Launched on December 28,2016,the Super View-1 satellite has operated for over 70 days at an altitude of 530km.The initial results of in-orbit commissioning show that the images from the Super View-1 satellite are clea...Launched on December 28,2016,the Super View-1 satellite has operated for over 70 days at an altitude of 530km.The initial results of in-orbit commissioning show that the images from the Super View-1 satellite are clear with radiation resolution reaching 11 bits pixel.The geospatial positioning accuracy without ground control pointing is5-8 m,the elevation relative accuracy is1 m.The maximum single scene can be60 km×70 km,enabling some 900。展开更多
This paper introduces a fully integrated low power consumption radio receiver frontend circuit for a Compass（Beidou） and GPS dual mode dual channel system with 2.5 dB NF,1.02 mm^2 areas,and 8 mA of current in 0.18μ...This paper introduces a fully integrated low power consumption radio receiver frontend circuit for a Compass（Beidou） and GPS dual mode dual channel system with 2.5 dB NF,1.02 mm^2 areas,and 8 mA of current in 0.18μm TSMC CMOS process.Except for a few passive components for input matching,other components such as an off-chip low noise amplifier or a balun are not required.With a non-tunable passive image rejection filter,the receiver frontend can achieve around 60 dB gain and 34 dB image rejection.展开更多
The topographies of the 410-km and 660-km discontinuities have important implications for mantle dynamics.Here we present high-resolution seismic imaging of the 410-km and 660-km discontinuities beneath the North Chin...The topographies of the 410-km and 660-km discontinuities have important implications for mantle dynamics.Here we present high-resolution seismic imaging of the 410-km and 660-km discontinuities beneath the North China Craton (NCC) employing the receiver function method.Depth anomalies (deeper or shallower than the global average depths) at both discontinuities were detected by introducing a three-dimensional regional velocity model.The depressions of the 410-km discontinuity are mostly located in the eastern NCC.A local elevation of the 660-km discontinuity appeared in the northwest of the NCC and a significant depression of the 660-km discontinuity is located in the southeast of the NCC.Two dynamic mantle regimes are speculated to explain the formation of the anomalous depth zones in the NCC.One possibility is a complex mantle upwelling linked to edge-derived convection between the stagnant slab and the thick cratonic root.The other potential dynamic regime is slab stagnating,sinking,and induced upwelling at the neighboring slab front.These regimes hint that the mantle flow was possibly dominated by dynamic interactions among the subducting slab,cratonic root,and ambient mantle beneath the NCC.展开更多
文摘Launched on December 28,2016,the Super View-1 satellite has operated for over 70 days at an altitude of 530km.The initial results of in-orbit commissioning show that the images from the Super View-1 satellite are clear with radiation resolution reaching 11 bits pixel.The geospatial positioning accuracy without ground control pointing is5-8 m,the elevation relative accuracy is1 m.The maximum single scene can be60 km×70 km,enabling some 900。
基金supported by the Economic & Information Commission Program of Guangdong,China(No.2011912004)the Department of Science and Technology of Guangdong Province Program,China(Nos.2011 B0 10700065,2011A090200106)the High-Tech Industry Development Funding of Guangdong Province,China(No.2010A011300006)
文摘This paper introduces a fully integrated low power consumption radio receiver frontend circuit for a Compass（Beidou） and GPS dual mode dual channel system with 2.5 dB NF,1.02 mm^2 areas,and 8 mA of current in 0.18μm TSMC CMOS process.Except for a few passive components for input matching,other components such as an off-chip low noise amplifier or a balun are not required.With a non-tunable passive image rejection filter,the receiver frontend can achieve around 60 dB gain and 34 dB image rejection.
基金supported by National Natural Science Foundation of China (Grant No. 90814002)Chinese Academy of Sciences
文摘The topographies of the 410-km and 660-km discontinuities have important implications for mantle dynamics.Here we present high-resolution seismic imaging of the 410-km and 660-km discontinuities beneath the North China Craton (NCC) employing the receiver function method.Depth anomalies (deeper or shallower than the global average depths) at both discontinuities were detected by introducing a three-dimensional regional velocity model.The depressions of the 410-km discontinuity are mostly located in the eastern NCC.A local elevation of the 660-km discontinuity appeared in the northwest of the NCC and a significant depression of the 660-km discontinuity is located in the southeast of the NCC.Two dynamic mantle regimes are speculated to explain the formation of the anomalous depth zones in the NCC.One possibility is a complex mantle upwelling linked to edge-derived convection between the stagnant slab and the thick cratonic root.The other potential dynamic regime is slab stagnating,sinking,and induced upwelling at the neighboring slab front.These regimes hint that the mantle flow was possibly dominated by dynamic interactions among the subducting slab,cratonic root,and ambient mantle beneath the NCC.
