电磁频谱管控（electromagnetic frequency spectrum management,EFSM）是联合作战中各作战单元有效联合的关键环节。加强信息化条件下联合作战电磁频谱管控建设是一项重大而又紧迫的课题。分析了信息化条件下联合作战对电磁频谱管控的...电磁频谱管控（electromagnetic frequency spectrum management,EFSM）是联合作战中各作战单元有效联合的关键环节。加强信息化条件下联合作战电磁频谱管控建设是一项重大而又紧迫的课题。分析了信息化条件下联合作战对电磁频谱管控的总体需求,论述了电磁频谱管控建设的重点内容,最后提出了做好电磁频谱管控建设应着重把握的几个问题。展开更多
Local segregation in Cu-In precursors and its effects on the element distribution and microstructures of selenized CuInSe2 thin films were investigated. Cu-In precursors with an ideal total mole ratio of Cu to In of 0...Local segregation in Cu-In precursors and its effects on the element distribution and microstructures of selenized CuInSe2 thin films were investigated. Cu-In precursors with an ideal total mole ratio of Cu to In of 0.92 were prepared by middle frequency alternating current magnetron sputtering with Cu-In alloy target, then CuInSe2 absorbers for solar cells were formed by selenization process in selenium atmosphere. Scanning electron microscope and energy dispersive X-ray spectroscope were used respectively to observe the surface morphologies and determine the compositions of both Cu-In precursors and CuInSe2 thin films. Their microstructures were characterized by X-ray diffractometry and Raman spectroscope. The results show that Cu-In precursors are mainly composed of (Cu11In9) phase with In-rich solid solution. Stoichiometric CuInSe2 thin films with a homogeneous element distribution and single chalcopyrite phase can be synthesized from a segregated Cu-In precursor film with an ideal total mole ratio of Cu to In of 0.92. CuInSe2 thin film shows P-type conductivity and its resistivity reaches 1.2×103Ω·cm.展开更多
ZrTiO4 is a small ceramic constituent material which has very good thermal and electrical properties. ZrTiO4 thin films were deposited by reactive dc magnetron co-sputtering method. The crystal structure, surface morp...ZrTiO4 is a small ceramic constituent material which has very good thermal and electrical properties. ZrTiO4 thin films were deposited by reactive dc magnetron co-sputtering method. The crystal structure, surface morphology, thickness and dielectric properties were characterized by XRD （X-ray diffraction）, AFM （atomic force microscopy）, FE-SEM （field emission scanning electron microscope）, and precision impedance analyzer respectively. These films were crystallization of the orthorhombic phase （111） of ZrTiOa. The microstructure of well-crystallized ZrTiO4 thin films had the surface morphology was smooth with 1.695 nmrms roughness. The high dielectric constant width decreases from 129.2 to 110.6 when sputtering current increases which are higher more than that had researched because of higher energy but impedance; ｜Z｜ increases from 1.97 to 2.47 kΩ. These results are consistent with the RMS roughness results, which are the RMS roughness decrease with increasing sputtering current.展开更多
This paper presents a transition-mode zero-voltage-switching inverter for the cooker magnetron of household microwave ovens. The inverter drives a leakage transformer to generate the required high voltage and stabiliz...This paper presents a transition-mode zero-voltage-switching inverter for the cooker magnetron of household microwave ovens. The inverter drives a leakage transformer to generate the required high voltage and stabilized current. For achieving zero-voltage switching, a transition-mode driver L6561 is utilized to detect the ending of transformer resonance and drive an insulated-gate-bipolar-transistor. As transistor is conducted, rectified direct-current voltage drives the transformer. While transistor is cut off, transformer resonates with a parallel capacitor. Transistor conduction time and magnetron power are controlled with a 16-bit digital signal controller dsPIC30F4011. For widening the working range, transistor conduction time is set to be inversely changed with line-frequency input voltage. To demonstrate the analysis and design of this paper, a 1 kW inverter circuit is built. Experimental results show the feasibility and usefulness of the designed magnetron power supply.展开更多
The composite films of GaSb nanoparticles embedded in SiO2 matrices were fabricated by radio-frequency magnetron co-sputtering. Transmission electron microscope and X-ray diffraction pattern indicate that the GaSb nan...The composite films of GaSb nanoparticles embedded in SiO2 matrices were fabricated by radio-frequency magnetron co-sputtering. Transmission electron microscope and X-ray diffraction pattern indicate that the GaSb nanoparticles were uniformly dispersed in SiO2 matrices. Room temperature transmission spectra exhibit a blue shift of about 2.73 eV. The blue shift increases with decreasing size of GaSb nanoparticles, suggesting the existence of quantum size effects. Room temperature Raman spectra show that there is a larger Raman peak red shift and broadening of the composite films than that of bulk GaSb. This phenomenon is explained by photon confinement effect and tensile stress effect.展开更多
