Refinement of the crystal structure of holmium tetranickel boride, HoNi4B

BHoNi4, hexagonal, P6/mmm (No. 191), a = 4.9696(4) Å, c = 6.9419(5) Å, V= 148.5 Å3, Z= 2, ρm = 9.13(1) g·cm-3, R(P) = 0.072, wR(P) = 0.099, R(I) = 0.065, T= 300 K

Refinement of the crystal structure of diholmium trinickel hexaboride, Ho2Ni3B6

B6Ho2Ni3, orthorhombic, Cmmm (No. 65), a = 7.6865(9) Å, b = 8.6679(9) Å, c = 3.4742(4) Å, V = 231.5 Å3, Z = 2, Rgt(F) = 0.021, wRref(F2) = 0.048, T= 300 K

Crystal structure of tetraholmium nickel tetradecaboride, Ho4NiB14

B14Ho4Ni, tetragonal, P4/mnc (No. 128), a = 7.2097(8) Å, c = 7.4587(9) Å, V = 387.7 Å3, Z = 2, Rgt(F) = 0.049, wRref(F2) = 0.087, T = 300 K

Refinement of the crystal structure of holmium nickel borocarbide, HoNiBC

BCHoNi, tetragonal, P4/nmm (No. 129), a =3.5621(5) Å, c = 7.556(2) Å, V = 95.9 Å3, Z = 2, Rgt(F) = 0.030, wRref(F2) = 0.076, T= 300 K

Yang-Mills action from minimally coupled bosons on R^4 and on the 4D Moyal plane

We consider bosons on Euclidean R^4 that are minimally coupled to an external Yang-Mills field. We compute the logarithmically divergent part of the cut-off regularized quantum effective action of this system. We confirm the known result that this term is proportional to the Yang-Mills action. We use pseudodifferential operator methods throughout to prepare the ground for a generalization of our calculation to the noncommutative four-dimensional Moyal plane (also known as noncommutative flat space). We also include a detailed comparison of our cut-off regularization to heat kernel techniques. In the case of the noncommutative space, we complement the usual technique of asymptotic expansion in the momentum variable with operator theoretic arguments in order to keep separated quantum from noncommutativity effects. We show that the result from the commutative space R^4 still holds if one replaces all pointwise products by the noncommutative Moyal product.Comment: 37 pages, v2 contains an improved treatment of the theta function in Appendix A.

Einpluss des alters und des thioaminosäurengehalts im futter auf die reproduktionsleistung des kaninchens bei postpartaler insemination

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Singular factorizations, self-adjoint extensions, and applications to quantum many-body physics

We study self-adjoint operators defined by factorizing second order differential operators in first order ones. We discuss examples where such factorizations introduce singular interactions into simple quantum mechanical models like the harmonic oscillator or the free particle on the circle. The generalization of these examples to the many-body case yields quantum models of distinguishable and interacting particles in one dimensions which can be solved explicitly and by simple means. Our considerations lead us to a simple method to construct exactly solvable quantum many-body systems of Calogero-Sutherland type.Comment: 17 pages, LaTe

Generalized local interactions in 1D: solutions of quantum many-body systems describing distinguishable particles

As is well-known, there exists a four parameter family of local interactions in 1D. We interpret these parameters as coupling constants of delta-type interactions which include different kinds of momentum dependent terms, and we determine all cases leading to many-body systems of distinguishable particles which are exactly solvable by the coordinate Bethe Ansatz. We find two such families of systems, one with two independent coupling constants deforming the well-known delta interaction model to non-identical particles, and the other with a particular one-parameter combination of the delta- and (so-called) delta-prime interaction. We also find that the model of non-identical particles gives rise to a somewhat unusual solution of the Yang-Baxter relations. For the other model we write down explicit formulas for all eigenfunctions.Comment: 23 pages v2: references adde

Temperature and pressure evolution of the crystal structure of Ax(Fe1-ySe)2 (A = Cs, Rb, K) studied by synchrotron powder diffraction

Temperature-dependent synchrotron powder diffraction on Cs0.83(Fe0.86Se)2 revealed first order I4/m to I4/mmm structural transformation around 216{\deg}C associated with the disorder of the Fe vacancies. Irreversibility observed during the transition is likely associated with a mobility of intercalated Alkali atoms. Pressure-dependent synchrotron powder diffraction on Cs0.83(Fe1-ySe)2, Rb0.85(Fe1-ySe)2 and K0.8(Fe1-ySe)2 (y ~ 0.14) indicated that the I4/m superstructure reflections are present up to pressures of 120 kbar. This may indicate that the ordering of the Fe vacancies is present in both superconducting and non-superconductive states.Comment: 11 pages, 5 figures, 1 tabl

Indoor air particles in office buildings with suspected indoor air problems in the Helsinki area

Objectives: Airborne particle concentrations can be used as quality indicators of indoor environments. The previous lack of reference data has limited the use of particle measurements in offi ce environments. The aim of this study was to describe the concentrations of airborne particles (≥ 0.5 μm and ≥ 5.0 μm) in 122 Finnish offi ce buildings with suspected indoor air problems. Materials and Methods: The database consisted of indoor air and supply air particle samples collected in 2001–2006 from the Helsinki area. The particle concentrations (≥ 0.5 μm and ≥ 5.0 μm) were measured in the indoor air (528 samples from 122 offi ce rooms) and in the supply air (384 samples from 105 offi ce rooms) with an optical particle counter. Airborne particle concentrations ≥ 0.5 μm were categorized according to the effi ciency of supply air fi ltration and health survey data. Results: The mean concentrations in the indoor air equaled 1900 particles/l and in the supply air 1300 particles/l. The effi ciency of supply air fi ltration decreased the fi ne particles counts in both the indoor and supply air. The counts of large particles, ≥ 5.0 μm, were low in the indoor air. Airborne counts of ≥ 0.5 μm particles (geometric mean) were statistically higher in the offi ces whose occupants had work-related symptoms (eye and/or upper respiratory symptoms or upper respiratory infections) than in the offi ces whose occupants had no such symptoms. However, the symptoms may also be linked to other indoor air problems or particle characteristics not studied in this work. Conclusions: This study indicates typical airborne particle levels (≥ 0.5 μm and ≥ 5.0 μm) in Finnish offi ce buildings with suspected indoor air problems. The results can be used to evaluate the quality of indoor environment, possible indoor air problems, and the need for additional investigations