Impact of Air Pollution on Genetic Material of Shallot (Allium cepa L. var. ascalonicum) Exposed at Differently Polluted Sites in Slovenia     

Erika Glasenčnik  Cvetka Ribarič-Lasnik  Karin Savinek  Meta Zaluberšek  Maria Mueller  Franc Batič 《Journal of Atmospheric Chemistry》2004,49(1-3):363-376

Test shallot plants Allium cepa L. var. ascalonicum were exposed to field conditions at six research plots in the most polluted areas in Slovenia in the vegetation seasons in 1999 and 2000. The intention of this research was to evaluate the influence of air pollution on mitotic activity and frequency of chromosomal aberrations in meristematic tissues of root tips of bioindication plants. Significant differences in the mitotic index and in frequency of chromosomal aberrations at different sampling plots in pot experiments were found and the correlation between the ozone concentration and the mitotic index was determined. The results showed the presence of cytotoxic substances at chosen sampling sites, which caused the decrease of mitotic cell division and the presence of genotoxic substances, which resulted in the increase of frequency of chromosomal aberrations.  相似文献   

Synoptic Situations and Pollutant Concentrations in Fog Water Samples from the Milešovka Mt.     

Fišák  J.  Řezáčová  D.  Weignerová  V.  Tesař  M. 《Studia Geophysica et Geodaetica》2004,48(2):469-481

This contribution presents the results of chemical analyses of the fog and/or cloud water samples, which were collected at the Mileovka Mt. during the years 2000 and 2001. The study aims mainly at proving the dependence of pollutant concentration on the direction of the atmospheric steering flow. It is evident that the highest mean pollutant concentration in fog water appeared at the steering flow from south or at the flow with an east component. The lowest pollutant concentrations were reported during the synoptic situations with considerable west component of the steering flow. Furthermore, we compare the characteristic values of pollutant concentrations from the Mileovka Mt. with similar results from other sites abroad.  相似文献   

Determination of non-linear effects of limb-darkening in eclipsing variables from observations of their light minima     

Zdeněk Kopal 《Astrophysics and Space Science》1971,12(1):147-150

The aim of the present note is to point out that observations of eclipsing variables within minima do not, in general, allow a separation of the quadratic terms of limb-darkening from the first-order effects of the gravity-darkening of distorted components undergoing eclipse. Only a difference of the two can be deduced from the observations, but — especially in close binaries — the net effect will be dominated by gravity-darkening.  相似文献   

Model for the evaluation of mean emission potential of the air pollution with SO2 in basins     

Prof. Dr. Z. Petkovšek 《Theoretical and Applied Climatology》1978,26(2-3):199-206

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Theorie der im Elastischen Halbraum Durch eine Flächenförmige Quelle Erregten Weller (3. Teil)     

Karel Pěč 《Studia Geophysica et Geodaetica》1962,6(2):152-167

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Höhenbestimmung aus Elektrooptisch Gemessenen Längen (Fortsetzung)     

Ludvík Hradilek 《Studia Geophysica et Geodaetica》1962,6(4):317-330

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Delta formation at the southern entrance of Istanbul Strait (Marmara sea, Turkey): a new interpretation based on high-resolution seismic stratigraphy     

Erkan Gökaşan  Oya Algan  Hüseyin Tur  Engin Meriç  Ahmet Türker  Mehmet Şimşek 《Geo-Marine Letters》2005,25(6):370-377

A detailed stratigraphic investigation based on high-resolution seismic profiles revealed that the delta at the southern entrance of the Istanbul Strait consists of three parasequence sets. The lowermost parasequence shows a sea-level stillstand at the beginning of the lowstand systems tract, possibly at 11,000±1,100 a b.p., whereas the upper two parasequences reflect deposition at lowstand and during the subsequent transgression. A maximum flooding surface may be developing on the delta at present. The delta is located on the eastern side of the Istanbul Strait canyon, with east–west prograding parasequences. The development of the delta is clearly associated with the Kurbağalı Stream on the east coast, and not with the Black Sea outflow through the strait. The geometry of the delta indicates a radial architecture arranged from northeast to southwest.  相似文献   

Evidence and implications of massive erosion along the Strait of İstanbul (Bosphorus)     

Erkan Gökaşan  Hüseyin Tur  Berkan Ecevitoğlu  Tolga Görüm  Ahmet Türker  Buğser Tok  Faruk Çağlak  Halim Birkan  Mehmet Şimşek 《Geo-Marine Letters》2005,25(5):324-342

The Strait of İstanbul (SoI) (Bosphorus) is a narrow valley, which has evolved tectonically from a stream, and in which thick sediment deposits have accumulated in the course of its evolution. Detailed seismic and multi-beam bathymetric data have revealed that the upper parts of the deeper channel deposits consist of parallel strata, which have mostly been eroded subsequently to their deposition. The resulting erosion surface is represented by the present channel floor in the strait, the estimated volume of the eroded material being approximately 2×10⁸ m³ . Erosion rate and seafloor morphology indicate that the flow direction was from the south to the north. This inner channel may have been formed by an abrupt flooding of the Black Sea by Mediterranean waters at the beginning of the latest connection between the Marmara and the Black seas. Subsequently, the Mediterranean bottom current of the modern two-way flow system, which was established at about 5–4 ka b.p., has given the latest shape to the strait floor.  相似文献   

Cartographic Design and Usability of Visual Variables for Linear Features   总被引：1，自引：0，他引：1  

Petr Kubíček  Zdeněk Stachoň  Zbyněk Štěrba  Jiří Apeltauer  Tomáš Urbánek 《The Cartographic journal》2017,54(1):91-102

This article addresses the measurement and assessment of response times and error rates in map-reading tasks relative to various modes of linear feature visualization. In a between-subject design study, participants completed a set of map-reading tasks generated by approaches to a traffic problem. These entailed quick and correct decoding of graphically represented quantitative and qualitative spatial information. The tasks first involved the decoding of one graphic variable, then of two variables simultaneously. While alternative representations of qualitative information included colour hue and symbol shape, the quantitative information was communicated either through symbol size or colour value. In bivariate tasks, quantitative and qualitative graphical elements were combined in a single display. Individual differences were also examined. The concept of cognitive style partially explains the variability in people’s perception and thinking, describing individual preferences in object representation and problem-solving strategies. The data obtained in the experiment suggest that alternative forms of visualization may have different impacts on performance in map-reading tasks: colour hue and size proved more efficient in communicating information than shape and colour value. Apart from this, it was shown that individual facets of cognitive style may affect task performance, depending on the type of visualization employed.  相似文献   

Estimation of the accuracy of geopotential models   总被引：1，自引：0，他引：1  

M. Burša  B. Bystrzycká  K. Raděj  V. Vatrt 《Studia Geophysica et Geodaetica》1995,39(4):365-374

Summary The new Geopotential Model Testing (GMT) method has been theoretically developed and practically applied. It is free of any hypothesis, the limiting factors are the accuracy of the geocentric position of the GMT sites and of their normal heights, as well as the accuracy of the geopotential value W₀ on the geoid used as the testing value given a-priori. The GMT procedure occurs on the physical Earth's surface, no reductions are applied. No limits as regards the magnitude of the heights above sea level of the GMT sites are required. The rms error at discrete points of the most recent geopotential model JGM-3 comes out at about ± 1·5 m.  相似文献