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Research in Astronomy and Astrophysics 2021年第9期21卷 237-242页

作者： Yun-Li Li Sheng Zheng lin-hua deng Shu-Guang Zeng Gang-hua lin Center of Astronomy and Space Science China Three Gorges UniversityYichang 443002China Yunnan Observatories Chinese Academy of SciencesKunming 650216China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

Solar filaments,hypothermia and dense structures suspended in the solar corona are formed above the magnetic polarity inversion line.Polar crown filaments(PCFs)at high-latitude regions of the Sun are of profound significance to the periodic variation of solar activities.In this paper,we statistically analyze PCFs by using full disk Ha data from 1912 to 2018,which were obtained by Kodaikanal Solar Observatory(KODA,India),National Solar Observatory(NSO,USA),Kanzelhohe Solar Observatory(KSO,Austria),Big Bear Solar Observatory(BBSO,USA),and huairou Solar Observing Station(HSOS,China).We first manually identify PCFs from every solar image based on the centennial data,and record the latitude and other features corresponding to the PCFs.Then we plot the PCF latitude distribution as a function of time,which clearly shows that PCFs rush to the poles at the ascending phase of each solar cycle.Our results show that the filaments drift toward mid-latitude covering solar cycle 15 to 24 after the PCFs reach the highest latitudes.The poleward migration rates of PCFs are calculated in ten solar cycles,and the range is about 0.12 degree to 0.50 degree per Carrington Rotation(CR).We also investigate the north-south(N-S)asymmetry of migration rates and the normalized N-S asymmetry index.

关键词： Sun:filaments prominences Sun:evolution Sun:activity

Long-term hemispheric variation of the flare index

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Research in Astronomy and Astrophysics 2013年第3期13卷 343-350页

作者： Song Feng lin-hua deng Shi-Chun Xu Computer Technology Application Key Lab of Yunnan Province and Faculty of Information Engineering and Automation Kunming University of Science and Technology Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences National Astronomical Observatories / Yunnan Astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences Kunming Institute of Physics

The long-term hemispheric variation of the flare index is investigated. It is found that, （1） the phase difference of the flare index between the northern and southern hemispheres is about 6-7 months, which is near the time delay between flare activity and sunspot activity; （2） both the dominant and phase-leading hemisphere of the flare index is the northern hemisphere in the considered time interval, implying that the hemispheric asynchrony of solar activity has a close connection with the N-S asymmetry of solar activity.

关键词： Sun： activity -- Sun： flares -- methods： data analysis

Spatial distributions of sunspot oscillation modes at different temperatures

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Research in Astronomy and Astrophysics 2020年第1期20卷 43-48页

作者： Zheng-Kai Wang Song Feng lin-hua deng Yao Meng Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China Yunnan Observatories Chinese Academy of SciencesKunming 650216China College of Science China Three Gorges UniversityYichang 443002China Chongqing University of Arts and Sciences Chongqing 402160China

Three-and five-minute sunspot oscillations have different spatial distributions in the solar atmospheric layers.The spatial distributions are crucial for revealing the physical origin of sunspot oscillations and to investigate their propagation.In this study,six sunspots observed by Solar Dynamics Observatory/Atmospheric Imaging Assembly were used to obtain the spatial distributions of three-and five-minute oscillations.The fast Fourier transform method is applied to represent the power spectra of oscillation modes.We find that,from the temperature minimum to the lower corona,the powers of the fiveminute oscillation exhibit a circle-shape distribution around its umbra,and the shapes gradually expand with temperature increase.However,the circle-shape disappears and the powers of the oscillations appear to be very disordered in the higher corona.This indicates that the five-minute oscillation can be suppressed in the high-temperature region.For the three-minute oscillations,from the temperature minimum to the high corona,their powers mostly distribute within an umbra,and part of them are located at the coronal fan loop structures.Moreover,those relative higher powers are mostly concentrated in the position of coronal loop footpoints.

关键词： Sun:atmosphere Sun:sunspots Sun:oscillations

Chinese Sunspot Drawings and Their Digitization—(Ⅶ) Sunspot Penumbra to Umbra Area Ratio Using the Hand-Drawing Records from Yunnan Observatories

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Research in Astronomy and Astrophysics 2022年第9期22卷 132-139页

作者： Jia-Wei Hou Shu-Guang Zeng Sheng Zheng Xiao-Yu Luo lin-hua deng Yang-Yang Li Yan-Qing Chen Gang-hua lin Yong-Li Feng Jin-Ping Tao Center for Astronomy and Space Sciences China Three Gorges UniversityYichang 443002China College of Science China Three Gorges UniversityYichang 43002China Yunnan Observatories Chinese Academy of SciencesKunming.650216China National Astronomical Observatories Chinese Academy of SciencesKunming650216China

