Pancreatic carcinoma occasionally associated with prominent mucin production and this type of tumor designated as PCM (pancreatic carcinoma with prominent mucin production) was diagnosed depends on subjective estimati...Pancreatic carcinoma occasionally associated with prominent mucin production and this type of tumor designated as PCM (pancreatic carcinoma with prominent mucin production) was diagnosed depends on subjective estimation of the amount of mucous area, and there has been no report on a quantitative evaluation of the amount of mucinous area in the tumor. To examine the feature of PCM, we analyzed 9 cases of PCM among 243 cases of pancreas carcinoma and evaluated the amount of mucin by imaging analysis. Morphologically, 5 cases were classified as intradactal papillary mucinous neoplasms (IPMN)-derived PCM and 4 cases were as ductal adenocarcinoma (DA)-derived PCM. Mucous composition was found to be more than 50% in all IPMN-derived PCM cases, and that was 40% - 50% in DA-derived PCM cases with one exception. IPMN-derived PCM cases showed expansive growth with pancreatic duct dilatation filled with mucin, while DA-derived PCM cases possessed mucin infiltration into interstitial tissue. Immunohisto-chemically, three of 4 DA-derived PCM cases were MUC1(–)/MUC2(+), and the results of expressions for p16 and Dpc4 suggesting that DA-derived PCM was similar to IPMN-derived PCM rather than ordinary DA. Survival rate of DA-derived PCM cases was lower than that of IPMN-derived PCM cases. We advocate that DA-derived PCM may constitute a borderline group between IPMN and ordinary DA.展开更多
A lot ofotoplasty techniques have been developed during the past years. However, there is no single perfect technique which is worldwide accepted. We present our assessment of a Chong-Chet anterior scoring technique f...A lot ofotoplasty techniques have been developed during the past years. However, there is no single perfect technique which is worldwide accepted. We present our assessment of a Chong-Chet anterior scoring technique for the correction of prominent ears which we applied in 30 patients between 2005 and 2010. This study is a report of creating a natural fold of cartilage using Chong-Chet anterior scoring technique by cartilage incision at the border between the antihelix and scapha, with medial scoring of the scapha and lateral scoring of the antihelix. Sutures were used to maintain the created fold. There were no major complications at the 1-year follow-up evaluation. None of the patients developed a recurrence, or retro protrusion of the helix which required a second operation for correction. The procedure is a simple surgical technique. The reconstructed ear shows reliable results in stability, size and normal convolutions. Furthermore, sharp cartilaginous ridges and hidden helix are avoided.展开更多
Adevelopmentally normal,15-year-old boy presented with complaint of gait abnormalities since 8 years of age.The child complained of difficulty in climbing stairs and running.He could not climb stairs without the suppo...Adevelopmentally normal,15-year-old boy presented with complaint of gait abnormalities since 8 years of age.The child complained of difficulty in climbing stairs and running.He could not climb stairs without the support of railing.There was no problem with rising from sitting or lying down position.展开更多
Introduction Bullous pemphigoid (BP) is an autoimmune blistering disease that affects patients of advanced age. BP is characterized clinically by tense bullae on the extremities and trunk, histopathologically by subep...Introduction Bullous pemphigoid (BP) is an autoimmune blistering disease that affects patients of advanced age. BP is characterized clinically by tense bullae on the extremities and trunk, histopathologically by subepi-dermal blisters with eosinophilic infiltration, and immunologically by autoantibodies to BP180 and BP230. Direct immunofluorescence of perilesional skin shows depositions of IgG and C3 in the basement membrane zone(1)BP rarely shows prominent milia formation, which is a hallmark of epidermolysis bullosa acquisita. We herein describe a 53-year-old man with refractory BP showing numerous milia during recovery.展开更多
