排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
We report on the occurrence of Hα dimming associated with a sigmoid eruption in a quiet-sun region on 14 August 2001. The
coronal sigmoid in soft X-ray images from the Yohkoh Soft X-ray Telescope was located over an Hα filament channel. Its eruption was accompanied by a flare of GOES X-ray class
C2.3 and possibly associated with a halo coronal mass ejection (CME) observed with the Large Angle and Spectroscopic Coronagraphs (LASCO) on board the Solar and Heliospheric Observatory (SOHO). During the eruption, coronal bipolar double dimming took place at the regions with opposite magnetic polarities around
the two sigmoid ends, but the underlying chromospheric channel did not show observable changes corresponding to the coronal
eruption. Different from the erupting coronal sigmoid itself, however, the coronal dimming had a detectable chromosphere counterpart,
i.e., Hα dimming. By regarding the sigmoid as a coronal sign for a flux rope, these observations are explained in the framework
of the flux rope model of CMEs. The flux rope is possibly deeply rooted in the chromosphere, and the coronal and Hα dimming
regions mark its evacuated feet, through which the material is possibly fed to the halo CME. 相似文献
2.
本研究根据从云南省高黎贡山(保山市段)洞穴采集的伪蝎标本,整理并描述了阿伪蝎科安伪蝎属一新种,即禾木安伪蝎(Anatemnus hemuensis sp. nov.)。该属的主要特征在于触肢粗壮,腿节和膝节多具明显颗粒,不动指上的听毛it位于指的中部,听毛esb到est之间的距离大于isb到ist之间的距离,背板不完全分隔。世界已知22种(不包含本文新种),主要分布于非洲和美洲,中国仅知3种:任氏安伪蝎(A. reni Gao & Zhang, 2016)、宝安伪蝎(A. orites (Thorell, 1889))、潮州安伪蝎(A. chaozhouensis Hu & Zhang, 2012)。该新种背甲的眼部已经完全退化,依据该特征,很容易区分,除分布于澳大利亚的2个物种(A. subvastus Alexander, Burger & Harvey 2014,采集自地下环境;A. cavernicola Berier, 1976,采集自Jump Up Cave),然后依据步足I和步足IV跗节端部具有极其弯曲的刚毛将新种与这两种进行区分。新种触肢转节具有1个明显的背突,1.7倍长于宽(0.47/0.28 mm),腿节2.8倍长于宽(0.90/0.32 mm),膝节2.2倍长于宽(0.82/0.37 mm),螯肢指明显短于具柄的螯掌;前螯螯掌具有4根刚毛,基部2根末端齿状,盔状物具有5个分叉,鞭状毛4根,末端2根齿状;口下突有5根顶端毛和1根亚中毛。在文中提供了新种的整体图以及特征图,另外还提供了中国安伪蝎属的分种检索表,所检视的标本保存于西华师范大学生命科学学院昆虫标本馆。 相似文献
3.
1 IntroductionItisnowwellacceptedthemagneticfieldinfilamentisnearlyhorizontalandthecomponentofthefieldalongthefilamentaxisisdominant (D啨moulin ,1 997) .Whenafilamentispresentinactiveregion ,thephotospherictransversefieldbeneathfilamentmostlyliealongthepolar… 相似文献
4.
The pollution of soil and groundwater by halogenated organic compounds (HOCs) is more and more severe. HOCs are of strong toxicity and difficult to be biodegraded. Due to its unique advantages, nanoscale zerovalent iron (NZVI) has become a hot research topic in the field of in situ remediation around the world. In this paper, basic reaction theories and kinetics of HOCs degradation by NZVI are briefly summarized. The influence factors on the in situ remediation of HOCs by NZVI are comprehensively discussed. The influence factors include the intrinsic properties of NZVI due to its different preparation and modification methods, and environment factors, such as pH, dissolved oxygen, ionic species, metals, nonreactive hydrophobic and natural organic compounds, concentrations and components of HOCs, microorganisms and subsurface heterogeneity. The effects of all these factors on NZVI stability, deliverability, targeting ability, and reactivity during in situ remediation are emphasized. Finally, the practical application of this technology are summarized and prospected. 相似文献
5.
Jiayan Yang Yunchun Jiang Bo Yang Junchao Hong Dan Yang Yi Bi Ruisheng Zheng Haidong Li 《New Astronomy》2012,17(8):732-738
By means of Hα, EUV, soft X-ray, hard X-ray, and photospheric magnetic field observations, we report the surge-like eruption of a small-scale filament, called “blowout surge” according to recent observations, occurring on a plage region around AR 10876 on 1 May 2006. Along magnetic polarity reversal boundaries with obvious magnetic cancelations, the filament was located underneath a compact coronal arcade and close to one end of large coronal loops around the AR’s periphery. The filament started to erupt about 8 min before the main impulsive phase of a small two-ribbon flare, which had two Hα blue-wing kernels connected by hard X-ray loop-top sources on the both sides of the filament. After the flare end, the filament further underwent a distant eruption following a path nearly along the preexisting large loops, and thus looked like an Hα surge and an EUV jet. During the eruption, a small coronal dimming was formed near the flare, while weak brightenings appeared around the remote end of the large loops. We interpret these joint observations as the filament eruption being confined and guided by the large loops. The filament eruption, initially embedded in one footpoint region of the large loops, can break away from the magnetic restraint of the overlying compact arcade, but might be still limited inside the large loops. As a result, the eruption took a surge form that can only expand laterally along the large loops rather than erupt radially. 相似文献
6.
