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Distortion mapping correction in the AIMS primary mirror testing by a computer-generated hologram

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Research in Astronomy and Astrophysics 2021年第7期21卷 99-106页

作者： Ke-Wei E Jian-Ke Zhao Bo wang dong-guang wang Yu-Liang Shen Xin Fu Song-Bo Xu Jing Li Xun Xue Ming Chang Yan Zhou Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China Nanjing Astronomical Instruments Chinese Academy of SciencesNanjing 210042China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

The National Solar Observatory is currently developing the Accurate Infrared Magnetic Field Measurements of the Sun(AIMS). The primary mirror of the AIMS solar telescope is an off-axis parabolic with a diameter of 1 m and with a large off-axis amount of 1 m. Due to the surface figure of the primary mirror under the used state is directly related to image quality of the whole system, a computer-generated hologram(CGH) is carried out to test the primary mirror, and the test results are used to polish the mirror to a higher surface accuracy. However, the fact that the distortion exists in the testing results leads to the failure of a further guide to deterministic optical processing. In this paper, a distortion correction method is proposed, which uses an orthogonal set of vector polynomials to mapping the coordinates of the mirror and the pixels of fringes, and then an interpolation method is adopted to obtain the corrected results. The testing accuracy by using CGH is also verified by an auto-collimate test experiment. According to the distorted corrected results, the root-mean-square of the surface figure is about 1/50λ(λ=632.8 nm) after polishing.

关键词： telescopes techniques:interferometric methods:astronomical instrumentation methods and techniques

A Region Selection Method for Real-time Local Correlation Tracking of Solar Full-disk Magnetographs

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Research in Astronomy and Astrophysics 2022年第9期22卷 106-115页

作者： Yang Bai Jia-Ben Lin Xian-Yong Bai Xiao Yang dong-guang wang Yuan-Yong Deng Xiao-Ming Zhu Xing Hu Wei Huang Li-Yue Tong Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Hundreds of images with the same polarization state are first registered to compensate for the jitters during an observation and then integrated to realize the needed spatial resolution and sensitivity for solar magnetic field measurement. Due to the feature dependent properties of the correlation tracker technique, an effective method to select the feature region is critical for low-resolution full-disk solar filtergrams, especially those with less significant features when the Sun is quiet. In this paper, we propose a region extraction method based on a Hessian matrix and information entropy constraints for local correlation tracking(CT) to get linear displacement between different images. The method is composed of three steps:(1) extract feature points with the Hessian matrix,(2)select good feature points with scale spaces and thresholds, and(3) locate the feature region with the twodimensional information entropy constraints. Both the simulated and observational experiments demonstrated that our region selection method can efficiently detect the linear displacement and improve the quality of a groundbased full-disk solar magnetogram. The local CT with the selected regions can obtain displacement detection results as good as the global CT and at the same time significantly reduce the average calculation time.

关键词： Sun:photosphere Sun:magnetic fields techniques:image processing

Spectro-polarimetric observations at the NVST:I.instrumental polarization calibration and primary measurements

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Research in Astronomy and Astrophysics 2020年第4期20卷 7-18页

作者： Jun-Feng Hou Zhi Xu Shu Yuan Yu-Chao Chen Jian-Guo Peng dong-guang wang Jun Xu Yuan-Yong Deng Zhen-Yu Jin Kai-Fan Ji Zhong Liu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

This paper is devoted to the primary spectro-polarimetric observation performed at the New Vacuum Solar Telescope(NVST)of China since 2017,and our aim is to precisely evaluate the real polarimetric accuracy and sensitivity of this polarimetry by using full Stokes spectro-polarimetric observations of the photospheric line Fe I 532.4 nm.In the work,we briefly describe the salient characteristic of the NVST as a polarimeter in terms of technology and then characterize its instrumental polarization based on the operation in 2017 and 2019.It is verified that the calibration method utilizing the instrumental polarization calibration unit(ICU)is stable and credible.The calibration accuracy can reach up to 3×10^-3.Based on the scientific observation of NOAA Active Region 12645 on 2017 April 5,we estimate that the residual cross-talk from Stokes I to Stokes Q,U and V,after the instrumental polarization calibration,is about 4×10^-3 on average,which is consistent with the calibration accuracy and close to the photon noise.The polarimetric sensitivity(i.e.,the detection limit)for polarized light is of the order of 10-3 with an integration time over 20 s.Slow modulation rate is indeed an issue for the present system.The present NVST polarimeter is expected to be integrated with a high-order adaptive optics system and a field scanner to realize 2 D vector magnetic field measurements in the following instrumentation update.