Lyα(Lyα,1216 A)is the strongest emission line in the solar ultraviolet spectrum.In the present work,we obtained a Lyαenhancement catalog covering flares larger than B1 class from the GOES/EUVS data during 2010-2016...Lyα(Lyα,1216 A)is the strongest emission line in the solar ultraviolet spectrum.In the present work,we obtained a Lyαenhancement catalog covering flares larger than B1 class from the GOES/EUVS data during 2010-2016.We focused on the 242 B-class events which are less investigated,however,show non-negligible Lyαemission enhancement.We found that on average the Lyαpeak of B-class flares is 0.85%stronger than the background.For the flare energetics,it is found that the weaker the soft X-ray(SXR)flare,the larger the ratio of the radiated energy in Lyαto SXR.Using the RHESSI data and multi-wavelength observations taken by SDO-AIA,we diagnose the thermal and non-thermal properties of several flares.Three case studies show that the coincidence of the Lyαpeak with the SXR time-derivative peak is not a sufficient condition of the nonthermal property of a Lyαmicroflare.The Lyαenhancement in the microflares may be caused by the nonthermal electron beams or/and thermal conduction.However for typeⅢevents,we found that the delay of the Lyαpeak with respect to the SXR peak can be attributed to either the Lyαemission from a filament erupted or the cooling of the thermal plasma in flare loops.Furthermore,interestingly the Lyαemission from filaments can not only occur in the decay phase of the flare,but also in the preflare phase.In this case,the Lyαemission was originated from an erupted filament which probably initiated the flare.展开更多
The assortedness of Chinese food,together with the complexity of their naming elements,has ignited numerous scholars' interests in this field and prompted them to make abundant analyses of Chinese dish names.Most ...The assortedness of Chinese food,together with the complexity of their naming elements,has ignited numerous scholars' interests in this field and prompted them to make abundant analyses of Chinese dish names.Most of them,however,were done in studies of traditional linguistics,rhetoric,translatology and cross-cultural communication.And studies,based on corpus,on the naming elements of Chinese dishes under cognitive linguistic theories almost remain a blank.This paper aims to conduct a quantitative analysis of 4,000 Chinese dish names(500 ones selected freely from each of the eight cuisines),based on the Prominence Principle,in order to identify the specific naming elements of Chinese dishes and forward related statistics and ratios.展开更多
Canadian classical works are becoming more and more popular all over the world. People began to understand and mar-vel at the Canadian literatures that are quite life-meaningful and full of lessons and tips for lives....Canadian classical works are becoming more and more popular all over the world. People began to understand and mar-vel at the Canadian literatures that are quite life-meaningful and full of lessons and tips for lives. The classic works in CanadianLiteratures that advantageously elaborated the characteristics of sublimation under the background for Canada's particular history,geography, climate, religion, demographic factors, generation, development and continuous construction of Canadian literatures.The greatest masterpieces can highlight powerfully the certain mindset of Canadian and the permanent theme for Canadian Litera-ture: keep working hard for survival and love bravely. Meanwhile, modern people will learn a lot from reading Canadian classic lit-erary works.展开更多
We observed an Hα surge that occurred in NOAA Active Region 12401 on 2015 August 17, and we discuss its trigger mechanism, and kinematic and thermal properties. It is suggested that this surge was caused by a chromos...We observed an Hα surge that occurred in NOAA Active Region 12401 on 2015 August 17, and we discuss its trigger mechanism, and kinematic and thermal properties. It is suggested that this surge was caused by a chromospheric reconnection which ejected cool and dense material with transverse velocity of about 21–28 km s-1 and initial Doppler velocity of 12 km s^-1. This surge is similar to the injection of newly formed filament materials from their footpoints, except that the surge here occurred in a relatively weak magnetic environment of 100 G. Thus, we discuss the possibility of filament material replenishment via the erupting mass in such a weak magnetic field, which is often associated with quiescent filaments. It is found that the local plasma can be heated up to about 1.3 times the original temperature, which results in an acceleration of about –0.017 km s^-2. It can lift the dense material up to 10 Mm and higher with an inclination angle smaller than 50°, namely the typical height of active region filaments, but it can hardly inject the material up to those filaments higher than 25 Mm, like some quiescent filaments. Thus, we think that the injection model does not work well in describing the formation of quiescent filaments.展开更多
