Nanoplastic(NP)contaminants are receiving increasing attention due to the harm they can cause to aquatic organisms and their accumulation in the human body through the food web.The goal of this study was to evaluate t...Nanoplastic(NP)contaminants are receiving increasing attention due to the harm they can cause to aquatic organisms and their accumulation in the human body through the food web.The goal of this study was to evaluate the oxidative stress caused by NPs on the clams Meretrix meretrix and Sinonovacula constricta.Specimens were exposed to three concentrations of fluorescently labeled polystyrene NPs(PS-NPs;0,0.1,and 1 mg L^(-1))for 7 d followed by a 3 d recovery period.The activities of antioxidant enzymes,such as catalase(CAT),superoxide dismutase(SOD),glutathione peroxidase(GPx)and the content of malonaldehyde(MDA)were measured in the digestive gland,gills,and mantle tissues.Results showed that the SOD activity in the gills of M.meretrix was significantly higher than that of the control at day 1,and PS-NPs exposure inhibited the CAT activity in the gills and SOD and GPx activities in the mantle.Exposure to low or high concentrations of PS-NPs increased the activities of both CAT and GPx in the gills of S.constricta at day 3.The oxidative damage was more severe in the digestive gland of M.meretrix and in the mantle of S.constricta based on MDA level,and it returned to normal after recovery.Integrated biomarker response,index version 2(IBRv2)values showed that the gills were more sensitive to PS-NPs than mantle and digestive gland.Therefore,the oxidative stress by PS-NPs depended on exposure time,dose,organ,and species.展开更多
This research proposes a new offshore wind energy generation system that uses a tension leg platform (TLP) and describes experiments performed on a TLP type wind turbine in both waves and wind. The following conclusio...This research proposes a new offshore wind energy generation system that uses a tension leg platform (TLP) and describes experiments performed on a TLP type wind turbine in both waves and wind. The following conclusions can be made from the results of this research. 1) In the case of coexisting wave-wind fields, the wind effect stabilizes the pitch motion. 2) The wind effect decreases vibration of the mooring lines when waves and wind coexist. In particular, the springing (2nd or 3rd order force) also decreases in this field. 3) It can be estimated that the reduction in the rate of generation of electrical power can be up to about 6% as a result of the heel angle. In addition, the annual amount of electricity generated was estimated along with the utilization factor based on the experimental results.展开更多
Beyond conventional methods for CO2 capture and storage, a promising technology of sub-seabed CO2 storage in the form of gas hydrate has come into the limelight nowadays. In order to estimate CO2 storage capacity in t...Beyond conventional methods for CO2 capture and storage, a promising technology of sub-seabed CO2 storage in the form of gas hydrate has come into the limelight nowadays. In order to estimate CO2 storage capacity in the real sub-seabed sediments by gas hydrate, a large-scale geological model with the radius of 100 m and the thickness of 160 m was built in this study, and the processes of CO2 injection and CO2 hydrate formation in the sediments with two-phase flow were simulated numerically at three different injection rates of 10 ton/day, 50 ton/day, and 100 ton/day for an injection period of 150 days. Then, the evolutions of CO2 reaction, free CO2, and hydrate formation over time were analyzed quantitatively, and the spatial distributions of the physical properties in the sediments were presented to investigate the behaviors of CO2 hydrate formation in the sediments with two-phase flow. For CO2 storage capacity, a total amount of 15,000-ton CO2 can be stored safely in the sediments at the injection rate of 100 ton/day for 150 days, and a maximum amount of 36,500-ton CO2 could be stored in the sub-seabed sediments per year for a CO2 storage reservoir with the thickness of 100 m. For the practical scenario, an average value of 1 ton/day/m could be used to determine the actual injection rate based on the thickness of the real sub-seabed sediments.展开更多
This paper presents the numerical study on the nonlinear sound propagation for the parametric array using the compressible form of Navier-Stokes equations combined with the mass and energy conservation equations and t...This paper presents the numerical study on the nonlinear sound propagation for the parametric array using the compressible form of Navier-Stokes equations combined with the mass and energy conservation equations and the state equation. These governing equations are solved by finite difference time domain (FDTD) based method. The numerical result is shown for the parametric sound propagation in the near field of the sound source in cylindrical coordinate. The result indicates the generation of low-frequency unsteady beat by the interaction of two frequency sound waves in the near field, which grows to a difference frequency sound in the far field.展开更多
