<div style="text-align:justify;"> The large aperture mirror surface test is the basis of optical processing and alignment, and is also the key to the development of remote sensing device. The simulatio...<div style="text-align:justify;"> The large aperture mirror surface test is the basis of optical processing and alignment, and is also the key to the development of remote sensing device. The simulation results show that the RMS values of 1.07 m primary mirror with multi-point support and sling support are 1.86 nm and 3.28 nm respectively. Using 36 point unloading device, sponge 36 point free support and sling support to test the mirror surface, the results are basically consistent, RMS is better than 0.02λ (λ = 632.8 nm). </div>展开更多
Interferometry with computer-generated holograms(CGHs)is a unique solution for the highly accurate testing of large-aperture aspheric mirrors.However,no direct testing method for quantifying the measurement accuracy o...Interferometry with computer-generated holograms(CGHs)is a unique solution for the highly accurate testing of large-aperture aspheric mirrors.However,no direct testing method for quantifying the measurement accuracy of CGHs has been developed.In this study,we developed a methodology for verifying CGH accuracy based on an element that is functionally equivalent to a large-aperture mirror in terms of accuracy verification.The equivalent element decreased the aperture by one or higher orders of magnitude,implying that the mirror could be replaced by a non-CGH technology in a comparison test.In this study,a 281 mm diamond-turned mirror was fabricated as the equivalent element of a 3.5 m aspheric mirror and measured using CGH and LUPHOScan profilometers.Surface error composition and root-mean-square(RMS)density analyses were performed.The methodology verification accuracy of the CGH was 4 nm(RMS)in the low-to mid-frequency bands,with a measured surface accuracy of approximately 10 nm(RMS).This methodology provides a feasible solution for CGH accuracy verification,ensuring high-accuracy and reliable testing of large-aperture aspheric mirrors.展开更多
Fabrication of the lightweight mirror is one of the key techniques for many large optical systems. CAD,CAM and CNC technologies are adopted in designing and manufacturing such mirrors in CIOMP. Better working efficien...Fabrication of the lightweight mirror is one of the key techniques for many large optical systems. CAD,CAM and CNC technologies are adopted in designing and manufacturing such mirrors in CIOMP. Better working efficiency and higher lightweight grade have been achieved. The results show that mirrors up to 70% weight reduction and 0.02λ(rms.) surface accuracy or better can be obtained.展开更多
Congenital mirror movements retard typical hand functions, but no definite therapeutic modality is available to treat such movements. We report an 8-year-old boy with severe mirror movements of both hands. His mirror ...Congenital mirror movements retard typical hand functions, but no definite therapeutic modality is available to treat such movements. We report an 8-year-old boy with severe mirror movements of both hands. His mirror movements were assessed using the Woods and Teuber grading scale and his fine motor skills were also evaluated by the Purdue Pegboard Test. A 2-week regimen of repetitive transcranial magnetic stimulation produced markedly diminished mirror movement symptoms and increased the fine motor skills of both hands. Two weeks after the completion of the regimen, mirror movement grades had improved from grade 4 to 1 in both hands and the Purdue Pegboard Test results of the right and left hands also improved from 12 to 14 or 13. These improvements were maintained for 1 month after the 2-week repetitive transcranial magnetic stimulation regimen. After 18 months, the mirror movement grade was maintained and the Purdue Pegboard test score had improved to 15 for the right hand while the left hand score was maintained at 13. This occurred without any additional repetitive transcranial magnetic stimulation or other treatment. These findings suggest that repetitive transcranial magnetic stimulation for this patient had a therapeutic and long-term effect on mirror movements.展开更多
In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed i...In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.展开更多
文摘<div style="text-align:justify;"> The large aperture mirror surface test is the basis of optical processing and alignment, and is also the key to the development of remote sensing device. The simulation results show that the RMS values of 1.07 m primary mirror with multi-point support and sling support are 1.86 nm and 3.28 nm respectively. Using 36 point unloading device, sponge 36 point free support and sling support to test the mirror surface, the results are basically consistent, RMS is better than 0.02λ (λ = 632.8 nm). </div>
基金supported by the National Natural Science Foundation of China(62127901,52375471,and 62305333)supported by the National Key Research and Development Program(2022YFB3403405)+2 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(2019221)Young Elite Scientists Sponsorship Program of CAST(2022QNRC001)Young Elite Scientists Sponsorship Program of Jilin Province(QT202222).
文摘Interferometry with computer-generated holograms(CGHs)is a unique solution for the highly accurate testing of large-aperture aspheric mirrors.However,no direct testing method for quantifying the measurement accuracy of CGHs has been developed.In this study,we developed a methodology for verifying CGH accuracy based on an element that is functionally equivalent to a large-aperture mirror in terms of accuracy verification.The equivalent element decreased the aperture by one or higher orders of magnitude,implying that the mirror could be replaced by a non-CGH technology in a comparison test.In this study,a 281 mm diamond-turned mirror was fabricated as the equivalent element of a 3.5 m aspheric mirror and measured using CGH and LUPHOScan profilometers.Surface error composition and root-mean-square(RMS)density analyses were performed.The methodology verification accuracy of the CGH was 4 nm(RMS)in the low-to mid-frequency bands,with a measured surface accuracy of approximately 10 nm(RMS).This methodology provides a feasible solution for CGH accuracy verification,ensuring high-accuracy and reliable testing of large-aperture aspheric mirrors.
文摘Fabrication of the lightweight mirror is one of the key techniques for many large optical systems. CAD,CAM and CNC technologies are adopted in designing and manufacturing such mirrors in CIOMP. Better working efficiency and higher lightweight grade have been achieved. The results show that mirrors up to 70% weight reduction and 0.02λ(rms.) surface accuracy or better can be obtained.
基金supported by Yeungnam University research grants in 2010
文摘Congenital mirror movements retard typical hand functions, but no definite therapeutic modality is available to treat such movements. We report an 8-year-old boy with severe mirror movements of both hands. His mirror movements were assessed using the Woods and Teuber grading scale and his fine motor skills were also evaluated by the Purdue Pegboard Test. A 2-week regimen of repetitive transcranial magnetic stimulation produced markedly diminished mirror movement symptoms and increased the fine motor skills of both hands. Two weeks after the completion of the regimen, mirror movement grades had improved from grade 4 to 1 in both hands and the Purdue Pegboard Test results of the right and left hands also improved from 12 to 14 or 13. These improvements were maintained for 1 month after the 2-week repetitive transcranial magnetic stimulation regimen. After 18 months, the mirror movement grade was maintained and the Purdue Pegboard test score had improved to 15 for the right hand while the left hand score was maintained at 13. This occurred without any additional repetitive transcranial magnetic stimulation or other treatment. These findings suggest that repetitive transcranial magnetic stimulation for this patient had a therapeutic and long-term effect on mirror movements.
文摘In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.
