A new electrical resistance tomography (ERT) system, based on the bi-directional current pulse technique, is de- veloped. Polarization effects at the electrodes are eliminated. During each half cycle of the excitation...A new electrical resistance tomography (ERT) system, based on the bi-directional current pulse technique, is de- veloped. Polarization effects at the electrodes are eliminated. During each half cycle of the excitation process, direct current (DC) is used as the excitation source and filtering is not needed. Moreover, using optimized data collection protocol, the number of current injections for a 16-electrode system is reduced to 14 for 104 independent readings of an image. Experimental results showed that the system is effective using the sensitivity coefficient algorithm for image reconstruction.展开更多
This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium do...This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium dodecyl sulfate） into the HANR （high-ammoniated natural rubber latex） and followed by centrifugation. It was found that DPNR was successfully prepared with the lowest nitrogeneous content about 0.034±0.01% w/w by adding SDS for 1.00 phr and centrifugation at 12,000 rpm. Then DPNR was grafted with styrene and methyl methacrylate （DPNR-g-S/MMA） obtained by emulsion polymerization. The effects of DPNR-g-S/MMA were studied by varied the amount of SDS and redox initiator. From this result the grafting efficiency DPNR-g-S/MMA was higher than that of NR-g-S/MMA. The DPNR-g-S/MMA was used as an impact modifier in S-co-MMA sheet. Furthermore, the appropriate quantities of styrene monomer and DPNR-g-S/MMA were also investigated. While DPNR-g-S/MMA was used as impact modifier in S-co-MMA sheet, the result was shown DPNR-g-S/MMA improve impact strength of S-co-MMA sheet. Scanning electron micrographs of S-co-MMA sheet with DPNR-g-S/MMA was found the smooth fracture surface. Thus impact strength of S-co-MMA/gDPNR sheet was high and physical properties of S-co-MMA/gDPNR sheet could be able to be accepted in industry. Concisely, DPNR-g-S/MMA can be used as an impact modifier in S-co-MMA sheet.展开更多
基金Project (No. 2001BA701A46) supported by the Hi-Tech Researchand Development Program (863) of China
文摘A new electrical resistance tomography (ERT) system, based on the bi-directional current pulse technique, is de- veloped. Polarization effects at the electrodes are eliminated. During each half cycle of the excitation process, direct current (DC) is used as the excitation source and filtering is not needed. Moreover, using optimized data collection protocol, the number of current injections for a 16-electrode system is reduced to 14 for 104 independent readings of an image. Experimental results showed that the system is effective using the sensitivity coefficient algorithm for image reconstruction.
文摘This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium dodecyl sulfate） into the HANR （high-ammoniated natural rubber latex） and followed by centrifugation. It was found that DPNR was successfully prepared with the lowest nitrogeneous content about 0.034±0.01% w/w by adding SDS for 1.00 phr and centrifugation at 12,000 rpm. Then DPNR was grafted with styrene and methyl methacrylate （DPNR-g-S/MMA） obtained by emulsion polymerization. The effects of DPNR-g-S/MMA were studied by varied the amount of SDS and redox initiator. From this result the grafting efficiency DPNR-g-S/MMA was higher than that of NR-g-S/MMA. The DPNR-g-S/MMA was used as an impact modifier in S-co-MMA sheet. Furthermore, the appropriate quantities of styrene monomer and DPNR-g-S/MMA were also investigated. While DPNR-g-S/MMA was used as impact modifier in S-co-MMA sheet, the result was shown DPNR-g-S/MMA improve impact strength of S-co-MMA sheet. Scanning electron micrographs of S-co-MMA sheet with DPNR-g-S/MMA was found the smooth fracture surface. Thus impact strength of S-co-MMA/gDPNR sheet was high and physical properties of S-co-MMA/gDPNR sheet could be able to be accepted in industry. Concisely, DPNR-g-S/MMA can be used as an impact modifier in S-co-MMA sheet.
