In this article,we report a few advances in the studies based on the solar vector magnetic field observations which were carried out mainly with the Solar Magnetic Field Telescope at the Huairou Solar Observing Statio...In this article,we report a few advances in the studies based on the solar vector magnetic field observations which were carried out mainly with the Solar Magnetic Field Telescope at the Huairou Solar Observing Station in the 1990s.(1) We developed necessary methodology and concepts in vector magnetogram analysis(Wang et al.1996).For the first time,we proposed to use the photospheric free magnetic energy to quantify the major flare productivity of solar active regions(ARs),and it had been proved to be the best parameter in representing the major flare activity.(2) We revealed that there was always a dominant sense of magnetic shear in a given AR(Wang 1994),which was taken as the premise of the helicity calculation in ARs;we made the first quantitative estimation of magnetic helicity evolution in ARs(Wang 1996).(3) We identified the first group of evidence of magnetic reconnection in the lower solar atmosphere with vector magnetic field observations and proposed a two-step reconnection flare model to interpret the observed association of flux cancellation and flares(Wang and Shi 1993).Efforts to quantify the major flare productivity of super active regions with vector magnetic field observations have been also taken.展开更多
Solar activity,in which there is an explosive release of magnetic energy in the solar atmosphere,is one of the most spectacular manifestations of space plasma activity.Non-potential,free magnetic energy is accumulated...Solar activity,in which there is an explosive release of magnetic energy in the solar atmosphere,is one of the most spectacular manifestations of space plasma activity.Non-potential,free magnetic energy is accumulated by the interaction between plasma and magnetic fields in the photosphere and sub-photospheric layer.In the photosphere and lower solar atmosphere,plasma is only partially ionized and there is three-species(or three-fluid)plasma.Cowling conductivity should therefore be considered in explaining solar observations.On the other hand,the explosive release of magnetic energy is believed to be caused by magnetic reconnection in the corona,where plasma is fully ionized and essentially collisionless.However,for collisionless plasma,we seem to have no precise quantitative description or formulation of its conductivity.To physically understand magnetic reconnection in collisionless plasma is an important task in making further progress in solar activity studies.This article discusses the plasma perspective of solar activity studies.The discussion begins with solar observations,and then,an analysis of the plasma problems that we face and need to better understand.展开更多
The concept of the Solar Ring mission was gradually formed from L5/L4 mission concept, and the proposal of its pre-phase study was funded by the National Natural Science Foundation of China in November 2018 and then b...The concept of the Solar Ring mission was gradually formed from L5/L4 mission concept, and the proposal of its pre-phase study was funded by the National Natural Science Foundation of China in November 2018 and then by the Strategic Priority Program of Chinese Academy of Sciences in space sciences in May 2019. Solar Ring mission will be the first attempt to routinely monitor and study the Sun and inner heliosphere from a full 360-degree perspective in the ecliptic plane. The current preliminary design of the Solar Ring mission is to deploy six spacecraft, grouped in three pairs, on a sub-AU orbit around the Sun. The two spacecraft in each group are separated by about 30?and every two groups by about 120?. This configuration with necessary science payloads will allow us to establish three unprecedented capabilities:(1) determine the photospheric vector magnetic field with unambiguity,(2) provide 360-degree maps of the Sun and the inner heliosphere routinely, and(3) resolve the solar wind structures at multiple scales and multiple longitudes. With these capabilities, the Solar Ring mission aims to address the origin of solar cycle, the origin of solar eruptions, the origin of solar wind structures and the origin of severe space weather events. The successful accomplishment of the mission will advance our understanding of the star and the space environment that hold our life and enhance our capability of expanding the next new territory of human.展开更多
