A systemic strategy was proposed to improve aerobic granular sludge(AGS)stability and nitrogen(N)removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater characteristics.Key functio...A systemic strategy was proposed to improve aerobic granular sludge(AGS)stability and nitrogen(N)removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater characteristics.Key functional groups at the genus level identified by high-throughput sequencing were evaluated as well.The results showed that anaerobic feeding mode and acetate promoted the compact AGS formation with excellent total nitrogen(TN)removal efficiency(averaging 91.7%±4.1%)at various dissolved oxygen conditions.While the aerobic feeding mode led to a loose AGS structure with a vulnerable anaerobic core and poor TN removal efficiency(averaging58.8%±7.4%).Simultaneous nitrification and denitrification process played the dominant role in N removal in compact AGS over the alternating nitrification and denitrification process.High-concentration glucose undermined feast-famine condition with filamentous bacteria growth out of granule and decreased TN removal efficiency to 67.3%±15.2%.Lower food to microorganism ratio may result in a lower N removal rate attributed to the sharply increased biomass concentration fed by glucose.Ammonia-oxidizing bacteria,nitrite-oxidizing bacteria,denitrifying bacteria,and denitrifying phosphorus accumulation organisms enriched during AGS granulation also contributed to the efficient N removal.The proposed strategy provided insights into the relationship between various factors and stable AGS formation,and systemic operation methods for various complicated wastewater treatment.展开更多
A new feeding mode for a simulated moving bed(SMB) is proposed.The outlet stream from zone II is collected at regular intervals.The concentration of the solution is increased by dissolving raw materials and then fed t...A new feeding mode for a simulated moving bed(SMB) is proposed.The outlet stream from zone II is collected at regular intervals.The concentration of the solution is increased by dissolving raw materials and then fed to zone III as the feed stream during the next collection interval.In this feeding mode,the concentration of the stream fed to zone III is identical to that of original feed,while in a conventional SMB,the feed is diluted by mix-ing with the outlet stream of zone II before feeding to zone III.The new feeding mode increases the inlet concentra-tion of zone III.A modeling investigation shows that higher inlet concentration of zone III increases the height of concentration band in SMB,improving the separation performance significantly.In comparison with the traditonal feeding mode,the new feeding mode increases the productivity by 23.52%and decreases the solvent consumption by 22.56%,so as to increase the raffinate and extract concentrations by 53.17%and 20.38%,respectively.The col-lection interval for the outlet stream from zone II has no effect on the separation performance after reaching the steady state,so that the collection interval can be increased to make the operation more convenient.展开更多
In order to prepare hollow latex particles with optimum morphology based on osmotic swelling principle, three- layer core/shell latex particles with 40 wt% MAA in the core were first prepared via multistep seeded emul...In order to prepare hollow latex particles with optimum morphology based on osmotic swelling principle, three- layer core/shell latex particles with 40 wt% MAA in the core were first prepared via multistep seeded emulsion copolymerization, in which monomers were added by a semi-continuous process with monomer addition under two different forms： pure monomers＇ mixture （monomer addition）, and pre-emulsified monomers （pre-emulsion addition）. Then, the hollow latex particles with different morphologies were obtained after alkali post-treatment. Influences of the monomer feeding mode on the emulsion polymerization and the particle morphology were investigated. Results showed that the pre- emulsion addition could significantly improve the polymerization stability in each step, and greatly enhance the uniformity of shell encapsulation. The sizes of the core and core/shell latex particles obtained by the pre-emulsion addition were smaller and more uniform than those synthesized by the monomer addition, and the hollow latex particles with intact morphology were generated by alkali post-treating of the core/shell latexes prepared from the pre-emulsion addition. As the core size increased, the morphology of the post-treated particles underwent evolution from hollow to collapse. Moreover, the mechanism of the particle morphological evolution was proposed.展开更多
