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Disappearance of a coronal hole induced by a filament activation

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Research in Astronomy and Astrophysics 2014年第11期14卷 1481-1490页

作者： Lin Ma zhong-quan qu Xiao-Li Yan Zhi-Ke Xue Yunnan Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

We present a rare observation of direct magnetic interaction between an activating filament and a coronal hole （CH）. The filament was a quiescent one located at the northwest of the CH. It underwent a nonradial activation, during which filament material constantly fell and intruded into the CH. As a result, the CH was clearly destroyed by the intrusion. Brightenings appeared at the boundaries and in the interior of the CH, meanwhile, its west boundaries began to retreat and the area gradually shrank. It is noted that the CH went on shrinking after the end of the intrusion and finally disappeared entirely. Following the filament activation, three coronal dimmings （D1-D3） were formed, among which D1 and D2 persisted throughout the complete disappearance of the CH. The derived coronal magnetic configuration shows that the filament was located below an extended loop system, which obviously linked D1 to D2. By extrapolating this result, our observations imply that the interaction between the filament and the CH involved direct intrusion of the filament material to the CH and the disappearance of the CH might be due to interchange reconnection between the expanding loop system and the CH＇s open field.

关键词： Sun activity -- Sun filaments -- Sun magnetic fields -- Sun evolution

Interchange reconnection between an active region and a coronal hole

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Research in Astronomy and Astrophysics 2014年第2期14卷 221-228页

作者： Lin Ma zhong-quan qu Xiao-Li Yan Zhi-Ke Xue Yunnan Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

With data from the Atmospheric Imaging Assembly and the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory, we present a mag- netic interaction between an isolated coronal hole （CH） and an emerging active re- gion （AR）. The AR emerged nearby the CH and interacted with it. Bright loops con- stantly formed between them, which led to a continuous retreat of the CH boundaries （CHBs）. Meanwhile, two coronal dimmings respectively appeared at the negative po- laxity of the AR and the east boundary of the bright loops, and the AR was partly disturbed. Loop eruptions followed by a flare occurred in the AR. The interaction was also accompanied by many jets and an arc-shaped brightening that appeared to be observational signatures of magnetic reconnection at the CHBs. By comparing the observations with the derived coronal magnetic configuration, it is suggested that the interaction between the CH and the AR excellently agreed with the model of inter- change reconnection. It appears that our observations provide obvious evidence for interchange reconnection.

关键词： Sun: activity -- Sun: corona -- Sun: magnetic fields -- Sun: evolution

A new way to measure the departure from thermodynamic equilibrium in stellar atmospheres

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Chinese Journal of Astronomy and Astrophysics 2009年第2期9卷 205-212页

作者： zhong-quan qu Long-Fei Hao Xiao-Li Yan Cheng-Lin Xu Yunnan Astronomical Observatory/National Astronomical Observatories Chinese Academy of Sciences Kunming 650011 China Graduate School Chinese Academy of Sciences Beijing 100049 China Mathematics Department Yunnan Normal University Kunming 650122 China

A new way to measure the departure from thermodynamic equilibrium is proposed based on the departure factor which evaluates the deviation from a Boltzmann level distribution, used by Short and Hauschildt （2005） and others. The way is based on an explicit relationship describing the departure factor as a function of line to continuum source, dynamic temperature and line photon frequency, under three assumptions that the scattering can be neglected, the background continuum can be treated as a Planck function, and finally the complete redistribution can be true. It has the advantage that the departure can be very conveniently evaluated from the spectral analysis with only the radiative transfer involved. Some physical insights are recovered for some extreme cases. Some example calculations of the departure are presented for the quiet Sun, faint solar flare and strong solar flare for the generally used solar chromospheric lines： Hα, Hβ, CaII H, K and triplet. It is revealed that in the case of solar flares, the departure is less than thermodynamic equilibrium along the larger depth range than in the quiet sun due to chromospheric condensation. It becomes hard to distinguish the departures for the different lines of the same atom or ion. It is expected that this investigation can be constructive for studying stellar atmospheres in cases where the three assumptions are close to reality.

