A new method of the design and machining the casting moulds of helical intake ports of diesel engines is presented based on CAD / CAM technique. The problems about the smooth continuity between patches, the cutter int...A new method of the design and machining the casting moulds of helical intake ports of diesel engines is presented based on CAD / CAM technique. The problems about the smooth continuity between patches, the cutter interference and the determination of the mould split curve are discussed in details.The CAGD system of the intake port has been developed. and the casting mould is machined sucessfully on NC machine.展开更多
As the growing criterion of electromagnetic wave (EMW) absorption materials, micro/nano-scale magnetic materials are drawing more and more attention for their unique features compared to bulky absorbers. Generally, th...As the growing criterion of electromagnetic wave (EMW) absorption materials, micro/nano-scale magnetic materials are drawing more and more attention for their unique features compared to bulky absorbers. Generally, the complex permeability of micro/nano-scale magnetic absorbers varies in a relatively narrow range, whatever for the storage of magnetic energy or the dissipation of magnetic energy. If so, how the small variation of permeability affects the ultimate performances is still unclear. Here, a strategy of electromagnetic parameters regulation for the magnetic materials is applied to understand the loss contribution in micro/nanoscale magnetic absorbers. After analyzing the evolution of electromagnetic maps of ten ferrosoferric oxide samples, it can be found that the dissipation contribution of permeability for magnetic materials is weaker than that of permittivity, in spite of its significant role in determining the impedance matching characteristics. In summary, this work systematically explores the loss contribution in micro/nano-magnetic absorbers for the first time, which is of great importance in designing and optimizing the microwave absorption properties of magnetic absorbers.展开更多
文摘A new method of the design and machining the casting moulds of helical intake ports of diesel engines is presented based on CAD / CAM technique. The problems about the smooth continuity between patches, the cutter interference and the determination of the mould split curve are discussed in details.The CAGD system of the intake port has been developed. and the casting mould is machined sucessfully on NC machine.
基金This work was supported by the National Natural Science Foundation of China(No.51402154)the Natural Science Foundation of Jiangsu Province(No.BK20180091)the Startup Foundation for Introducing Talent of NUIST,and Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology.
文摘As the growing criterion of electromagnetic wave (EMW) absorption materials, micro/nano-scale magnetic materials are drawing more and more attention for their unique features compared to bulky absorbers. Generally, the complex permeability of micro/nano-scale magnetic absorbers varies in a relatively narrow range, whatever for the storage of magnetic energy or the dissipation of magnetic energy. If so, how the small variation of permeability affects the ultimate performances is still unclear. Here, a strategy of electromagnetic parameters regulation for the magnetic materials is applied to understand the loss contribution in micro/nanoscale magnetic absorbers. After analyzing the evolution of electromagnetic maps of ten ferrosoferric oxide samples, it can be found that the dissipation contribution of permeability for magnetic materials is weaker than that of permittivity, in spite of its significant role in determining the impedance matching characteristics. In summary, this work systematically explores the loss contribution in micro/nano-magnetic absorbers for the first time, which is of great importance in designing and optimizing the microwave absorption properties of magnetic absorbers.
