The ratio of crack initiation stress to the uniaxial compressive strength(SCI,B/SUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A...The ratio of crack initiation stress to the uniaxial compressive strength(SCI,B/SUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A/SSSS) were studied by performing numerical stress analysis on blocks having multi flaws at close spacing's under uniaxial loading using PFC3 D. The following findings are obtained: SCI,B/SUC,B has an average value of about 0.5 with a variability of ± 0.1. This range agrees quite well with the values obtained by former research. For joint inclination angle, β=90°,B,UCB,CI,A,A/SSSS is found to be around 0.48 irrespective of the value of joint continuity factor, k. No particular relation is found betweenB,UCB,CI,A,A/SSSS and β; however, the average B,UCB,CI,A,A/SSSS seems to slightly decrease with increasing k. The variability ofB,UCB,CI,A,A/SSSS is found to increase with k.Based on the cases studied in this work,B,UCB,CI,A,A/SSSS ranges between 0.3 and 0.5. This range is quite close to the range of 0.4to 0.6 obtained for SCI,B/SUC,B. The highest variability of ± 0.12 forB,UCB,CI,A,A/SSSS is obtained for k=0.8. For the remaining k values the variability ofB,UCB,CI,A,A/SSSS can be expressed within ± 0.05. This finding is very similar to the finding obtained for the variability of SCI,B/SUC,B.展开更多
1 INTRODUCTIONThe determination of the solids hold-up and local solidfluxes is of paramount importance in the study ofthe hydrodynamics of a two-phase flow.Several tech-niques have been used during the past decades(Ta...1 INTRODUCTIONThe determination of the solids hold-up and local solidfluxes is of paramount importance in the study ofthe hydrodynamics of a two-phase flow.Several tech-niques have been used during the past decades(Table1).These methods can be classified in two groups,depending on their possible disturbance of the two-展开更多
Severe wind-wave due to tropical cyclone Linda can cause port downtime which affects port operations such as berthing, mooting and （un）loading of the ship. The ship motions are criteria for limiting the port operati...Severe wind-wave due to tropical cyclone Linda can cause port downtime which affects port operations such as berthing, mooting and （un）loading of the ship. The ship motions are criteria for limiting the port operations, human safety and preventing the damage of port equipment and furniture. Therefore, this study discusses moored ship motions due to severe wind-wave during the tropical cyclone Linda which entered the Gulf of Thailand in November 1997. The ship motions are represented in the moored ship analysis at SRH （Sriracha Harbour Port） and BLCP （BLCP Coal-Fired Power Plant Port）, and are subject to the static environmental load on the ship in accordance with Spanish Standard （ROM 0.2-1990） [1]. The environment in numerical model is derived from the wave model and hydrodynamics model using the application of Delft3D-WAVE and Delft3D-FLOW. The model location includes Ao Udom Bay and Rayong Sea. The model results represent the environment at Rayong Sea which is more severe than Ao Udom Bay. The ship motions at BLCP are mostly larger than SRH.展开更多
Although CO_(2)photoreduction is a promising method for solar‐to‐fuel conversion,it suffers from low charge transfer efficiency of the photocatalysts.To improve the CO_(2)photoreduction performance,introduction of e...Although CO_(2)photoreduction is a promising method for solar‐to‐fuel conversion,it suffers from low charge transfer efficiency of the photocatalysts.To improve the CO_(2)photoreduction performance,introduction of electron‐accumulated materials on the photocatalyst surface is considered an effective method.In this study,the Bi_(19)S_(27)Br_(3)/BiOBr composites were designed and synthesized.The Bi19S27Br3 nanorod in this photocatalytic system acts as an electron‐accumulated active site for extracting the photogenerated electrons on the BiOBr surface and for effectively activating the CO2 molecules.As a result,Bi_(19)S_(27)Br_(3)/BiOBr composites exhibit the higher charge carrier transfer efficiency and further improves the CO_(2)photoreduction performance relative to that of pure Bi_(19)S_(27)Br_(3)and BiOBr.The rate of CO formation using Bi_(19)S_(27)Br_(3)/BiOBr‐5 is about 8.74 and 2.40 times that using Bi_(19)S_(27)Br_(3)and BiOBr,respectively.This work provides new insights for the application of Bi_(19)S_(27)Br_(3)as an electron‐accumulating site for achieving high photocatalytic CO2 reduction performance in the future.展开更多
