The electronic structure of vanadium carbide, VC

Within an energy range of 2.4 eV, we have explored 29 of the 36 states of the diatomic molecule VC that arise from the atoms in their ground state, V(4s23d3;4F)+C(2s2 2p2;3P). We use multireference methods with large atomic natural orbital basis sets. The ground state is of 2Delta symmetry with the first two excited states, 4Delta and 2Sigma+, located 4.2 and 7.0 kcal/mol above the X state. All the states examined in this work are relatively strongly bound and show significant charge transfer from V to C. The binding energy of the X 2Delta state is estimated to be 95.3 kcal/mol in good agreement with the experimental value.     

Prospects for p̄p → ȲY studies at PANDA

Strangeness and charm production provide an excellent probe of QCD in the confinement domain. With the PANDA detector at FAIR, this can be studied in e.g., hyperon production in the p?p → ?Y reactions. In PANDA, all ground state strange hyperons and single charmed Λ’s will be accessible. Simulations show that the differential cross sections and spin observables can be well reconstructed for these reaction channels.     

Validation of a coupled FE-model for the simulation of methane oxidation via thermal imaging

To simulate the processes of methane oxidation in landfill cover layers, a new computational model was created. The purpose of the model is to allow a forecast on the performance of methanotrophic activity in landfill cover layers under changing environmental conditions. Therefore, a thermodynamic consistent model based on the well-known Theory of Porous Media (TPM) combined with the mixture theory was developed, which analyzes the relevant gas productions of methane, oxygen and carbon dioxide. Diffusion, advection and conversion processes are considered as well as the energy production during methane oxidation. With the help of the thermal imaging technique a new experimental setup was developed in order to validate the coupled model in terms of the heat generation. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Catalytic,Asymmetric Synthesis of Phosphonic γ‐(Hydroxyalkyl)butenolides with Contiguous Quaternary and Tertiary Stereogenic Centers

A procedure that enables high yielding access to phosphonic γ‐(hydroxyalkyl)butenolides with excellent regio‐, diastereo‐ and enantiocontrol is reported. The simultaneous construction of up to two adjacent quaternary stereogenic centers by a catalytic asymmetric vinylogous Mukaiyama aldol reaction unites biologically and medicinally relevant entities, namely α‐hydroxy phosphonates and γ‐(hydroxyalkyl)butenolides. This is achieved by utilizing a readily available chiral copper‐sulfoximine catalyst showing a broad functional group tolerance for both the electrophilic and nucleophilic reactants. A discussion about potential factors affecting the observed level of enantioselectivity, which stems from the enantiopure sulfoximine ligand, is also included.     

Impurity-defect interaction and diffusion in In-implanted nickel

Rutherford backscattering and time-differential perturbed angular correlation experiments were performed on In-implanted nickel foils annealed up to 900 K. The impuritydamage interaction is shown to anneal out just at (or very slightly below) the In diffusion temperature.Work partially supported by CNRS under RCP-157.     

On sequential labelings of graphs

A valuation on a simple graph G is an assignment of labels to the vertices of G which induces an assignment of labels to the edges of G. β-valuations, also called graceful labelings, and α-valuations, a subclass of graceful labelings, have an extensive literature; harmonious labelings have been introduced recently by Graham and Sloane. This paper introduces sequential labelings, a subclass of harmonious labelings, and shows that any tree admitting an α-valuation also admits a sequential labeling and hence is harmonious. Constructions are given for new families of graceful and sequential graphs, generalizing some earlier results. Finally, a conjecture of Frucht is shown to be wrong by exhibiting several graceful labelings of wheels in which the center label is larger than previously thought possible.     

The expected degree of minimal spanning forests

We give a lower bound on the expected degree of the free minimal spanning forest of a vertex transitive graph in terms of its spectral radius. This result answers a question of Lyons-Peres-Schramm and simplifies the Gaboriau-Lyons proof of the measurable-group-theoretic solution to von Neumann’s problem.In the second part we study a relative version of the free minimal spanning forest. As a consequence of this study we can show that non-torsion unitarizable groups have fixed price one.     

Interpolation on a triangulated 3D surface

An interpolation method for scalar functions on a rectangular grid on a planar surface is extended to the interpolation function on a closed three-dimensional triangulated surface of arbitrary shape. Two variants are considered. The first one constrains the Laplacian of the function to be zero at points where the function values are unknown. The second one minimizes the Laplacian at all points of the surface considered. Some illustrative examples of both variants are given in applications to the display of potential distributions on the boundary surface of an electrical volume conductor.