This paper studies the mass transfer performance of structured packings in the absorption of CO2 from air with aqueous Na OH solution. The Eight structured packings tested are sheet metal ones with corrugations of dif...This paper studies the mass transfer performance of structured packings in the absorption of CO2 from air with aqueous Na OH solution. The Eight structured packings tested are sheet metal ones with corrugations of different geometry parameters. Effective mass transfer area and overall gas phase mass transfer coefficient have been measured in an absorption column of 200 mm diameter under the conditions of gas F-factor in 0.38–1.52 Pa0.5and aqueous Na OH solution concentration of 0.10–0.15 kmol·m-3. The effects of gas/liquid phase flow rates and packing geometry parameters are also investigated. The results show that the effective mass transfer area changes not only with packing geometry parameters and liquid load, but also with gas F-factor. A new effective mass transfer area correlation on the gas F-factor and the liquid load was proposed, which is found to fit experiment data very well.展开更多
Similarity measurement is one of key operations to retrieve “desired” images from an image database. As a famous psychological similarity measure approach, the Feature Contrast (FC) model is defined as a linear comb...Similarity measurement is one of key operations to retrieve “desired” images from an image database. As a famous psychological similarity measure approach, the Feature Contrast (FC) model is defined as a linear combination of both common and distinct features. In this paper, an adaptive feature contrast (AdaFC) model is proposed to measure similarity between satellite images for image retrieval. In the AdaFC, an adaptive function is used to model a variable role of distinct features in the similarity measurement. Specifically, given some distinct features in a satellite image, e.g., a COAST image, they might play a significant role when the image is compared with an image including different semantics, e.g., a SEA image, and might be trivial when it is compared with a third image including same semantics, e.g., another COAST image. Experimental results on satellite images show that the proposed model can consistently improve similarity retrieval effectiveness of satellite images including multiple geo-objects, for example COAST images.展开更多
Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons,however,the combined effect of BC and RL in phytoremediation has not been studied until now.In this paper,the phytoremediation of p...Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons,however,the combined effect of BC and RL in phytoremediation has not been studied until now.In this paper,the phytoremediation of petroleum hydrocarbon-contaminated soil using novel plant Spartina anglica was enhanced by the combination of biochar (BC) and rhamnolipid (RL).Samples of petroleum-contaminated soil (10,30 and 50 g/kg) were amended by BC,BC+ RL and rhamnolipid modified biochar (RMB),respectively.After 60 day's cultivation,the removal rate of total petroleum hydrocarbons (TPHs) for unplanted soil (UP),planted soil (P),planted soil with BC addition (P-BC),planted soil with BC and RL addition (P-BC + RL) and planted soil with addition ofRMB (P-RMB) were 8.6%,19.1%,27.7%,32.4% and 35.1% in soil with TPHs concentration of 30 g/kg,respectively.Compared with UP,the plantation of Spartina anglica significantly decreased the concentration of C8-14 and tricyclic PAHs.Furthermore,the application of BC and RMB alleviated the toxicity of petroleum hydrocarbons to Spartina anglica via improving plant growth with increasing plant height,root vitality and total chlorophyll content.High-throughput sequencing result indicated that rhizosphere microbial community of Spartina anglica was regulated by the application of BC and RMB,with increase of bacteria and plant mycorrhizal symbiotic fungus in biochar and RMB amended soil.展开更多
Permeable reactive barriers （PRBs） show remarkable Cr（VI） removal performance. However, the diminished removal rate because of mineral fouling over time is the bottleneck for application of PRBs. The present study...Permeable reactive barriers （PRBs） show remarkable Cr（VI） removal performance. However, the diminished removal rate because of mineral fouling over time is the bottleneck for application of PRBs. The present study demonstrated that electrochemical depassivation was effective for recovering the Fe^0 reactivity, and minerals can be cleaned layer by layer with no secondary ion contamination and no transformation from Cr（III） to Cr（VI）. The removal recovery rate increased with increasing electrolysis voltage before reaching the optimal electrolysis voltage, and then decreased as the electrolysis voltage further increased. The recovery effect at electrolysis voltages of 5, 10, and 15 V show the same trend as a function of electrolysis time, where recovery rate first increased and then decreased after reaching the optimal electrolysis time. The Cr（VI） removal rate significantly decreased with increasing electrolysis distance. Furthermore, Fe^0 brush meshes electrode, Fe^0 fillings, and polyvinyl chloride （PVC） meshes separators were combined to create an Electro-PRB configuration for the caisson excavation construction technique, which lays the foundation for establishment of promising Electro-PRB systems to treat Cr（VI）-contaminated groundwater.展开更多
基金Supported by the National Natural Science Foundation of China(51134017)and Petro China(2011E-24-09)
文摘This paper studies the mass transfer performance of structured packings in the absorption of CO2 from air with aqueous Na OH solution. The Eight structured packings tested are sheet metal ones with corrugations of different geometry parameters. Effective mass transfer area and overall gas phase mass transfer coefficient have been measured in an absorption column of 200 mm diameter under the conditions of gas F-factor in 0.38–1.52 Pa0.5and aqueous Na OH solution concentration of 0.10–0.15 kmol·m-3. The effects of gas/liquid phase flow rates and packing geometry parameters are also investigated. The results show that the effective mass transfer area changes not only with packing geometry parameters and liquid load, but also with gas F-factor. A new effective mass transfer area correlation on the gas F-factor and the liquid load was proposed, which is found to fit experiment data very well.
