An extended interaction oscillator (EIO) generating 120 GHz wave in sub-terahertz waves is studied by using the three-dimensional electromagnetic simulation software CST and PIC codes. A rectangular reentrant couple...An extended interaction oscillator (EIO) generating 120 GHz wave in sub-terahertz waves is studied by using the three-dimensional electromagnetic simulation software CST and PIC codes. A rectangular reentrant coupled-cavity is proposed as the slow-wave structure of EIO. By CST, the circuit parameters including frequency-phase dispersion, interaction impedance and characteristic impedance are simulated and calculated. The operation mode of EIO is chosen very close to the point where βL = 2π with corresponding frequency 120 GHz, the beam voltage 12 kV and the dimensions of the cavity with the period 0.5mm, the height 3mm and the width 1.4mm. Simulation results of beam-wave interaction by PIC show that the exciting frequency is 120.85 GHz and output peak power 465 W with 12-period coupled-cavity with the perveance 0.17 μP. Simulation results indicate that the EIO has very wide range of the operation voltage.展开更多
The prime standard for audio/video transport in IP networks is the Real-time Transport Protocol (RTP) and it is targeted at useful services for the transport of real-time multimedia data. RTP was originally designed...The prime standard for audio/video transport in IP networks is the Real-time Transport Protocol (RTP) and it is targeted at useful services for the transport of real-time multimedia data. RTP was originally designed for use in multicast conferences, using the lightweight sessions model. RTP (in particular, the data part) is so tightly coupled to the application that a number of people have developed libraries that implement RTP. However, little is known about the RTP overheads between user area and kernel area within operating systenl. Actually, unnecessary copying between user area and kernel area lowers the system efficiency. In this paper, we present the design and implementation of Enhanced Multimedia Input/Output Scheme based on LINUX. We brought focus to the crossover architecture supporting RTP. Our contributions are able to be summarized into two components: 1) Enhanced Input/Output (EIO) scheme based on LINUX improves the transmission speed by reducing the overheads generated from data copy and context switch between user area and kernel area. And this enables server-based system to transport multimedia data more efficiently. 2) Furthermore, Enhanced Input/Output scheme with RTP (EIORTP) scheme supports efficient multimedia data transmission architecture. The two schemes improve the performance of massive multimedia data transmission.展开更多
As IT time and knowledge economy is coming, we should have informationalized the basic management of the enterprises. The paper is concerned with the awkward situation in the basic management as well as the confused m...As IT time and knowledge economy is coming, we should have informationalized the basic management of the enterprises. The paper is concerned with the awkward situation in the basic management as well as the confused management process in the enterprises and expounds theoretically the significance of enterprises informationalization with an example. A proposal frame of input output management information system is put forward.展开更多
Evaporation plavs an important role in the cylinder combustion process.so the study of fiel evaporation characteristics is very important to improve the combustion performance of internal combustion engine.In this stu...Evaporation plavs an important role in the cylinder combustion process.so the study of fiel evaporation characteristics is very important to improve the combustion performance of internal combustion engine.In this study,ethanol diesel was used as the base fuel.The evaporation characteristics of droplets at different ambient temperatures(623 K.923 K)were investigated by adding alumina nanoparticles with different mass fractions(1%,2.5%)to ethanol diesel.The results show that the evaporation states of three kinds of droplets(et hanol diesel,base fuel with 1%alumina nanoparticles,base fuel with 2.5%alumina nanoparticles)are similar in the low temperature environment,and nanoparticles inhibit the evaporation of the droplets.At low temperature,the higher the concentration of nanoparticles is,the slower the evaporation rate is.However.in the high temperature environment,nanoparticles significantly promote droplet evaporation.and the phenomenon of micro explosion is obvious.By analvzine the evaporation processes of two different temperatures,we kuow that nanoparticles first.gather on the surface of the droplet,theu form a protective shell,and finally reduce the evaporation rate of the droplet at low temperature.In the high temperature environment,mucleation sites and bubbles are formed in the interior of the droplet:as the droplet is heated further,mucleation sites and bubbles first gather and then fuse:the bubbles gradually expand and burst rapidly.causing micro explosion of the droplets.and most of them are evaporated in the micro explosion.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 10676110)the National Basic Research Program of China (Grant No 2007CB310401)
文摘An extended interaction oscillator (EIO) generating 120 GHz wave in sub-terahertz waves is studied by using the three-dimensional electromagnetic simulation software CST and PIC codes. A rectangular reentrant coupled-cavity is proposed as the slow-wave structure of EIO. By CST, the circuit parameters including frequency-phase dispersion, interaction impedance and characteristic impedance are simulated and calculated. The operation mode of EIO is chosen very close to the point where βL = 2π with corresponding frequency 120 GHz, the beam voltage 12 kV and the dimensions of the cavity with the period 0.5mm, the height 3mm and the width 1.4mm. Simulation results of beam-wave interaction by PIC show that the exciting frequency is 120.85 GHz and output peak power 465 W with 12-period coupled-cavity with the perveance 0.17 μP. Simulation results indicate that the EIO has very wide range of the operation voltage.
