Stability of prominences exposing helical-like patterns     

B. Vršnak  V. Ruždjak  B. Rompolt 《Solar physics》1991,136(1):151-167

The internal structure of prominences appearing as twisted tubes was studied. The sample embraced 15 stable and 13 eruptive prominences, exposing patterns which possibly reflect a helical configuration. The equivalent pitch angles () of twisted fine structure features were measured. In some cases the evolution of the internal structure was followed and 49 independent measurements of the parameter were performed in total. The results are presented in the plane relating the parameter and the normalized prominence height. The eruptive prominences occupy the region characterized by > 50° and h > 0.8d, where h and d are the prominence height and the footpoint half-separation, respectively. All prominences characterized by h < 0.6d or by < 35° were stable. Such a result is in good agreement with an order of magnitude treatment of the forces acting in a curved magnetic tube, anchored at both ends in the photosphere.  相似文献   

Spotless flares and the associated radio continuum emission     

V. Ruždjak  M. Messerotti  M. Nonino  A. Schroll  B. Vršnak  P. Zlobec 《Solar physics》1987,111(1):103-111

We studied 24 spotless flares of Ha importance 1 which occurred during the 21st cycle of solar activity. The spotless flares could be grouped in three categories according to their location and time history of the associated active region. Our association of the flares with radio events was based on relative timing and on the flare importances. Weak microwave gradual rise and fall events were frequently recorded during the occurrence of the spotless flares. A few flares from our sample could be associated with impulsive and complex microwave bursts. Only in one case an association of a spotless flare with a significant metric type II/IV event seems to be justified.Proceedings of the Second CESRA Workshop on Particle Acceleration and Trapping in Solar Flares, held at Aubigny-sur-Nère (France), 23–26 June, 1986.  相似文献   

Engineering Geological Properties of Building Stones from the North-Eastern Part of the Vienna Basin in the Western Carpathians     

Bednarik  Martin  Holzer  Rudolf  Pivko  Daniel  Tornyai  Rudolf  Hornáčková  Alžbeta 《Geotechnical and Geological Engineering》2022,40(6):3287-3305

Geotechnical and Geological Engineering - This research focuses on assessing the most important physical and mechanical properties of rocks that were quarried from the north-eastern part of the...  相似文献   

Population structure and conservation status of the red gorgonian Paramuricea clavata (Risso, 1826) in the Eastern Adriatic Sea          下载免费PDF全文

Silvija Kipson  Cristina Linares  Hrvoje Čižmek  Emma Cebrián  Enric Ballesteros  Tatjana Bakran‐Petricioli  Joaquim Garrabou 《Marine Ecology》2015,36(4):982-993

Gorgonians are important structuring species of the Mediterranean hard‐bottom communities that are threatened by disturbances such as increasing seawater temperature, mucilaginous events and destructive fishing, among others. In this study we assessed for the first time the population structure and conservation status of one of the most common gorgonians in the Eastern Adriatic Sea, the red gorgonian Paramuricea clavata. During late spring 2009, nine populations dwelling between 30 and 50 m depth were examined by SCUBA diving along 200 km of the Croatian coastline. The density ranged between 7 and 20 colonies·m^?2. The mean and maximum colony heights were 31.2 ± 22.7 cm (±SD) and 138 cm, respectively. Two main patterns of P. clavata size frequency distributions were observed: the first one with a higher proportion of juveniles (~30%) observed mostly in the northernmost populations, and the second one with a higher proportion of larger colonies (>25% of colonies >40 cm in height). Regarding the disturbance impact level, the proportion of healthy colonies (with <10% of injured surface) was high in almost all of the studied populations (>60%) and the mean extent of injury (i.e. denuded axis or epibiosis) was 9.7 ± 4% (±SD), indicating low impacts. Contrasting population size structures with high recruitment in mature populations provides new insights into the demographic structure of the Mediterranean gorgonian forests dwelling in their upper bathymetric range (<50 m depth). Furthermore, these size structures and the low impact levels suggest a current favorable conservation status of the studied populations in the Eastern Adriatic Sea and provide a baseline for their monitoring in the future.  相似文献   

Distribution of some elements in surface soil over the Kavadarci region,Republic of Macedonia   总被引：2，自引：0，他引：2  