The first decision we need to make in a structural load assessment is what approach should be applied, a linear approach or a non-linear one. The correct decision comes from understanding of the technology used in the...The first decision we need to make in a structural load assessment is what approach should be applied, a linear approach or a non-linear one. The correct decision comes from understanding of the technology used in the linear and non-linear approaches and also comes from the understanding of the problem to he analyzed. From engineering practice, it has been found that many non-linear effects can be taken into account in a linear model with appropriate approach. A study of hydrodynamic structural load on a stinger of a pipe-laying vessel is presented in this paper. The results of a non-linear analysis are compared to those of linear models with different approaches, and how the nonlinear effect can be involved in a linear model is discussed. The recommendations on how to estimate the non-linear effects in a linear structural load model is discussed.展开更多
Reynold＇s averaged Navier-Stokes based CFD （computational fluid dynamics） technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR1...Reynold＇s averaged Navier-Stokes based CFD （computational fluid dynamics） technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR108 and KCS in 120 degree regular oblique wave conditions. WISDAM has the capability of handling 6DOF （six degrees of freedom） in ship motions. Finite volume method with structured and overlapping grid system is employed. The flow variables are described in staggered manner, i.e., velocity components arc defined at the face center while pressure is at the cell center. Computational results agree favorably well with existing towing tank results especially for ship motions. Computational results also show that ship with bulbous bow experience higher hydrodynamic loads on bow section.展开更多
The purpose of this paper is to apply ＂Soil and Water Assessment Tool （SWAT）＂ model to simulate the impacts of climate change and deforestation on nutrient （nitrogen and phosphorus） yield from Phu Luong watershe...The purpose of this paper is to apply ＂Soil and Water Assessment Tool （SWAT）＂ model to simulate the impacts of climate change and deforestation on nutrient （nitrogen and phosphorus） yield from Phu Luong watershed in Northern Viet Nam. Among the three climate change scenarios B1, B2 and A2, which represented low, medium, and high levels of greenhouse gas emission respectively, were set up for Viet Nam. The B2 scenario was selected for this study. Two land use scenarios （SI-2030 and S2-2050 which converted 4.43%. and 13.40% forest-mixed land into agricultural land, respectively） were formulated by combination with climatic change in SWAT simulation. In B2 climate change scenario, mean temperature increases 0.7 ℃ （2030） and 1.3 ℃（2050）; annual rainfall increases 2.1% （2030） and 3.80% （2050） with respect to baseline scenario. The results showed that monthly Nash-Sutcliffe coefficient of Efficiency （NSE） ranged from 0.81 to 0.96 and percent bias （PB1AS） ranged from -7.88 to 9.38. Additionally, SWAT simulation results also showed that climate change and deforestation caused significant percentage of changes in total N and P loads within Phu Luong watershed.展开更多
基金Project(11102224)supported by the National Natural Science Foundation of ChinaProject(201206370124)supported by the China Scholarship Council,China
文摘The ratio of crack initiation stress to the uniaxial compressive strength(SCI,B/SUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A/SSSS) were studied by performing numerical stress analysis on blocks having multi flaws at close spacing's under uniaxial loading using PFC3 D. The following findings are obtained: SCI,B/SUC,B has an average value of about 0.5 with a variability of ± 0.1. This range agrees quite well with the values obtained by former research. For joint inclination angle, β=90°,B,UCB,CI,A,A/SSSS is found to be around 0.48 irrespective of the value of joint continuity factor, k. No particular relation is found betweenB,UCB,CI,A,A/SSSS and β; however, the average B,UCB,CI,A,A/SSSS seems to slightly decrease with increasing k. The variability ofB,UCB,CI,A,A/SSSS is found to increase with k.Based on the cases studied in this work,B,UCB,CI,A,A/SSSS ranges between 0.3 and 0.5. This range is quite close to the range of 0.4to 0.6 obtained for SCI,B/SUC,B. The highest variability of ± 0.12 forB,UCB,CI,A,A/SSSS is obtained for k=0.8. For the remaining k values the variability ofB,UCB,CI,A,A/SSSS can be expressed within ± 0.05. This finding is very similar to the finding obtained for the variability of SCI,B/SUC,B.
