An aero-engine is a typically repairable and complex system and its maintenance level has a close relationship with the maintenance cost. The inaccurate measurement for the maintenance level of an aero-engine can indu...An aero-engine is a typically repairable and complex system and its maintenance level has a close relationship with the maintenance cost. The inaccurate measurement for the maintenance level of an aero-engine can induce higher overhaul maintenance costs. Variable precision rough set （VPRS） theory is used to determine the maintenance level of an aero-engine. According to the relationship between condition information and performance parameters of aero-engine modules, decision rules are established for reflecting the real condition of an aeroengine when its maintenance level needs to be determined. Finally, the CF6 engine is used as an example to illustrate the method to be effective.展开更多
The coarse grained(CG)model implements the molecular dynamics simulation by simplifying atom properties and interaction between them.Despite losing certain detailed information,the CG model is still the first-thought ...The coarse grained(CG)model implements the molecular dynamics simulation by simplifying atom properties and interaction between them.Despite losing certain detailed information,the CG model is still the first-thought option to study the large molecule in long time scale with less computing resource.The deep learning model mainly mimics the human studying process to handle the network input as the image to achieve a good classification and regression result.In this work,the TorchMD,a MD framework combining the CG model and deep learning model,is applied to study the protein folding process.In 3D collective variable(CV)space,the modified find density peaks algorithm is applied to cluster the conformations from the TorchMD CG simulation.The center conformation in different states is searched.And the boundary conformations between clusters are assigned.The string algorithm is applied to study the path between two states,which are compared with the end conformations from all atoms simulations.The result shows that the main phenomenon of protein folding with TorchMD CG model is the same as the all-atom simulations,but with a less simulating time scale.The workflow in this work provides another option to study the protein folding and other relative processes with the deep learning CG model.展开更多
Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate (HMS) dispersed in lubricant oil on steel-to-steel friction pairs with various surface roughness were analyzed.The friction-reductio...Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate (HMS) dispersed in lubricant oil on steel-to-steel friction pairs with various surface roughness were analyzed.The friction-reduction,anti-wear and self-repairing performance of various surface roughness friction pairs were examined by friction testing machine.An operation comparison was made between SJ10W-40 lubricant with and without HMS.The surface morphology and elementary composition of the grinding cracks were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The results show that the lubrication state changes from boundary lubrication into mixed lubrication after operation in lubricant with HMS.The friction-reduction,anti-wear and self-repairing performance of the friction pairs with various surface roughness are distinctly different.There is a repairing film whose material is different from substrate material on the grinding cracks.In addition,Si,Mg,O,Al and other elements are deposited on the repairing film which contains nanocrystals of these elements.And HMS self-repairing material possesses superior performance of friction-reduction,anti-wear and self-repairing effects.展开更多
The effects of wood roughness, modification and sanding on the water contact angle values of pine spruce and aspen wood surfaces were evaluated. Contact angle values set by time linear part extrapolation give increase...The effects of wood roughness, modification and sanding on the water contact angle values of pine spruce and aspen wood surfaces were evaluated. Contact angle values set by time linear part extrapolation give increased values in comparison with ones obtained after water drop spreading on the surface. Water drop side-view contact angle along wood fiber directions is less influenced by surface roughness. Wood water activity （aw） can be used to ascertain available water content on surface.展开更多
文摘An aero-engine is a typically repairable and complex system and its maintenance level has a close relationship with the maintenance cost. The inaccurate measurement for the maintenance level of an aero-engine can induce higher overhaul maintenance costs. Variable precision rough set （VPRS） theory is used to determine the maintenance level of an aero-engine. According to the relationship between condition information and performance parameters of aero-engine modules, decision rules are established for reflecting the real condition of an aeroengine when its maintenance level needs to be determined. Finally, the CF6 engine is used as an example to illustrate the method to be effective.
基金supported by the National Natural Science Foundation of China(No.31800615 and No.21933010)。
文摘The coarse grained(CG)model implements the molecular dynamics simulation by simplifying atom properties and interaction between them.Despite losing certain detailed information,the CG model is still the first-thought option to study the large molecule in long time scale with less computing resource.The deep learning model mainly mimics the human studying process to handle the network input as the image to achieve a good classification and regression result.In this work,the TorchMD,a MD framework combining the CG model and deep learning model,is applied to study the protein folding process.In 3D collective variable(CV)space,the modified find density peaks algorithm is applied to cluster the conformations from the TorchMD CG simulation.The center conformation in different states is searched.And the boundary conformations between clusters are assigned.The string algorithm is applied to study the path between two states,which are compared with the end conformations from all atoms simulations.The result shows that the main phenomenon of protein folding with TorchMD CG model is the same as the all-atom simulations,but with a less simulating time scale.The workflow in this work provides another option to study the protein folding and other relative processes with the deep learning CG model.
基金Projects(50735006,50904072) supported by the National Natural Science Foundation of ChinaProject(2007CB607601) supported by the National Basic Research Program of China
文摘Tribological characteristics and self-repairing effect of hydroxy-magnesium silicate (HMS) dispersed in lubricant oil on steel-to-steel friction pairs with various surface roughness were analyzed.The friction-reduction,anti-wear and self-repairing performance of various surface roughness friction pairs were examined by friction testing machine.An operation comparison was made between SJ10W-40 lubricant with and without HMS.The surface morphology and elementary composition of the grinding cracks were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The results show that the lubrication state changes from boundary lubrication into mixed lubrication after operation in lubricant with HMS.The friction-reduction,anti-wear and self-repairing performance of the friction pairs with various surface roughness are distinctly different.There is a repairing film whose material is different from substrate material on the grinding cracks.In addition,Si,Mg,O,Al and other elements are deposited on the repairing film which contains nanocrystals of these elements.And HMS self-repairing material possesses superior performance of friction-reduction,anti-wear and self-repairing effects.
文摘The effects of wood roughness, modification and sanding on the water contact angle values of pine spruce and aspen wood surfaces were evaluated. Contact angle values set by time linear part extrapolation give increased values in comparison with ones obtained after water drop spreading on the surface. Water drop side-view contact angle along wood fiber directions is less influenced by surface roughness. Wood water activity （aw） can be used to ascertain available water content on surface.
