A parameterized internal tide dissipation term and self-attraction and loading(SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M_2 and S_2 in...A parameterized internal tide dissipation term and self-attraction and loading(SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M_2 and S_2 in the Bohai Sea, Yellow Sea and East China Sea(BYECS). The optimal parameters for bottom friction and internal dissipation are obtained through a series of numerical computations. Numerical simulation shows that the tide-generating force contributes 1.2% of M_2 power for the entire BYECS and up to 2.8% for the East China Sea deep basin. SAL tide contributes 4.4% of M_2 power for the BYECS and up to 9.3% for the East China Sea deep basin. Bottom friction plays a major role in dissipating tidal energy in the shelf regions, and the internal tide eff ect is important in the deep water regions. Numerical experiments show that artifi cial removal of tide-generating force in the BYECS can cause a signifi cant dif ference(as much as 30 cm) in model output. Artifi cial removal of SAL tide in the BYECS can cause even greater diff erence, up to 40 cm. This indicates that SAL tide should be taken into account in numerical simulations, especially if the tide-generating force is considered.展开更多
In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the...In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the root and stem yield of these varieties together with an old improved variety currently in farmers＇ field. In all the locations, root yield of all the new materials were significantly higher （P 〈 0.05） than the old improved variety. The root yields of the new varieties were between 40%-50% higher than the old improved varieties. Overall yield advantages of the new materials over the old improved material ranged between 40%-150%. Stem yield figures showed significant variations with few of the new varieties producing higher stem yield in comparison with the old improved variety due to inherent growth pattern. Figures for tuber girth and node numbers per unit of stem were similar. The high yield levels of the new varieties might lead to high demand for stems indicating the likely wider spread and higher demand for varieties with high stem yield potentials.展开更多
The Lagrangian DDM （discrete droplet model） is state-of-the-art for CFD （computational fluid dynamics） simulations of mixture formation and combustion in industrial engines. A commonly known drawback of the DDM ap...The Lagrangian DDM （discrete droplet model） is state-of-the-art for CFD （computational fluid dynamics） simulations of mixture formation and combustion in industrial engines. A commonly known drawback of the DDM approach is the attenuated validity in the dense spray, where the bulk liquid disintegrates into droplets. There the assumption of single droplets surrounded by a homogenous gas field is not reasonable. In this region, the Eulerian-Eulerian multi-phase approach performs better because instead of parcels the spray is represented by the volume fractions of one bulk liquid and several droplet size class phases. A further drawback of the DDM approach is that increasing the spatial resolution of the computational grid leads to a reduced statistical convergence, since the number of spray parcels per computational cell becomes smaller. It is desirable to combine the benefits of both spray approaches in coupled CFD simulations. Therefore, the dense spray region is simulated separately with the Eulerian spray approach on a highly resolved mesh covering only the region close to the nozzle orifice. The entire engine domain with combustion and emission models is simulated with the Eulerian-Lagrangian spray approach for the dilute spray region. The two simulations are coupled through exchange of boundary conditions and model source terms. An on-line coupling interface manages the data transfer between the two simulation clients, i.e., Eulerian spray and engine client. The aim of this work is to extend the coupled spray approach in terms of exchanging combustion related heat and species sources, and consequently creating the link between Eulerian spray and combustion models. The results show mixture formation and combustion in real-case engine simulations, and demonstrate the feasibility of spray model combination in engineering applications.展开更多
The interactive Lagrangian density of massive photons and gravitons is proposed after an investigation into the interaction between photons with or without mass under the influence of gravity either as classical field...The interactive Lagrangian density of massive photons and gravitons is proposed after an investigation into the interaction between photons with or without mass under the influence of gravity either as classical field, gravitational wave, or gravitons from a perspective of quantum field. This interactive Lagrangian density can provide a step-stone for further research of gravitational wave and the possible rest mass of photon.展开更多
This paper is preliminary information on some empirical findings based on an analysis of Thailand＇s macroeconomic data. The purpose of the study is to quantify social-economic well-being development with special emph...This paper is preliminary information on some empirical findings based on an analysis of Thailand＇s macroeconomic data. The purpose of the study is to quantify social-economic well-being development with special emphasis on poverty. The maximum entropy bootstrap was presented that did not require the property of stationarity. Moreover, the methodology was stratified both the ergodic theorem and the central limit theorem. Thailand＇s GINI index and Thailand-Japan＇s volume of trade data cover the 14-year period from 1998 to 2011. There is a statistically significant negative non-linear relationship between endogenous Thailand＇s GINI index and exogenous Thailand-Japan＇s volume of trade. The results confirmed that every lagged one percent increase in Thailand-Japan＇s volume of trade influenced by a decrease of Thailand＇s GINI index coefficient 0.039 percent with the asymmetric around 0-almost closed to range condition -0.034824348 at 2.5%.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.40676009,40606006)the Qingdao Science and Technology Basic Research Program(No.11-1-4-98-jch)
文摘A parameterized internal tide dissipation term and self-attraction and loading(SAL) tide term are introduced in a barotropic numerical model to investigate the dynamics of semidiurnal tidal constituents M_2 and S_2 in the Bohai Sea, Yellow Sea and East China Sea(BYECS). The optimal parameters for bottom friction and internal dissipation are obtained through a series of numerical computations. Numerical simulation shows that the tide-generating force contributes 1.2% of M_2 power for the entire BYECS and up to 2.8% for the East China Sea deep basin. SAL tide contributes 4.4% of M_2 power for the BYECS and up to 9.3% for the East China Sea deep basin. Bottom friction plays a major role in dissipating tidal energy in the shelf regions, and the internal tide eff ect is important in the deep water regions. Numerical experiments show that artifi cial removal of tide-generating force in the BYECS can cause a signifi cant dif ference(as much as 30 cm) in model output. Artifi cial removal of SAL tide in the BYECS can cause even greater diff erence, up to 40 cm. This indicates that SAL tide should be taken into account in numerical simulations, especially if the tide-generating force is considered.