关键词： techniques:polarimetric techniques:spectroscopic Sun:magnetic fields

A Novel Method for Forecasting Freak Wave Occurrence in A Short Crested Coastal Sea

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China Ocean Engineering 2024年第1期38卷 104-116页

作者： wang Ying-guang State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Ocean and Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite transformation model expressed as a monotonic cubic polynomial serves as the foundation for the novel simulation technique.The wave crest amplitude exceedance probabilities of two sea states-one with a directional wave spectrum based on the measured wave elevation data at the Yura coast and the other with a typical directional JONSWAP wave spectrum-have been predicted using the novel simulation method that has been proposed.The likelihood that a particular critical wave crest amplitude will be exceeded is directly correlated with the probability that freak waves will occur.It is shown that the novel simulation approach suggested can provide predictions that are more precise than those obtained from the Rayleigh crest amplitude distribution model,the Jahns and Wheeler crest amplitude distribution model,or the conventional linear simulation method.This study also demonstrated that the nonlinear simulation method is less effective than the novel simulation method in terms of efficiency.

关键词： wave crest amplitude freak waves short crested sea transformed linear simulation

Solar Magnetism and the Activity Telescope at HSOS

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Chinese Journal of Astronomy and Astrophysics 2007年第2期7卷 281-288页

作者： Hong-Qi Zhang dong-guang wang Yuan-Yong Deng Ke-Liang Hu Jiang-Tao Su Jia-Ben Lin Gang-Hua Lin Shi-Mo Yang Wei-Jun Mao Ya-Nan wang Qi-Qian Hu Jun-Sun Xue Hai-Tian Lu Hou-Kun Ni Han-Liang Chen Xiao-Jun Zhou Qing-Sheng Zhu Lu-Jun Yuan YongZhu Huairou Solar Observing Station National Astronomical Observatories Chinese Academy of SciencesBeijing 100012 Space Technical Laboratory National Astronomical Observatories Chinese Academy of SciencesBeijing 100012 Nanjing Institute of Astronomical Optics and Technology National Astronomical ObservatoriesChinese Academy of Sciences Nanjing 210042

A new solar telescope system is described, which has been operating at Huairou Solar Observing Station （HSOS）, National Astronomical Observatories, Chinese Academy of Sciences （CAS）, since the end of 2005. This instrument, the Solar Magnetism and Activity Telescope （SMAT）, comprises two telescopes which respectively make measurements of full solar disk vector magnetic field and Ha observation. The core of the full solar disk video vector magnetograph is a birefringent filter with 0.1A bandpass, installed in the tele-centric optical system of the telescope. We present some preliminary observational results of the full solar disk vector magnetograms and Ha filtergrams obtained with this telescope system.

关键词： Sun activity - Sun telescope - Sun： magnetic fields

A clinical comparative study of polymerase chain reaction assay for diagnosis of pneumocystis pneumonia in non-AIDS patients

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Chinese Medical Journal 2011年第17期124卷 2683-2686页

作者： MU Xiang-dong wang guang-fa SU Li Department of Respiratory Medicine Peking University First Hospital Beijing 100034 China

Background Pneumocystis jirovecii pneumonia （PCP） is one of the most common and fatal infections in non-AIDS immunocompromised patients, which is difficult to diagnose by traditional morphologic methods. This study evaluated polymerase chain reaction （PCR） assays of Pneumocystis jirovecii mitochondrial large subunits ribosomal RNA in sputum and bronchioalveolar lavage fluid （BALF） for diagnosing PCP. Methods Sputum and BALF specimens from two groups were collected： one group （PCP group） included 20 patients definitely diagnosed of PCP by Gomori methenamine silver （GMS） stains of BALF; the other group （non-PCP group） included 40 patients. Each specimen was examined by GMS stains and PCR assays. Results GMS stains of BALF in PCP group were 100% positive （20/20）, GMS stains of sputum in PCP group were 35% positive （7/20）; GMS stains of BALF in non-PCP group were 100% negative （40/40）, GMS stains of sputum in non-PCP group were 100% negative （40/40）. PCR assays of BALF in PCP group were 100% positive （20/20）, PCR assays of sputum in PCP group were 100% positive （20/20）; PCR assays of BALF in non-PCP group were 100% negative （40/40）, PCR assays of sputum in non-PCP group were 100% negative （40/40）. Sensitivity and specificity of PCR assays of sputum and BALF were both 100%; positive and negative predictive values were also both 100%. Conclusion The diagnostic value of PCR assays of Pneumocystisjirovecii mitochondrial large subunits ribosomal RNA on sputum and BALF for pneumocystis pneumonia are both high and equivalent.

关键词： Pneumocystis jirovecii pneumonia sputum bronchioalveolar lavage fluid Gomori methenamine silver stains polymerase chain reaction

Successful splenic artery embolization in a patient with Behçet’s syndrome-associated splenic rupture:A case report

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World Journal of Gastrointestinal Surgery 2024年第4期16卷 1184-1188页

作者： guang-Zhao Zhu dong-Hua Ji Department of Interventional Therapy The First Affiliated Hospital of Dalian Medical UniversityDalian 116011Liaoning ProvinceChina

BACKGROUND Splenic rupture associated with Behçet’s syndrome(BS)is extremely rare,and there is no consensus on its management.In this case report,a patient with BSassociated splenic rupture was successfully treated with splenic artery embolization(SAE)and had a good prognosis after the intervention.CASE SUMMARY The patient was admitted for pain in the left upper abdominal quadrant.He was diagnosed with splenic rupture.Multiple oral and genital aphthous ulcers were observed,and acne scars were found on his back.He had a 2-year history of BS diagnosis,with symptoms of oral and genital ulcers.At that time,he was treated with oral corticosteroids for 1 month,but the symptoms did not alleviate.He underwent SAE to treat the rupture.On the first day after SAE,the patient reported a complete resolution of abdominal pain and was discharged 5 d later.Three months after the intervention,a computed tomography examination showed that the splenic hematoma had formed a stable cystic effusion,suggesting a good prognosis.CONCLUSION SAE might be a good choice for BS-associated splenic rupture based on good surgical practice and material selection.