Pun,as a figure of speech applied in advertisements,can make the advertisements more vivid and indelible by adding attraction and humor,stimulating consumers' purchasing desire.Based on the elaboration of puns in ...Pun,as a figure of speech applied in advertisements,can make the advertisements more vivid and indelible by adding attraction and humor,stimulating consumers' purchasing desire.Based on the elaboration of puns in English advertisements from the cognitive perspective,this paper attempts to analyze those puns under the guidance of relevant cognitive theoretical framework such as figure/ground theory,prominence view and conceptual blending theory.It also aims to explore the human cognitive activities involved in creation and understanding of advertising language.展开更多
The mean length of the stria vascularis (SV) and the basilar membrane of four normalguinea pigs measured by means of surface preparation was 21.11 mm and 19. 90 mm respectively,and the mean width of their apical turns...The mean length of the stria vascularis (SV) and the basilar membrane of four normalguinea pigs measured by means of surface preparation was 21.11 mm and 19. 90 mm respectively,and the mean width of their apical turns of SV and the turns of the cochlear basis was 0. 44 mmand 0. 86 mm respectively. The ultrastructure of SV, spiral ligament (SL) and spiral prominence(SP) of both ears of eight guinea pigs were observed by scanning electron microscopy(SEM) andtransmission electron microsoopy(TEM). There were a large number of coated vesicles in thesupranuclear region of SV, some opened to the endolymph. A great number of folding cytoplasmicprojections were filled with small vesicles The capillary network was extremely rich indicating thatthe endolymph could be secreted and absorbed by SV. The cellular conjunction in the SV. SL andSP formed an effective barrier. It has not been proved in this study that the melanin offers resistanceto acoustic stimulation.展开更多
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 signi...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.展开更多
We investigate the evolutions of two prominences(P1, P2) and two bundles of coronal loops(L1, L2), observed with SDO/AIA near the east solar limb on 2012 September 22. It is found that there were large-amplitude oscil...We investigate the evolutions of two prominences(P1, P2) and two bundles of coronal loops(L1, L2), observed with SDO/AIA near the east solar limb on 2012 September 22. It is found that there were large-amplitude oscillations in P1 and L1 but no detectable motions in P2 and L2. These transverse oscillations were triggered by a large-scale coronal wave, originating from a large flare in a remote active region behind the solar limb. By carefully comparing the locations and heights of these oscillating and non-oscillating structures, we conclude that the propagating height of the wave is between 50 Mm and130 Mm. The wave energy deposited in the oscillating prominence and coronal loops is at least of the order of 10^(28) erg. Furthermore, local magnetic field strength and Alfv ′en speeds are derived from the oscillating periods and damping time scales, which are extracted from the time series of the oscillations. It is demonstrated that oscillations can be used in not only coronal seismology, but also to reveal the properties of the wave.展开更多
Solar filaments are an intriguing phenomenon,like cool clouds suspended in the hot corona.Similar structures exist in the intergalactic medium as well.Despite being a long-studied topic,solar filaments have continuall...Solar filaments are an intriguing phenomenon,like cool clouds suspended in the hot corona.Similar structures exist in the intergalactic medium as well.Despite being a long-studied topic,solar filaments have continually attracted intensive attention because of their link to coronal heating,coronal seismology,solar flares and coronal mass ejections(CMEs).In this review paper,by combing through the solar filament-related work done in the past decade,we discuss several controversial topics,such as the fine structures,dynamics,magnetic configurations and helicity of filaments.With high-resolution and highsensitivity observations,combined with numerical simulations,it is expected that resolving these disputes will definitely lead to a huge leap in understanding the physics related to solar filaments,and even shed light on galactic filaments.展开更多