文摘In 2005, 10 new cassava varieties were officially selected and released to farmers in Nigeria for high root yield, high dry matter content and acceptability for food. This work compared in three on farm locations, the root and stem yield of these varieties together with an old improved variety currently in farmers＇ field. In all the locations, root yield of all the new materials were significantly higher （P 〈 0.05） than the old improved variety. The root yields of the new varieties were between 40%-50% higher than the old improved varieties. Overall yield advantages of the new materials over the old improved material ranged between 40%-150%. Stem yield figures showed significant variations with few of the new varieties producing higher stem yield in comparison with the old improved variety due to inherent growth pattern. Figures for tuber girth and node numbers per unit of stem were similar. The high yield levels of the new varieties might lead to high demand for stems indicating the likely wider spread and higher demand for varieties with high stem yield potentials.
文摘The Lagrangian DDM （discrete droplet model） is state-of-the-art for CFD （computational fluid dynamics） simulations of mixture formation and combustion in industrial engines. A commonly known drawback of the DDM approach is the attenuated validity in the dense spray, where the bulk liquid disintegrates into droplets. There the assumption of single droplets surrounded by a homogenous gas field is not reasonable. In this region, the Eulerian-Eulerian multi-phase approach performs better because instead of parcels the spray is represented by the volume fractions of one bulk liquid and several droplet size class phases. A further drawback of the DDM approach is that increasing the spatial resolution of the computational grid leads to a reduced statistical convergence, since the number of spray parcels per computational cell becomes smaller. It is desirable to combine the benefits of both spray approaches in coupled CFD simulations. Therefore, the dense spray region is simulated separately with the Eulerian spray approach on a highly resolved mesh covering only the region close to the nozzle orifice. The entire engine domain with combustion and emission models is simulated with the Eulerian-Lagrangian spray approach for the dilute spray region. The two simulations are coupled through exchange of boundary conditions and model source terms. An on-line coupling interface manages the data transfer between the two simulation clients, i.e., Eulerian spray and engine client. The aim of this work is to extend the coupled spray approach in terms of exchanging combustion related heat and species sources, and consequently creating the link between Eulerian spray and combustion models. The results show mixture formation and combustion in real-case engine simulations, and demonstrate the feasibility of spray model combination in engineering applications.
基金Funded by the National Basic Research Programs of China under Grant No. 2003CB716300, the Natural Science Foundation of Chongqing under Grant No. 8562, and the Natural Science Foundation of China under Grant No. 10575140.
文摘The interactive Lagrangian density of massive photons and gravitons is proposed after an investigation into the interaction between photons with or without mass under the influence of gravity either as classical field, gravitational wave, or gravitons from a perspective of quantum field. This interactive Lagrangian density can provide a step-stone for further research of gravitational wave and the possible rest mass of photon.
文摘This paper is preliminary information on some empirical findings based on an analysis of Thailand＇s macroeconomic data. The purpose of the study is to quantify social-economic well-being development with special emphasis on poverty. The maximum entropy bootstrap was presented that did not require the property of stationarity. Moreover, the methodology was stratified both the ergodic theorem and the central limit theorem. Thailand＇s GINI index and Thailand-Japan＇s volume of trade data cover the 14-year period from 1998 to 2011. There is a statistically significant negative non-linear relationship between endogenous Thailand＇s GINI index and exogenous Thailand-Japan＇s volume of trade. The results confirmed that every lagged one percent increase in Thailand-Japan＇s volume of trade influenced by a decrease of Thailand＇s GINI index coefficient 0.039 percent with the asymmetric around 0-almost closed to range condition -0.034824348 at 2.5%.
