The optical communication technology features low cost,wide band,low loss,and anti-electromagnetic interference performance.By combining the optical communication technology with the radio millimeter wave communicatio...The optical communication technology features low cost,wide band,low loss,and anti-electromagnetic interference performance.By combining the optical communication technology with the radio millimeter wave communication system,the Millimeter Wave Radio over Fiber (MM-RoF) system boasts a lot of advantages,including wide band,small size,light weight,low cost,low loss,and resistance of electromagnetic interference as well as high transmission quality.The MM-RoF technology solves the problems faced by traditional microwave transmission system at the millimeter wave band,namely,high loss and inability to resist interference efficiently.Meanwhile,it puts an end to the bottleneck of millimeter wave electronic devices and thus is deemed as with great potentials.The MM-ROF technology that supports multiple formats and services signifies one of the significant trends for future development of the MM-RoF system.展开更多
As China expands its opening to the outside world, hotels in Beijing are developing rapidly. At the end of 1997, there were 259 hotels in Beijing, including 15 fivestar ones, 25 four-star ones and 46 three-star ones a...As China expands its opening to the outside world, hotels in Beijing are developing rapidly. At the end of 1997, there were 259 hotels in Beijing, including 15 fivestar ones, 25 four-star ones and 46 three-star ones and having more than 60,000 rooms.If hotels not appraised for star grade are taken into account, the hotel market in Beijing will be much larger.展开更多
1. History The vehicles with load capacity over 8 tons are classified as heavy vehicles according to China auto industry standards. The first 8t track, JN150, was made in 1960 by Jinan Auto Works. This COE, 4×2 t...1. History The vehicles with load capacity over 8 tons are classified as heavy vehicles according to China auto industry standards. The first 8t track, JN150, was made in 1960 by Jinan Auto Works. This COE, 4×2 truck, simple in structure, OK in technical展开更多
基金supported by the National Natural Science Foundation under Grant No.60736003the National Basic Research Program of China("973" Program)under Grant No.2006CB302800
文摘The optical communication technology features low cost,wide band,low loss,and anti-electromagnetic interference performance.By combining the optical communication technology with the radio millimeter wave communication system,the Millimeter Wave Radio over Fiber (MM-RoF) system boasts a lot of advantages,including wide band,small size,light weight,low cost,low loss,and resistance of electromagnetic interference as well as high transmission quality.The MM-RoF technology solves the problems faced by traditional microwave transmission system at the millimeter wave band,namely,high loss and inability to resist interference efficiently.Meanwhile,it puts an end to the bottleneck of millimeter wave electronic devices and thus is deemed as with great potentials.The MM-ROF technology that supports multiple formats and services signifies one of the significant trends for future development of the MM-RoF system.
文摘As China expands its opening to the outside world, hotels in Beijing are developing rapidly. At the end of 1997, there were 259 hotels in Beijing, including 15 fivestar ones, 25 four-star ones and 46 three-star ones and having more than 60,000 rooms.If hotels not appraised for star grade are taken into account, the hotel market in Beijing will be much larger.
文摘1. History The vehicles with load capacity over 8 tons are classified as heavy vehicles according to China auto industry standards. The first 8t track, JN150, was made in 1960 by Jinan Auto Works. This COE, 4×2 truck, simple in structure, OK in technical
