Improvement in the performance of solar adaptive optics

Adaptive optics （AO）, which provides diffraction limited imaging over a field-of-view （FOV）, is a powerful technique for solar observation. In the tomographic approach, each wavefront sensor （WFS） is looking at a single reference that acts as a guide star. This allows a 3D reconstruction of the distorted wavefront to be made. The correction is applied by one or more deformable mirrors （DMs）. This technique benefits from information about atmospheric turbulence at different layers, which can be used to reconstruct the wavefront extremely well. With the assistance of the MAOS software package, we consider the tomography errors and WFS aliasing errors, and focus on how the performance of a solar telescope （pointing toward zenith） is related to atmospheric anisoplanatism. We theoretically quantify the performance of the to- mographic solar AO system. The results indicate that the tomographic AO system can improve the average Strehl ratio of a solar telescope in a 10＂ - 80＂ diameter FOV by only employing one DM conjugated to the telescope pupil. Furthermore, we discuss the effects of DM conjugate altitude on the correction achievable by the AO system by selecting two atmospheric models that differ mainly in terms of atmospheric prop- erties at ground level, and present the optimum DM conjugate altitudes for different observation sites.

Long-term outcomes of wedge resection at the limbus for high irregular corneal astigmatism after repaired corneal laceration

AIM： To evaluate the clinical value of wedge resection at corneal limbus in patients with traumatic corneal scarring and high irregular astigmatism. METHODS： Patients with traumatic corneal astigmatism received wedge resection at least 6mo after suture removal from corneal wound. The uncorrected distance visual acuities （UCVA） and best corrected distance visual acuities （BCVA）, pre- and post-operation astigmatism, spherical equivalent （SE）, safety and complications were evaluated. RESULTS： Ten eyes （10 patients） were enrolled in this study. Mean follow-up time after wedge resection was 37.8±15.4mo （range, 20-61mo）. The mean UCVA improved from ＋1.07±0.55 IogMAR to ＋0.43±0.22 IogMAR （P=0.000） and the mean BCVA from ＋0.50±0.30 IogMAR to ＋0.15± 0.17 IogMAR （P=0.000）. The mean astigmatism power measured by retinoscopy was -2.03±2.27 D postoperatively and -2.83±4,52 D preoperatively （P=0.310）. The mean SE was -0.74±1.61 D postoperatively and -0.64±1.89 D preoperatively （P=0.601）. Two cases developed mild pannus near the sutures. No corneal perforation, infectious keratitis or wound gape occurred. CONCLUSION： Corneal-scleral limbal wedge resection with compression suture is a safe, effective treatment for poor patients with high irregular corneal astigmatism after corneal-scleral penetrating injury. Retinoscopy can prove particularly useful for high irregular corneal astigmatism when other measurements are not amenable.

Effect of Chinese Herbal Medicine Jinlida Granule in Treatment of Patients with Impaired Glucose Tolerance

Background：Diabetes mellitus （DM） remains a major health problem worldwide.Several clinical trials have shown the superiority of the Traditional Chinese Medicine in delaying or reversing the development and progression of DM.This study aimed to evaluate the efficacy of Jinlida （JLD） granule,a Chinese herbal recipe,in the treatment of impaired glucose tolerance （IGT） and its effect on the prevention of DM.Methods：Sixty-five IGT patients were randomized to receive one bag of JLD granules three times daily （JLD group,n =34） or no drug intervention （control group,n =31） for 12 weeks.Oral glucose tolerance test,glycated hemoglobin A1c （HbA1c）,body mass index,blood lipids levels,fasting insulin,and insulin resistance calculated using homeostatic model assessment （HOMA-IR） of all the patients were observed and compared before and after the treatment.Results：Sixty-one participants completed the trial （32 in JLD group and 29 in the control group）.There were statistically significant decreases in HbA1c （P 〈 0.001）,2-h plasma glucose （P 〈 0.001）,and HOMA-IR （P =0.029） in JLD group compared with the control group after 12 weeks of treatment.After 12 weeks of treatment,two （6.9%） patients returned to normal blood glucose,and five （17.2%） patients turned into DM in control group,while in the JLD group,14 （43.8%） returned to normal blood glucose and 2 （6.2%） turned into DM.There was a significant difference in the number of subjects who had normal glucose at the end of the study between two groups （P =0.001）.Conclusions：JLD granule effectively improved glucose control,increased the conversion of IGT to normal glucose,and improved the insulin resistance in patients with IGT.This Chinese herbal medicine may have a clinical value for IGT.

Thermal Shock Behavior Analysis of Tungsten-Armored Plasma-Facing Components for Future Fusion Reactor

In a fusion reactor, plasma-facing components（PFCs） will suffer severe thermal shock; behavior and performance of PFCs under high heat flux（HHF） loads are of major importance for the long-term stable operation of the reactor. This work investigates the thermo-mechanical behaviors of tungsten armor under high heat loads by the method of finite element modeling and simulating. The temperature distribution and corresponding thermal stress changing rule under different HHF are analyzed and deduced. The Manson–Coffin equation is employed to evaluate the fatigue lifetime（cyclic times of HHF loading） of W-armored first wall under cyclic HHF load. The results are useful for the formulation design and structural optimization of tungsten-armored PFCs for the future demonstration fusion reactor and China fusion experimental thermal reactor.

Longitudinal Image Analysis via Path Regression on the Image Manifold

Longitudinal image analysis plays an important role in depicting the development of the brain structure,where image regression and interpolation are two commonly used techniques.In this paper,we develop an efficient model and approach based on a path regression on the image manifold instead of the geodesic regression to avoid the complexity of the geodesic computation.Concretely,first we model the deformation by diffeomorphism;then,a large deformation is represented by a path on the orbit of the diffeomorphism group action.This path is obtained by compositing several small deformations,which can be well approximated by its linearization.Second,we introduce some intermediate images as constraints to the model,which guides to form the best-fitting path.Thirdly,we propose an approximated quadratic model by local linearization method,where a closed form is deduced for the solution.It actually speeds up the algorithm.Finally,we evaluate the proposed model and algorithm on a synthetic data and a real longitudinal MRI data.The results show that our proposed method outperforms several state-of-the-art methods.

Enhanced Reproducibility of Positive Temperature Coefficient Effect of CB/HDPE/PVDF Composites with the Addition of Ionic Liquid

Developing an effective method for improving the reproducibility of positive temperature coefficient(PTC)effect is of great significance for large-scale application of polymer based PTC composites,owing to its contribution to the security and reliability.Herein,we developed a carbon black(CB)/high density polyethylene(HDPE)/poly(vinylidene fluoride)(PVDF)composite with outstanding PTC reproducibility,by incorporating 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([OMIm][NTf2])into the composite.After multiple repeated temperature cycles,the PTC performance of as-prepared material keeps almost unchanged and the varition of resistance at room temperature is less than 7%.Our studies revealed that[OMIm][NTf2]contributes to the improvement of PTC reproducibility in two ways:(i)it acts as an efficient plasticizer for refining the co-continuous phase morphology of HDPE/PVDE blends;(ii)it inhibits the crystallization of PVDF through the dilution effect,leading to more overlaps of the volume shrinkage process of HDPE and PVDF melt which results in the decrease of interface gap between HDPE and PVDF.This study demonstrated that ionic liquids as the multifunctional agents have great potential for improving the reproducibility in the application of the binary polymer based PTC composites.