The drum shearer and high pressure water jet combined cutting system is an effective technology to cut hard coal-rock, but one problem of the technology is the choice of pick and nozzle location parameters. In order t...The drum shearer and high pressure water jet combined cutting system is an effective technology to cut hard coal-rock, but one problem of the technology is the choice of pick and nozzle location parameters. In order to solve the problem, the process and mechanism of combined cutting arc studied and mining seepage catastrophe theory is used to construct the mathematic and physical model of combined cutting hard coal-rock. Based on the model and detailed analysis of combined cutting mechanism, the single pick and nozzle combined cutting test-bed is built to test the main pick and nozzle location parameters of drum shearer and water jet combined cutting system. Test results show that the best vertical distance between the pick-tip and nozzle center point is the sum of cutting thickness and proper target distance in the Y axial direction; the best horizontal distance is the length between pick-tip point and coal-rock surface bursting crack point in the X axial direction. The best incident angle of water jet should be the same as the bursting crack line＇s angle in theory, but considering other important factors comprehensively, it is more reasonable when the incident angle of water jet is 90°.展开更多
To model Skeletonema costatum blooms and their relationship with environmental parameters in situ, a S. costatum-specific zero-dimensional box model based on the mechanistic model Eco3M was established using physiolog...To model Skeletonema costatum blooms and their relationship with environmental parameters in situ, a S. costatum-specific zero-dimensional box model based on the mechanistic model Eco3M was established using physiological features. The parameters were calibrated using experimental counterparts, and simulations were compared with published laboratory findings. The resulting normalized objective function （NOF） values are less than 1.0 （and in most cases less than 0.58） and the values for the slope y （between 0.656 7-1.127 4） and R2 （between 0.806 8-0.971） are close to 1.0 for most of the sub-figures. This indicates good agreement between simulated and measured data and suggests that the model reproduces the general characteristics of S. costatum growth and use of nutrients under different N- or P-limiting conditions. The model is appropriate for further applications and can be used to test more scenarios using other nutrients.展开更多
The elasto-plastic-damage behavior of anisotropic aluminum alloys is investigated under finite deformation using a physical mechanism based constitutive model.With an application to the structural calculation,the pres...The elasto-plastic-damage behavior of anisotropic aluminum alloys is investigated under finite deformation using a physical mechanism based constitutive model.With an application to the structural calculation,the present model is used to describe and analyze the mechanical response of anisotropic 6260-T6 aluminum alloy extrusions.For the tensile specimens extracted along three different material orientations from the extruded aluminum profile,twelve simulations are carried out covering four different specimen geometries.The simulation results in force-displacement response and central logarithmic axial strain evolution are compared with experimental results.From the comparisons,it can be concluded that the present model has the capacity to describe the behavior of anisotropic material.From the force-displacement curves,the anisotropy is observed in different material orientations,and the physical mechanism of anisotropy is analyzed.展开更多
基金Project(2012AA062104) supported by the National High Technology Research and Development Program of ChinaProject(201104583) supported by the Postdoctoral Special Funded Projects,China
文摘The drum shearer and high pressure water jet combined cutting system is an effective technology to cut hard coal-rock, but one problem of the technology is the choice of pick and nozzle location parameters. In order to solve the problem, the process and mechanism of combined cutting arc studied and mining seepage catastrophe theory is used to construct the mathematic and physical model of combined cutting hard coal-rock. Based on the model and detailed analysis of combined cutting mechanism, the single pick and nozzle combined cutting test-bed is built to test the main pick and nozzle location parameters of drum shearer and water jet combined cutting system. Test results show that the best vertical distance between the pick-tip and nozzle center point is the sum of cutting thickness and proper target distance in the Y axial direction; the best horizontal distance is the length between pick-tip point and coal-rock surface bursting crack point in the X axial direction. The best incident angle of water jet should be the same as the bursting crack line＇s angle in theory, but considering other important factors comprehensively, it is more reasonable when the incident angle of water jet is 90°.
基金Supported by the National Natural Science Foundation of China(Nos.40821004,41276186)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-Q07-02)
文摘To model Skeletonema costatum blooms and their relationship with environmental parameters in situ, a S. costatum-specific zero-dimensional box model based on the mechanistic model Eco3M was established using physiological features. The parameters were calibrated using experimental counterparts, and simulations were compared with published laboratory findings. The resulting normalized objective function （NOF） values are less than 1.0 （and in most cases less than 0.58） and the values for the slope y （between 0.656 7-1.127 4） and R2 （between 0.806 8-0.971） are close to 1.0 for most of the sub-figures. This indicates good agreement between simulated and measured data and suggests that the model reproduces the general characteristics of S. costatum growth and use of nutrients under different N- or P-limiting conditions. The model is appropriate for further applications and can be used to test more scenarios using other nutrients.
基金supported by the National Natural Science Foundation of China(Grant No.11021262)the Fundamental Research Funds for the Central Universities(Grant No.WUT:2013-IV-021)
文摘The elasto-plastic-damage behavior of anisotropic aluminum alloys is investigated under finite deformation using a physical mechanism based constitutive model.With an application to the structural calculation,the present model is used to describe and analyze the mechanical response of anisotropic 6260-T6 aluminum alloy extrusions.For the tensile specimens extracted along three different material orientations from the extruded aluminum profile,twelve simulations are carried out covering four different specimen geometries.The simulation results in force-displacement response and central logarithmic axial strain evolution are compared with experimental results.From the comparisons,it can be concluded that the present model has the capacity to describe the behavior of anisotropic material.From the force-displacement curves,the anisotropy is observed in different material orientations,and the physical mechanism of anisotropy is analyzed.
