As potential alternative power sources used in portable electric generators, opposite axial piston engines in small-scale were investigated to show their advantages in power density. A novel cylinder charge system was...As potential alternative power sources used in portable electric generators, opposite axial piston engines in small-scale were investigated to show their advantages in power density. A novel cylinder charge system was introduced, based on which a quasi-dimension model and a CFD(computational fluid dynamics) model were established. Comparison of those two models was carried out to validate the quasi-dimension model. Furthermore, optimal diameter of charge cylinder and speed were determined after evaluating the quasi-dimension model based on different parameters. High agreement between the quasi-dimension model and the CFD model validates the quasi-dimension model. Further studies show that the power of engine increases with the diameter of charge cylinder. However, a too big charge cylinder lowers the fuel efficiency instead. Taking economic influence into consideration the charge cylinder should be 1.4 times power cylinder, which could ensure the power density, volumetric efficiency and fuel economic at the same time. Axial piston engine running at 1.0×104 r/min could achieve a better overall performance. The maximal power of engine with optimal parameters is 0.82 k W, which fits the power need of the portable electric generators completely.展开更多
Iodine-doped (C22H16N2SO2) was prepared by doping the dye with iodine vapor. The following characteristics were obtained by structure analysis.1. The doped iodine exists as I3-anion and I2.2. Because the electron loca...Iodine-doped (C22H16N2SO2) was prepared by doping the dye with iodine vapor. The following characteristics were obtained by structure analysis.1. The doped iodine exists as I3-anion and I2.2. Because the electron located on the sulphur atom was transferred to iodine, a charge transfer complx of (C22H16N2SO2I5) was formed.3. The complex was proved to exist in a quasi-one dimension conductor state, forming two ordered molecular stacks.4. From the volt-ampere curve with sandwich cell, the room temperature resistivity (ρ)and the exciting energe (ΔE) of the doped complex were shown to he 3.47×107Ω·cm-1and 0.4eV respectivily.5. Its electrical behavior obeys the fomula ρ = ρ0exp(ΔE/kt), showing the behavior of a typical semicanductor.展开更多
Understanding laser induced ultrafast processes with complex three-dimensional(3D)geometries and extreme property evolution offers a unique opportunity to explore novel physical phenomena and to overcome the manufactu...Understanding laser induced ultrafast processes with complex three-dimensional(3D)geometries and extreme property evolution offers a unique opportunity to explore novel physical phenomena and to overcome the manufacturing limitations.Ultrafast imaging offers exceptional spatiotemporal resolution and thus has been considered an effective tool.However,in conventional single-view imaging techniques,3D information is projected on a two-dimensional plane,which leads to significant information loss that is detrimental to understanding the full ultrafast process.Here,we propose a quasi-3D imaging method to describe the ultrafast process and further analyze spatial asymmetries of laser induced plasma.Orthogonally polarized laser pulses are adopted to illuminate reflection-transmission views,and binarization techniques are employed to extract contours,forming the corresponding two-dimensional matrix.By rotating and multiplying the two-dimensional contour matrices obtained from the dual views,a quasi-3D image can be reconstructed.This successfully reveals dual-phase transition mechanisms and elucidates the diffraction phenomena occurring outside the plasma.Furthermore,the quasi-3D image confirms the spatial asymmetries of the picosecond plasma,which is difficult to achieve with two-dimensional images.Our findings demonstrate that quasi-3D imaging not only offers a more comprehensive understanding of plasma dynamics than previous imaging methods,but also has wide potential in revealing various complex ultrafast phenomena in related fields including strong-field physics,fluid dynamics,and cutting-edge manufacturing.展开更多
基金Projects(51475464,51175500) supported by the National Natural Science Foundation of China
文摘As potential alternative power sources used in portable electric generators, opposite axial piston engines in small-scale were investigated to show their advantages in power density. A novel cylinder charge system was introduced, based on which a quasi-dimension model and a CFD(computational fluid dynamics) model were established. Comparison of those two models was carried out to validate the quasi-dimension model. Furthermore, optimal diameter of charge cylinder and speed were determined after evaluating the quasi-dimension model based on different parameters. High agreement between the quasi-dimension model and the CFD model validates the quasi-dimension model. Further studies show that the power of engine increases with the diameter of charge cylinder. However, a too big charge cylinder lowers the fuel efficiency instead. Taking economic influence into consideration the charge cylinder should be 1.4 times power cylinder, which could ensure the power density, volumetric efficiency and fuel economic at the same time. Axial piston engine running at 1.0×104 r/min could achieve a better overall performance. The maximal power of engine with optimal parameters is 0.82 k W, which fits the power need of the portable electric generators completely.
文摘Iodine-doped (C22H16N2SO2) was prepared by doping the dye with iodine vapor. The following characteristics were obtained by structure analysis.1. The doped iodine exists as I3-anion and I2.2. Because the electron located on the sulphur atom was transferred to iodine, a charge transfer complx of (C22H16N2SO2I5) was formed.3. The complex was proved to exist in a quasi-one dimension conductor state, forming two ordered molecular stacks.4. From the volt-ampere curve with sandwich cell, the room temperature resistivity (ρ)and the exciting energe (ΔE) of the doped complex were shown to he 3.47×107Ω·cm-1and 0.4eV respectivily.5. Its electrical behavior obeys the fomula ρ = ρ0exp(ΔE/kt), showing the behavior of a typical semicanductor.
文摘Understanding laser induced ultrafast processes with complex three-dimensional(3D)geometries and extreme property evolution offers a unique opportunity to explore novel physical phenomena and to overcome the manufacturing limitations.Ultrafast imaging offers exceptional spatiotemporal resolution and thus has been considered an effective tool.However,in conventional single-view imaging techniques,3D information is projected on a two-dimensional plane,which leads to significant information loss that is detrimental to understanding the full ultrafast process.Here,we propose a quasi-3D imaging method to describe the ultrafast process and further analyze spatial asymmetries of laser induced plasma.Orthogonally polarized laser pulses are adopted to illuminate reflection-transmission views,and binarization techniques are employed to extract contours,forming the corresponding two-dimensional matrix.By rotating and multiplying the two-dimensional contour matrices obtained from the dual views,a quasi-3D image can be reconstructed.This successfully reveals dual-phase transition mechanisms and elucidates the diffraction phenomena occurring outside the plasma.Furthermore,the quasi-3D image confirms the spatial asymmetries of the picosecond plasma,which is difficult to achieve with two-dimensional images.Our findings demonstrate that quasi-3D imaging not only offers a more comprehensive understanding of plasma dynamics than previous imaging methods,but also has wide potential in revealing various complex ultrafast phenomena in related fields including strong-field physics,fluid dynamics,and cutting-edge manufacturing.