文摘电磁频谱管控（electromagnetic frequency spectrum management,EFSM）是联合作战中各作战单元有效联合的关键环节。加强信息化条件下联合作战电磁频谱管控建设是一项重大而又紧迫的课题。分析了信息化条件下联合作战对电磁频谱管控的总体需求,论述了电磁频谱管控建设的重点内容,最后提出了做好电磁频谱管控建设应着重把握的几个问题。
基金Project(2004AA513023) supported by the National High Technology Research and Development Program of China
文摘Local segregation in Cu-In precursors and its effects on the element distribution and microstructures of selenized CuInSe2 thin films were investigated. Cu-In precursors with an ideal total mole ratio of Cu to In of 0.92 were prepared by middle frequency alternating current magnetron sputtering with Cu-In alloy target, then CuInSe2 absorbers for solar cells were formed by selenization process in selenium atmosphere. Scanning electron microscope and energy dispersive X-ray spectroscope were used respectively to observe the surface morphologies and determine the compositions of both Cu-In precursors and CuInSe2 thin films. Their microstructures were characterized by X-ray diffractometry and Raman spectroscope. The results show that Cu-In precursors are mainly composed of (Cu11In9) phase with In-rich solid solution. Stoichiometric CuInSe2 thin films with a homogeneous element distribution and single chalcopyrite phase can be synthesized from a segregated Cu-In precursor film with an ideal total mole ratio of Cu to In of 0.92. CuInSe2 thin film shows P-type conductivity and its resistivity reaches 1.2×103Ω·cm.
文摘ZrTiO4 is a small ceramic constituent material which has very good thermal and electrical properties. ZrTiO4 thin films were deposited by reactive dc magnetron co-sputtering method. The crystal structure, surface morphology, thickness and dielectric properties were characterized by XRD （X-ray diffraction）, AFM （atomic force microscopy）, FE-SEM （field emission scanning electron microscope）, and precision impedance analyzer respectively. These films were crystallization of the orthorhombic phase （111） of ZrTiOa. The microstructure of well-crystallized ZrTiO4 thin films had the surface morphology was smooth with 1.695 nmrms roughness. The high dielectric constant width decreases from 129.2 to 110.6 when sputtering current increases which are higher more than that had researched because of higher energy but impedance; ｜Z｜ increases from 1.97 to 2.47 kΩ. These results are consistent with the RMS roughness results, which are the RMS roughness decrease with increasing sputtering current.
文摘This paper presents a transition-mode zero-voltage-switching inverter for the cooker magnetron of household microwave ovens. The inverter drives a leakage transformer to generate the required high voltage and stabilized current. For achieving zero-voltage switching, a transition-mode driver L6561 is utilized to detect the ending of transformer resonance and drive an insulated-gate-bipolar-transistor. As transistor is conducted, rectified direct-current voltage drives the transformer. While transistor is cut off, transformer resonates with a parallel capacitor. Transistor conduction time and magnetron power are controlled with a 16-bit digital signal controller dsPIC30F4011. For widening the working range, transistor conduction time is set to be inversely changed with line-frequency input voltage. To demonstrate the analysis and design of this paper, a 1 kW inverter circuit is built. Experimental results show the feasibility and usefulness of the designed magnetron power supply.
基金the Chinese Climbing Program. We would like to thank Profs. Xu Cunyi and Zuo Jian for Raman measurements at the Center of Structure and Element Analysis (USTC) .
文摘The composite films of GaSb nanoparticles embedded in SiO2 matrices were fabricated by radio-frequency magnetron co-sputtering. Transmission electron microscope and X-ray diffraction pattern indicate that the GaSb nanoparticles were uniformly dispersed in SiO2 matrices. Room temperature transmission spectra exhibit a blue shift of about 2.73 eV. The blue shift increases with decreasing size of GaSb nanoparticles, suggesting the existence of quantum size effects. Room temperature Raman spectra show that there is a larger Raman peak red shift and broadening of the composite films than that of bulk GaSb. This phenomenon is explained by photon confinement effect and tensile stress effect.
