There are abundant water power resources in the Yalong River which are suitable for the large hydroelectric engineering. But a reliability study should be made for the valley which liable to frequent earthquakes. The ...There are abundant water power resources in the Yalong River which are suitable for the large hydroelectric engineering. But a reliability study should be made for the valley which liable to frequent earthquakes. The color infrared aerophotos, multi-spectral photography and thermal infrared scanning had been specially done besides MSS image, processing. Researches on remote sensing applications to engineering geology, hydrogeology, deformation of neo-tectonics, Iandslide, mud-rock flow, ecological environment and geographical information system had been carried out by more than 20 research units.展开更多
In this paper, aiming at practical dense wavelength division multiplexing （DWDM） system with ultralong fiber span, a simple co-fiber remotely pumped erbium-doped fiber amplifier （RP-EDFA） scheme is proposed to ext...In this paper, aiming at practical dense wavelength division multiplexing （DWDM） system with ultralong fiber span, a simple co-fiber remotely pumped erbium-doped fiber amplifier （RP-EDFA） scheme is proposed to extend span distance with simple configuration and low pump power. Equivalent noise figure of -6 dB is achieved under 300-mW pump power. Using the experiment results, numerical simulation of ultra-long span systems shows that for a 40 × 11.6-Gb/s transmission system, the RP-EDFA scheme can support transmission of 1760 km with a fiber span of 160 km. These results demonstrate the potential of the PR-EDFA scheme in ultra-long span transmission.展开更多
Background White Rabbit(WR)is a deterministic Ethernet-based network for general-purpose data transfer and subnanosecond time synchronization in large distributed systems.WR has been used in Large Hadron Collider and ...Background White Rabbit(WR)is a deterministic Ethernet-based network for general-purpose data transfer and subnanosecond time synchronization in large distributed systems.WR has been used in Large Hadron Collider and Large High-Altitude Air Shower Observatory for physics experiment.Purpose WR mainly uses the optical fiber for data transmission between WR devices.Commercial off-the-shelf Direct Attach Cable is not suitable for WR network at 100m level distance.Considering the lower cost of Category(CAT)Ethernet cable compared to optical fiber and the demand of remote power supply in distributed system at 100m level length,we developed a novel transmission scheme with CAT Ethernet cable for WR.Methods The novel transmission scheme uses the CAT Ethernet cable and small form-factor pluggable connector which is compatible with the optical links.This scheme only uses two pairs of twisted lines in the CAT Ethernet cable for data uplink and downlink.The other two pairs of twisted lines are used for remote power supply.Results and conclusion The novel transmission scheme could use the CAT Ethernet cable to complete remote power supply and time synchronization with expected time offset of less than 100 ps and standard deviation of less than 20 ps in the WR distributed system.The distance of distributed nodes could be 80m with one CAT 7 Ethernet cable or 150m with relay transceiver connecting two CAT 7 Ethernet cables.In the short-distance scenarios,the novel transmission scheme has lower cost than the optical fiber and additional power supply function.展开更多
文摘There are abundant water power resources in the Yalong River which are suitable for the large hydroelectric engineering. But a reliability study should be made for the valley which liable to frequent earthquakes. The color infrared aerophotos, multi-spectral photography and thermal infrared scanning had been specially done besides MSS image, processing. Researches on remote sensing applications to engineering geology, hydrogeology, deformation of neo-tectonics, Iandslide, mud-rock flow, ecological environment and geographical information system had been carried out by more than 20 research units.
文摘In this paper, aiming at practical dense wavelength division multiplexing （DWDM） system with ultralong fiber span, a simple co-fiber remotely pumped erbium-doped fiber amplifier （RP-EDFA） scheme is proposed to extend span distance with simple configuration and low pump power. Equivalent noise figure of -6 dB is achieved under 300-mW pump power. Using the experiment results, numerical simulation of ultra-long span systems shows that for a 40 × 11.6-Gb/s transmission system, the RP-EDFA scheme can support transmission of 1760 km with a fiber span of 160 km. These results demonstrate the potential of the PR-EDFA scheme in ultra-long span transmission.
基金the State Key Laboratory of Particle Detection and Electronics,SKLPDE-ZZ-201918.
文摘Background White Rabbit(WR)is a deterministic Ethernet-based network for general-purpose data transfer and subnanosecond time synchronization in large distributed systems.WR has been used in Large Hadron Collider and Large High-Altitude Air Shower Observatory for physics experiment.Purpose WR mainly uses the optical fiber for data transmission between WR devices.Commercial off-the-shelf Direct Attach Cable is not suitable for WR network at 100m level distance.Considering the lower cost of Category(CAT)Ethernet cable compared to optical fiber and the demand of remote power supply in distributed system at 100m level length,we developed a novel transmission scheme with CAT Ethernet cable for WR.Methods The novel transmission scheme uses the CAT Ethernet cable and small form-factor pluggable connector which is compatible with the optical links.This scheme only uses two pairs of twisted lines in the CAT Ethernet cable for data uplink and downlink.The other two pairs of twisted lines are used for remote power supply.Results and conclusion The novel transmission scheme could use the CAT Ethernet cable to complete remote power supply and time synchronization with expected time offset of less than 100 ps and standard deviation of less than 20 ps in the WR distributed system.The distance of distributed nodes could be 80m with one CAT 7 Ethernet cable or 150m with relay transceiver connecting two CAT 7 Ethernet cables.In the short-distance scenarios,the novel transmission scheme has lower cost than the optical fiber and additional power supply function.