Prominence plumes are evacuated upflows that emerge from bubbles below prominences,whose formation mechanism is still unclear.Here we present a detailed study of plumes in a quiescent prominence using the high-resolut...Prominence plumes are evacuated upflows that emerge from bubbles below prominences,whose formation mechanism is still unclear.Here we present a detailed study of plumes in a quiescent prominence using the high-resolution Hαfiltergrams at the line center as well as line wing at±0.4 A from the New Vacuum Solar Telescope.Enhancements of brightening,blue shifts,and turbulence at the fronts of plumes are found during their formation.Some large plumes split at their heads and finger-shaped structures are formed between them.Blue-shifted flows along the bubble-prominence interface are found before and during the plume formation.Our observations are consistent with the hypothesis that prominence plumes are related to coupled Kelvin-Helmholtz and Rayleigh-Taylor(KH/RT)instabilities.Plume splittings and fingers are evidence of RT instability,and the flows may increase the growth rate of KH/RT instabilities.However,the significant turbulence at plume fronts may suggest that the RT instability is triggered by the plumes penetrating into the prominence.In this scenario,extra mechanisms are necessary to drive the plumes.展开更多
Magnetic flux ropes are characterized by coherently twisted magnetic field lines,which are ubiquitous in magnetized plasmas.As the core structure of various eruptive phenomena in the solar atmosphere,flux ropes hold t...Magnetic flux ropes are characterized by coherently twisted magnetic field lines,which are ubiquitous in magnetized plasmas.As the core structure of various eruptive phenomena in the solar atmosphere,flux ropes hold the key to understanding the physical mechanisms of solar eruptions,which impact the heliosphere and planetary atmospheres.The strongest disturbances in the Earth’s space environments are often associated with large-scale flux ropes from the Sun colliding with the Earth’s magnetosphere,leading to adverse,sometimes catastrophic,space-weather effects.However,it remains elusive as to how a flux rope forms and evolves toward eruption,and how it is structured and embedded in the ambient field.The present paper addresses these important questions by reviewing current understandings of coronal flux ropes from an observer’s perspective,with an emphasis on their structures and nascent evolution toward solar eruptions,as achieved by combining observations of both remote sensing and in-situ detection with modeling and simulation.This paper highlights an initiation mechanism for coronal mass ejections(CMEs)in which plasmoids in current sheets coalesce into a’seed’flux rope whose subsequent evolution into a CME is consistent with the standard model,thereby bridging the gap between microscale and macroscale dynamics.展开更多
文摘Pancreatic carcinoma occasionally associated with prominent mucin production and this type of tumor designated as PCM (pancreatic carcinoma with prominent mucin production) was diagnosed depends on subjective estimation of the amount of mucous area, and there has been no report on a quantitative evaluation of the amount of mucinous area in the tumor. To examine the feature of PCM, we analyzed 9 cases of PCM among 243 cases of pancreas carcinoma and evaluated the amount of mucin by imaging analysis. Morphologically, 5 cases were classified as intradactal papillary mucinous neoplasms (IPMN)-derived PCM and 4 cases were as ductal adenocarcinoma (DA)-derived PCM. Mucous composition was found to be more than 50% in all IPMN-derived PCM cases, and that was 40% - 50% in DA-derived PCM cases with one exception. IPMN-derived PCM cases showed expansive growth with pancreatic duct dilatation filled with mucin, while DA-derived PCM cases possessed mucin infiltration into interstitial tissue. Immunohisto-chemically, three of 4 DA-derived PCM cases were MUC1(–)/MUC2(+), and the results of expressions for p16 and Dpc4 suggesting that DA-derived PCM was similar to IPMN-derived PCM rather than ordinary DA. Survival rate of DA-derived PCM cases was lower than that of IPMN-derived PCM cases. We advocate that DA-derived PCM may constitute a borderline group between IPMN and ordinary DA.
文摘A lot ofotoplasty techniques have been developed during the past years. However, there is no single perfect technique which is worldwide accepted. We present our assessment of a Chong-Chet anterior scoring technique for the correction of prominent ears which we applied in 30 patients between 2005 and 2010. This study is a report of creating a natural fold of cartilage using Chong-Chet anterior scoring technique by cartilage incision at the border between the antihelix and scapha, with medial scoring of the scapha and lateral scoring of the antihelix. Sutures were used to maintain the created fold. There were no major complications at the 1-year follow-up evaluation. None of the patients developed a recurrence, or retro protrusion of the helix which required a second operation for correction. The procedure is a simple surgical technique. The reconstructed ear shows reliable results in stability, size and normal convolutions. Furthermore, sharp cartilaginous ridges and hidden helix are avoided.
