A high pressure oil pump has the advantages of compact structure, high working pressure, and it canstill maintain a high efficiency when it is working, so it is very important to analyze its structural strength. A hig...A high pressure oil pump has the advantages of compact structure, high working pressure, and it canstill maintain a high efficiency when it is working, so it is very important to analyze its structural strength. A high-pressure diesel monomer pump is the research object, it is using the finite element software Hypermesh to do thepretreatment of the finite element model, then using Fluent software to analysis the fluid finite element modelwhen it pumped oil to obtain the distribution of oil pressure in the process of pumping oil. And then it is usingAbaqus software to analyze the strength of the related components of the model through mapping oil pressure at thetime of the maximum oil pressure distribution to the model by the structure finite element interpolation, so it canobtain the stress distribution of each component. According to this coupling method to analyze the structuralstrength of high pressure oil pump, it provided the better guidance and reference for the design and optimization ofhigh pressure oil pump.展开更多
The collective behaviors of two coupled harmonic oscillators with dichotomous fluctuating frequency are investigated,including stability, synchronization, and stochastic resonance(SR). First, the synchronization condi...The collective behaviors of two coupled harmonic oscillators with dichotomous fluctuating frequency are investigated,including stability, synchronization, and stochastic resonance(SR). First, the synchronization condition of the system is obtained. When this condition is satisfied, the mean-field behavior is consistent with any single particle behavior in the system. On this basis, the stability condition and the exact steady-state solution of the system are derived. Comparative analysis shows that, the stability condition is stronger than the synchronization condition, that is to say, when the stability condition is satisfied, the system is both synchronous and stable. Simulation analysis indicates that increasing the coupling strength will reduce the synchronization time. In weak coupling region, there is an optimal coupling strength that maximizes the output amplitude gain(OAG), thus the coupling-induced SR behavior occurs. In strong coupling region, the two particles are bounded as a whole, so that the coupling effect gradually disappears.展开更多
Ecological restoration refers to the containment of soil erosion,restoration of water conservation,climate regulation,maintenance of ecological functions of biodiversity,and improvement of ecological environment and l...Ecological restoration refers to the containment of soil erosion,restoration of water conservation,climate regulation,maintenance of ecological functions of biodiversity,and improvement of ecological environment and landscape pattern based on self-repairing capacity of the nature and combined with appropriate artificial measures. Since the natural restoration process of karst desertification mountain is very long,it needs to be supplemented by artificial vegetation restoration. This paper introduced the ecological restoration technologies implemented in karst rocky desertification mountains in Xixiu District,Anshun City of Guizhou Province,and also introduced the afforestation tending management measures. It assessed the ecological benefits of the ecological restoration project from five aspects: mountain community characteristics,vegetation coverage,species diversity,afforestation survival rate and landscape effect.展开更多
文摘A high pressure oil pump has the advantages of compact structure, high working pressure, and it canstill maintain a high efficiency when it is working, so it is very important to analyze its structural strength. A high-pressure diesel monomer pump is the research object, it is using the finite element software Hypermesh to do thepretreatment of the finite element model, then using Fluent software to analysis the fluid finite element modelwhen it pumped oil to obtain the distribution of oil pressure in the process of pumping oil. And then it is usingAbaqus software to analyze the strength of the related components of the model through mapping oil pressure at thetime of the maximum oil pressure distribution to the model by the structure finite element interpolation, so it canobtain the stress distribution of each component. According to this coupling method to analyze the structuralstrength of high pressure oil pump, it provided the better guidance and reference for the design and optimization ofhigh pressure oil pump.
基金supported by the National Natural Science Foundation of China for the Youth (Grant Nos. 11501385 and 11801385)。
文摘The collective behaviors of two coupled harmonic oscillators with dichotomous fluctuating frequency are investigated,including stability, synchronization, and stochastic resonance(SR). First, the synchronization condition of the system is obtained. When this condition is satisfied, the mean-field behavior is consistent with any single particle behavior in the system. On this basis, the stability condition and the exact steady-state solution of the system are derived. Comparative analysis shows that, the stability condition is stronger than the synchronization condition, that is to say, when the stability condition is satisfied, the system is both synchronous and stable. Simulation analysis indicates that increasing the coupling strength will reduce the synchronization time. In weak coupling region, there is an optimal coupling strength that maximizes the output amplitude gain(OAG), thus the coupling-induced SR behavior occurs. In strong coupling region, the two particles are bounded as a whole, so that the coupling effect gradually disappears.
基金Supported by the Construction Science and Technology Plan Program of Chongqing "Study on Landscape and Ecological Restoration Technology for Karst Rocky Desertification Landforms"(2015-1-19)
文摘Ecological restoration refers to the containment of soil erosion,restoration of water conservation,climate regulation,maintenance of ecological functions of biodiversity,and improvement of ecological environment and landscape pattern based on self-repairing capacity of the nature and combined with appropriate artificial measures. Since the natural restoration process of karst desertification mountain is very long,it needs to be supplemented by artificial vegetation restoration. This paper introduced the ecological restoration technologies implemented in karst rocky desertification mountains in Xixiu District,Anshun City of Guizhou Province,and also introduced the afforestation tending management measures. It assessed the ecological benefits of the ecological restoration project from five aspects: mountain community characteristics,vegetation coverage,species diversity,afforestation survival rate and landscape effect.