关键词： line formation -- radiative transfer -- stars atmospheres

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

The causality between the rapid rotation of a sunspot and an X3.4 flare

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Chinese Journal of Astronomy and Astrophysics 2009年第5期9卷 596-602页

作者： Xiao-Li Yan zhong-quan qu Cheng-Lin Xu Zhi-Ke Xue De-Fang Kong National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Graduate School of Chinese Academy of Sciences Beijing 100049 China Yunnan Normal University Kunming 650092 China Jiaxing University Jiaxing 314001 China

Using multi-wavelength data of Hinode, the rapid rotation of a sunspot in active region NOAA 10930 is studied in detail. We found extraordinary counterclockwise rotation of the sunspot with positive polarity before an X3.4 flare. From a series of vector magnetograms, it is found that magnetic force lines are highly sheared along the neutral line accompanying the sunspot rotation. Furthermore, it is also found that sheared loops and an inverse S-shaped magnetic loop in the corona formed gradually after the sunspot rotation. The X3.4 flare can be reasonably regarded as a result of this movement. A detailed analysis provides evidence that sunspot rotation leads to magnetic field lines twisting in the photosphere. The twist is then transported into the corona and triggers flares.

关键词： Sun sunspots - Sun flares - Sun magnetic fields

Magneto-induced Line Broadening of Magneto-sensitive Lines in Solar Magnetized Atmospheres

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Chinese Journal of Astronomy and Astrophysics 2005年第4期5卷 426-432页

作者： zhong-quan qu Shuai Wang Cheng-Lin Xu Xiao-Yu Zhang Ming-Guo Sun Chun-Lan Jin National Astronomical Observatories/Yunnan Astronomical Observatory Chinese Academyof Sciences Kunming 650011 Graduate School of the Chinese Academy of Sciences Beijing 100039

We analyze the spectral line broadening of those magneto-sensitive lines in solar magnetized atmospheres. The broadening at the line wings is due to the increase of the effective width of energy levels involved in Zeeman splitting,and the broadening at the line core also originated in Zeeman splitting under the condition that the Zeeman components are mixed. Therefore, the magneto-induced or Zeeman broadening take effects on the whole line. The observed Stokes parameter data in a sunspot and outside it acquired by Solar Stokes Spectrum Telescope （S^3T） are analyzed for the demonstration of this mechanism, and the Zeeman broadening rates are calculated for Fe16302.5 under some *** result shows that the broadening is increased as the magnetic field strength becomes stronger, but the rate of increase at the line core is decreased as the field strength increases, while the rate at the wing does not show such an obvious regularity. The broadening is more effective in the line core than in the wings.

关键词： sunspots - line: profiles-magnetic fields - radiative transfer-polarization

Albumin–bilirubin grade as a predictor of survival in hepatocellular carcinoma patients with thrombocytopenia

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 1763-1772页

作者： zhong-Ran Man Xuan-Kun Gong Kang-Lin qu Qing Pang Bin-quan Wu Department of Hepatobiliary Surgery The First Affiliated Hospital of Bengbu Medical CollegeBengbu 233000Anhui ProvinceChina Department of Hepatobiliary Surgery Anhui No.2 Provincial People’s HospitalHefei 230041Anhui ProvinceChina