Using data from the Transition Region and Coronal Explorer (TRACE), Solar and Heliospheric Observatory (SOHO), Ramaty High Energy Solar Spectroscopic Imager (RHESSI), and Hida Observatory (HO), we present a detailed study of an EUV jet and the associated Hα filament eruption in
a major flare in the active region NOAA 10044 on 29 July 2002. In the Hα line wings, a small filament was found to erupt out
from the magnetic neutral line of the active region during the flare. Two bright EUV loops were observed rising and expanding
with the filament eruption, and both hot and cool EUV plasma ejections were observed to form the EUV jet. The two thermal
components spatially separated from each other and lasted for about 25 minutes. In the white-light corona data, a narrow coronal
mass ejection (CME) was found to respond to this EUV jet. We cannot find obvious emerging flux in the photosphere accounting
for the filament eruption and the EUV jet. However, significant sunspot decay and magnetic-flux cancelation owing to collision
of opposite flux before the events were noticed. Based on the hard X-ray data from RHESSI, which showed evidence of magnetic
reconnection along the main magnetic neutral line, we think that all of the observed dynamical phenomena, including the EUV
jet, filament eruption, flare, and CME, should have a close relation to the flux cancelation in the low atmosphere. 相似文献
7.
为有效解决松辽盆地南部油气田储集层取心钻头选型困难、机械钻速低和岩心收获率不稳定等难题,在分析取心井段地质特征、XRD元素组分占比、地层可钻性的基础上,开展了取心筒和岩心爪比选、取心钻头选型和个性化取心钻头的研制,同时优选取心钻具组合和优化取心参数,完善不同储集层取心工艺技术配套。比选后的取心工具配合新型取心钻头在多口井的取心实践中,取得了平均岩心收获率>98.98%、最高机械钻速达到6.03 m/h的效果。系列取心钻头优选和配套关键技术的应用解决了目前松辽盆地南部储集层取心的技术难题,可为后续取心提供可靠的参考和技术支持。 相似文献
8.
2002年8月1日晚北京东北部密云县发生了降雨量达到280.2 mm的局地短历时特大暴雨,并引发了洪水和泥石流。卫星云图分析表明,它是由一个中-β尺度对流系统在北京北部山区停留造成的。TBB图的等值线密集区和上冲云顶对暴雨落区有指示意义。大尺度环流诊断表明,暴雨前一天存在较深厚的下沉运动,其伴随的逆温层抑制对流的发生,使不稳定能量得以积累。各种稳定参数的计算结果证实了这一能量的积累过程。暴雨当天,下沉运动转为微弱的上升运动,使对流的发生成为可能。大尺度水汽场的诊断表明,北京处在西太平洋副热带高压边缘的高温高湿气流的控制下,有很强的水汽输送。地面中尺度分析表明,中尺度低压和辐合线是对流的触发系统,北京地区北部处于中尺度低压东部暖湿气流的辐合区中,在有利的地形条件下使密云县西部山区产生了局地特大暴雨。 相似文献
9.
????????????????е????????????????????????????????????????????????????????????????????????????????????????????????????????????????16????????????????????ж????????????????????????????????????????????????????輼??????????????????????????????μ?? 相似文献
10.
Jingxiu Wang Yuzong Zhang Guiping Zhou Louise K. Harra David R. Williams Yunchun Jiang 《Solar physics》2007,244(1-2):75-94
We have found that solar flares in NOAA active region (AR) 10696 were often associated with large-scale trans-equatorial activities.
These trans-equatorial activities appeared to be very common and manifest themselves through i) the formation and eruption of trans-equatorial loops (TELs), ii) the formation and eruption of trans-equatorial filaments (TEFs), and iii) the trans-equatorial brightening (TEB) in the chromosphere. It is determined that the TEF was formed following episodic
plasma ejecta from flares occurring in the AR. The TEF eruption was associated with a trans-equatorial flare. All flares in
the AR that were accompanied by trans-equatorial activities were associated with halo coronal mass ejections (CMEs). It was
noticed that one or several major flares in the AR were followed by an increase of brightness and nonpotentiality of a TEL.
These coupled events had a lifetime of more than 12 hours. In addition their associated halo CMEs always had a positive acceleration,
indicating prolonged magnetic reconnections in the outer corona at high altitudes. 相似文献