Convolutional Neural Networks(CNNs)have recently attracted much attention in the ship detection from Synthetic Aperture Radar(SAR)images.However,compared with optical images,SAR ones are hard to understand.Moreover,du...Convolutional Neural Networks(CNNs)have recently attracted much attention in the ship detection from Synthetic Aperture Radar(SAR)images.However,compared with optical images,SAR ones are hard to understand.Moreover,due to the high similarity between the man-made targets near shore and inshore ships,the classical methods are unable to achieve effective detection of inshore ships.To mitigate the influence of onshore ship-like objects,this paper proposes an inshore ship detection method in SAR images by using hybrid features.Firstly,the sea-land segmentation is applied in the pre-processing to exclude obvious land regions from SAR images.Then,a CNN model is designed to extract deep features for identifying potential ship targets in both inshore and offshore water.On this basis,the high-energy point number of amplitude spectrum is further introduced as an important and delicate feature to suppress false alarms left.Finally,to verify the effectiveness of the proposed method,numerical and comparative studies are carried out in experiments on Sentinel-1 SAR images.展开更多
Through unconfined compressive strength test,influencing factors on compressive strength of solidified inshore saline soil with SH lime-ash,ratio of lime-ash(1-K),quantity of lime-ash,age,degree of compression and sal...Through unconfined compressive strength test,influencing factors on compressive strength of solidified inshore saline soil with SH lime-ash,ratio of lime-ash(1-K),quantity of lime-ash,age,degree of compression and salt content were studied.The results show that because inshore saline soil has special engineering characteristic,more influencing factors must be considered compared with ordinary soil for the perfect effect of solidifying.展开更多
This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. Th...This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. The complexity of this system is also analyzed. Moreover, the optimal harvesting policy are given for the inshore subpopulation, which includes the maximum sustainable yield and the corresponding harvesting effort.展开更多
Effects of heavy metals on Isochrysis galbana (Parke ) were studied in our laboratory. The research focused on toxic effects of metals on algal cells, effects of water-soluble and lipid-soluble organic ligands on meta...Effects of heavy metals on Isochrysis galbana (Parke ) were studied in our laboratory. The research focused on toxic effects of metals on algal cells, effects of water-soluble and lipid-soluble organic ligands on metal toxicity and processes of metal uptake by cells. Interactions between two metals and the mechanisms involved were also studied in detail. Finally, some relationships between toxicity and chemical property of metals were revealed.展开更多
Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil...Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil diatom species derived from modern surface sediments. The best-fit relationships between two multivariate datasets(diatom species and environmental variables) were identified using canonical correspondence analysis(CCA), which is a constrained ordination technique. The absolute abundance of diatoms in the Chinese inshore waters ranged from 500 to 48 000 valves/g, and the average absolute abundance of all the 29 sites was 11 300 valves/g. 153 species and varieties of diatoms belonging to 42 genera in all were identified in the Chinese inshore waters. There were 28 dominant diatom species in all. According to the absolute abundance of the dominant species and the spatial distribution of the currents from the Chinese inshore waters, 12 diatom assemblages were distinguished from north to south, which refl ected the different oceanographic conditions at the regional scale. Of the eight environmental variables considered, the most important environmental variable is winter sea surface salinity(WSS), which was also the only environmental variable with statistical significance. Therefore, it may be used to establish a transfer functions for the Chinese inshore waters in future paleoclimate studies.展开更多
A fishing model with stage structure in inshore and offshore areas is considered.Steady states of the dynamical system representing fishery are derived and their local,as well as global,stability is discussed.The opti...A fishing model with stage structure in inshore and offshore areas is considered.Steady states of the dynamical system representing fishery are derived and their local,as well as global,stability is discussed.The optimal harvest policy is formulated and solved as an optimal control problem.A numerical example is given to illustrate the solution procedure.展开更多
基金Aeronautical Science Foundation of China(No.2018ZC51022)。
文摘Convolutional Neural Networks(CNNs)have recently attracted much attention in the ship detection from Synthetic Aperture Radar(SAR)images.However,compared with optical images,SAR ones are hard to understand.Moreover,due to the high similarity between the man-made targets near shore and inshore ships,the classical methods are unable to achieve effective detection of inshore ships.To mitigate the influence of onshore ship-like objects,this paper proposes an inshore ship detection method in SAR images by using hybrid features.Firstly,the sea-land segmentation is applied in the pre-processing to exclude obvious land regions from SAR images.Then,a CNN model is designed to extract deep features for identifying potential ship targets in both inshore and offshore water.On this basis,the high-energy point number of amplitude spectrum is further introduced as an important and delicate feature to suppress false alarms left.Finally,to verify the effectiveness of the proposed method,numerical and comparative studies are carried out in experiments on Sentinel-1 SAR images.
基金Project(05YFSYSF00300) supported by the Natural Science Foundation of Tianjin
文摘Through unconfined compressive strength test,influencing factors on compressive strength of solidified inshore saline soil with SH lime-ash,ratio of lime-ash(1-K),quantity of lime-ash,age,degree of compression and salt content were studied.The results show that because inshore saline soil has special engineering characteristic,more influencing factors must be considered compared with ordinary soil for the perfect effect of solidifying.
文摘This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. The complexity of this system is also analyzed. Moreover, the optimal harvesting policy are given for the inshore subpopulation, which includes the maximum sustainable yield and the corresponding harvesting effort.
基金This paper was published in Chinese in Acta Scientiae Circumstautiae,8(2),1988
文摘Effects of heavy metals on Isochrysis galbana (Parke ) were studied in our laboratory. The research focused on toxic effects of metals on algal cells, effects of water-soluble and lipid-soluble organic ligands on metal toxicity and processes of metal uptake by cells. Interactions between two metals and the mechanisms involved were also studied in detail. Finally, some relationships between toxicity and chemical property of metals were revealed.
基金Supported by the National Natural Science Foundation of China(No.41306083)the Special Fund for Basic Work of Science and Technology from the Ministry of Science and Technology of China(No.2009FY210400)the Special Fund of the Third Institute of Oceanography,State Oceanic Administration for Basic Scientific Research Operations(No.HSK 2011028)
文摘Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil diatom species derived from modern surface sediments. The best-fit relationships between two multivariate datasets(diatom species and environmental variables) were identified using canonical correspondence analysis(CCA), which is a constrained ordination technique. The absolute abundance of diatoms in the Chinese inshore waters ranged from 500 to 48 000 valves/g, and the average absolute abundance of all the 29 sites was 11 300 valves/g. 153 species and varieties of diatoms belonging to 42 genera in all were identified in the Chinese inshore waters. There were 28 dominant diatom species in all. According to the absolute abundance of the dominant species and the spatial distribution of the currents from the Chinese inshore waters, 12 diatom assemblages were distinguished from north to south, which refl ected the different oceanographic conditions at the regional scale. Of the eight environmental variables considered, the most important environmental variable is winter sea surface salinity(WSS), which was also the only environmental variable with statistical significance. Therefore, it may be used to establish a transfer functions for the Chinese inshore waters in future paleoclimate studies.
基金Supported by the Special Fund for Major State Basic Research Projects(G1 9990 3 2 80 5 ) and the Na-tional Natural Science Foundation of China(1 0 1 71 1 0 6)
文摘A fishing model with stage structure in inshore and offshore areas is considered.Steady states of the dynamical system representing fishery are derived and their local,as well as global,stability is discussed.The optimal harvest policy is formulated and solved as an optimal control problem.A numerical example is given to illustrate the solution procedure.
