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Inverse Calculation and Regularization Process for the Solar Aspect System(SAS) of HXI Payload on ASO-S Spacecraft

Research in Astronomy and Astrophysics 2024年第4期24卷 13-34页

作者： Ji-Rui Yu Ping Ruan yang Su Ying-Hong He Jin-You Tao Zhe Zhang Song Guo Bin Xue jian-feng yang Xi'an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences Xi'an 710119China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 20034China School ofAstronomy and Space Science Universityof Science and Technology of ChinaHefei 230026China

For the ASO-S/HXI payload, the accuracy of the flare reconstruction is reliant on important factors such as the alignment of the dual grating and the precise measurement of observation orientation. To guarantee optimal functionality of the instrument throughout its life cycle, the Solar Aspect System (SAS) is imperative to ensure that measurements are accurate and reliable. This is achieved by capturing the target motion and utilizing a physical model-based inversion algorithm. However, the SAS optical system’s inversion model is a typical ill-posed inverse problem due to its optical parameters, which results in small target sampling errors triggering unacceptable shifts in the solution. To enhance inversion accuracy and make it more robust against observation errors, we suggest dividing the inversion operation into two stages based on the SAS spot motion model. First, the as-rigid-aspossible (ARAP) transformation algorithm calculates the relative rotations and an intermediate variable between the substrates. Second, we solve an inversion linear equation for the relative translation of the substrates, the offset of the optical axes, and the observation orientation. To address the ill-posed challenge, the Tikhonov method grounded on the discrepancy criterion and the maximum a posteriori (MAP) method founded on the Bayesian framework are utilized. The simulation results exhibit that the ARAP method achieves a solution with a rotational error of roughly±3 5 (1/2-quantile);both regularization techniques are successful in enhancing the stability of the solution, the variance of error in the MAP method is even smaller—it achieves a translational error of approximately±18μm (1/2-quantile) in comparison to the Tikhonov method’s error of around±24μm (1/2-quantile). Furthermore, the SAS practical application data indicates the method’s usability in this study. Lastly, this paper discusses the intrinsic interconnections between the regularization methods.

关键词： methods:data analysis Sun:flares Sun:X-rays gamma rays

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Bilateral retinal nerve fiber layer thickness reduction in a 9-year-old myopic boy suffering from unilateral optic neuritis:A case report

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世界临床病例杂志 2023年第28期11卷 6806-6811页

作者： Fang-Fang Zhao Shi-Qi Yao Yun Wang Tai-Ping Li jian-feng yang Chi-Pui Pang Ling-Ping Cen Department of Medical Retina and Neuro-ophthalmology Joint Shantou International Eye Centre of Shantou University and The Chinese University of Hong KongShantou 515041Guangdong ProvinceChina Department of Ophthalmology&Visual Sciences The Chinese University of Hong KongHong Kong 999077China

BACKGROUND In this paper,we present a 9-year-old boy who demonstrates a complex interplay between myopia progression,axial length(AL)extension,and retinal nerve fiber layer(RNFL)thickness loss in both eyes.Additionally,concurrent optic neuritis has directly impacted RNFL thickness in his right eye,and its potential indirect influence on RNFL and macular ganglion cell layer(mGCL)thickness in his left eye is also noteworthy.CASE SUMMARY A 9-year-old boy with bilateral myopia presented with diminished vision and pain in his right eye due to optic neuritis,while his left eye showed pseudopapilledema.Steroid therapy improved his vision in the right eye,and 16-mo follow-up revealed recovery without recurrence despite myopia progression.Follow-up optical coherence tomography conducted 16 mo later revealed a notable thinning of the RNFL in both eyes,especially along with a reduction in mGCL thickness in the left eye.This intricate interaction between optic neuritis,myopia,and retinal changes underscores the need for comprehensive management,highlighting potential long-term visual implications in young patients.CONCLUSION The progression of myopia and AL extension led to the loss of RNFL thickness in both eyes in a 9-year-old boy.Concurrently,optic neuritis directly affected RNFL thickness in his right eye and may indirectly play a role in the thickness of RNFL and mGCL in his left eye.

