and experimental results verified the performance of the proposed methodologies.
文摘Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this paper,unbalanced output of conventional forward and reverse traveling wave differential currents under normal operating conditions and external faults was analyzed.A new type of traveling wave differential current was defined by combining forward and reverse traveling wave differential currents.Expressions of the defined differential current when internal and external faults occur were deduced.On this basis,a new principle of traveling wave module differential protection on series-capacitor-compensated lines was proposed,and characteristics of module differential current under different faults were analyzed.The priniciple is immune to line distributed capacity,series capacitor positions,and presence or absence of MOV breakovers.The validity of this scheme was verified by PSACD simulations.
