This paper describes optimization process of nozzle cup based on a device for contactless code marking to rough and contaminated surfaces--semiautomatic code marker. During tests using the CFD （computational fluid dy...This paper describes optimization process of nozzle cup based on a device for contactless code marking to rough and contaminated surfaces--semiautomatic code marker. During tests using the CFD （computational fluid dynamics） software different geometry of nozzle cups were compared by such parameters as pressure, velocity and direction of flow. Goal of digital experiments was to find sprayer nozzle geometry that can keep stream of paint in diameter of 10 mm on 10-20 mm distance. Main problem is to avoid low-pressure regions around the stream. The optimal geometry of nozzle cup is designed to get adjusted code dimensions on given distance展开更多
A stretch-release strategy is proposed to analyze the problem of surface energy-induced stress fields in nanocrystals,which is resolved into a stretch sub-problem and a release sub-problem using the superposition prin...A stretch-release strategy is proposed to analyze the problem of surface energy-induced stress fields in nanocrystals,which is resolved into a stretch sub-problem and a release sub-problem using the superposition principle.The surface effect of silicon nanowires with hexagonal cross-sections is analyzed by the proposed method.The severe stress concentration near the triple junctions of the wire surfaces and the large shear stress on the plane{111}is quantified,which provides a solid mechanical explanation for the kink phenomena in growth transition from direction〈111〉to〈112〉observed in experiments.Different from the conventional view of negligible surface effect for bulk material,we found that there exists a size-independent part of the surface effect on the stress in the order of tens or hundreds of mega Pascal,which corresponds to the stretch-induced biaxial stress in the surface layer and the shape influence of the geometry of nanocrystals.This size-independent part could well explain the size-independent kinking phenomenon during the growth of silicon nanowires.展开更多
文摘This paper describes optimization process of nozzle cup based on a device for contactless code marking to rough and contaminated surfaces--semiautomatic code marker. During tests using the CFD （computational fluid dynamics） software different geometry of nozzle cups were compared by such parameters as pressure, velocity and direction of flow. Goal of digital experiments was to find sprayer nozzle geometry that can keep stream of paint in diameter of 10 mm on 10-20 mm distance. Main problem is to avoid low-pressure regions around the stream. The optimal geometry of nozzle cup is designed to get adjusted code dimensions on given distance
基金the National Natural Science Foundation of China(Grant No.11872237)the Natural Science Foundation of Shanghai(Grant No.18ZR1414600)the Challenging Project from China Academy of Engineering Physics.
文摘A stretch-release strategy is proposed to analyze the problem of surface energy-induced stress fields in nanocrystals,which is resolved into a stretch sub-problem and a release sub-problem using the superposition principle.The surface effect of silicon nanowires with hexagonal cross-sections is analyzed by the proposed method.The severe stress concentration near the triple junctions of the wire surfaces and the large shear stress on the plane{111}is quantified,which provides a solid mechanical explanation for the kink phenomena in growth transition from direction〈111〉to〈112〉observed in experiments.Different from the conventional view of negligible surface effect for bulk material,we found that there exists a size-independent part of the surface effect on the stress in the order of tens or hundreds of mega Pascal,which corresponds to the stretch-induced biaxial stress in the surface layer and the shape influence of the geometry of nanocrystals.This size-independent part could well explain the size-independent kinking phenomenon during the growth of silicon nanowires.