关键词： Retinal nerve fiber layer Myopia Optic neuritis Macular ganglion cell Case report

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Improved performances of lithium disilicate glass-ceramics by seed induced crystallization

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Journal of Advanced Ceramics 2021年第3期10卷 614-626页

作者： Ting ZHAO Mei-Mei LIAN Yi QIN jian-feng ZHU Xin-Gang KONG jian-feng yang School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

Self-reinforced lithium disilicate(Li_(2)Si_(2)O_(5),LD)glass-ceramics were hot pressing sintered by introducing 5 wt%Li_(2)Si_(2)O_(5)crystal seeds into two different glass compositions of SiO_(2)-Li_(2)O-P2O_(5)-ZrO_(2)-Al_(2)O_(3)-K_(2)O-La_(2)O_(3)(7C LD)and SiO_(2)-Li_(2)O-K_(2)O-La_(2)O_(3)(4C LD).The results show that the seeds play an important role in the crystallization inducement,and microstructural and property improvement of the glass,especially for the glass powder without the nucleating agent of P_(2)O_(5).The microstructure features a wider bimodal grain size distribution with large rod-like crystals epitaxially grown along the seeds and small crystals nucleated from the glass powder itself,contributing to the improvement of the performance especially the fracture toughness.The specimen of 4C LD glass with the addition of 5 wt%Li_(2)Si_(2)O_(5) seeds exhibited the best comprehensive properties with a good flexural strength(396±7 MPa),improved fracture toughness(3.31±0.19 MPa·m^(1/2)),and comparable translucency as IPS e.max.This research provides a new idea and method for the improvement of the fracture toughness of lithium disilicate glass-ceramics without affecting its aesthetic appearance,and lays the foundation for its clinical applications.

关键词： lithium disilicate(LD) seeds mechanical properties translucency

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Column-orthogonal designs with multi-dimensional stratifications

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Science China Mathematics 2021年第6期64卷 1291-1304页

作者： Xue yang jian-feng yang Min-Qian Liu Qi Zhou School of Statistics Tianjin University of Finance and EconomicsTianjin 300222China School of Statistics and Data Science LPMC&KLMDASRNankai UniversityTianjin 300071China

The orthogonal Latin hypercube design and its relaxation,and column-orthogonal design,are two kinds of orthogonal designs for computer experiments.However,they usually do not achieve maximum stratifications in multi-dimensional margins.In this paper,we propose some methods to construct column-orthogonal designs with multi-dimensional stratifications by rotating symmetric and asymmetric orthogonal arrays.The newly constructed column-orthogonal designs ensure that the estimates of all linear effects are uncorrelated with each other and even uncorrelated with the estimates of all second-order effects(quadratic effects and bilinear effects)when the rotated orthogonal arrays have strength larger than two.Besides orthogonality,the resulting designs also preserve better space-filling properties than those constructed by using the existing methods.In addition,we provide a method to construct a new class of orthogonal Latin hypercube designs with multi-dimensional stratifications by rotating regular factorial designs.Some newly constructed orthogonal Latin hypercube designs are tabulated for practical use.

关键词： computer experiment Latin hypercube design orthogonal array orthogonality rotation matrix

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Rare variant of pancreaticobiliary maljunction associated with pancreas divisum in a child diagnosed and treated by endoscopic retrograde cholangiopancreatography: A case report

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World Journal of Clinical Cases 2019年第9期7卷 1073-1079页

作者： Guang-Xing Cui Hai-Tao Huang jian-feng yang Xiao-feng Zhang Department of Gastroenterology Affiliated Hangzhou First People’s Hospital Zhejiang University School of Medicine

