Light and heat induced denaturation of CP47, the core antenna complex of photosystem Ⅱ purified from spinach, were investigated using absorption and circular dichroism spectra. Light caused the destruction of chlorop...Light and heat induced denaturation of CP47, the core antenna complex of photosystem Ⅱ purified from spinach, were investigated using absorption and circular dichroism spectra. Light caused the destruction of chlorophyll a and excitonic interaction of chlorophyll a in CP47, while the protein secondary structure was not apparently changed. Heat induced the destruction of protein secondary structure and excitonic interaction of chlorophyll a, but the chlorophyll a molecule was not damaged. The results suggest that both the chlorophyll a molecular structure and the protein native conformation are necessary for excitonic interaction of chlorophyll a and the energy transfer function of the chlorophyll a binding protein.展开更多
This paper presents the development of circularly polarized microstrip antenna using Kevlar honeycomb core as the substrates for application of CP-SAR （circularly polarized synthetic aperture radar） which signal pro...This paper presents the development of circularly polarized microstrip antenna using Kevlar honeycomb core as the substrates for application of CP-SAR （circularly polarized synthetic aperture radar） which signal propagation is not affected by Faraday rotation effect in the ionosphere, as compared to linearly polarized systems especially at the L-band. The reason why Kevlar honeycomb core is used is because it is suitable for space environment in terms of lightweight and resistant to heat and shock. Measurements of the fabricated antenna were performed to confirm the simulation results. The results show good characteristics of the antennas except the axial ratio. The reason of insufficient axial ratio is assumed as fabrication error of the radiator and microstrip line.展开更多
基金the National Natural Science Foundation of China !(No .39890 390 )
文摘Light and heat induced denaturation of CP47, the core antenna complex of photosystem Ⅱ purified from spinach, were investigated using absorption and circular dichroism spectra. Light caused the destruction of chlorophyll a and excitonic interaction of chlorophyll a in CP47, while the protein secondary structure was not apparently changed. Heat induced the destruction of protein secondary structure and excitonic interaction of chlorophyll a, but the chlorophyll a molecule was not damaged. The results suggest that both the chlorophyll a molecular structure and the protein native conformation are necessary for excitonic interaction of chlorophyll a and the energy transfer function of the chlorophyll a binding protein.
文摘This paper presents the development of circularly polarized microstrip antenna using Kevlar honeycomb core as the substrates for application of CP-SAR （circularly polarized synthetic aperture radar） which signal propagation is not affected by Faraday rotation effect in the ionosphere, as compared to linearly polarized systems especially at the L-band. The reason why Kevlar honeycomb core is used is because it is suitable for space environment in terms of lightweight and resistant to heat and shock. Measurements of the fabricated antenna were performed to confirm the simulation results. The results show good characteristics of the antennas except the axial ratio. The reason of insufficient axial ratio is assumed as fabrication error of the radiator and microstrip line.