文摘Adevelopmentally normal,15-year-old boy presented with complaint of gait abnormalities since 8 years of age.The child complained of difficulty in climbing stairs and running.He could not climb stairs without the support of railing.There was no problem with rising from sitting or lying down position.
文摘Introduction Bullous pemphigoid (BP) is an autoimmune blistering disease that affects patients of advanced age. BP is characterized clinically by tense bullae on the extremities and trunk, histopathologically by subepi-dermal blisters with eosinophilic infiltration, and immunologically by autoantibodies to BP180 and BP230. Direct immunofluorescence of perilesional skin shows depositions of IgG and C3 in the basement membrane zone(1)BP rarely shows prominent milia formation, which is a hallmark of epidermolysis bullosa acquisita. We herein describe a 53-year-old man with refractory BP showing numerous milia during recovery.
基金supported by the National Key R&D Program of China under grants 2022YFF0503003(2022YFF0503000)and 2018YFA0404200the National Natural Science Foundation of China(NSFC,Grant Nos.11921003,11973012,and 11820101002)+1 种基金CAS Strategic Pioneer Program on Space Science(Grant Nos.XDA15018300,XDA15052200,XDA15320103,and XDA15320301)the mobility program(M-0068)of the Sino-German Science Center。
文摘Lyα(Lyα,1216 A)is the strongest emission line in the solar ultraviolet spectrum.In the present work,we obtained a Lyαenhancement catalog covering flares larger than B1 class from the GOES/EUVS data during 2010-2016.We focused on the 242 B-class events which are less investigated,however,show non-negligible Lyαemission enhancement.We found that on average the Lyαpeak of B-class flares is 0.85%stronger than the background.For the flare energetics,it is found that the weaker the soft X-ray(SXR)flare,the larger the ratio of the radiated energy in Lyαto SXR.Using the RHESSI data and multi-wavelength observations taken by SDO-AIA,we diagnose the thermal and non-thermal properties of several flares.Three case studies show that the coincidence of the Lyαpeak with the SXR time-derivative peak is not a sufficient condition of the nonthermal property of a Lyαmicroflare.The Lyαenhancement in the microflares may be caused by the nonthermal electron beams or/and thermal conduction.However for typeⅢevents,we found that the delay of the Lyαpeak with respect to the SXR peak can be attributed to either the Lyαemission from a filament erupted or the cooling of the thermal plasma in flare loops.Furthermore,interestingly the Lyαemission from filaments can not only occur in the decay phase of the flare,but also in the preflare phase.In this case,the Lyαemission was originated from an erupted filament which probably initiated the flare.
文摘The assortedness of Chinese food,together with the complexity of their naming elements,has ignited numerous scholars' interests in this field and prompted them to make abundant analyses of Chinese dish names.Most of them,however,were done in studies of traditional linguistics,rhetoric,translatology and cross-cultural communication.And studies,based on corpus,on the naming elements of Chinese dishes under cognitive linguistic theories almost remain a blank.This paper aims to conduct a quantitative analysis of 4,000 Chinese dish names(500 ones selected freely from each of the eight cuisines),based on the Prominence Principle,in order to identify the specific naming elements of Chinese dishes and forward related statistics and ratios.
文摘Canadian classical works are becoming more and more popular all over the world. People began to understand and mar-vel at the Canadian literatures that are quite life-meaningful and full of lessons and tips for lives. The classic works in CanadianLiteratures that advantageously elaborated the characteristics of sublimation under the background for Canada's particular history,geography, climate, religion, demographic factors, generation, development and continuous construction of Canadian literatures.The greatest masterpieces can highlight powerfully the certain mindset of Canadian and the permanent theme for Canadian Litera-ture: keep working hard for survival and love bravely. Meanwhile, modern people will learn a lot from reading Canadian classic lit-erary works.
