We propose a novel two-species aggregation-annihilation model, in which irreversible aggregation reactions occur between any two aggregates of the same species and biased annihilations occur simultaneously between two...We propose a novel two-species aggregation-annihilation model, in which irreversible aggregation reactions occur between any two aggregates of the same species and biased annihilations occur simultaneously between two different species. The kinetic scaling behavior of the model is then analytically investigated by means of the mean-field rate equation. For the system without the seff-aggregation of the un-annihilated species, the aggregate size distribution of the annihilated species always approaches a modified scaling form and vanishes finally; while for the system with the self-aggregation of the un-annihilated species, its scaling behavior depends crucially on the details of the rate kernels. Moreover, the results also exhibit that both species are conserved together in some cases, while only the un-annihilated species survives finally in other cases.展开更多
It is necessary to treat wastewater in a more environment-friendly fashion.Vegetated submerge bed constructed wetlands (CWs) has become the focus of the research in this field. In this paper, the overall capacity of v...It is necessary to treat wastewater in a more environment-friendly fashion.Vegetated submerge bed constructed wetlands (CWs) has become the focus of the research in this field. In this paper, the overall capacity of vertical subsurface flow CWs in the removal of pollutants from municipal wastewater effluent and the effects of the depth of vegetated submerged bed on the removal efficiency were studied. The results showed that the COD, NH+4-N and TN could be removed effectively in the vertical subsurface flow CWs and the best efficiency was obtained from the 10 cm run. However, the TP removal was not effective in all vertical CWs. A shallow depth of vegetated submerged bed may avoid the risk of substrate plugging effectively, and may keep a stable operation of CWs in long term. Decreasing the depth of vegetated submerged bed could create a sufficient aerobic circumstance in which the concentration of DO (dissolved oxygen) in bed was super saturation.展开更多
Research on damage stability and unsinkability is a valuable source of knowledge of behaving a ship while flooding its compartments. The time when compartment is flooded （ty） and stability parameters are key element...Research on damage stability and unsinkability is a valuable source of knowledge of behaving a ship while flooding its compartments. The time when compartment is flooded （ty） and stability parameters are key elements which have influence on a rescue action. The knowledge of the time mentioned is very important for a commanding officer to make decisions while fighting for survival of the ship. Therefore, the purpose of research was to develop a method to accurately and quickly calculate the flooding time of selected ship compartment. To provide the information about the time ty, a new method was designed. This method was based on an accurate determination of the amount of water entering to the compartment. For this purpose, the permeability depends on the water level in the compartment. Next, the computer program was built for both the time tfcalculation and showing the flooding process. This method was tested experimentally and the results of the tests are presented in the paper. In the next part of research, which was carried out on the laboratory stand bed, the flooding time of damaged compartment of warship model was measured. The results of calculation are compared to the experiments and discussed.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 10305009 and the Natural Science Foundation of Zhejiang Province of China under Grant No. 102067
文摘We propose a novel two-species aggregation-annihilation model, in which irreversible aggregation reactions occur between any two aggregates of the same species and biased annihilations occur simultaneously between two different species. The kinetic scaling behavior of the model is then analytically investigated by means of the mean-field rate equation. For the system without the seff-aggregation of the un-annihilated species, the aggregate size distribution of the annihilated species always approaches a modified scaling form and vanishes finally; while for the system with the self-aggregation of the un-annihilated species, its scaling behavior depends crucially on the details of the rate kernels. Moreover, the results also exhibit that both species are conserved together in some cases, while only the un-annihilated species survives finally in other cases.
基金supported by the Scientific Research Foundation of the State Human Resource Ministry for Returned Chinese Scholars, China (Grant No.SLZ2008012)Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. SJ08-ZT07)+1 种基金the Research Program of the Education Department of Shannxi Province of China (Grant No. 08JK327)Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT) (Grant No. IRT0853)
文摘It is necessary to treat wastewater in a more environment-friendly fashion.Vegetated submerge bed constructed wetlands (CWs) has become the focus of the research in this field. In this paper, the overall capacity of vertical subsurface flow CWs in the removal of pollutants from municipal wastewater effluent and the effects of the depth of vegetated submerged bed on the removal efficiency were studied. The results showed that the COD, NH+4-N and TN could be removed effectively in the vertical subsurface flow CWs and the best efficiency was obtained from the 10 cm run. However, the TP removal was not effective in all vertical CWs. A shallow depth of vegetated submerged bed may avoid the risk of substrate plugging effectively, and may keep a stable operation of CWs in long term. Decreasing the depth of vegetated submerged bed could create a sufficient aerobic circumstance in which the concentration of DO (dissolved oxygen) in bed was super saturation.
文摘Research on damage stability and unsinkability is a valuable source of knowledge of behaving a ship while flooding its compartments. The time when compartment is flooded （ty） and stability parameters are key elements which have influence on a rescue action. The knowledge of the time mentioned is very important for a commanding officer to make decisions while fighting for survival of the ship. Therefore, the purpose of research was to develop a method to accurately and quickly calculate the flooding time of selected ship compartment. To provide the information about the time ty, a new method was designed. This method was based on an accurate determination of the amount of water entering to the compartment. For this purpose, the permeability depends on the water level in the compartment. Next, the computer program was built for both the time tfcalculation and showing the flooding process. This method was tested experimentally and the results of the tests are presented in the paper. In the next part of research, which was carried out on the laboratory stand bed, the flooding time of damaged compartment of warship model was measured. The results of calculation are compared to the experiments and discussed.