BACKGROUND The models for assessing liver function,mainly the Child–Pugh(CP),albuminbilirubin(ALBI),and platelet–ALBI(PALBI)classifications,have been validated for use in estimating the prognosis of hepatocellular carcinoma(HCC)***,thrombocytopenia is a common finding and may influence the prognostic value of the three models in *** To investigate and compare the prognostic performance of the above three models in thrombocytopenic HCC *** A total of 135 patients with thrombocytopenic HCC who underwent radical surgery were retrospectively *** scores on the CP,ALBI and PALBI classifications were estimated ***–Meier curves with logrank tests and Cox regression models were used to explore the significant factors associated with overall survival(OS)and recurrence-free survival(RFS).RESULTS The preoperative platelet counts were significantly different among the CP,ALBI and PALBI *** a median follow-up of 28 mo,39.3%(53/135)of the patients experienced postoperative recurrence,and 36.3%(49/135)*** analysis suggested thatα-fetoprotein levels,tumor size,vascular invasion,and ALBI grade were significant predictors of OS and *** to the multivariate Cox regression model,ALBI was identified as an independent prognostic ***,CP and PALBI grades were not statistically significant prognostic *** The ALBI grade,rather than CP or PALBI grade,is a significant prognostic indicator for thrombocytopenic HCC patients.

关键词： Hepatocellular carcinoma Thrombocytopenia Child-Pugh Albumin-bilirubin Platelet-albumin-bilirubin

A Lightweight Network with Dual Encoder and Cross Feature Fusion for Cement Pavement Crack Detection

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 255-273页

作者： zhong qu Guoqing Mu Bin Yuan School of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqing400065China School of Software Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

Automatic crack detection of cement pavement chiefly benefits from the rapid development of deep learning,with convolutional neural networks(CNN)playing an important role in this ***,as the performance of crack detection in cement pavement improves,the depth and width of the network structure are significantly increased,which necessitates more computing power and storage *** limitation hampers the practical implementation of crack detection models on various platforms,particularly portable devices like small mobile *** solve these problems,we propose a dual-encoder-based network architecture that focuses on extracting more comprehensive fracture feature information and combines cross-fusion modules and coordinated attention mechanisms formore efficient feature ***,we use small channel convolution to construct shallow feature extractionmodule(SFEM)to extract low-level feature information of cracks in cement pavement images,in order to obtainmore information about cracks in the shallowfeatures of *** addition,we construct large kernel atrous convolution(LKAC)to enhance crack information,which incorporates coordination attention mechanism for non-crack information filtering,and large kernel atrous convolution with different cores,using different receptive fields to extract more detailed edge and context ***,the three-stage feature map outputs from the shallow feature extraction module is cross-fused with the two-stage feature map outputs from the large kernel atrous convolution module,and the shallow feature and detailed edge feature are fully fused to obtain the final crack prediction *** evaluate our method on three public crack datasets:DeepCrack,CFD,and *** results on theDeepCrack dataset demonstrate the effectiveness of our proposed method compared to state-of-the-art crack detection methods,which achieves Precision(P)87.2%,Recall(R)87.7%,and F-score(F1)87.4%.Thanks to our lightweight cr

关键词： Shallow feature extraction module large kernel atrous convolution dual encoder lightweight network crack detection

An object detection approach with residual feature fusion and second-order term attention mechanism

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 411-424页

作者： Cuijin Li zhong qu Shengye Wang College of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqingChina College of Electronic Information Chongqing Institute of EngineeringChongqingChina

Automatically detecting and locating remote occlusion small objects from the images of complex traffic environments is a valuable and challenging *** the boundary box location is not sufficiently accurate and it is difficult to distinguish overlapping and occluded objects,the authors propose a network model with a second-order term attention mechanism and occlusion ***,the backbone network is built on *** a method is designed for the feature extraction network based on an item-wise attention mechanism,which uses the filtered weighted feature vector to replace the original residual fusion and adds a second-order term to reduce the information loss in the process of fusion and accelerate the convergence of the ***,an objected occlusion regression loss function is studied to reduce the problems of missed detections caused by dense *** experimental results demonstrate that the authors’method achieved state-of-the-art performance without reducing the detection *** mAP@.5 of the method is 85.8%on the Foggy_cityscapes dataset and the mAP@.5 of the method is 97.8%on the KITTI dataset.

关键词： artificial intelligence computer vision image processing machine learning neural network object recognition