文摘Similarity measurement is one of key operations to retrieve “desired” images from an image database. As a famous psychological similarity measure approach, the Feature Contrast (FC) model is defined as a linear combination of both common and distinct features. In this paper, an adaptive feature contrast (AdaFC) model is proposed to measure similarity between satellite images for image retrieval. In the AdaFC, an adaptive function is used to model a variable role of distinct features in the similarity measurement. Specifically, given some distinct features in a satellite image, e.g., a COAST image, they might play a significant role when the image is compared with an image including different semantics, e.g., a SEA image, and might be trivial when it is compared with a third image including same semantics, e.g., another COAST image. Experimental results on satellite images show that the proposed model can consistently improve similarity retrieval effectiveness of satellite images including multiple geo-objects, for example COAST images.
基金supported by the National Natural Science Foundation of China(Nos.U1806216,41877372)the CNPC scientific research and technological development project(No.2016D-4610)+1 种基金the Tianjin S&T Program(Nos.17ZXSTSF00050,17PTGCCX00240,16YFXTSF00520)the 111 program,Ministry of Education,China(No.T2017002)
文摘Biochar (BC) and rhamnolipid (RL) is used in bioremediation of petroleum hydrocarbons,however,the combined effect of BC and RL in phytoremediation has not been studied until now.In this paper,the phytoremediation of petroleum hydrocarbon-contaminated soil using novel plant Spartina anglica was enhanced by the combination of biochar (BC) and rhamnolipid (RL).Samples of petroleum-contaminated soil (10,30 and 50 g/kg) were amended by BC,BC+ RL and rhamnolipid modified biochar (RMB),respectively.After 60 day's cultivation,the removal rate of total petroleum hydrocarbons (TPHs) for unplanted soil (UP),planted soil (P),planted soil with BC addition (P-BC),planted soil with BC and RL addition (P-BC + RL) and planted soil with addition ofRMB (P-RMB) were 8.6%,19.1%,27.7%,32.4% and 35.1% in soil with TPHs concentration of 30 g/kg,respectively.Compared with UP,the plantation of Spartina anglica significantly decreased the concentration of C8-14 and tricyclic PAHs.Furthermore,the application of BC and RMB alleviated the toxicity of petroleum hydrocarbons to Spartina anglica via improving plant growth with increasing plant height,root vitality and total chlorophyll content.High-throughput sequencing result indicated that rhizosphere microbial community of Spartina anglica was regulated by the application of BC and RMB,with increase of bacteria and plant mycorrhizal symbiotic fungus in biochar and RMB amended soil.
文摘Permeable reactive barriers （PRBs） show remarkable Cr（VI） removal performance. However, the diminished removal rate because of mineral fouling over time is the bottleneck for application of PRBs. The present study demonstrated that electrochemical depassivation was effective for recovering the Fe^0 reactivity, and minerals can be cleaned layer by layer with no secondary ion contamination and no transformation from Cr（III） to Cr（VI）. The removal recovery rate increased with increasing electrolysis voltage before reaching the optimal electrolysis voltage, and then decreased as the electrolysis voltage further increased. The recovery effect at electrolysis voltages of 5, 10, and 15 V show the same trend as a function of electrolysis time, where recovery rate first increased and then decreased after reaching the optimal electrolysis time. The Cr（VI） removal rate significantly decreased with increasing electrolysis distance. Furthermore, Fe^0 brush meshes electrode, Fe^0 fillings, and polyvinyl chloride （PVC） meshes separators were combined to create an Electro-PRB configuration for the caisson excavation construction technique, which lays the foundation for establishment of promising Electro-PRB systems to treat Cr（VI）-contaminated groundwater.