基金supported by the National Natural Science Foundation of China (41731067 and 41822404)Shenzhen Technology Project (JCYJ20170307150645407)+6 种基金the Fundamental Research Funds for the Central Universities (Grant No. HIT.BRETV.201901)the support by China Postdoctoral Science Foundation (2018M641812)support of the US NSF (AGS-1821294)the National Natural Science Foundation of China (11729301)supported by NJIT and US NSF AGS 1821294 grantpartly supported by the Korea Astronomy and Space Science Institute and Seoul National Universitythe strategic priority research program of Chinese Academy of Science (CAS) (Grant No. XDB09000000)
文摘We observed an Hα surge that occurred in NOAA Active Region 12401 on 2015 August 17, and we discuss its trigger mechanism, and kinematic and thermal properties. It is suggested that this surge was caused by a chromospheric reconnection which ejected cool and dense material with transverse velocity of about 21–28 km s-1 and initial Doppler velocity of 12 km s^-1. This surge is similar to the injection of newly formed filament materials from their footpoints, except that the surge here occurred in a relatively weak magnetic environment of 100 G. Thus, we discuss the possibility of filament material replenishment via the erupting mass in such a weak magnetic field, which is often associated with quiescent filaments. It is found that the local plasma can be heated up to about 1.3 times the original temperature, which results in an acceleration of about –0.017 km s^-2. It can lift the dense material up to 10 Mm and higher with an inclination angle smaller than 50°, namely the typical height of active region filaments, but it can hardly inject the material up to those filaments higher than 25 Mm, like some quiescent filaments. Thus, we think that the injection model does not work well in describing the formation of quiescent filaments.
文摘Pun,as a figure of speech applied in advertisements,can make the advertisements more vivid and indelible by adding attraction and humor,stimulating consumers' purchasing desire.Based on the elaboration of puns in English advertisements from the cognitive perspective,this paper attempts to analyze those puns under the guidance of relevant cognitive theoretical framework such as figure/ground theory,prominence view and conceptual blending theory.It also aims to explore the human cognitive activities involved in creation and understanding of advertising language.
文摘The mean length of the stria vascularis (SV) and the basilar membrane of four normalguinea pigs measured by means of surface preparation was 21.11 mm and 19. 90 mm respectively,and the mean width of their apical turns of SV and the turns of the cochlear basis was 0. 44 mmand 0. 86 mm respectively. The ultrastructure of SV, spiral ligament (SL) and spiral prominence(SP) of both ears of eight guinea pigs were observed by scanning electron microscopy(SEM) andtransmission electron microsoopy(TEM). There were a large number of coated vesicles in thesupranuclear region of SV, some opened to the endolymph. A great number of folding cytoplasmicprojections were filled with small vesicles The capillary network was extremely rich indicating thatthe endolymph could be secreted and absorbed by SV. The cellular conjunction in the SV. SL andSP formed an effective barrier. It has not been proved in this study that the melanin offers resistanceto acoustic stimulation.
基金The National Natural Science Foundation of China supports this work under Grant numbers U2031202,U1531247 and U1731124the 13th Five-year Informatization Plan of Chinese Academy of Sciences under Grant number XXH13505-04the special foundation work of the Ministry of Science and Technology of China under Grant number 2014FY120300。
文摘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.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41131065, 41574165, 41421063 and 41304134)MOEC (20113402110001)+2 种基金CAS Key Research Program (KZZD-EW-01-4)the fundamental research funds for the central universities (WK2080000077)the foundation for Young Talents in College of Anhui Province (2013SQRL044ZD)
文摘We investigate the evolutions of two prominences(P1, P2) and two bundles of coronal loops(L1, L2), observed with SDO/AIA near the east solar limb on 2012 September 22. It is found that there were large-amplitude oscillations in P1 and L1 but no detectable motions in P2 and L2. These transverse oscillations were triggered by a large-scale coronal wave, originating from a large flare in a remote active region behind the solar limb. By carefully comparing the locations and heights of these oscillating and non-oscillating structures, we conclude that the propagating height of the wave is between 50 Mm and130 Mm. The wave energy deposited in the oscillating prominence and coronal loops is at least of the order of 10^(28) erg. Furthermore, local magnetic field strength and Alfv ′en speeds are derived from the oscillating periods and damping time scales, which are extracted from the time series of the oscillations. It is demonstrated that oscillations can be used in not only coronal seismology, but also to reveal the properties of the wave.
