An Introduction to Geotechnical Engineering     

M.E. Popescu 《Engineering Geology》1986,22(4):377

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Unusual Emissions at Various Energies Prior to the Impulsive Phase of the Large Solar Flare and Coronal Mass Ejection of 4 November 2003     

Pierre Kaufmann  Gordon D. Holman  Yang Su  C. Guillermo Gimenez de?Castro  Emilia Correia  Luis O. T. Fernandes  Rodney V. de Souza  Adolfo Marun  Pablo Pereyra 《Solar physics》2012,279(2):465-475

The GOES X28 flare of 4 November 2003 was the largest ever recorded in its class. It produced the first evidence for two spectrally separated emission components, one at microwaves and the other in the THz range of frequencies. We analyzed the pre-flare phase of this large flare, twenty?minutes before the onset of the major impulsive burst. This period is characterized by unusual activity in X-rays, sub-THz frequencies, H??, and microwaves. The CME onset occurred before the onset of the large burst by about 6?min. It was preceded by pulsations of 3??C?5?s periods at sub-THz frequencies together with X-ray and microwave enhancements. The sub-THz pulsations faded out as impulsive bursts were detected at 100??C?300?keV and 7?GHz, close to the time of the first H?? brightening and the CME onset. The activities detected prior to and at the CME onset were located nearly 2?arcmin south of the following large flare, suggesting they were separate events. This unusual activity brings new clues to understanding the complex energy buildup mechanisms prior to the CME onset, occurring at a distinct location and well before the major flare that exploded afterwards.  相似文献   

New <Superscript>40</Superscript>Ar/<Superscript>39</Superscript>Ar laser single-grain ages of muscovites from mylonitic schists in the Rodna Mountains,Eastern Carpathians,Romania: correlations with microstructure   总被引：2，自引：0，他引：2  

Nicholas Culshaw  Emilia Mosonyi  Peter Reynolds 《International Journal of Earth Sciences》2012,101(1):291-306

The Rodna Mountains afford the most internal structural window into the crystalline units of the Eastern Carpathians in Romania. The Rodna Mountains consist of Variscan metamorphic nappes that were restacked in the Alpine phase of Carpathian development forming the Subbucovinian and Infrabucovinian nappes. In order to evaluate age of deformation, ten samples were taken from the zone of greenschist facies mylonitic schist that marks the Alpine tectonic boundary between the Subbucovinian and Infrabucovinian nappes and ⁴⁰Ar/³⁹Ar laser single-grain ages determined for schistosity-forming muscovite. Microstructural assessment of quartz and muscovite distinguished two deformation events. Single-grain ages from the microstructurally most strongly reworked samples (four samples) give a tight clustering of ages at ca. 95 Ma. The least reworked schists have a broader clustering of ages spanning ca. 200–280 Ma with a late Permian peak and some samples showing outlier ages in the range 200–100 Ma. The relative development of the outliers, which correlates with evidence for increased microstructural reworking, is interpreted to mark progressive isotopic resetting. The ca. 95 Ma ages for the most reworked schists are estimates for the age of the Alpine nappe stacking. The ca. 200–280 Ma ages are similar to those of magmatism, metamorphism, and sedimentation thought to mark post-Variscan-pre-Alpine rifting and ocean basin formation in parts of the Alps and may be the thermal imprint of a related event in the Eastern Carpathians.  相似文献