Magnetic reconnection is a main process converting the magnetic energy into thermal and kinetic energy in plasmas. It is one of the fundamental problems of crucial importance not only to space plasmas physics and spac...Magnetic reconnection is a main process converting the magnetic energy into thermal and kinetic energy in plasmas. It is one of the fundamental problems of crucial importance not only to space plasmas physics and space weather studies,such as the solar flare,coronal mass ejections and magnetospheric substorms,but also to the stability analysis in magnetically confined fusion. In general,except for cases with periodical boundary conditions,three-dimensional(3D) magnetic re-connection occurs on magnetic separatrices generated by magnetic nulls. Here we briefly introduce/review the theories and some recent satellite observations of 3D magnetic reconnection. Topics to be further studied are also discussed.展开更多
round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ...round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ARs are clustered, creating a favorable magnetic environment for the onset of coronal mass ejections(CMEs). In this work, we describe a new type of magnetic complex: cluster of solar ARs. An AR cluster is referred to as the close connection of two or more ARs which are located in nearly the same latitude and a narrow span of longitude. We illustrate three examples of AR clusters, each of which has two ARs connected and formed a common dome of magnetic flux system. They are clusters of NOAA(i.e., National Oceanic and Atmospheric Administration) ARs 11226 & 11227, 11429 & 11430, and 11525 & 11524. In these AR clusters, CME initiations were often tied to the instability of the magnetic structures connecting two partner ARs, in the form of inter-connecting loops and/or channeling filaments between the two ARs. We show the evidence that, at least, some of the flare/CMEs in an AR cluster are not a phenomenon of a single AR, but the result of magnetic interaction in the whole AR cluster. The observations shed new light on understanding the mechanism(s) of solar activity. Instead of the simple bipolar topology as suggested by the so-called standard flare model, a multi-bipolar magnetic topology is more common to host the violent solar activity in solar atmosphere.展开更多
"Solar storm" has been commonly accepted by academic community and the public as a very popular scientific term. It is avivid description of violent ejections of a huge amount of magnetized plasma from the S..."Solar storm" has been commonly accepted by academic community and the public as a very popular scientific term. It is avivid description of violent ejections of a huge amount of magnetized plasma from the Sun as strong flare/CMEs, which sweepover into interplanetary space, develop, and affect our space environment. The solar storm could bring us disastrous spaceweather, destroy crucial technology, and cause a large-scale blackout. It is one of the natural disasters faced by modern humanbeings. Here we first briefly summarize the observational features of solar storms and introduce some key issues, and then wefocus on major advances in observational studies. We mainly introduce the efforts made by the Chinese scientists and comment on the challenges and opportunities that they are facing. In this era when scientific breakthroughs in solar storm studiescrucially depend on space-borne devices and large-aperture ground-based telescopes, the Chinese solar research communityneeds to develop its own major observational facilities and improve space weather forecasting abilities.展开更多
为评估中国农业大学培育的非转基因抗除草剂玉米品系958R和335R在大田条件下对乙酰乳酸合成酶(acetolactate synthase,ALS)抑制剂类除草剂的抗性表现,利用甲咪唑烟酸、砜嘧磺隆、唑嘧磺草胺3种除草剂对郑单958、958R、先玉335、335R共4...为评估中国农业大学培育的非转基因抗除草剂玉米品系958R和335R在大田条件下对乙酰乳酸合成酶(acetolactate synthase,ALS)抑制剂类除草剂的抗性表现,利用甲咪唑烟酸、砜嘧磺隆、唑嘧磺草胺3种除草剂对郑单958、958R、先玉335、335R共4种玉米杂交种进行了播后苗前土壤处理,每种除草剂设3个处理剂量(1、3、9倍推荐剂量),并于施药2周和4周后进行株高测定,于收获晾干后测产。结果表明,在甲咪唑烟酸216、648 g (a.i.)/hm^2处理下,郑单958和先玉335均已绝产,而958R和335R产量均未受影响;在砜嘧磺隆或唑嘧磺草胺高剂量处理下,常规玉米品种郑单958和先玉335株高的最高降幅分别为25.7%和35.2%,田间药害反应显著,而958R和335R则抗性反应显著。研究表明,非转基因抗除草剂玉米杂交种具有良好的田间抗性,不仅能有效解决玉米田砜嘧磺隆和唑嘧磺草胺等ALS除草剂的药害问题,还能够通过引入甲咪唑烟酸等新的ALS除草剂更好地防除玉米田的杂草。展开更多
文摘In this article,we report a few advances in the studies based on the solar vector magnetic field observations which were carried out mainly with the Solar Magnetic Field Telescope at the Huairou Solar Observing Station in the 1990s.(1) We developed necessary methodology and concepts in vector magnetogram analysis(Wang et al.1996).For the first time,we proposed to use the photospheric free magnetic energy to quantify the major flare productivity of solar active regions(ARs),and it had been proved to be the best parameter in representing the major flare activity.(2) We revealed that there was always a dominant sense of magnetic shear in a given AR(Wang 1994),which was taken as the premise of the helicity calculation in ARs;we made the first quantitative estimation of magnetic helicity evolution in ARs(Wang 1996).(3) We identified the first group of evidence of magnetic reconnection in the lower solar atmosphere with vector magnetic field observations and proposed a two-step reconnection flare model to interpret the observed association of flux cancellation and flares(Wang and Shi 1993).Efforts to quantify the major flare productivity of super active regions with vector magnetic field observations have been also taken.