文摘1 INTRODUCTIONThe determination of the solids hold-up and local solidfluxes is of paramount importance in the study ofthe hydrodynamics of a two-phase flow.Several tech-niques have been used during the past decades(Table1).These methods can be classified in two groups,depending on their possible disturbance of the two-
文摘Severe wind-wave due to tropical cyclone Linda can cause port downtime which affects port operations such as berthing, mooting and （un）loading of the ship. The ship motions are criteria for limiting the port operations, human safety and preventing the damage of port equipment and furniture. Therefore, this study discusses moored ship motions due to severe wind-wave during the tropical cyclone Linda which entered the Gulf of Thailand in November 1997. The ship motions are represented in the moored ship analysis at SRH （Sriracha Harbour Port） and BLCP （BLCP Coal-Fired Power Plant Port）, and are subject to the static environmental load on the ship in accordance with Spanish Standard （ROM 0.2-1990） [1]. The environment in numerical model is derived from the wave model and hydrodynamics model using the application of Delft3D-WAVE and Delft3D-FLOW. The model location includes Ao Udom Bay and Rayong Sea. The model results represent the environment at Rayong Sea which is more severe than Ao Udom Bay. The ship motions at BLCP are mostly larger than SRH.
文摘Although CO_(2)photoreduction is a promising method for solar‐to‐fuel conversion,it suffers from low charge transfer efficiency of the photocatalysts.To improve the CO_(2)photoreduction performance,introduction of electron‐accumulated materials on the photocatalyst surface is considered an effective method.In this study,the Bi_(19)S_(27)Br_(3)/BiOBr composites were designed and synthesized.The Bi19S27Br3 nanorod in this photocatalytic system acts as an electron‐accumulated active site for extracting the photogenerated electrons on the BiOBr surface and for effectively activating the CO2 molecules.As a result,Bi_(19)S_(27)Br_(3)/BiOBr composites exhibit the higher charge carrier transfer efficiency and further improves the CO_(2)photoreduction performance relative to that of pure Bi_(19)S_(27)Br_(3)and BiOBr.The rate of CO formation using Bi_(19)S_(27)Br_(3)/BiOBr‐5 is about 8.74 and 2.40 times that using Bi_(19)S_(27)Br_(3)and BiOBr,respectively.This work provides new insights for the application of Bi_(19)S_(27)Br_(3)as an electron‐accumulating site for achieving high photocatalytic CO2 reduction performance in the future.
文摘The first decision we need to make in a structural load assessment is what approach should be applied, a linear approach or a non-linear one. The correct decision comes from understanding of the technology used in the linear and non-linear approaches and also comes from the understanding of the problem to he analyzed. From engineering practice, it has been found that many non-linear effects can be taken into account in a linear model with appropriate approach. A study of hydrodynamic structural load on a stinger of a pipe-laying vessel is presented in this paper. The results of a non-linear analysis are compared to those of linear models with different approaches, and how the nonlinear effect can be involved in a linear model is discussed. The recommendations on how to estimate the non-linear effects in a linear structural load model is discussed.
文摘Reynold＇s averaged Navier-Stokes based CFD （computational fluid dynamics） technique WISDAM developed at The University of Tokyo is used to investigate and compare the hydrodynamic loads on container ship models SR108 and KCS in 120 degree regular oblique wave conditions. WISDAM has the capability of handling 6DOF （six degrees of freedom） in ship motions. Finite volume method with structured and overlapping grid system is employed. The flow variables are described in staggered manner, i.e., velocity components arc defined at the face center while pressure is at the cell center. Computational results agree favorably well with existing towing tank results especially for ship motions. Computational results also show that ship with bulbous bow experience higher hydrodynamic loads on bow section.
文摘The purpose of this paper is to apply ＂Soil and Water Assessment Tool （SWAT）＂ model to simulate the impacts of climate change and deforestation on nutrient （nitrogen and phosphorus） yield from Phu Luong watershed in Northern Viet Nam. Among the three climate change scenarios B1, B2 and A2, which represented low, medium, and high levels of greenhouse gas emission respectively, were set up for Viet Nam. The B2 scenario was selected for this study. Two land use scenarios （SI-2030 and S2-2050 which converted 4.43%. and 13.40% forest-mixed land into agricultural land, respectively） were formulated by combination with climatic change in SWAT simulation. In B2 climate change scenario, mean temperature increases 0.7 ℃ （2030） and 1.3 ℃（2050）; annual rainfall increases 2.1% （2030） and 3.80% （2050） with respect to baseline scenario. The results showed that monthly Nash-Sutcliffe coefficient of Efficiency （NSE） ranged from 0.81 to 0.96 and percent bias （PB1AS） ranged from -7.88 to 9.38. Additionally, SWAT simulation results also showed that climate change and deforestation caused significant percentage of changes in total N and P loads within Phu Luong watershed.
