Chongming Island, the third largest island in China and the largest alluvial island in the world, is situated in the north of Shanghai Municipality at the mouth of the Changjiang (Yangtze) River. Along the fertile and...Chongming Island, the third largest island in China and the largest alluvial island in the world, is situated in the north of Shanghai Municipality at the mouth of the Changjiang (Yangtze) River. Along the fertile and prosperous sea coast there are a total area of over 120×103ha, with a population of 735 0 00, accruing some 500ha of new tidal land resources come from silt, sand and mud carried by the Changjiang River every year, extending about 140m per year. This dynamic process of alluvial growth has run for some 1500 years. Mudflat on Chon gming Island at the mouth of the Changjiang River is a resting ground for migrat ory birds and host more than a hundred species, including rare cranes and geese. But the local people keep reclaiming the tidal land for economic development. O bviously, it is crucial to have a well-concerted plan for future exploitation. In this study, we attempted to investigate the status changes of land use and wi ld life habitats on Chongming Island in recent 10 years, and then analyzed diffe rent human activities and their effects on wild life habitats using satellite im age data (1990, 1997 and 2000) as well as field survey. Based on the analysis, t his study explored the relationships between island growth and land use/cover ch ange (LUCC), predicted what the habitat would be like in the future and tried to find more effective use of this new growing resource. At last, this study provi ded some preliminary management plans for Chongming Island that will coordinate the development of local economies and the conservation of wild life and their h abitats.展开更多
The imaging and target detection methods for stepped frequency signal based on the wavelet transform and its power spectrum are investigated. Not only an imaging and target detection algorithm for stepped frequency si...The imaging and target detection methods for stepped frequency signal based on the wavelet transform and its power spectrum are investigated. Not only an imaging and target detection algorithm for stepped frequency signal based on the wavelet transform, but also its respective power spectrum are proposed. The multisampling property of stepped frequency signal is studied and wavelet transform is well suited for analyzing the signal. After multisampling property of stepped frequency signal being studied, it is shown that the wavelet transform is appropriate to analyze the signal. Based on the theory, the wavelet power spectrum analysis is applied to obtain the target range profile and the binary wavelet transform is used to perform target detection. To determine a suitable wavelet scaling for imaging of range profile's MMW radar, the distance resolution ΔR technique is proposed. The effectiveness of this new method is evaluated using simulated noisy radar signal. Results show that the proposed method can bring out the exactness and low computational complexity of this method.展开更多
Cobb syndrome, also known as cutaneo-meningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere. 1 It was f...Cobb syndrome, also known as cutaneo-meningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere. 1 It was first described by Berenbruch in 1890 and did not receive recognition until Cobb’s description 2 in 1915. Only few documents about this disease had been reported. 1 We present two cases here and review the other reported cases.展开更多
文摘Chongming Island, the third largest island in China and the largest alluvial island in the world, is situated in the north of Shanghai Municipality at the mouth of the Changjiang (Yangtze) River. Along the fertile and prosperous sea coast there are a total area of over 120×103ha, with a population of 735 0 00, accruing some 500ha of new tidal land resources come from silt, sand and mud carried by the Changjiang River every year, extending about 140m per year. This dynamic process of alluvial growth has run for some 1500 years. Mudflat on Chon gming Island at the mouth of the Changjiang River is a resting ground for migrat ory birds and host more than a hundred species, including rare cranes and geese. But the local people keep reclaiming the tidal land for economic development. O bviously, it is crucial to have a well-concerted plan for future exploitation. In this study, we attempted to investigate the status changes of land use and wi ld life habitats on Chongming Island in recent 10 years, and then analyzed diffe rent human activities and their effects on wild life habitats using satellite im age data (1990, 1997 and 2000) as well as field survey. Based on the analysis, t his study explored the relationships between island growth and land use/cover ch ange (LUCC), predicted what the habitat would be like in the future and tried to find more effective use of this new growing resource. At last, this study provi ded some preliminary management plans for Chongming Island that will coordinate the development of local economies and the conservation of wild life and their h abitats.
文摘The imaging and target detection methods for stepped frequency signal based on the wavelet transform and its power spectrum are investigated. Not only an imaging and target detection algorithm for stepped frequency signal based on the wavelet transform, but also its respective power spectrum are proposed. The multisampling property of stepped frequency signal is studied and wavelet transform is well suited for analyzing the signal. After multisampling property of stepped frequency signal being studied, it is shown that the wavelet transform is appropriate to analyze the signal. Based on the theory, the wavelet power spectrum analysis is applied to obtain the target range profile and the binary wavelet transform is used to perform target detection. To determine a suitable wavelet scaling for imaging of range profile's MMW radar, the distance resolution ΔR technique is proposed. The effectiveness of this new method is evaluated using simulated noisy radar signal. Results show that the proposed method can bring out the exactness and low computational complexity of this method.
文摘Cobb syndrome, also known as cutaneo-meningospinal angiomatosis, is a rare clinical entity characterized by the combination of a vascular skin nevus and an angioma in the spinal canal at the same metamere. 1 It was first described by Berenbruch in 1890 and did not receive recognition until Cobb’s description 2 in 1915. Only few documents about this disease had been reported. 1 We present two cases here and review the other reported cases.