A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this ...A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this technique, the conventional acoustic shadow method is modified by using the secondary wave generated by nonlinear interaction of two primary sound waves emitted from parametric array. Either conventional or nonlinear acoustic shadow imaging is carried out for aluminum square cylinder and the size of the shadow is compared. The result shows that the nonlinear acoustic shadow method reduces reverberation artifact inside the square cylinder and has better accuracy in the size measurement than conventional acoustic shadow method.展开更多
The Chinese herb Houttuynia cordata Thunb(abbreviated as HCT hereafter)has been widely used in human and livestock medical research.However,few studies have tested the effects of HCT in aquaculture systems,particularl...The Chinese herb Houttuynia cordata Thunb(abbreviated as HCT hereafter)has been widely used in human and livestock medical research.However,few studies have tested the effects of HCT in aquaculture systems,particularly in echinoderms.In this study,the impact of HCT was evaluated when used as a feed additive to enhance the immune response of the sea cucumber,Apostichopus japonicus.Two concentrations,1.5%and 3%,of HCT powder were tested by adding them to the feed.Feeding experiments had a four week duration and each week,the humoral and cellular immunity index of the intestine,tentacles,peristome,and coelomic fluid were analyzed.The results indicated that the percentage of A.japonicus coelomocytes significantly increased after supplementing feed with HCT,and reached a peak after one week of feeding with the 3%HCT supplementation.Analysis of reactive oxygen species(ROS)indicated that HCT in feed caused a notable increase in the coelomocyte ROS concentrations over the experimental period.In both the 1.5%and 3%HCT addition groups,the ROS peaked in the third week and then remained stable.In addition,alkaline phosphatase,acid phosphatase,superoxide dismutase,lysozyme activity of the intestine,tentacles,peristome and coelomic fluid were significantly improved during the four-week test period.In conclusion,1.5%and 3%HCT added to feed boosts the immune responses of A.japonicus.HCT has potential as an immune enhancer for mariculture of sea cucumbers.展开更多
Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Li...Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Linked Immunosorbent Assay(Dot-ELISA)and an Indirect Fluorescence Antibody technique(IFAT)for detecting Edwardsiella ictaluri were developed by using a monoclonal antibody,5D11.For DotELISA,the working dilutions of 5D11 and the secondary antisera(enzyme-labeled goat anti-mouse Ig)were 1:320 dilution and 1:3000 dilution,respectively.For IFAT,the working dilutions of 5D11 and goatanti-mouse Ig conjugated with fluorescein isothiocyanate were as respectively 1:80 and 1:256.Both of the methods established were highly sensitivity(Minimum detectable concentration,5107 CFU/mL)and had a high degree of accuracy(positive rate was 100%for both artificial infected fish and spontaneous diseased Pelteobagrus fulvidraco).The two reliable methods developed have high potential for quick and efficient detection of Edwardsiella ictaluri in aquaculture production units.展开更多
基金supported by the Natural Natural Science Foundation of China(No.41706142)the Earmarked Fund for CARS-49(No.CARS-49).
文摘Nanoplastic(NP)contaminants are receiving increasing attention due to the harm they can cause to aquatic organisms and their accumulation in the human body through the food web.The goal of this study was to evaluate the oxidative stress caused by NPs on the clams Meretrix meretrix and Sinonovacula constricta.Specimens were exposed to three concentrations of fluorescently labeled polystyrene NPs(PS-NPs;0,0.1,and 1 mg L^(-1))for 7 d followed by a 3 d recovery period.The activities of antioxidant enzymes,such as catalase(CAT),superoxide dismutase(SOD),glutathione peroxidase(GPx)and the content of malonaldehyde(MDA)were measured in the digestive gland,gills,and mantle tissues.Results showed that the SOD activity in the gills of M.meretrix was significantly higher than that of the control at day 1,and PS-NPs exposure inhibited the CAT activity in the gills and SOD and GPx activities in the mantle.Exposure to low or high concentrations of PS-NPs increased the activities of both CAT and GPx in the gills of S.constricta at day 3.The oxidative damage was more severe in the digestive gland of M.meretrix and in the mantle of S.constricta based on MDA level,and it returned to normal after recovery.Integrated biomarker response,index version 2(IBRv2)values showed that the gills were more sensitive to PS-NPs than mantle and digestive gland.Therefore,the oxidative stress by PS-NPs depended on exposure time,dose,organ,and species.
基金Supported by The Japan Science Society(Foundation: Grant No.23-708K)
文摘This research proposes a new offshore wind energy generation system that uses a tension leg platform (TLP) and describes experiments performed on a TLP type wind turbine in both waves and wind. The following conclusions can be made from the results of this research. 1) In the case of coexisting wave-wind fields, the wind effect stabilizes the pitch motion. 2) The wind effect decreases vibration of the mooring lines when waves and wind coexist. In particular, the springing (2nd or 3rd order force) also decreases in this field. 3) It can be estimated that the reduction in the rate of generation of electrical power can be up to about 6% as a result of the heel angle. In addition, the annual amount of electricity generated was estimated along with the utilization factor based on the experimental results.
