Same taxonomic name, different species: a threat to stromatoporoid biodiversity research

Taxonomic inconsistencies between two published collections on Devonian stromatoporoids were examined. The studied collections contain stromatoporoids sampled from the Middle and Upper Devonian from the Ardennes (collection by Lecompte) and the Holy Cross Mountains (collection by Kazmierczak). The study was limited to stromatoporoid species that were assigned to the order Stromatoporellida. At least eight species which were described from the Devonian of both the Ardennes and the Holy Cross Mountains should be revised: F. ruedemanni, H. crassum, H. porosum, H. perseptatum, S. lensiforme, S. socialis, T. laceratum, T. pingue . Specimens that were assigned to C. damnoniensis, C. spissa, H. episcopale, H. schlueteri, P. cellulosum and S. huronense do not need to be revised. The inconsistencies may severely influence the outcome of palaeogeographic and biodiversity studies, since the error in not distributed randomly among stratigraphic intervals and it affects classification at the genus-level

Electric dipole rovibrational transitions in HD molecule

The rovibrational electric dipole transitions in the ground electronic state of the HD molecule are studied. A simple, yet rigorous formula is derived for the transition rates in terms of the electric dipole moment function $D(R)$, which is calculated in a wide range of $R$. Our numerical results for transition rates are in moderate agreement with experiments and previous calculations, but are at least an order of magnitude more accurate.Comment: 7 pages, 1 figur

ASSESSMENT OF GEOMETRIC ACCURACY OF VHR SATELLITE IMAGES

VHR images of earths ’ surface are more frequently used and taken advantage of in substitution to aerial photographs. Geometric dependences of creation orthophoto based on aerial photos are known and distinguished from images of VHR. Results of work led are presented in this article within the confines of an investigative project under the Committee of Scientific Research of Poland concerning the geometric mechanism of VHR images and corrections. Two test fields have been made up for this project (city, country and mountain terrain). For those test fields, images from IKONOS, QuickBird were ordered. In the conducted research the angle of the axes was take into consideration: 0 ° – 15 ° In each test field area, after the identification of control points on the VHR images, about 30 – 90 GCP have been measured with GPS in accuracy of 10 cm. For image geometric corrections in this project two types of available DTM models in Poland have been applied with varying accuracy. Geometric correction have been realized with the aid of generally available software as PCI Geomatica 9 with taking into consideration RPC method and camera ( rigorous) model. Throughout the work investigated, in each of the individual scenes of VHR various distribution and number of GCP was utilized for the process of orthorectification. Accuracy of orthorectification process received in result of led work, for VHR images at different configuration of geometry and methodology. Detailed results of experiments allow determining the optimal foundation for different methods of geometric corrections from IKONOS, QuickBird images and establishing effective process of dependence and defining geometric accuracy for different applications. 1

Double-well states of ungerade symmetry in H-2: First observation and comparison with ab initio calculations

A class of long-lived outer well states of ungerade symmetry lying above the ionization threshold in molecular hydrogen is investigated. A triple resonance scheme is used to study the rovibrational levels within a potential extended over internuclear separations. Good agreement with updated ab initio calculations is found. This demonstrates that for as long as the interaction with the Rydberg manifolds is shielded by a barrier, such calculations can be extended to an energetic range above the ionization

Formation Pumping of Molecular Hydrogen in Dark Clouds

Many theoretical and laboratory studies predict H2 to be formed in highly excited ro-vibrational states. The consequent relaxation of excited levels via a cascade of infrared transitions might be observable in emission from suitable interstellar regions. In this work, we model H2 formation pumping in standard dense clouds, taking into account the H/H2 transition zone, through an accurate description of chemistry and radiative transfer. The model includes recent laboratory data on H2 formation, as well as the effects of the interstellar UV field, predicting the populations of gas-phase H2 molecules and their IR emission spectra. Calculations suggest that some vibrationally excited states of H2 might be detectable towards lines of sight where significant destruction of H2 occurs, such as X-ray sources, and provide a possible explanation as to why observational attempts resulted in no detections reported to date.Comment: 32 pages, 8 figures, 5 table

Calculations of exchange interaction in impurity band of two-dimensional semiconductors with out of plane impurities

We calculate the singlet-triplet splitting for a couple of two-dimensional electrons in the potential of two positively charged impurities which are located out of plane. We consider different relations between vertical distances of impurities $h_1$ and $h_2$ and their lateral distance $R$. Such a system has never been studied in atomic physics but the methods, worked out for regular two-atomic molecules and helium atom, have been found to be useful. Analytical expressions for several different limiting configurations of impurities are obtained an interpolated formula for intermediate range of parameters is proposed. The $R$-dependence of the splitting is shown to become weaker with increasing $h_1,h_2$.Comment: 14 pages, RevTeX, 5 figures. Submitted to Phys Rev.

Low-energy Antiproton Interaction with Helium

An ab initio potential for the interaction of the neutral helium atom with antiprotons and protons is calculated using the Born-Oppenheimer approximation. Using this potential, the annihilation cross section for antiprotons in the energy range 0.01 microvolt to 1 eV is calculated.Comment: 13 pages, 7 figures, LaTe

Vibrational level population of H2_2 and H2+_2^+ in the early Universe

We formulate a vibrationally resolved kinetics for molecular hydrogen and its cation in the primordial Universe chemistry. Formation, destruction and relaxation processes for each vibrational level are studied and included as chemical pathways of the present model. The fractional abundance of each vibrational level as a function of the redshift is given: a strong deviation from the Boltzmann distribution is found at low $z$. A discussion of the results is provided, also evaluating the effects of relaxation processes on the level populations. Analytical fits for some LTE rate coefficients are given in the Appendix.Comment: 12 pages, 14 figures, 3 tables; published on ApJS 2011, 193,