By studying current seedling production in Honghe Hani and Yi Nationality Autonomous Prefecture, tropical and subtropical urban landscape plant production in southwest China was analyzed. Local nurseries total 6.40 km...By studying current seedling production in Honghe Hani and Yi Nationality Autonomous Prefecture, tropical and subtropical urban landscape plant production in southwest China was analyzed. Local nurseries total 6.40 km 2 , accounting for 5.1% of total constructed land area in the prefecture, and only 0.02% of the total land area in the prefecture. Application of local plant species in landscape engineering and green coverage ratio lags far behind the indexes of Chinese livable city and indexes of relieving urban heat island effect. By making proper policies and measures, seedling production can be promoted, rare and endanged wild plant species should be fully used to construct garden city, control PM2.5 and protect the living environment.展开更多
Development trend of Yunnan gardens are analyzed from domestic and international perspectives, and domestic opportunities for Yunnan gardens are explored. Concept, properties, location and significance of Yunnan garde...Development trend of Yunnan gardens are analyzed from domestic and international perspectives, and domestic opportunities for Yunnan gardens are explored. Concept, properties, location and significance of Yunnan gardens are introduced; the guiding concepts and development principles of Yunnan gardens are summarized. Through further study of Yunnan gardens, the authors promote the understanding of government and the public, research within academic circles, and applied practices by enterprises. Finally, development trend and mission of Yunnan gardens are discussed.展开更多
The production mechanism of non-return-to-zero(NRZ),return-to-zero(RZ)and carrier suppressed return-to-zero(CSRZ)was analyzed theoretically in this paper.We compared the transmission performance of CSRZ with RZ and NR...The production mechanism of non-return-to-zero(NRZ),return-to-zero(RZ)and carrier suppressed return-to-zero(CSRZ)was analyzed theoretically in this paper.We compared the transmission performance of CSRZ with RZ and NRZ formats at 10 Gb/s system by numerical simulation.And we simulated the transmission model constructed with Erbium-doped fiber amplifier(EDFA)as the solo amplifier and the chirped fiber Bragg grating(CFBG)as the solo dispersion compensator used in the system.A practical 8x10 Gb/s 2560 km transmitted experiment was conducted in straight line with these different modulation formats mentioned above and the experiment results show very good agreement with the result of computer simulation.The CSRZ format is more effective than other formats in the system,and involved only 2.5 dB power penalty cost in the practical 2560 km error-free experiment.The results also show that CSRZ will help to optimize the transmitted results and reduce the transmitted penalty further.展开更多
文摘By studying current seedling production in Honghe Hani and Yi Nationality Autonomous Prefecture, tropical and subtropical urban landscape plant production in southwest China was analyzed. Local nurseries total 6.40 km 2 , accounting for 5.1% of total constructed land area in the prefecture, and only 0.02% of the total land area in the prefecture. Application of local plant species in landscape engineering and green coverage ratio lags far behind the indexes of Chinese livable city and indexes of relieving urban heat island effect. By making proper policies and measures, seedling production can be promoted, rare and endanged wild plant species should be fully used to construct garden city, control PM2.5 and protect the living environment.
文摘Development trend of Yunnan gardens are analyzed from domestic and international perspectives, and domestic opportunities for Yunnan gardens are explored. Concept, properties, location and significance of Yunnan gardens are introduced; the guiding concepts and development principles of Yunnan gardens are summarized. Through further study of Yunnan gardens, the authors promote the understanding of government and the public, research within academic circles, and applied practices by enterprises. Finally, development trend and mission of Yunnan gardens are discussed.
基金supported by Hi-Tech Research and Development Program of China(No.2001AA122012)the National Natural Science Foundation of China(Grant No.60337010).
文摘The production mechanism of non-return-to-zero(NRZ),return-to-zero(RZ)and carrier suppressed return-to-zero(CSRZ)was analyzed theoretically in this paper.We compared the transmission performance of CSRZ with RZ and NRZ formats at 10 Gb/s system by numerical simulation.And we simulated the transmission model constructed with Erbium-doped fiber amplifier(EDFA)as the solo amplifier and the chirped fiber Bragg grating(CFBG)as the solo dispersion compensator used in the system.A practical 8x10 Gb/s 2560 km transmitted experiment was conducted in straight line with these different modulation formats mentioned above and the experiment results show very good agreement with the result of computer simulation.The CSRZ format is more effective than other formats in the system,and involved only 2.5 dB power penalty cost in the practical 2560 km error-free experiment.The results also show that CSRZ will help to optimize the transmitted results and reduce the transmitted penalty further.