基金supported by the National Natural Science Foundation of China(11003024,40974112,10973019,10921303,11025315)the National Basic Research Program of China(G2011CB811403)
文摘Solar activity,in which there is an explosive release of magnetic energy in the solar atmosphere,is one of the most spectacular manifestations of space plasma activity.Non-potential,free magnetic energy is accumulated by the interaction between plasma and magnetic fields in the photosphere and sub-photospheric layer.In the photosphere and lower solar atmosphere,plasma is only partially ionized and there is three-species(or three-fluid)plasma.Cowling conductivity should therefore be considered in explaining solar observations.On the other hand,the explosive release of magnetic energy is believed to be caused by magnetic reconnection in the corona,where plasma is fully ionized and essentially collisionless.However,for collisionless plasma,we seem to have no precise quantitative description or formulation of its conductivity.To physically understand magnetic reconnection in collisionless plasma is an important task in making further progress in solar activity studies.This article discusses the plasma perspective of solar activity studies.The discussion begins with solar observations,and then,an analysis of the plasma problems that we face and need to better understand.
基金supported by the Strategic Priority Program of CAS (Grant Nos. XDB41000000 and XDA15017300)the National Natural Science Foundation of China (NSFC)(Grant No. 41842037)+5 种基金supported by the CAS Key Research Program of Frontier Sciences (Grant No. QYZDB-SSW-DQC015)the NSFC (Grant Nos. 417741784176113408841750110481 and 11925302)the NSFC (Grant No. 11790302)the NSFC (Grant No. 41627806)。
文摘The concept of the Solar Ring mission was gradually formed from L5/L4 mission concept, and the proposal of its pre-phase study was funded by the National Natural Science Foundation of China in November 2018 and then by the Strategic Priority Program of Chinese Academy of Sciences in space sciences in May 2019. Solar Ring mission will be the first attempt to routinely monitor and study the Sun and inner heliosphere from a full 360-degree perspective in the ecliptic plane. The current preliminary design of the Solar Ring mission is to deploy six spacecraft, grouped in three pairs, on a sub-AU orbit around the Sun. The two spacecraft in each group are separated by about 30?and every two groups by about 120?. This configuration with necessary science payloads will allow us to establish three unprecedented capabilities:(1) determine the photospheric vector magnetic field with unambiguity,(2) provide 360-degree maps of the Sun and the inner heliosphere routinely, and(3) resolve the solar wind structures at multiple scales and multiple longitudes. With these capabilities, the Solar Ring mission aims to address the origin of solar cycle, the origin of solar eruptions, the origin of solar wind structures and the origin of severe space weather events. The successful accomplishment of the mission will advance our understanding of the star and the space environment that hold our life and enhance our capability of expanding the next new territory of human.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40390150, 40504021, 10575018, 40536030, 10603008 and 10778613)the National Basic Research Program of China (Grant No. 2006CB806300)+1 种基金as well as the Chinese Academy of Sciences Project (Grant No. KJCX2-YW-T04)the China Double Star-Cluster Science Team