关键词： Splenic artery embolization Behçet’s syndrome Splenic rupture Case report

Study on tungsten sintering temperature field based on electromagnetic simulation and computational fluid dynamics

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Tungsten 2024年第2期6卷 355-366页

作者： Lu-Yan wang Yue-guang Yu Jian-Xin dong Kai-Ping Du Shan-Yu Liu Cao-Bing Li University of Science and Technology Beijing Beijing 100083China BGRIMM Technology Group Beijing 100160China China Iron&Steel Research Institute Group Beijing 100081China

In order to study the influence of various sintering variables more intuitively and clearly,electromagnetic field analysis and computational fl uid dynamics are used to analyze the infl uence of gas flow,heating power and other process parameters on the temperature range of medium-frequency sintering in this paper.The results indicate that the uniformity of temperature fi eld is determined by the gas flow rate and heating power.When the heating power is 50 kW,the stable temperature drops about 10 K for every 1 m^(3)·h^(−1)increase of hydrogen flow.The peak value of the maximum temperature diff erence on the tungsten rods gradually increases with the increase of the hydrogen flow rate,and it appears slightly later.The temperature distribution of tungsten rods in furnace is similar with diff erent hydrogen flow rate.At the same time,the closer to the furnace wall,the higher the temperature of the tungsten rod.The temperature diff erence between tungsten rods mainly occurred within 1 h after the beginning of heating.Increasing the heating power can improve the stable temperature,but has little eff ect on the heating time.Increasing heating power can increase the peak value of the maximum temperature diff erence on the tungsten rods,but has little eff ect on the occurrence time of the peak value of the maximum temperature diff erence on the tungsten rods.Increasing the heating power will increase the temperature diff erence of a single tungsten rod,but the temperature diff erence of a single tungsten rod never exceeds 65 K.This study can be used to guide the process optimization design.Combined with numerical simulation calculation,the sintering parameters with low energy consumption and high temperature uniformity can be quickly and eff ectively found,thus improving the microstructure and properties of sintered tungsten products.

关键词： Tungsten products Sintering Hydrogen flow rate Heating power

Jianpi Qinghua Formula Alleviates Diabetic Myocardial Injury Through Inhibiting JunB/c-Fos Expression

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Current Medical Science 2024年第1期44卷 144-155页

作者： Lin wang Qing-guang CHEN Hao LU Department of Endocrinology Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese MedicineShanghai 201203China Department of Traditional Chinese Medicine Naval Medical UniversityShanghai 200433China

Objective Diabetic cardiomyopathy(DCM)represents a substantial risk factor for heart failure and increased mortality in individuals afflicted with diabetes mellitus(DM).DCM typically manifests as myocardial fibrosis,myocardial hypertrophy,and impaired left ventricular diastolic function.While the clinical utility of the Jianpi Qinghua(JPQH)formula has been established in treating diabetes and insulin resistance,its potential efficacy in alleviating diabetic cardiomyopathy remains uncertain.This study aims to investigate the impact and underlying molecular mechanisms of the JPQH formula(JPQHF)in ameliorating myocardial injury in nonobese diabetic rats,specifically focusing on apoptosis and inflammation.Methods Wistar rats were assigned as the normal control group(CON),while Goto-Kakizaki(GK)rats were randomly divided into three groups:DM,DM treated with the JPQHF,and DM treated with metformin(MET).Following a 4-week treatment regimen,various biochemical markers related to glucose metabolism,cardiac function,cardiac morphology,and myocardial ultrastructure in GK rats were assessed.RNA sequencing was utilized to analyze differential gene expression and identify potential therapeutic targets.In vitro experiments involved high glucose to induce apoptosis and inflammation in H9c2 cells.Cell viability was evaluated using CCK-8 assay,apoptosis was monitored via flow cytometry,and the production of inflammatory cytokines was measured using quantitative real-time PCR(qPCR)and ELISA.Protein expression levels were determined by Western blotting analysis.The investigation also incorporated the use of MAPK inhibitors to further elucidate the mechanism at both the transcriptional and protein levels.Results The JPQHF group exhibited significant reductions in interventricular septal thickness at end-systole(IVSs)and left ventricular internal diameter at end-systole and end-diastole(LVIDs and LVIDd).JPQHF effectively suppressed high glucose-induced activation of IL-1βand caspase 3 in cardiomyocytes.Furthermore,JPQHF downregulated

关键词： Jianpi Qinghua formula diabetic cardiomyopathy AP-1 transcription factor apoptosis inflammation