文摘Beyond conventional methods for CO2 capture and storage, a promising technology of sub-seabed CO2 storage in the form of gas hydrate has come into the limelight nowadays. In order to estimate CO2 storage capacity in the real sub-seabed sediments by gas hydrate, a large-scale geological model with the radius of 100 m and the thickness of 160 m was built in this study, and the processes of CO2 injection and CO2 hydrate formation in the sediments with two-phase flow were simulated numerically at three different injection rates of 10 ton/day, 50 ton/day, and 100 ton/day for an injection period of 150 days. Then, the evolutions of CO2 reaction, free CO2, and hydrate formation over time were analyzed quantitatively, and the spatial distributions of the physical properties in the sediments were presented to investigate the behaviors of CO2 hydrate formation in the sediments with two-phase flow. For CO2 storage capacity, a total amount of 15,000-ton CO2 can be stored safely in the sediments at the injection rate of 100 ton/day for 150 days, and a maximum amount of 36,500-ton CO2 could be stored in the sub-seabed sediments per year for a CO2 storage reservoir with the thickness of 100 m. For the practical scenario, an average value of 1 ton/day/m could be used to determine the actual injection rate based on the thickness of the real sub-seabed sediments.
文摘This paper presents the numerical study on the nonlinear sound propagation for the parametric array using the compressible form of Navier-Stokes equations combined with the mass and energy conservation equations and the state equation. These governing equations are solved by finite difference time domain (FDTD) based method. The numerical result is shown for the parametric sound propagation in the near field of the sound source in cylindrical coordinate. The result indicates the generation of low-frequency unsteady beat by the interaction of two frequency sound waves in the near field, which grows to a difference frequency sound in the far field.
文摘A novel technique for reducing reverberation artifact in acoustic shadow imaging using nonlinear ultrasound interaction, called nonlinear acoustic shadow method, has been developed and experimentally studied. In this technique, the conventional acoustic shadow method is modified by using the secondary wave generated by nonlinear interaction of two primary sound waves emitted from parametric array. Either conventional or nonlinear acoustic shadow imaging is carried out for aluminum square cylinder and the size of the shadow is compared. The result shows that the nonlinear acoustic shadow method reduces reverberation artifact inside the square cylinder and has better accuracy in the size measurement than conventional acoustic shadow method.
基金This work was funded in part by the State Key Research Project"Marine environment safety"(2017YFC1404503)General Scientific Research Project of Education Department in Liaoning Province(L2015077)+1 种基金Doctoral Research Project of Science and Technology Department program in in Liaoning Province(201601287)Doctoral Research Project of Dalian Ocean University(HDYJ201617).
文摘The Chinese herb Houttuynia cordata Thunb(abbreviated as HCT hereafter)has been widely used in human and livestock medical research.However,few studies have tested the effects of HCT in aquaculture systems,particularly in echinoderms.In this study,the impact of HCT was evaluated when used as a feed additive to enhance the immune response of the sea cucumber,Apostichopus japonicus.Two concentrations,1.5%and 3%,of HCT powder were tested by adding them to the feed.Feeding experiments had a four week duration and each week,the humoral and cellular immunity index of the intestine,tentacles,peristome,and coelomic fluid were analyzed.The results indicated that the percentage of A.japonicus coelomocytes significantly increased after supplementing feed with HCT,and reached a peak after one week of feeding with the 3%HCT supplementation.Analysis of reactive oxygen species(ROS)indicated that HCT in feed caused a notable increase in the coelomocyte ROS concentrations over the experimental period.In both the 1.5%and 3%HCT addition groups,the ROS peaked in the third week and then remained stable.In addition,alkaline phosphatase,acid phosphatase,superoxide dismutase,lysozyme activity of the intestine,tentacles,peristome and coelomic fluid were significantly improved during the four-week test period.In conclusion,1.5%and 3%HCT added to feed boosts the immune responses of A.japonicus.HCT has potential as an immune enhancer for mariculture of sea cucumbers.
基金This study was supported by Public Science and Technology Research Funds Projects of Ocean(201405003)Cultivation Plan for Youth Agricultural Science and Technology Innovative Talents of Liaoning Province(2014003)+1 种基金Program of Liaoning Excellent Talents in University(LJQ2011075)to Prof.Qiang Li,General Scientific Research Project of Liaoning Education Department(L2015077)Doctoral Research Program of Liaoning Science and Technology Department(201601287)to Dr.Ruijun Li.
文摘Edwardsiella ictaluri is known as the etiological agent of Red-head disease of yellow catfish(Pelteobagrus fulvidraco),and is the cause of heavy economic losses in the aquaculture industry.In this study,a DotEnzyme Linked Immunosorbent Assay(Dot-ELISA)and an Indirect Fluorescence Antibody technique(IFAT)for detecting Edwardsiella ictaluri were developed by using a monoclonal antibody,5D11.For DotELISA,the working dilutions of 5D11 and the secondary antisera(enzyme-labeled goat anti-mouse Ig)were 1:320 dilution and 1:3000 dilution,respectively.For IFAT,the working dilutions of 5D11 and goatanti-mouse Ig conjugated with fluorescein isothiocyanate were as respectively 1:80 and 1:256.Both of the methods established were highly sensitivity(Minimum detectable concentration,5107 CFU/mL)and had a high degree of accuracy(positive rate was 100%for both artificial infected fish and spontaneous diseased Pelteobagrus fulvidraco).The two reliable methods developed have high potential for quick and efficient detection of Edwardsiella ictaluri in aquaculture production units.
