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21.
Arzu Çöltekin Rebecca Francelet Kai-Florian Richter John Thoresen Sara Irina Fabrikant 《制图学和地理信息科学》2018,45(4):339-353
We report on how visual realism might influence map-based route learning performance in a controlled laboratory experiment with 104 male participants in a competitive context. Using animations of a dot moving through routes of interest, we find that participants recall the routes more accurately with abstract road maps than with more realistic satellite maps. We also find that, irrespective of visual realism, participants with higher spatial abilities (high-spatial participants) are more accurate in memorizing map-based routes than participants with lower spatial abilities (low-spatial participants). On the other hand, added visual realism limits high-spatial participants in their route recall speed, while it seems not to influence the recall speed of low-spatial participants. Competition affects participants’ overall confidence positively, but does not affect their route recall performance neither in terms of accuracy nor speed. With this study, we provide further empirical evidence demonstrating that it is important to choose the appropriate map type considering task characteristics and spatial abilities. While satellite maps might be perceived as more fun to use, or visually more attractive than road maps, they also require more cognitive resources for many map-based tasks, which is true even for high-spatial users. 相似文献
22.
Natural Hazards - Up-to-date information about an emergency is crucial for effective disaster management. However, severe restrictions impede the creation of spatiotemporal information by current... 相似文献
23.
G. A. Richter 《Astronomische Nachrichten》1986,307(4):221-230
After a survey of the latest state of knowledge on cataclysmic variables in general (Chapter 1) and recurrent novae in particular (Chapter 2), the amplitude-cycle length relationship (A-C relation) is rederived (Chapter 3) after statistical correction for published incorrect values of C. While the A-C relationship of dwarf novae is of the form A = -0.40 + 2.50 log C, it is, presumably for physical reasons less sharply defined for the few known recurrent novae. 相似文献
24.
W. R. Dick H. Lorenz P. Notni E. Schilbach R.-D. Scholz G. A. Richter 《Astronomische Nachrichten》1986,307(2):85-88
We have determined the positions of 65 compact extragalactic objects with magnitudes between 16m and 21m.7. The mean error of one position is about 0″.3 in α cos δ and in δ. Some hitherto unpublished redshifts are also listed. 相似文献
25.
Bernd R. Schöne 《Geo-Marine Letters》2008,28(5-6):269-285
Physiology corrupts geochemical records of mollusk shells in many ways, e.g., by actively controlling the incorporation of trace elements in the skeleton. However, the effects of variable biomineralization rates and growth cessation have largely remained unconsidered. Mediated by endogenous timekeeping mechanisms, mollusks stop growing skeletal material on a regular basis ranging from ultradian to annual timescales. During growth cessation, the shells do not record environmental conditions. Shell growth also stops when environmental conditions are beyond the physiological tolerance of the organism, e.g., above and below genetically determined, species-specific thermal extremes where shell growth slows and eventually ceases. Such growth disruptions can occur at non-periodic time intervals. Due to growth retardations and halts, proxy records of mollusk shells are thus incomplete, and reconstructed environmental amplitudes prone to truncation. Furthermore, environmental records are biased toward the physiological optimum of the animal. Favorable environmental conditions increase shell growth, whereas adverse environmental conditions result in reduced shell production and lowered overall metabolism. Not least, the duration of the growing season and overall growth rate decrease as the mollusk grows older. Mathematical modeling approaches can significantly improve proxy records obtained from mollusk shells. For example, if the duration of growth cessation is known, it may be possible to model the missing environmental record. It is also fairly easy to account for age-related growth trends, or variable time-averaging in different portions of the shell. However, a major premise for a reliable interpretation of proxy records from a mollusk shell or other organisms secreting biogenic hard parts is a proper understanding of the physiology, and of course, a high-resolution record of the many different environmental factors that may influence physiology and shell growth. The present paper reviews examples from the literature, and unpublished data on how physiology influences geochemical proxy records from mollusk shells, and presents methods how to eliminate such adverse effects. 相似文献
26.
G. A. Richter P. Notni F. Brngen V. Afanasjev I. D. Karachentsev A. Kopylov 《Astronomische Nachrichten》1981,302(5):211-218
With the aid of silt spectrograms gained at the 6 meter telescope Selenchukskaja and at the 2 meter telescope Tautenburg a brightness outburst (the only one so far observed) could be followed up spectroscopically. The spectral behaviour resembles SS Cygni, but the presence of CIII and NIII emission is not typical of dwarf novae. Possibly the object is related to the anomalous recurrent nova WZ Sge. The definite determination of its belonging to a known subclass of cataclysmic variables will be possible only after obtainment of extensive photometric material. 相似文献
27.