The ratio of penumbral to umbra area of sunspots plays a crucial role in the solar physics fields, especially for understanding the origin and evolution of the solar activity cycle. By analyzing the recently digitized sunspot drawings observed from Yunnan Observatories(1957–2021), we investigate the long-term variation of the penumbral to umbra area ratio of sunspots. An automatic extraction method, based on the maximum between-class variance and the morphological discrimination, is used to accurately extract penumbra and umbra and to calculate the ratio over six solar cycles(cycle 19–24). The expected value of the ratio of penumbra to umbra area is found to be 6.63 ± 0.98, and it does not exhibit any systematic variation with sunspot latitudes and phases. The average ratio fluctuates from 5 to 7.5 per year and the overall trend has decreased after 1999 compared to the previous one.The ratio of sunspot penumbra to umbra area satisfies the log-normal distribution, implying that its variation is related to the evolution of the photospheric magnetic field. Our results are consistent with previous works.

关键词： Sun:sunspots Sun:photosphere Sun:activity techniques:image processing

Predicting the 25th solar cycle using deep learning methods based on sunspot area data

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Research in Astronomy and Astrophysics 2021年第7期21卷 290-298页

作者： Qiang Li Miao Wan Shu-Guang Zeng Sheng Zheng lin-hua deng College of Science China Three Gorges UniversityYichang 443002China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

It is a significant task to predict the solar activity for space weather and solar physics. All kinds of approaches have been used to forecast solar activities, and they have been applied to many areas such as the solar dynamo of simulation and space mission planning. In this paper, we employ the long-shortterm memory(LSTM) and neural network autoregression(NNAR) deep learning methods to predict the upcoming 25 th solar cycle using the sunspot area(SSA) data during the period of May 1874 to December2020. Our results show that the 25 th solar cycle will be 55% stronger than Solar Cycle 24 with a maximum sunspot area of 3115±401 and the cycle reaching its peak in October 2022 by using the LSTM method. It also shows that deep learning algorithms perform better than the other commonly used methods and have high application value.

关键词： Sun:activity Sun:solar cycle prediction Sun:sunspot area Method:deep neural network

Phase analysis of sunspot group numbers on both solar hemispheres

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Research in Astronomy and Astrophysics 2013年第1期13卷 104-114页

作者： lin-hua deng Zhong-Quan Qu Xiao-Li Yan Kai-Rang Wang National Astronomical Observatories /Yunnan Astronomical Observatory Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences North China Electric Power University

Cross-correlation analysis and wavelet transform methods are proposed to investigate the phase relationship between the monthly sunspot group numbers in the solar northern and southern hemispheres. It is found that （1） the monthly sunspot group numbers in the northern hemisphere begin two months earlier than those in the southern one, which should lead to phase asynchrony between them but with a slight effect; （2） the Schwabe cycle length for the monthly sunspot group numbers in the two hemispheres obviously differs from each other, and the mean Schwabe cycle length of the monthly sunspot group numbers in the northern hemisphere is slightly larger than that in the southern one; （3） the monthly sunspot group numbers in the northern hemisphere precede those in the southern hemisphere during the years of about 1874- 1927, after which, the southern hemisphere leads the northern hemisphere in the years 1928-1964, and then the northern hemisphere leads in time till the present.

关键词： methods data analysis -- Sun activity -- Sun sunspots

Chinese sunspot drawings and their digitization–(Ⅱ)accuracy analysis for digitized sunspot hand-drawing records of Yunnan Observatories

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Research in Astronomy and Astrophysics 2020年第4期20卷 156-162页

作者： Yang Peng Xiao-Yu Luo Shu-Guang Zeng lin-hua deng Sheng Zheng Gang-hua lin Yu-lin Cheng Jin-Ping Tao Yong-Li Feng College of Science China Three Gorges UniversityYichang 443002China Yunnan Observatories Chinese Academy of SciencesKunming 650216China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Chongqing University of Arts and Sciences Chongqing 402160China

Sunspots are the most striking and easily observed magnetic structures of the Sun,and statistical analysis of solar historical data could reveal a wealth of information on the long-term variation of solar activity cycle.The hand-drawn sunspot records of Yunnan Observatories,Chinese Academy of Sciences have been accumulating for more than 60 years,and nearly 16000 images have been preserved.In the future,the observation mode of recording sunspots by hand-drawing will be replaced inevitably by digital images observed either at ground or in space.To connect the hand-drawn sunspot data and the purely digital sunspot data in future,it is necessary to analyze the systematic errors of the data which are observed by the two observation modes in the period of transition.In this paper,we choose 268 round sunspots(Htype in modified Zurich sunspot classification)from the drawing of Yunnan Observatories to compare their positions and areas with the CCD observations made by Helioseismic and Magnetic Imager(HMI)on board Solar Dynamic Observatory(SDO)and Global Oscillation Network Group(GONG).We find that the latitude and longitude accuracy of hand-drawn sunspot are within-0.127 and 2.29 degree respectively,and the area accuracy is about 16.36 sunspot unit(μHem).Systematic errors apparently decrease with large sunspot.

