Optimal design and analysis of a space lightweight mirror with a directionally oriented 2.5D-CVT structure.

Reflective mirrors are the key imaging components of space-borne telescopes, which require a high lightweight ratio integrated with excellent optical properties. In this context, a novel, to our knowledge, 2.5D centroidal Voronoi tessellation (CVT) generation methodology is proposed for designing and optimizing a lightweight mirror structure.

Research on the Design and Alignment Method of the Optic-Mechanical System of an Ultra-Compact Fully Freeform Space Camera.

As space resources become increasingly constrained, the major space-faring nations are establishing large space target monitoring systems. There is a demand for both the number and the detection capability of space-based optical monitoring equipment. The detection range (i.

Impact of rice straw biochar addition on the sorption and leaching of phenylurea herbicides in saturated sand column.

The application of phenylurea herbicides (PUHs) may lead to the extensive distribution in soils, while the role of straw biochar as a soil amendment on the transport and sorption of PUHs are still unclear. Thus, the transport and sorption behavior of three typical PUHs with rice straw biochar (RSB) was studied in both adsorption simulation experiments of aqueous solution and packed column experiments. The sorption mechanism of RSB to herbicides was investigated through batch sorption studies with three influencing factors including dosage of RSB, pH, and ionic strength (IS) with orthogonal test.

Post-discharge extended care contributes to the disease control of patients with COPD: a Chinese study.

Background: The aim of this study was to evaluate the efficacy of extended care in patients with COPD.

Patients And Methods: A total of 140 patients with GOLD-2 to -4 of COPD were included in final analysis. The care efficacy was evaluated by the St George's Respiratory Questionnaire 12-item General Health Questionnaire (GHQ-12), pulmonary function test and blood gas analysis.

Wavelet power spectrum-based autofocusing algorithm for time delayed and integration charge coupled device space camera.

A novel autofocusing algorithm using the directional wavelet power spectrum is proposed for time delayed and integration charge coupled device (TDI CCD) space cameras, which overcomes the difficulty of focus measure for the real-time change of imaging scenes. Using the multiresolution and band-pass characteristics of wavelet transform to improve the power spectrum based on fast Fourier transform (FFT), the wavelet power spectrum is less sensitive to the variance of scenes. Moreover, the new focus measure can effectively eliminate the impact of image motion mismatching by the directional selection.