Fourier-transform infrared（FTIR）,Raman and ultraviolet-visible spectra of 4,4＇-bipyridine and its me-tal-organic coordination compounds synthesized from 4,4＇-bipyridine and nitrate of Co（Ⅱ）,Ni（Ⅱ） and Zn（Ⅱ...Fourier-transform infrared（FTIR）,Raman and ultraviolet-visible spectra of 4,4＇-bipyridine and its me-tal-organic coordination compounds synthesized from 4,4＇-bipyridine and nitrate of Co（Ⅱ）,Ni（Ⅱ） and Zn（Ⅱ） were measured and analyzed,respectively.The main FTIR and Raman bands were assigned in detail.The relationship between these characteristic bands and the structure of ligands and coordination compounds were discussed.展开更多
Al2O3p/Al composite coatings were prepared on the surface of AZ31 magnesium alloy by plasma spraying technology with mixed powders of Al and Al2O3. An orthogonal test containing six factors and five levels was carried...Al2O3p/Al composite coatings were prepared on the surface of AZ31 magnesium alloy by plasma spraying technology with mixed powders of Al and Al2O3. An orthogonal test containing six factors and five levels was carried out to acquire the optimum technical parameters. Mierostruetures and properties of the composite coatings were studied. The results show that the coatings consist of Al2O3 particulates distributed uniformly and Al matrix, and the interface between the particulate and matrix is continuous, compact and clean. With increasing the mass fraction of Al2O3 in the mixed powders, the volume fraction of Al2O3 in the coatings iacreases. The Al2O3p/Al composite coating with 14% Al2O3 volume fraction has more compact microstrueture and more satisfactory properties.展开更多
Although the performance of space cameras has largely improved, the micro vibration from flywheel disturbances still significantly affects the image quality of these cameras. This study adopted a passive isolation met...Although the performance of space cameras has largely improved, the micro vibration from flywheel disturbances still significantly affects the image quality of these cameras. This study adopted a passive isolation method to reduce the negative effect of flywheel disturbance on image quality. A metal-rubber shock absorber was designed and installed in a real satellite. A finite element model of an entire satellite was constructed, and a transient analysis was conducted afterward. The change in the modulate transfer function was detected using ray tracing and optical transfer function formulas. Experiments based on real products were performed to validate the influence of the metal-rubber shock absorber. The experimental results confirmed the simulation results by showing that the negative effects of flywheel dis- turbance on the image quality of space cameras can be diminished significantly using the vibration isolation method.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20773044,20873050,20921003 and 20973074)the "111" Project of Minstry of Education of China(No.B06009)
文摘Fourier-transform infrared（FTIR）,Raman and ultraviolet-visible spectra of 4,4＇-bipyridine and its me-tal-organic coordination compounds synthesized from 4,4＇-bipyridine and nitrate of Co（Ⅱ）,Ni（Ⅱ） and Zn（Ⅱ） were measured and analyzed,respectively.The main FTIR and Raman bands were assigned in detail.The relationship between these characteristic bands and the structure of ligands and coordination compounds were discussed.
基金This research was supported by Jilin Province Science Foundation （No. 20090552）.
文摘Al2O3p/Al composite coatings were prepared on the surface of AZ31 magnesium alloy by plasma spraying technology with mixed powders of Al and Al2O3. An orthogonal test containing six factors and five levels was carried out to acquire the optimum technical parameters. Mierostruetures and properties of the composite coatings were studied. The results show that the coatings consist of Al2O3 particulates distributed uniformly and Al matrix, and the interface between the particulate and matrix is continuous, compact and clean. With increasing the mass fraction of Al2O3 in the mixed powders, the volume fraction of Al2O3 in the coatings iacreases. The Al2O3p/Al composite coating with 14% Al2O3 volume fraction has more compact microstrueture and more satisfactory properties.
文摘Although the performance of space cameras has largely improved, the micro vibration from flywheel disturbances still significantly affects the image quality of these cameras. This study adopted a passive isolation method to reduce the negative effect of flywheel disturbance on image quality. A metal-rubber shock absorber was designed and installed in a real satellite. A finite element model of an entire satellite was constructed, and a transient analysis was conducted afterward. The change in the modulate transfer function was detected using ray tracing and optical transfer function formulas. Experiments based on real products were performed to validate the influence of the metal-rubber shock absorber. The experimental results confirmed the simulation results by showing that the negative effects of flywheel dis- turbance on the image quality of space cameras can be diminished significantly using the vibration isolation method.