文摘The prime standard for audio/video transport in IP networks is the Real-time Transport Protocol (RTP) and it is targeted at useful services for the transport of real-time multimedia data. RTP was originally designed for use in multicast conferences, using the lightweight sessions model. RTP (in particular, the data part) is so tightly coupled to the application that a number of people have developed libraries that implement RTP. However, little is known about the RTP overheads between user area and kernel area within operating systenl. Actually, unnecessary copying between user area and kernel area lowers the system efficiency. In this paper, we present the design and implementation of Enhanced Multimedia Input/Output Scheme based on LINUX. We brought focus to the crossover architecture supporting RTP. Our contributions are able to be summarized into two components: 1) Enhanced Input/Output (EIO) scheme based on LINUX improves the transmission speed by reducing the overheads generated from data copy and context switch between user area and kernel area. And this enables server-based system to transport multimedia data more efficiently. 2) Furthermore, Enhanced Input/Output scheme with RTP (EIORTP) scheme supports efficient multimedia data transmission architecture. The two schemes improve the performance of massive multimedia data transmission.
文摘As IT time and knowledge economy is coming, we should have informationalized the basic management of the enterprises. The paper is concerned with the awkward situation in the basic management as well as the confused management process in the enterprises and expounds theoretically the significance of enterprises informationalization with an example. A proposal frame of input output management information system is put forward.
基金the Foundation Research Project of Jiangsu Province(the Natural Science Fund:No.BK20180982)。
文摘Evaporation plavs an important role in the cylinder combustion process.so the study of fiel evaporation characteristics is very important to improve the combustion performance of internal combustion engine.In this study,ethanol diesel was used as the base fuel.The evaporation characteristics of droplets at different ambient temperatures(623 K.923 K)were investigated by adding alumina nanoparticles with different mass fractions(1%,2.5%)to ethanol diesel.The results show that the evaporation states of three kinds of droplets(et hanol diesel,base fuel with 1%alumina nanoparticles,base fuel with 2.5%alumina nanoparticles)are similar in the low temperature environment,and nanoparticles inhibit the evaporation of the droplets.At low temperature,the higher the concentration of nanoparticles is,the slower the evaporation rate is.However.in the high temperature environment,nanoparticles significantly promote droplet evaporation.and the phenomenon of micro explosion is obvious.By analvzine the evaporation processes of two different temperatures,we kuow that nanoparticles first.gather on the surface of the droplet,theu form a protective shell,and finally reduce the evaporation rate of the droplet at low temperature.In the high temperature environment,mucleation sites and bubbles are formed in the interior of the droplet:as the droplet is heated further,mucleation sites and bubbles first gather and then fuse:the bubbles gradually expand and burst rapidly.causing micro explosion of the droplets.and most of them are evaporated in the micro explosion.
基金Natural Science Foundation of China(grant no.61671116)the Fundamental Research Funds for the Central Universities (Grant no.ZYGX2015J037,ZYGX2015J039)