文摘Magnetic reconnection is a main process converting the magnetic energy into thermal and kinetic energy in plasmas. It is one of the fundamental problems of crucial importance not only to space plasmas physics and space weather studies,such as the solar flare,coronal mass ejections and magnetospheric substorms,but also to the stability analysis in magnetically confined fusion. In general,except for cases with periodical boundary conditions,three-dimensional(3D) magnetic re-connection occurs on magnetic separatrices generated by magnetic nulls. Here we briefly introduce/review the theories and some recent satellite observations of 3D magnetic reconnection. Topics to be further studied are also discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.11221063,11373004,11322329,41404150,and 11303049)Ministry of Science and Technology(Grant No.2011CB811403)
文摘round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ARs are clustered, creating a favorable magnetic environment for the onset of coronal mass ejections(CMEs). In this work, we describe a new type of magnetic complex: cluster of solar ARs. An AR cluster is referred to as the close connection of two or more ARs which are located in nearly the same latitude and a narrow span of longitude. We illustrate three examples of AR clusters, each of which has two ARs connected and formed a common dome of magnetic flux system. They are clusters of NOAA(i.e., National Oceanic and Atmospheric Administration) ARs 11226 & 11227, 11429 & 11430, and 11525 & 11524. In these AR clusters, CME initiations were often tied to the instability of the magnetic structures connecting two partner ARs, in the form of inter-connecting loops and/or channeling filaments between the two ARs. We show the evidence that, at least, some of the flare/CMEs in an AR cluster are not a phenomenon of a single AR, but the result of magnetic interaction in the whole AR cluster. The observations shed new light on understanding the mechanism(s) of solar activity. Instead of the simple bipolar topology as suggested by the so-called standard flare model, a multi-bipolar magnetic topology is more common to host the violent solar activity in solar atmosphere.
基金supported by the National Basic Research Program of China (Grant Nos. 2011CB811402 and 2011CB811403)National Natural Science Foundation of China (Grant Nos. 11221063, 40890161 and 11173062)
文摘"Solar storm" has been commonly accepted by academic community and the public as a very popular scientific term. It is avivid description of violent ejections of a huge amount of magnetized plasma from the Sun as strong flare/CMEs, which sweepover into interplanetary space, develop, and affect our space environment. The solar storm could bring us disastrous spaceweather, destroy crucial technology, and cause a large-scale blackout. It is one of the natural disasters faced by modern humanbeings. Here we first briefly summarize the observational features of solar storms and introduce some key issues, and then wefocus on major advances in observational studies. We mainly introduce the efforts made by the Chinese scientists and comment on the challenges and opportunities that they are facing. In this era when scientific breakthroughs in solar storm studiescrucially depend on space-borne devices and large-aperture ground-based telescopes, the Chinese solar research communityneeds to develop its own major observational facilities and improve space weather forecasting abilities.
文摘为评估中国农业大学培育的非转基因抗除草剂玉米品系958R和335R在大田条件下对乙酰乳酸合成酶(acetolactate synthase,ALS)抑制剂类除草剂的抗性表现,利用甲咪唑烟酸、砜嘧磺隆、唑嘧磺草胺3种除草剂对郑单958、958R、先玉335、335R共4种玉米杂交种进行了播后苗前土壤处理,每种除草剂设3个处理剂量(1、3、9倍推荐剂量),并于施药2周和4周后进行株高测定,于收获晾干后测产。结果表明,在甲咪唑烟酸216、648 g (a.i.)/hm^2处理下,郑单958和先玉335均已绝产,而958R和335R产量均未受影响;在砜嘧磺隆或唑嘧磺草胺高剂量处理下,常规玉米品种郑单958和先玉335株高的最高降幅分别为25.7%和35.2%,田间药害反应显著,而958R和335R则抗性反应显著。研究表明,非转基因抗除草剂玉米杂交种具有良好的田间抗性,不仅能有效解决玉米田砜嘧磺隆和唑嘧磺草胺等ALS除草剂的药害问题,还能够通过引入甲咪唑烟酸等新的ALS除草剂更好地防除玉米田的杂草。