关键词： sunspots methods:data analysis techniques:image processing

Broadband angular spectrum analog processors based on all-dielectric metasurfaces

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 188-190页

作者： lin deng Yongmin Liu Department of Electrical and Computer Engineering Northeastern UniversityBoston 02115USA Department of Mechanical and Industrial Engineering Northeastern UniversityBoston 02115USA

Digital signal processors are extensively used to execute mathematical operations and advanced computational tasks on digital data.However,they suffer from several inherent limitations,including low speed,high energy consumption,and large memory requirements,because of the hardware bottleneck and the imperative conversion between digital and analogue signals.

关键词： dielectric spectrum hardware

Adsorptive interaction between typical VOCs and various topological zeolites:Mixture effect and mechanism

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Journal of Environmental Sciences 2024年第2期136卷 626-636页

作者： Bo Yu hua deng Yuqin Lu Tingting Pan Wenpo Shan Hong He Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Adsorption is one of the most feasible and effective methods to alleviate the volatile organic compounds(VOCs)pollution.However,the mixture effect and mechanism for competitive adsorption of VOCs on zeolites are barely addressed.In this study,toluene,acetone,and ethyl acetate as prevalent VOCs species were removed by four potential zeolites(13X,USY,Beta,ZSM-5)in both single-and multi-component systems.The structure-property relationship between adsorbate-adsorbent pairs was revealed by X-ray diffraction,scanning electron microscopy,energy dispersive spectrometer,X-ray fluorescence,N_(2) adsorption and density function theory calculation.The molecular polarity and volatility of VOCs species played key roles in adsorption and the dynamic uptakes were generally listed as follows:ethyl acetate>toluene>acetone.As for the above VOCs mixtures,13X zeolite selectively adsorbed oxygenated VOCs rather than toluene.In contrast,USY exhibited a preference to trap toluene.Ethyl acetate could be readily enriched by ZSM-5 and Beta selectively.The possible explanations and implications are discussed based on the subtle change in electron density.The results obtained are vital for understanding the mixture effect of VOCs adsorption and may guide the selection of proper adsorbent for real applications.

关键词： Adsorption Zeolites VOCs Mixture effect DFT

Efficacy of radiofrequency ablation combined with sorafenib for treating liver cancer complicated with portal hypertension and prognostic factors

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World Journal of Gastroenterology 2024年第11期30卷 1533-1544页

作者： Li-Min Yang Hong-Juan Wang Shan-lin Li Guan-hua Gan Wen-Wen deng Yong-Sheng Chang Lian-Feng Zhang Department of Gastroenterology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina Department of Gastroenterology Zhoukou Central Hospital of Henan ProvinceZhoukou 466000Henan ProvinceChina Department of Gastroenterology The First Affiliated Hospital of Xinxiang Medical CollegeXinxiang 453000Henan ProvinceChina

BACKGROUND Patients with liver cancer complicated by portal hypertension present complex challenges in treatment.AIM To evaluate the efficacy of radiofrequency ablation in combination with sorafenib for improving liver function and its impact on the prognosis of patients with this condition.METHODS Data from 100 patients with liver cancer complicated with portal hypertension from May 2014 to March 2019 were analyzed and divided into a study group(n=50)and a control group(n=50)according to the treatment regimen.The research group received radiofrequency ablation(RFA)in combination with sorafenib,and the control group only received RFA.The short-term efficacy of both the research and control groups was observed.Liver function and portal hypertension were compared before and after treatment.Alpha-fetoprotein(AFP),glypican-3(GPC-3),and AFP-L3 levels were compared between the two groups prior to and after treatment.The occurrence of adverse reactions in both groups was observed.The 3-year survival rate was compared between the two groups.Basic data were compared between the survival and non-surviving groups.To identify the independent risk factors for poor prognosis in patients with liver cancer complicated by portal hypertension,multivariate logistic regression analysis was employed.RESULTS When comparing the two groups,the research group's total effective rate(82.00%)was significantly greater than that of the control group(56.00%;P<0.05).Following treatment,alanine aminotransferase and aspartate aminotransferase levels increased,and portal vein pressure decreased in both groups.The degree of improvement for every index was substantially greater in the research group than in the control group(P<0.05).Following treatment,the AFP,GPC-3,and AFP-L3 levels in both groups decreased,with the research group having significantly lower levels than the control group(P<0.05).The incidence of diarrhea,rash,nausea and vomiting,and fatigue in the research group was significantly greater than that in the control group(P<0.05).The 1-

关键词： Radiofrequency ablation Sorafenib Liver cancer Portal hypertension Efficacy Prognosis analysis