F. Brngen V. E. Karachentseva R. Schmidt G. M. Richter W. Thnert 《Astronomische Nachrichten》1982,303(5):287-292
We present a list of 39 dwarf galaxies of the M 81/82 group. Three different methods are applied to determine their apparent integral magnitude: digital processing, equidensitometry, and calculation according to the formulae of FISHER and TULLY . The plates used were obtained with the Tautenburg Schmidt telescope. For a distance of the group of 3.5 Mpc the absolute magnitudes of the dwarf galaxies investigated are -15m < M < -9m. 相似文献
28.
Organic matter in eolian dusts over the Atlantic Ocean 总被引:1,自引:0,他引:1
Bernd R.T Simoneit 《Marine Chemistry》1977,5(4-6)
The elemental and mineralogical composition and the microfossil and detritus content of particulate fallout from the lower troposphere over the Atlantic Ocean have been extensively documented in earlier work, and it was possible to ascribe terrigenous source areas to such fallout. A brief review of the organic geochemistry of eolian dust is also presented here. The lipids of eolian dusts sampled from the air mass over the eastern Atlantic from about 35°N to 30°S were analyzed here.These lipids consisted mainly of normal alkanes, carboxylic acids and alcohols. The n-alkanes were found to range from n-C23 to n-C35, with high CPI values and maximizing at n-C27 in the North Atlantic, at n-C29 in the equatorial Atlantic and at n-C31 in the South Atlantic. The n-fatty acids had mostly bimodal distributions, ranging from n-C12 to n-C30 (high CPI), with maxima at n-C16 and in the northern samples at n-C24 and in the southern samples at n-C26. The n-alcohols ranged from n-C12 to n-C32, with high CPI values and maxima mainly at n-C28. The compositions of these lipids indicated that their terrigenous sources were comprised mainly of higher plant vegetation and desiccated lacustrine mud flats on the African continent. 相似文献
29.
Thomas Kenkmann Alex Deutsch Klaus Thoma Matthias Ebert Michael H. Poelchau Elmar Buhl Eva-Regine Carl Andreas N. Danilewsky Georg Dresen Anja Dufresne Nathanaël Durr Lars Ehm Christian Grosse Max Gulde Nicole Güldemeister Christopher Hamann Lutz Hecht Stefan Hiermaier Tobias Hoerth Astrid Kowitz Falko Langenhorst Bernd Lexow Hanns-Peter Liermann Robert Luther Ulrich Mansfeld Dorothee Moser Manuel Raith Wolf Uwe Reimold Martin Sauer Frank Schäfer Ralf Thomas Schmitt Frank Sommer Jakob Wilk Rebecca Winkler Kai Wünnemann 《Meteoritics & planetary science》2018,53(8):1543-1568
This paper reviews major findings of the Multidisciplinary Experimental and Modeling Impact Crater Research Network (MEMIN). MEMIN is a consortium, funded from 2009 till 2017 by the German Research Foundation, and is aimed at investigating impact cratering processes by experimental and modeling approaches. The vision of this network has been to comprehensively quantify impact processes by conducting a strictly controlled experimental campaign at the laboratory scale, together with a multidisciplinary analytical approach. Central to MEMIN has been the use of powerful two-stage light-gas accelerators capable of producing impact craters in the decimeter size range in solid rocks that allowed detailed spatial analyses of petrophysical, structural, and geochemical changes in target rocks and ejecta. In addition, explosive setups, membrane-driven diamond anvil cells, as well as laser irradiation and split Hopkinson pressure bar technologies have been used to study the response of minerals and rocks to shock and dynamic loading as well as high-temperature conditions. We used Seeberger sandstone, Taunus quartzite, Carrara marble, and Weibern tuff as major target rock types. In concert with the experiments we conducted mesoscale numerical simulations of shock wave propagation in heterogeneous rocks resolving the complex response of grains and pores to compressive, shear, and tensile loading and macroscale modeling of crater formation and fracturing. Major results comprise (1) projectile–target interaction, (2) various aspects of shock metamorphism with special focus on low shock pressures and effects of target porosity and water saturation, (3) crater morphologies and cratering efficiencies in various nonporous and porous lithologies, (4) in situ target damage, (5) ejecta dynamics, and (6) geophysical survey of experimental craters. 相似文献