We provide a way to precisely control the geometry of a SiNx nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiNx membrane, which is immersed in potassium...We provide a way to precisely control the geometry of a SiNx nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiNx membrane, which is immersed in potassium chloride solution. We can generate single conical and cylindrical pores with different electric pulses. A theoretical model based on the Poisson and Nernst-Planck equations is employed to simulate the ion transport properties in the channel. In turn, we can analyze pore geometries by fitting the experimental current-voltage （I-V） curves. for the conical pores with a pore size of 0.5-2nm in diameter, the slope angles are around -2.5% to -10%. Moreover, the pore orifice can be enlarged slightly by additional repeating pulses. The conic pore lumen becomes close to a cylindrical channel, resulting in a symmetry I-V transport under positive and negative biases. A qualitative understanding of these effects will help us to prepare useful solid-nanopores as demanded.展开更多
Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph(DLG)and up-to-date remote sensitive images which have high precision and have been orthographically rectified...Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph(DLG)and up-to-date remote sensitive images which have high precision and have been orthographically rectified precisely.Quick Bird panchromatic remote sensing image is used and an urban area with even terrain and dense buildings is selected as experimental area.Ground control points(GCPs)are selected on a new 1∶500 topographical map and multinomial model is applied for rectification.After rectification the absolute positional error of a single point of the image is less than 1m,therefore this method is suitable for renewing topographical maps of up to(1∶2000)scale.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 61471336,51503207 and 61504146the Joint-Scholar of West Light Foundation of Chinese Academy of Sciences
文摘We provide a way to precisely control the geometry of a SiNx nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiNx membrane, which is immersed in potassium chloride solution. We can generate single conical and cylindrical pores with different electric pulses. A theoretical model based on the Poisson and Nernst-Planck equations is employed to simulate the ion transport properties in the channel. In turn, we can analyze pore geometries by fitting the experimental current-voltage （I-V） curves. for the conical pores with a pore size of 0.5-2nm in diameter, the slope angles are around -2.5% to -10%. Moreover, the pore orifice can be enlarged slightly by additional repeating pulses. The conic pore lumen becomes close to a cylindrical channel, resulting in a symmetry I-V transport under positive and negative biases. A qualitative understanding of these effects will help us to prepare useful solid-nanopores as demanded.
文摘Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph(DLG)and up-to-date remote sensitive images which have high precision and have been orthographically rectified precisely.Quick Bird panchromatic remote sensing image is used and an urban area with even terrain and dense buildings is selected as experimental area.Ground control points(GCPs)are selected on a new 1∶500 topographical map and multinomial model is applied for rectification.After rectification the absolute positional error of a single point of the image is less than 1m,therefore this method is suitable for renewing topographical maps of up to(1∶2000)scale.
