58Ni: an unpaired band crossing at new heights of angular momentum for rotating nuclei

High-spin states in 58Ni have been investigated by means of the fusion-evaporation reaction 28Si(32S, 2p)58Ni at 130 MeV beam energy. Discrete-energy levels are observed in 58Ni at record-breaking 42 MeV excitation energy and angular momenta in excess of 30h. The states form regular rotational bands with unprecedented high rotational frequencies. A comparison with configuration dependent cranked Nilsson-Strutinsky calculations reveals an exceptional two-band crossing scenario, the interaction strength of which is strongly shape dependent.     

Vertex Operators, Grassmannians, and Hilbert Schemes

We approximate the infinite Grassmannian by finite-dimensional cutoffs, and define a family of fermionic vertex operators as the limit of geometric correspondences on the equivariant cohomology groups, with respect to a one-dimensional torus action. We prove that in the localization basis, these are the well-known fermionic vertex operators on the infinite wedge representation. Furthermore, the boson-fermion correspondence, locality, and intertwining properties with the Virasoro algebra are the limits of relations on the finite-dimensional cutoff spaces, which are true for geometric reasons. We then show that these operators are also, almost by definition, the vertex operators defined by Okounkov and the author in Carlsson and Okounkov ( [math.AG], 2009), on the equivariant cohomology groups of the Hilbert scheme of points on \mathbb C²{\mathbb C^2} , with respect to a special torus action.     

Covering homology

We introduce the notion of covering homology of a commutative S-algebra with respect to certain families of coverings of topological spaces. The construction of covering homology is extracted from Bökstedt, Hsiang and Madsen's topological cyclic homology. In fact covering homology with respect to the family of orientation preserving isogenies of the circle is equal to topological cyclic homology. Our basic tool for the analysis of covering homology is a cofibration sequence involving homotopy orbits and a restriction map similar to the restriction map used in Bökstedt, Hsiang and Madsen's construction of topological cyclic homology.Covering homology with respect to families of isogenies of a torus is constructed from iterated topological Hochschild homology. It receives a trace map from iterated algebraic K-theory and there is a hope that the rich structure, and the calculability of covering homology will make it useful in the exploration of J. Rognes' “red shift conjecture”.     

In situ growth of nano-structures by metal-organic vapour phase epitaxy

Using spontaneous self-organization effects is an efficient way to produce nano-structures, as for instance quantum wires and quantum dots. This article is focused on the strain-induced self-organization, or “self-assembling” effect, producing quantum dots. Particularly the following aspects will be addressed: (i) the phenomenology of the 2D–3d morphology transition, (ii) the effects of materials choices and growth conditions on density, size and homogeneity of dots, and (iii) manipulations to get laterally aligned and vertically stacked dot structures.     

Lectin affinity chromatography as a tool to differentiate endogenous and recombinant erythropoietins

This work exploits the combination of the lectin affinity chromatography (LAC) with an ultra-sensitive immunochromatographic assay to differentiate several types of erythropoietin (EPO). The chromatographic behaviours of different commercial types of recombinant human EPO (rhEPO), EPO analogues (Aranesp) and urine human EPO (uhEPO) from healthy individuals on eight lectin-Sepharose columns, have been worked out. Results show that when using wheat germ agglutinin (WGA)-Sepharose columns, a careful desorption regime starting with very low concentration (2mM) of the competitive sugar N-acetylglucosamine (GlcNAc) makes it possible to efficiently distinguish endogenous EPO from recombinant EPO and EPO analogues.     

Differential Equations with Infinitely Many Derivatives and the Borel Transform

Differential equations with infinitely many derivatives, sometimes also referred to as “nonlocal” differential equations, appear frequently in branches of modern physics such as string theory, gravitation and cosmology. We properly interpret and solve linear equations in this class with a special focus on a solution method based on the Borel transform. This method is a far-reaching generalization of previous studies of nonlocal equations via Laplace and Fourier transforms, see for instance (Barnaby and Kamran, J High Energy Phys 02:40, 2008; Górka et al., Class Quantum Gravity 29:065017, 2012; Górka et al., Ann Henri Poincaré 14:947–966, 2013). We reconsider “generalized” initial value problems within the present approach and we disprove various conjectures found in modern physics literature. We illustrate various analytic phenomena that can occur with concrete examples, and we also treat efficient implementations of the theory.     

Coupled LC‐GC‐NPD for Determination of Carbazole‐Type PANH and Its Application to Personal Exposure Measurement

A coupled LC‐GC method for the analysis of carbazole‐type PANH has been developed and evaluated. Group separation and isolation of carbazoles from interfering acridines in a complex sample matrix was accomplished by using a back‐flush technique and an in situ end‐capped dimethylaminopropyl silica column in the HPLC part of the system. On‐line injection of the carbazole fraction into the GC column was performed with a loop‐type interface utilizing concurrent solvent evaporation technique. An LOD of 1–3 pg of individual carbazole compounds was achieved by nitrogen selective detection using an NPD. The method is shown to be robust and is demonstrated by application to personal exposure measurement in an aluminum reduction plant.     

Deep levels in low‐energy electron‐irradiated 4H‐SiC

Deep levels introduced by low‐energy (200 keV) electron irradiation in n‐type 4H‐SiC epitaxial layers grown by chemical vapour deposition were studied by deep level transient spectroscopy (DLTS) and photoexcitation electron paramagnetic resonance (photo‐EPR). After irradiation, several DLTS levels, EH1, EH3, Z_1/2, EH5 and EH6/7, often reported in irradiated 4H‐SiC, were observed. In irradiated freestanding films from the same wafer, the EPR signals of the carbon vacancy in the positive and negative charge states, V_C⁺ and V_C^‐, respectively, can be observed simultaneously under illumination with light of certain photon energies. Comparing the ionization energies obtained from DLTS and photo‐EPR, we suggest that the EH6/7 (at ～E_C – 1.6 eV) and EH5 (at ～E_C – 1.0 eV) electron traps may be related to the single donor (+ | 0) and the double acceptor (1– | 2–) level of V_C, respectively. Judging from the relative intensity of the DLTS signals, the EH6/7 level may also be contributed to by other unidentified defects. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)