0 Introduction Fifteen years have passed since the first AlGaN/GaN HFET was reported in 1993.The FETs have already commercialized as microwave power devices,but volume production has not yet realized.The main applicat...0 Introduction Fifteen years have passed since the first AlGaN/GaN HFET was reported in 1993.The FETs have already commercialized as microwave power devices,but volume production has not yet realized.The main application field is mobile phone base stations.For such applications,GaAs power transistors and silicon LDMOS have already been used.Therefore,advantages compared with these existing devices will be required,such as high efficiency,low distortion,low noise,high reliability and,especially,low cost.However,the latter two items are normally difficult for devices using new materials.展开更多
Over the past three decades, power plant simulators have gone through several major phases of evolution and they have been widely used as a valuable toolfor training plant operational personnel. Looking forward ,the...Over the past three decades, power plant simulators have gone through several major phases of evolution and they have been widely used as a valuable toolfor training plant operational personnel. Looking forward ,the simulators willagain provetheirvaluefar beyondthe traditionaltraining applications.Simulators will serve asthe engine ofthe envisioned “TotalPlantSolution System”,which willprovide optimized solutionsto every aspectofthe plantoperationincluding on line plant monitoring,control,diagnostics,automation,optimization,aswellas simulation and analysis.Simulators willgreatly enhance operationalreliability,availability,efficiency,and safety.展开更多
Through 40 years development Ti hasbecame an important military and civil in-dustry material called "Air"—"Land"—"Ocean"metal.Ti is an ideal structurematerial and corrosion resistant ma...Through 40 years development Ti hasbecame an important military and civil in-dustry material called "Air"—"Land"—"Ocean"metal.Ti is an ideal structurematerial and corrosion resistant material,which has bright future in the developmentof modern technology.展开更多
文摘0 Introduction Fifteen years have passed since the first AlGaN/GaN HFET was reported in 1993.The FETs have already commercialized as microwave power devices,but volume production has not yet realized.The main application field is mobile phone base stations.For such applications,GaAs power transistors and silicon LDMOS have already been used.Therefore,advantages compared with these existing devices will be required,such as high efficiency,low distortion,low noise,high reliability and,especially,low cost.However,the latter two items are normally difficult for devices using new materials.
文摘Over the past three decades, power plant simulators have gone through several major phases of evolution and they have been widely used as a valuable toolfor training plant operational personnel. Looking forward ,the simulators willagain provetheirvaluefar beyondthe traditionaltraining applications.Simulators will serve asthe engine ofthe envisioned “TotalPlantSolution System”,which willprovide optimized solutionsto every aspectofthe plantoperationincluding on line plant monitoring,control,diagnostics,automation,optimization,aswellas simulation and analysis.Simulators willgreatly enhance operationalreliability,availability,efficiency,and safety.
文摘Through 40 years development Ti hasbecame an important military and civil in-dustry material called "Air"—"Land"—"Ocean"metal.Ti is an ideal structurematerial and corrosion resistant material,which has bright future in the developmentof modern technology.