A three-dimensional finite element method was developed to simulate the fluid flow,heat transfer and solidification for twin roll strip casting.An improved two-equationκ-εmodel was used to incorporate the turbulence...A three-dimensional finite element method was developed to simulate the fluid flow,heat transfer and solidification for twin roll strip casting.An improved two-equationκ-εmodel was used to incorporate the turbulence in fluid flow.The influence of vertical feeding and submerged entry nozzle feeding on the flow and temperature field was discussed.The optimum submersion depth and entry angle of submerged nozzle were obtained through comparison of the simulation results.展开更多
We conducted behavior experiments on the roles of vision, olfaction, and the lateral line in feeding in tongue sole Cynoglossus semilaevis Gtinter. Chemical cues from the prey alone could not elicit any searching or a...We conducted behavior experiments on the roles of vision, olfaction, and the lateral line in feeding in tongue sole Cynoglossus semilaevis Gtinter. Chemical cues from the prey alone could not elicit any searching or attacking behavior by the fish; only when moving foods were presented, the chemical nature of the foods affected feeding. In addition, we found that normal tongue sole did not accurately recognize moving artificial prey of different shapes. Neither chemosense nor vision plays an important role in prey detection. Reactions to moving objects and the response of the oropharyngeal cavity to different foods showed that the （eyeless） tongue sole use mainly the lateral line for prey detection and capture. Gustation in the oropharyngeal cavity is essential for the fish to swallow its prey.展开更多
Microplastic(MP)pollution has spread from the mainland to the ocean.However,Haizhou Bay,which is one of the important land-ocean transition zones,has been reported relatively little about the enrichment of MPs.To prov...Microplastic(MP)pollution has spread from the mainland to the ocean.However,Haizhou Bay,which is one of the important land-ocean transition zones,has been reported relatively little about the enrichment of MPs.To provide fundamental data for MP pollution in Haizhou Bay,we studied the occurrence of microplastics in the intestines of 8 species of fish with different habits and feeding modes.The fish intestines were digested with a 10%KOH solution,and MPs are separated with a glass fiber filter.Then,the size,shape,color,and composition of the MPs were analyzed using a stereomicroscope and Fourier transform infrared spectrometer.The results showed the abundance of MP intake ranged from 0.02 items g^(-1) to 0.16 items g^(-1) and the detection rate of MPs ranged from 53.33% to 80% across different fish species.The MP intake in benthic fish and omnivorous fish was significantly higher than that of pelagic fish and predatory fish.Smaller MPs(<0.25 mm)were the dominant types and accounted for 62.50% of the total.The fiber was the prevailing shape of MPs,and the black MPs were the most common,followed by red and yellow ones.Polyethylene terephthalate(PET),polyamide(PA),and polystyrene(PS)were the main components of MPs,accounting for 34.9%,29.9%,and 16.4%,respectively.According to the composition analysis of MPs,the main sources of MPs in fish of Haizhou Bay were attributed to marine aquaculture and port construction.The results are helpful for our better understanding of the status of MP pollution in this area,and further aid in the development of the pointed measures to mitigate and prevent the MP pollution in this ecologically important area.展开更多
The emulsion copolymerization of vinylidene chloride (VDC) with methyl-methacrylate(MMA) and acrylonitrile (AN) was carried out by batch, seeded batch and semicontinuous pro-cesses,respectively. Significant difference...The emulsion copolymerization of vinylidene chloride (VDC) with methyl-methacrylate(MMA) and acrylonitrile (AN) was carried out by batch, seeded batch and semicontinuous pro-cesses,respectively. Significant differences were found in the physical and mechanical propertiesof the latexes and films, depending on the methods of monomer feeding. The results both intheory and experiments demonstrated that the copolymer composition and the length of the VDC sequences in the copolymer could be controlled by the modes of monomer feeding process.展开更多
A 180 d feeding trial was conducted to evaluate the effect of different feeding modes on liver of Gushi chicken.The chickens from 1-day-old were fed in the warm house for 30 d,and then divided into four groups by diff...A 180 d feeding trial was conducted to evaluate the effect of different feeding modes on liver of Gushi chicken.The chickens from 1-day-old were fed in the warm house for 30 d,and then divided into four groups by different feeding modes(O-noant,outdoor without antibiotics;O-ant,outdoor with antibiotics;D-noant,indoor without antibiotics;D-ant,indoor with antibiotics),respectively,to evaluate the effect on liver.The results showed that different feeding modes significantly influenced the growth,liver weight,subcutaneous fat thickness,liver fat and liver free amino acid contents.The outdoor feeding without antibiotic reflected remarkably(P﹤0.05)low liver weight and fat content with normal morphology.While,other groups showed different levels of fat metabolism disorder in the liver.Based on chicken liver healthy,the outdoor feeding without antibiotic was the optimal feeding mode for Gushi chicken.展开更多