Trajče Stafilov  Robert Šajn  Blažo Boev  Julijana Cvetković  Duško Mukaetov  Marjan Andreevski  Sonja Lepitkova 《Environmental Earth Sciences》2010,61(7):1515-1530

The results of a first systematic study of spatial distribution of different elements in surface soil over of the Kavadarci region, Republic of Macedonia, known for its nickel industrial activity are reported. The investigated region (360 km²) is covered by a sampling grid of 2 × 2 km²; whereas the sampling grid of 1 × 1 km² was applied in the urban zone and around the ferronickel smelter plant (117 km²). In total 344 soil samples from 172 locations were collected. At each sampling point soil samples were collected at two depths, topsoil (0–5 cm) and bottom soil (20–30 cm). Inductively coupled plasma-mass spectrometry (ICP-MS) was applied for the determination of 36 elements (Ag, Al, As, Au, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mn, Na, Mg, Mo, Ni, P, Pb, S, Sb, Sc, Se, Sr, Th, Tl, Ti, U, V, W and Zn). Data analysis and construction of maps were performed using the Paradox (ver. 9), Statistica (ver. 6.1), AutoDesk Map (ver. 2008) and Surfer (ver. 8.09) software. Four geogenic and three anthropogenic geochemical associations were established. Within the research, natural and anthropogenic enrichment with heavy metals was determined. Principally, the natural enrichment is related especially to Ni. Pollution by As, Cd, Co, Cr, Cu, Hg, Mo, Pb and Zn is basically insignificant.  相似文献   

Erratum to “Mineral waters in Slovakia — Evaluation of chemical composition stability using both historical records and the most recent data” [J. Geochem. Explor. 107 (2010) 382–390]     

Dušan Bodiš  Jozef Kordik  Igor Slaninka  Peter Malík  Pavel Liščák  Daniel Panák  Jarmila Božíková  Daniel Marcin 《Journal of Geochemical Exploration》2011,108(3):233

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Attenuation of Peak Horizontal and Vertical Acceleration in the Dinarides Area     

Herak  Marijan  Markušić  Snježana  Ivančić  Ines 《Studia Geophysica et Geodaetica》2001,45(4):383-394

Peak acceleration attenuation relations for horizontal and vertical components are presented for the Dinarides region, based on 145 3-component accelerograms related to 46 earthquakes with local magnitudes of 4.5 or greater and with epicentral distances of less than 200 km as recorded on 39 recording sites in the greater Dinarides region. The attenuation functions were obtained by two-stage stratified regression on the local magnitude and epicentral distance as independent variables. The predicted peak acceleration values within the distance range covered by the data are comparable to the ones obtained for stiff-soil or rock sites when selected reference relations are used. The rather large average residuals are caused mostly by the lack of information on local site conditions and by the use of epicentral distance instead of fault distance.  相似文献   

Sur l'importance de la diffusion élevée pendant le crépuscule     

František Link  Luděk Neužil  Igor Zacharov 《Studia Geophysica et Geodaetica》1964,8(3):274-286

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Daily variations of the characteristics of beating-typePc3 (Bpc3) pulsations     

Jaroslav Střeštík  Karel Prikner  Karel Dobeš  Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1973,17(1):27-35

Summary The spectra of nearly 100 samples of Bpc3 pulsations were computed in the X and Y components of data from the Budkov Observatory. These spectra were used to study the daily variations of the fundamental characteristics of the pulsations, the frequency f ₀ and amplitude A ₀ of the main spectral peaks. The daily variation of the ellipticity of the polarization ellipses of oscillations in frequency f ₀ was also studied in the XY-plane.Part of these results was reported at the XVth General Assembly of the IUGG, Moscow, August 1971.  相似文献   

The telluric field in a halfspace with a spherical inhomogeneity     

Milan Hvoždara  Reviewer V. Petr 《Studia Geophysica et Geodaetica》1973,17(2):131-143

Summary An exact solution of the distribution of the intensity of the telluric field in a halfspace with a spherical inhomogeneity has been obtained by solving the Laplace equation in bipolar coordinates. This exact solution is compared with the presently known approximate solution, obtained by the method of images, and the region of their coincidence has been determined. For the image solution theoretical relations have been derived for computing the anomaly of the magnetic field. Craphs depict many of the properties of the telluric and magnetic fields on the surface of the considered halfspace for various parameters of the given problem.Dedicated to 90th Birthday of Professor Frantiek Fiala  相似文献