A pilot-scale experiment of 20t/h for the treatment of ship＇s ballast water is reported in this paper. When the concentration of the dissolved OH. was 0.68 mg/L during the experiment, the rate of destroying bacteria,...A pilot-scale experiment of 20t/h for the treatment of ship＇s ballast water is reported in this paper. When the concentration of the dissolved OH. was 0.68 mg/L during the experiment, the rate of destroying bacteria, mono-algae, protozoan reached 100% within 2.67 s. The effect of hydroxyl radicals on biochemical processes was also studied. The attenuation rate of photosynthesis pigment was 100%. And the main reason for the cells＇ death was the strong destruction of the monose, amylose, protein, DNA and RNA in the cells. As an advanced oxidation method, the procedure can destroy invasive marine species when a ship is in the process of discharging its ballast water.展开更多
With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship＇s ballast water....With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship＇s ballast water. The surface morphology of Al2O3 dielectric layer was analysed using Atomic Force Microscopy （AFM）, where the size of Al2O3 particles was in the range of 2 μm to 5 μm. At the same time, the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship＇s ballast water were studied. The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase （CAT）, Peroxidase （POD） and Superoxide dismutase （SOD）. In addition, the quality of the ballast water was greatly improved.展开更多
In the process of two-pass micro plasma arc welding of titanium alloy sheet,based on the thermal contact resistance theory,a three-dimensional transient heat transfer finite element model of contact heat transfer betw...In the process of two-pass micro plasma arc welding of titanium alloy sheet,based on the thermal contact resistance theory,a three-dimensional transient heat transfer finite element model of contact heat transfer between titanium alloy sheet and flexible fixture was established.The effects of contact upper surface temperature,micro-contact thermal resistance,micro-gap thermal resistance,DC and pulse welding on thermal contact resistance were investigated,and the simulation and experimental results were compared.The results show that the thermal contact resistance increases as the temperature increases when the temperature of the contact upper surface (titanium alloy sheet) is in the range of 290-350 K.The effect of micro-contact thermal resistance on the thermal contact resistance is 26.1%-46.3% larger than the micro-gap thermal resistance.The thermal contact resistance of pulse welding is 3.1%-3.5% larger than DC welding.The error of simulation and experimental results of weld pool depth is 8.6%,which verifies the reliability of the model.展开更多
基金The project supported by Key Project of National Foundation Research under the Ministry of Science and Technology of China(2002CCC00900) General Project of the National Natural Science Foundation of China (No. 60371035) and Project under the SocialDevelopment Program of Dalian City (2004B3SF181)
文摘A pilot-scale experiment of 20t/h for the treatment of ship＇s ballast water is reported in this paper. When the concentration of the dissolved OH. was 0.68 mg/L during the experiment, the rate of destroying bacteria, mono-algae, protozoan reached 100% within 2.67 s. The effect of hydroxyl radicals on biochemical processes was also studied. The attenuation rate of photosynthesis pigment was 100%. And the main reason for the cells＇ death was the strong destruction of the monose, amylose, protein, DNA and RNA in the cells. As an advanced oxidation method, the procedure can destroy invasive marine species when a ship is in the process of discharging its ballast water.
基金supported by the Key Project of National Support Plan from Science and Technology Ministry of China （2006BAC11B06） the Key Project of International Cooperation from the Ministry of Science and Technology of China （2005DFA20800）+1 种基金the Support Plan of National New Century Excellent Youth of China （NCET-04-0286, -05-0398） the Project of National Natural Science Foundation of China （No. 60371035）
文摘With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship＇s ballast water. The surface morphology of Al2O3 dielectric layer was analysed using Atomic Force Microscopy （AFM）, where the size of Al2O3 particles was in the range of 2 μm to 5 μm. At the same time, the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship＇s ballast water were studied. The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase （CAT）, Peroxidase （POD） and Superoxide dismutase （SOD）. In addition, the quality of the ballast water was greatly improved.
基金This work was supported by the Hebei Provincial Natural Science Fund Key Project(F2017202243)Hebei Provincial Natural Science Fund(E2019202132)+3 种基金Tianjin Natural Science Foundation(18JCTPJC54700)Hebei Province Higher Education Science and Technology Research Project(BJ2019049)China Postdoctoral Science Foundation(2018M641616)National Natural Science Foundation of China(51705128).
文摘In the process of two-pass micro plasma arc welding of titanium alloy sheet,based on the thermal contact resistance theory,a three-dimensional transient heat transfer finite element model of contact heat transfer between titanium alloy sheet and flexible fixture was established.The effects of contact upper surface temperature,micro-contact thermal resistance,micro-gap thermal resistance,DC and pulse welding on thermal contact resistance were investigated,and the simulation and experimental results were compared.The results show that the thermal contact resistance increases as the temperature increases when the temperature of the contact upper surface (titanium alloy sheet) is in the range of 290-350 K.The effect of micro-contact thermal resistance on the thermal contact resistance is 26.1%-46.3% larger than the micro-gap thermal resistance.The thermal contact resistance of pulse welding is 3.1%-3.5% larger than DC welding.The error of simulation and experimental results of weld pool depth is 8.6%,which verifies the reliability of the model.