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China (Nos. 2017ZX07102-003, 2017ZX07103)the China Postdoctoral Science Foundation (Nos. 2017M620799, 2018T110108)the National Natural Science Foundation of China (No. 51608298)
文摘A systemic strategy was proposed to improve aerobic granular sludge(AGS)stability and nitrogen(N)removal efficiency by optimizing feeding mode and substrate aiming at complicated wastewater characteristics.Key functional groups at the genus level identified by high-throughput sequencing were evaluated as well.The results showed that anaerobic feeding mode and acetate promoted the compact AGS formation with excellent total nitrogen(TN)removal efficiency(averaging 91.7%±4.1%)at various dissolved oxygen conditions.While the aerobic feeding mode led to a loose AGS structure with a vulnerable anaerobic core and poor TN removal efficiency(averaging58.8%±7.4%).Simultaneous nitrification and denitrification process played the dominant role in N removal in compact AGS over the alternating nitrification and denitrification process.High-concentration glucose undermined feast-famine condition with filamentous bacteria growth out of granule and decreased TN removal efficiency to 67.3%±15.2%.Lower food to microorganism ratio may result in a lower N removal rate attributed to the sharply increased biomass concentration fed by glucose.Ammonia-oxidizing bacteria,nitrite-oxidizing bacteria,denitrifying bacteria,and denitrifying phosphorus accumulation organisms enriched during AGS granulation also contributed to the efficient N removal.The proposed strategy provided insights into the relationship between various factors and stable AGS formation,and systemic operation methods for various complicated wastewater treatment.
基金Supported by the Natural Science Foundation of Ningbo（2009A610153）
文摘A new feeding mode for a simulated moving bed(SMB) is proposed.The outlet stream from zone II is collected at regular intervals.The concentration of the solution is increased by dissolving raw materials and then fed to zone III as the feed stream during the next collection interval.In this feeding mode,the concentration of the stream fed to zone III is identical to that of original feed,while in a conventional SMB,the feed is diluted by mix-ing with the outlet stream of zone II before feeding to zone III.The new feeding mode increases the inlet concentra-tion of zone III.A modeling investigation shows that higher inlet concentration of zone III increases the height of concentration band in SMB,improving the separation performance significantly.In comparison with the traditonal feeding mode,the new feeding mode increases the productivity by 23.52%and decreases the solvent consumption by 22.56%,so as to increase the raffinate and extract concentrations by 53.17%and 20.38%,respectively.The col-lection interval for the outlet stream from zone II has no effect on the separation performance after reaching the steady state,so that the collection interval can be increased to make the operation more convenient.
文摘In order to prepare hollow latex particles with optimum morphology based on osmotic swelling principle, three- layer core/shell latex particles with 40 wt% MAA in the core were first prepared via multistep seeded emulsion copolymerization, in which monomers were added by a semi-continuous process with monomer addition under two different forms： pure monomers＇ mixture （monomer addition）, and pre-emulsified monomers （pre-emulsion addition）. Then, the hollow latex particles with different morphologies were obtained after alkali post-treatment. Influences of the monomer feeding mode on the emulsion polymerization and the particle morphology were investigated. Results showed that the pre- emulsion addition could significantly improve the polymerization stability in each step, and greatly enhance the uniformity of shell encapsulation. The sizes of the core and core/shell latex particles obtained by the pre-emulsion addition were smaller and more uniform than those synthesized by the monomer addition, and the hollow latex particles with intact morphology were generated by alkali post-treating of the core/shell latexes prepared from the pre-emulsion addition. As the core size increased, the morphology of the post-treated particles underwent evolution from hollow to collapse. Moreover, the mechanism of the particle morphological evolution was proposed.
基金Item Sponsored by National Natural Science Foundation of China(59995440)
文摘A three-dimensional finite element method was developed to simulate the fluid flow,heat transfer and solidification for twin roll strip casting.An improved two-equationκ-εmodel was used to incorporate the turbulence in fluid flow.The influence of vertical feeding and submerged entry nozzle feeding on the flow and temperature field was discussed.The optimum submersion depth and entry angle of submerged nozzle were obtained through comparison of the simulation results.
