In order to achieve the model-based fault monitoring and diagnosis,an accurate model for the rotor system is necessary to locate and quantify faults.Since the dynamic characteristics of a blade-rotor system is influen...In order to achieve the model-based fault monitoring and diagnosis,an accurate model for the rotor system is necessary to locate and quantify faults.Since the dynamic characteristics of a blade-rotor system is influenced by foundation flexibility,the modeling and dynamic analyses on the foundation were sequentially investigated.Firstly,the effect of element size on the model convergence was investigated using the forward difference quotient as the slope of the frequency difference,which found that the model converged when the element size refined to 4mm.Secondly,a modal analysis and a harmonic response analysis were performed to obtain the dynamic characteristics of the foundation structure.Finally,an optimization to the foundation utilizing an additional stiffener was conducted to reduce the foundation response and make the critical speed far away from the working frequency band of 20—50Hz.展开更多
Continuous-wave blue light at 429 nm from a second harmonic process has been investigated at room temperature with Potassium Niobate (KNbO3) crystal. Optimum parameters for nonlinear conversion in our designing single...Continuous-wave blue light at 429 nm from a second harmonic process has been investigated at room temperature with Potassium Niobate (KNbO3) crystal. Optimum parameters for nonlinear conversion in our designing single-resonant, external ring cavity pumped by the Ti:sapphire laser are established. 39% of maximum overall conversion efficiency is obtained and factors that limit the conversion efficiency is discussed.展开更多
The term“beautiful economy”refers to an economic model emerging from China’s new development philosophy.This model focuses on leveraging ecological resources,cultural heritage and local customs-both tangible and in...The term“beautiful economy”refers to an economic model emerging from China’s new development philosophy.This model focuses on leveraging ecological resources,cultural heritage and local customs-both tangible and intangible-to drive economic vitality.By harmonizing industrial and capital utilization with these resources,the beautiful economy aims to create sustainable growth that benefits both society and environment.展开更多
基金supported by the National Key Research and Development Plan(No.2016YFF0203300)
文摘In order to achieve the model-based fault monitoring and diagnosis,an accurate model for the rotor system is necessary to locate and quantify faults.Since the dynamic characteristics of a blade-rotor system is influenced by foundation flexibility,the modeling and dynamic analyses on the foundation were sequentially investigated.Firstly,the effect of element size on the model convergence was investigated using the forward difference quotient as the slope of the frequency difference,which found that the model converged when the element size refined to 4mm.Secondly,a modal analysis and a harmonic response analysis were performed to obtain the dynamic characteristics of the foundation structure.Finally,an optimization to the foundation utilizing an additional stiffener was conducted to reduce the foundation response and make the critical speed far away from the working frequency band of 20—50Hz.
基金This work is partially supported by the program of TRAPOYT of MOE, PRC, the Overseas Youth Scholar Collaboration Foundation (No. 69928504), National Natural Science Foundation of China under Grant No.60178006 and Research Funds for Returned Scholar Abroa
文摘Continuous-wave blue light at 429 nm from a second harmonic process has been investigated at room temperature with Potassium Niobate (KNbO3) crystal. Optimum parameters for nonlinear conversion in our designing single-resonant, external ring cavity pumped by the Ti:sapphire laser are established. 39% of maximum overall conversion efficiency is obtained and factors that limit the conversion efficiency is discussed.
文摘The term“beautiful economy”refers to an economic model emerging from China’s new development philosophy.This model focuses on leveraging ecological resources,cultural heritage and local customs-both tangible and intangible-to drive economic vitality.By harmonizing industrial and capital utilization with these resources,the beautiful economy aims to create sustainable growth that benefits both society and environment.
