scholarly journals Transient Formation of C2 and CN in the Near-maximum Phase of Nova Cas 2020(=V1391 Cas)

2021 ◽  
Vol 907 (2) ◽  
pp. 70
Author(s):  
M. Fujii ◽  
A. Arai ◽  
H. Kawakita
Keyword(s):  
Author(s):  
Gundula F Starkulla ◽  
Elisabeth Kapatsina ◽  
Angelika Baro ◽  
Frank Giesselmann ◽  
Stefan Tussetschläger ◽  
...  

Based on 5-(4-hydroxyphenyl)-2-octylpyrimidine 8, 5-phenylpyrimidine derivatives 3–7, 9 with different spacer chain lengths (C2 up to C6) and different terminal polar groups (Br, Cl, N3, OH, CN) were synthesized by etherification and nucleophilic substitution. The mesomorphic behaviour of these compounds was investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (WAXS and SAXS) and revealed smectic A mesophases for bromides, chlorides and azides 3, 4 and 6. For these compounds a maximum phase width was observed for the C5 spacer regardless of the terminal group, whereas the hydroxy- and cyano-substituted derivatives 5 and 7, respectively, were non mesomorphic and showed only melting transitions.


2018 ◽  
Vol 616 ◽  
pp. A177 ◽  
Author(s):  
Hisashi Hayakawa ◽  
Yusuke Ebihara ◽  
José M. Vaquero ◽  
Kentaro Hattori ◽  
Víctor M. S. Carrasco ◽  
...  

Aims. Historical records provide evidence of extreme magnetic storms with equatorward auroral extensions before the epoch of systematic magnetic observations. One significant magnetic storm occurred on February 15, 1730. We scale this magnetic storm with auroral extension and contextualise it based on contemporary solar activity. Methods. We examined historical records in East Asia and computed the magnetic latitude (MLAT) of observational sites to scale magnetic storms. We also compared them with auroral records in Southern Europe. We examined contemporary sunspot observations to reconstruct detailed solar activity between 1729 and 1731. Results. We show 29 auroral records in East Asian historical documents and 37 sunspot observations. Conclusions. These records show that the auroral displays were visible at least down to 25.8° MLAT throughout East Asia. In comparison with contemporary European records, we show that the boundary of the auroral display closest to the equator surpassed 45.1° MLAT and possibly came down to 31.5° MLAT in its maximum phase, with considerable brightness. Contemporary sunspot records show an active phase in the first half of 1730 during the declining phase of the solar cycle. This magnetic storm was at least as intense as the magnetic storm in 1989, but less intense than the Carrington event.


2020 ◽  
pp. 12-16
Author(s):  
Yu. Klechkovskyi ◽  
K. Shmatkovska

Goal. To determine the species composition, dominant species, and territorial distribution of predatory and herbivorous ticks (phytophages) in the vineyards of southern Ukraine. Methods. Field — route surveys of vineyards to study the fauna, trophic links and colonization of vineyards with ticks. Laboratory — determination of the species composition of representatives of the acarofauna of vineyards. Results. During the study period, 17 species of ticks belonging to different trophic groups were identified, among which ticks dominate — phytophages of the Tetranychidae and Eriophyidae families. The most common among them were mites — phytophages, namely spider mites (Shhizotetranychus Oud., Tetranychus turkestanicus Ug.et Nich). Pests during the growing season go through four phases: prodromal, eruptive, gradation maximum and crisis. The graduation maximum phase, which is characterized by their greatest number, was noted during the period of intensive growth of berries and falls at the end of June — beginning of August (BBCH 71—79). The dynamics of the number of ticks by varieties is shown. The varieties most susceptible to spider mites were identified, the period of technical ripeness of which is medium, late or very late. Conclusions. Identified 17 species of ticks belonging to different trophic groups: phytophages, acariphages and mycophages. Based on observations of changes in the number of pests on vineyards during the growing season, four phases are distinguished. The graduation maximum phase occurs at the end of June — beginning of August (VVSN 71—79). It was established that all the studied grape varieties were populated by mites to varying degrees, the most susceptible were varieties of medium and late ripening.


2021 ◽  
Vol 60 (10) ◽  
pp. B106
Author(s):  
Ju-Yi Lee ◽  
Chia-Yu Chiang ◽  
Wei-Yi Sung ◽  
Tzu-Yang Weng ◽  
Jing-Heng Chen ◽  
...  

2008 ◽  
Vol 26 (11) ◽  
pp. 3279-3293 ◽  
Author(s):  
A. Kullen ◽  
S. Buchert ◽  
T. Karlsson ◽  
T. Johansson ◽  
S. Lileo ◽  
...  

Abstract. The role of intense high-altitude electric field (E-field) peaks for large-scale plasma convection is investigated with the help of Cluster E-field, B-field and density data. The study covers 32 E-field events between 4 and 7 RE geocentric distance, with E-field magnitudes in the range 500–1000 mV/m when mapped to ionospheric altitude. We focus on E-field structures above the ionosphere that are typically coupled to discrete auroral arcs and their return current region. Connected to such E-field peaks are rapid plasma flows directed along the discrete arcs in opposite directions on each side of the arc. Nearly all the E-field events occur during active times. A strong dependence on different substorm phases is found: a majority of intense E-field events appearing during substorm expansion or maximum phase are located on the nightside oval, while most recovery events occur on the dusk-to-dayside part of the oval. For most expansion and maximum phase cases, the average background plasma flow is in the sunward direction. For a majority of recovery events, the flow is in the anti-sunward direction. The net plasma flux connected to a strong E-field peak is in two thirds of the cases in the same direction as the background plasma flow. However, in only one third of the cases the strong flux caused by an E-field peak makes an important contribution to the plasma transport within the boundary plasma sheet. For a majority of events, the area covered by rapid plasma flows above discrete arcs is too small to have an effect on the global convection. This questions the role of discrete auroral arcs as major driver of plasma convection.


1950 ◽  
Vol 3 (2) ◽  
pp. 265 ◽  
Author(s):  
SF Smerd

The equation of transfer of radiation and the magneto-ionic theory are used to derive expressions for the degree of polarization of thermal " solar noise " due to a general magnetic field of the sun. In particular, the net polarization of 600 Mc/s. (50 cm.) radiation corresponding to the maximum phase of the eclipse of November 1, 1948, as seen from Melbourne, Victoria, is evaluated theoretically and compared with observational evidence. This leads to an upper limit of 11 gauss for the surface field- strength at the solar poles at the time of observation.


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