581 research outputs found
Absence of positive eigenvalues of magnetic Schr\"odinger operators
No full textWe study sufficient conditions for the absence of positive eigenvalues of
magnetic Schr\"odinger operators in . In our main
result we prove the absence of eigenvalues above certain threshold energy which
depends explicitly on the magnetic and electric field. A comparison with the
examples of Miller--Simon shows that our result is sharp as far as the decay of
the magnetic field is concerned. As applications, we describe several
consequences of the main result for two-dimensional Pauli and Dirac operators,
and two and three dimensional Aharonov--Bohm operators.Comment: accepted for publication in Calculus of Variations & PD
Digitale Medien als Mittler im Spannungsfeld zwischen naturwissenschaftlichem Unterricht und inklusiver Pädagogik
No full textStinken-Rösner L, Abels S. Digitale Medien als Mittler im Spannungsfeld zwischen naturwissenschaftlichem Unterricht und inklusiver Pädagogik. In: Hundertmark S, Sun X, Abels S, et al., eds. Naturwissenschaftsdidaktik und Inklusion . Beiheft zur Zeitschrift "Sonderpädagogische Förderung heute". Vol 4. 1st ed. Weinheim Basel: Beltz Juventa; 2021: 161-175
Detecting circumstellar disks around gravitational microlenses
No full textAims. We investigate the chance of detecting proto-planetary or debris disks in
stars that induce microlensing event (lenses), and consider the modification
of the light curve shapes due to occultation and extinction by the disks,
as well as the gravitational deflection caused by the additional mass.
Methods. The magnification of gravitational microlensing events is calculated using the ray shooting method. The occultation is taken into account by neglecting or weighting the images on the lens plane according to a transmission map of the corresponding disk for a point source point lens (PSPL) model. The estimated frequency of events is obtained by considering the possible inclinations and optical depths of the disk.
Results. We conclude that gravitational microlensing can be used, in principle, as a
tool for detecting debris disks beyond 1 kpc, but estimate that each year around 1 debris disk is expected for lens stars of F, G, or K spectral type and about 10 debris disks might have shown signatures in existing datasets
Inklusion und Naturwissenschaften systematisch verknüpfen
No full textStinken-Rösner L, Abels S, Hundertmark S, Menthe J, Nehring A, Rott L. Inklusion und Naturwissenschaften systematisch verknüpfen. In: Habig S, Gesellschaft für Didaktik der Chemie und Physik, eds. Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik online Jahrestagung 2020. Duisburg-Essen: Universität Duisburg-Essen; 2021: 169-172
Characterization of EM Emission during the Operation of Solid and Plasma Armature Rail Launchers
No full textWe present the results of an experimental analysis
aimed at investigating the electromagnetic (EM) emission during rail launcher operation. In order to obtain such data, an experimental
setup was assembled in a shielded semi-anechoic chamber, consisting of a pulsed power source-unit, a power coaxial cable and
a rail launcher prototype. Several experiments were performed
for different operating conditions and results were repeatable. Finally, we provide a qualitative modeling of some sources of
electromagnetic transients and we discuss basic aspects driving the EM emission phenomena in railgun systems
Making a difference in virtue epistemology
No full textHundertmark F, Kindley S. Making a difference in virtue epistemology. Synthese. 2021;199:11213–11229.Virtue Reliabilism holds that knowledge is a cognitive achievement-an epistemic success that is creditable to the cognitive abilities of the knowing subject. Beyond this consensus, there is much disagreement amongst proponents of virtue reliabilism about the conditions under which the credit-relation between an epistemic success and a person's cognitive abilities holds. This paper aims to establish a new and attractive view of this crucial relation in terms of difference-making. We will argue that the resulting theory, Difference-Making Virtue Epistemology, can deal with cases of epistemic luck and testimonial knowledge while revealing the common core of knowledge and other achievements
„Wieso wird der Mond immer weniger?“ – Fachliches Lernen im inklusionsorientierten Sachunterricht entlang von Schüler*innenfragen
No full textSchroeder R, Ernst J, Hummel R, Miller S, Stets M, Velten K. „Wieso wird der Mond immer weniger?“ – Fachliches Lernen im inklusionsorientierten Sachunterricht entlang von Schüler*innenfragen. In: Hundertmark S, Sun X, Abels S, et al., eds. Naturwissenschaftsdidaktik und Inklusion. Sonderpädagogische Förderung heute. Beiheft. Vol 4. Weinheim: Beltz; 2021: 234-248
Conservative Space and Time Regularizations for the ICON Model
No full textReports on Earth System Science/Berichte zur Erdsystemforschung 67, 2009, ISSN 1614-119
Junge, gut ausgebildete Menschen und ihre Selbstmedikationsprodukte - Informationsverhalten, geeignete Situationen und Ängste
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