基金Supported by Qingdao Natural Science Foundation (No. 09-1-3-10-jch)the National Natural Science Foundation of China (No. 30871913)+1 种基金"Taishan Scholar" Project Special Fundthe Yellow Sea Fisheries Research Institute Scientific and Research Fund
文摘We conducted behavior experiments on the roles of vision, olfaction, and the lateral line in feeding in tongue sole Cynoglossus semilaevis Gtinter. Chemical cues from the prey alone could not elicit any searching or attacking behavior by the fish; only when moving foods were presented, the chemical nature of the foods affected feeding. In addition, we found that normal tongue sole did not accurately recognize moving artificial prey of different shapes. Neither chemosense nor vision plays an important role in prey detection. Reactions to moving objects and the response of the oropharyngeal cavity to different foods showed that the （eyeless） tongue sole use mainly the lateral line for prey detection and capture. Gustation in the oropharyngeal cavity is essential for the fish to swallow its prey.
基金funded by research grants from the National Natural Science Foundation of China(Nos.41706142 and 32071615)the China Agriculture Research System of MOF and MARA(No.CARS-49)the Funding for School-Level Research Projects of Yancheng Institute of Technology(No.XJR2021035)。
文摘Microplastic(MP)pollution has spread from the mainland to the ocean.However,Haizhou Bay,which is one of the important land-ocean transition zones,has been reported relatively little about the enrichment of MPs.To provide fundamental data for MP pollution in Haizhou Bay,we studied the occurrence of microplastics in the intestines of 8 species of fish with different habits and feeding modes.The fish intestines were digested with a 10%KOH solution,and MPs are separated with a glass fiber filter.Then,the size,shape,color,and composition of the MPs were analyzed using a stereomicroscope and Fourier transform infrared spectrometer.The results showed the abundance of MP intake ranged from 0.02 items g^(-1) to 0.16 items g^(-1) and the detection rate of MPs ranged from 53.33% to 80% across different fish species.The MP intake in benthic fish and omnivorous fish was significantly higher than that of pelagic fish and predatory fish.Smaller MPs(<0.25 mm)were the dominant types and accounted for 62.50% of the total.The fiber was the prevailing shape of MPs,and the black MPs were the most common,followed by red and yellow ones.Polyethylene terephthalate(PET),polyamide(PA),and polystyrene(PS)were the main components of MPs,accounting for 34.9%,29.9%,and 16.4%,respectively.According to the composition analysis of MPs,the main sources of MPs in fish of Haizhou Bay were attributed to marine aquaculture and port construction.The results are helpful for our better understanding of the status of MP pollution in this area,and further aid in the development of the pointed measures to mitigate and prevent the MP pollution in this ecologically important area.
基金The project is supported by Beijing Natural Science Fund.
文摘The emulsion copolymerization of vinylidene chloride (VDC) with methyl-methacrylate(MMA) and acrylonitrile (AN) was carried out by batch, seeded batch and semicontinuous pro-cesses,respectively. Significant differences were found in the physical and mechanical propertiesof the latexes and films, depending on the methods of monomer feeding. The results both intheory and experiments demonstrated that the copolymer composition and the length of the VDC sequences in the copolymer could be controlled by the modes of monomer feeding process.
基金Supported by Sichuan Provincial Science and Technology Department Application Foundation Project(No.2019YJ0673)the Meat Processing Sichuan Key Laboratory Open Fund Project(No.20-r-11)Chengdu International Science and Technology Cooperation Project(No.2019-gh02-00004-hz).
文摘A 180 d feeding trial was conducted to evaluate the effect of different feeding modes on liver of Gushi chicken.The chickens from 1-day-old were fed in the warm house for 30 d,and then divided into four groups by different feeding modes(O-noant,outdoor without antibiotics;O-ant,outdoor with antibiotics;D-noant,indoor without antibiotics;D-ant,indoor with antibiotics),respectively,to evaluate the effect on liver.The results showed that different feeding modes significantly influenced the growth,liver weight,subcutaneous fat thickness,liver fat and liver free amino acid contents.The outdoor feeding without antibiotic reflected remarkably(P﹤0.05)low liver weight and fat content with normal morphology.While,other groups showed different levels of fat metabolism disorder in the liver.Based on chicken liver healthy,the outdoor feeding without antibiotic was the optimal feeding mode for Gushi chicken.