BACKGROUND Pancreaticobiliary maljunction(PBM) is an uncommon congenital anomaly of the pancreatic and biliary ductal system, defined as a union of the pancreatic and biliary ducts located outside the duodenal wall. According to the Komi classification of PBM, the common bile duct(CBD) directly fuses with the ventral pancreatic duct in all types. Pancreas divisum(PD) occurs when the ventral and dorsal ducts of the embryonic pancreas fail to fuse during the second month of fetal development. The coexistence of PBM and PD is an infrequent condition.Here, we report an unusual variant of PBM associated with PD in a pediatric patient, in whom an anomalous communication existed between the CBD and dorsal pancreatic duct.CASE SUMMARY A boy aged 4 years and 2 mo was hospitalized for abdominal pain with nausea and jaundice for 5 d. Abdominal ultrasound showed cholecystitis with cholestasis in the gallbladder, dilated middle-upper CBD, and a strong echo in the lower CBD, indicating biliary stones. The diagnosis was extrahepatic biliary obstruction caused by biliary stones, which is an indication for endoscopic retrograde cholangiopancreatography(ERCP). ERCP was performed to remove biliary stones. During the ERCP, we found a rare communication between the CBD and dorsal pancreatic duct. After clearing the CBD with a balloon, an 8.5 Fr 4-cm pigtail plastic pancreatic stent was placed in the biliary duct through the major papilla. Six months later, his biliary stent was removed after he had no symptoms and normal laboratory tests. In the following 4-year period, the child grew up normally with no more attacks of abdominal pain.CONCLUSION We consider that ERCP is effective and safe in pediatric patients with PBM combined with PD, and can be the initial therapy to manage such cases,especially when it is combined with aberrant communication between the CBD and dorsal pancreatic duct.

关键词： Pancreaticobiliary maljunction Pancreas divisum Endoscopic retrograde cholangiopancreatography Variant Communication Children Case report

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Interventional endoscopic ultrasound for a symptomatic pseudocyst secondary to gastric heterotopic pancreas

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World Journal of Gastroenterology 2017年第34期23卷 6365-6370页

作者： hang-bin jin lei lu jian-feng yang qi-feng lou jing yang hong-zhang shen xiao-wei tang xiao-feng zhang Department of Gastroenterology Hangzhou First People’s HospitalNanjing Medical University

Heterotopic pancreas(HP) is a relatively uncommon entity that is defined as pancreatic tissue without a true anatomical or vascular connection to the pancreas. HP does not cause symptoms in most cases but can occasionally produce various manifestations, including nausea, vomiting, abdominal pain, and even heterotopic pancreatitis. Here, we report an unusual case in which heterotopic pancreatitis complicated by the formation of a pseudocyst that caused gastric outlet obstruction was diagnosed based on serum hyperamylasemia and findings from endoscopic ultrasonography(EUS)-guided fine needle aspiration(EUS-FNA) cytology. EUS-guided single pigtail stent insertion was successfully performed for recurrent gastric outlet obstruction. The patient has remained healthy and symptom-free during 4 years of surveillance. In the context of the relevant literature, the described case is a rare case of HP complicated by a pseudocyst treated via EUS-FNA and stent insertion.

关键词： Heterotopic 胰 Pseudocyst 胃的插头阻塞内视镜的指导超声的好针渴望

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Microstructure and mechanical properties of reaction-bonded B_(4)C–SiC composites

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1828-1835页

作者： Rong-zhen Liu Wen-wei Gu Yu yang Yuan Lu Hong-bin Tan jian-feng yang State Key Laboratory of Materials Processing and Die&Mould Technology School of Material Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Environment-Friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang 621010China

Reaction-bonded B_(4)C–SiC composites are highly promising materials for numerous advanced technological applications.However,their microstructure evolution mechanism remains unclear.Herein,B_(4)C–SiC composites were fabricated through the Si-melt infiltration process.The influences of the sintering time and the B_(4)C content on the mechanical properties,microstructure,and phase evolution were investigated.X-ray diffraction results showed the presence of SiC,boron silicon,boron silicon carbide,and boron carbide.Scanning electron microscopy results showed that with the increase in the boron carbide content,the Si content decreased and the unreacted B_(4)C amount increased when the sintering temperature reached 1650°C and the sintering time reached 1 h.The unreacted B_(4)C diminished with increasing sintering time and temperature when B_(4)C content was lower than 35wt%.Further microstructure analysis showed a transition area between B_(4)C and Si,with the C content marginally higher than in the Si area.This indicates that after the silicon infiltration,the diffusion mechanism was the primary sintering mechanism of the composites.As the diffusion process progressed,the hardness increased.The maximum values of the Vickers hardness,flexural strength,and fracture toughness of the reaction-bonded B_(4)C–SiC ceramic composite with 12wt%B_(4)C content sintered at 1600°C for 0.5 h were about HV 2400,330 MPa,and 5.2 MPa·m^(0.5),respectively.