基金supported by the National Natural Science Foundation of China(NSFC 11533005,11961131002,11733003 and U1731241)supported by the Science and Technology Development Fund of Macao(275/2017/A)。
文摘Solar filaments are an intriguing phenomenon,like cool clouds suspended in the hot corona.Similar structures exist in the intergalactic medium as well.Despite being a long-studied topic,solar filaments have continually attracted intensive attention because of their link to coronal heating,coronal seismology,solar flares and coronal mass ejections(CMEs).In this review paper,by combing through the solar filament-related work done in the past decade,we discuss several controversial topics,such as the fine structures,dynamics,magnetic configurations and helicity of filaments.With high-resolution and highsensitivity observations,combined with numerical simulations,it is expected that resolving these disputes will definitely lead to a huge leap in understanding the physics related to solar filaments,and even shed light on galactic filaments.
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.11427803,U1731241,U1631242 and 11820101002)by CAS Strategic Pioneer Program on Space Science(Grant Nos.XDA15052200,XDA15320103,XDA15320300 and XDA15320301)+2 种基金the Jiangsu Double Innovation PlanNSFC(Grant No.11873091)Yunnan Province Basic Research Plan(No.2019FA001)。
文摘Prominence plumes are evacuated upflows that emerge from bubbles below prominences,whose formation mechanism is still unclear.Here we present a detailed study of plumes in a quiescent prominence using the high-resolution Hαfiltergrams at the line center as well as line wing at±0.4 A from the New Vacuum Solar Telescope.Enhancements of brightening,blue shifts,and turbulence at the fronts of plumes are found during their formation.Some large plumes split at their heads and finger-shaped structures are formed between them.Blue-shifted flows along the bubble-prominence interface are found before and during the plume formation.Our observations are consistent with the hypothesis that prominence plumes are related to coupled Kelvin-Helmholtz and Rayleigh-Taylor(KH/RT)instabilities.Plume splittings and fingers are evidence of RT instability,and the flows may increase the growth rate of KH/RT instabilities.However,the significant turbulence at plume fronts may suggest that the RT instability is triggered by the plumes penetrating into the prominence.In this scenario,extra mechanisms are necessary to drive the plumes.
基金supported by the National Natural Science Foundation of China(Grant Nos.41761134088,41774150,and 11925302)CAS Key Research Program(Grant No.KZZD-EW-01-4)the fundamental research funds for the central universities,and the Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)。
文摘Magnetic flux ropes are characterized by coherently twisted magnetic field lines,which are ubiquitous in magnetized plasmas.As the core structure of various eruptive phenomena in the solar atmosphere,flux ropes hold the key to understanding the physical mechanisms of solar eruptions,which impact the heliosphere and planetary atmospheres.The strongest disturbances in the Earth’s space environments are often associated with large-scale flux ropes from the Sun colliding with the Earth’s magnetosphere,leading to adverse,sometimes catastrophic,space-weather effects.However,it remains elusive as to how a flux rope forms and evolves toward eruption,and how it is structured and embedded in the ambient field.The present paper addresses these important questions by reviewing current understandings of coronal flux ropes from an observer’s perspective,with an emphasis on their structures and nascent evolution toward solar eruptions,as achieved by combining observations of both remote sensing and in-situ detection with modeling and simulation.This paper highlights an initiation mechanism for coronal mass ejections(CMEs)in which plasmoids in current sheets coalesce into a’seed’flux rope whose subsequent evolution into a CME is consistent with the standard model,thereby bridging the gap between microscale and macroscale dynamics.