关键词： reaction sintering B_(4)C-SiC composites mechanical properties microstructural characterization microstructure evolution mechanism

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A method and results of color calibration for the Chang'e-3 terrain camera and panoramic camera

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Research in Astronomy and Astrophysics 2014年第12期14卷 1557-1566页

作者： Xin Ren Chun-Lai Li jian-Jun Liu Fen-Fei Wang jian-feng yang En-Hai Liu Bin Xue Ru-Jin Zhao Key Laboratory of Lunar and Deep Space Exploration National Astronomical ObservatoriesChinese Academy of Sciences Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Institute of Optics and Electronics Chinese Academy of Sciences

The terrain camera （TCAM） and panoramic camera （PCAM） are two of the major scientific payloads installed on the lander and rover of the Chang＇e 3 mission re- spectively. They both use a Bayer color filter array covering CMOS sensor to capture color images of the Moon＇s surface. RGB values of the original images are related to these two kinds of cameras. There is an obvious color difference compared with human visual perception. This paper follows standards published by the International Commission on Illumination to establish a color correction model, designs the ground calibration experiment and obtains the color correction coefficient. The image qual- ity has been significantly improved and there is no obvious color difference in the corrected images. Ground experimental results show that：（1） Compared with uncor- rected images, the average color difference of TCAM is 4.30, which has been reduced by 62.1%. （2） The average color differences of the left and right cameras in PCAM are 4.14 and 4.16, which have been reduced by 68.3% and 67.6% respectively.

关键词： Moon -- methods： data analysis -- techniques： image processing

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The alignment of AlN platelets in polymer matrix and its anisotropic thermal properties

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Journal of Materiomics 2019年第4期5卷 679-687页

作者： Chang-Yeoul Kim Thi My Linh Dang Yaming Zhang jian-feng yang Bo Wang Nano-Convergence Materials Team Korea Institute of Ceramic Engineering and Technology Jinju-siGyeongsangnam-do660-031South Korea State Key Laboratory of Mechanical Behavior of Materials Xi'an Jiaotong UniversityXi'an71004China

The thermal conductivity of polymer composites can be enhanced by the vertical alignment of anisotropic aluminum nitride(AlN)platelet fillers in polymer matrices.The AlN platelets in polymer matrix were aligned in the direction of in-plane and out-of-plane by using the doctor blading and the lamination process.The alignment of AlN plates in the out-of-plane or the in-plane direction has been confirmed by XRD and FE-SEM investigations.The polymer composite with the out-of-plane aligned AlN platelets showed almost 1.5 times or 2 times higher thermal conductivity than those with the AlN spheres or the in-plane aligned AlN platelets at the same filler content,respectively.This result could be attributed to the improvement of thermal pathway generated along the plane of platelets and the decrease of interfaces between the filler and the polymer.

关键词： Thermal conductivity Aluminum nitride plate Polymer composite Alignment Out-of-direction In-plane direction

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Design and verification of the HXI collimator on the ASO-S mission

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Research in Astronomy and Astrophysics 2021年第6期21卷 241-252页

作者： Deng-Yi Chen Yi-Ming Hu Tao Ma yang Su jian-feng yang jian-Ping Wang Guang-Zhou Xu Xian-Kai jiang jian-Hua Guo Yong-Qiang Zhang Yan Zhang Wei Chen Jin Chang Zhe Zhang Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China University of Science and Technology of China Hefei 230026China Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China Innovation Academy for Microsatellites of Chinese Academy of Sciences Shanghai 201210China

A space-borne hard X-ray collimator,comprising 91 pairs of grids,has been developed for the Hard X-ray Imager(HXI).The HXI is one of the three scientific instruments onboard the first Chinese solar mission:the Advanced Space-based Solar Observatory(ASO-S).The HXI collimator(HXI-C)is a spatial modulation X-ray telescope designed to observe hard X-rays emitted by energetic electrons in solar flares.This paper presents the detailed design of the HXI-C for the qualification model that will be inherited by the flight model.Series tests on the HXI-C qualification model are reported to verify the ability of the HXI-C to survive the launch and to operate normally in on-orbit environments.Furthermore,results of the X-ray beam test for the HXI-C are presented to indirectly identify the working performance of the HXI-C.

关键词： Solar observation ASO-S X-ray telescope the collimator verification

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