Colorimetrische und gas-chromatographische Analyse von Imidan

Ohne Zusammenfassung     

Bei der Bestimmung kleiner Kohlenstoffgehalte in Nickel und anderen Metallen

Analytical and Bioanalytical Chemistry -     

In einer derivatographischen Untersuchung von 26 Ammoniumsalzen

Ohne Zusammenfassung     

Einfluß interstitiellen Wasserstoffs auf Magnetismus und Gitterkonstante ferromagnetischer NiCr-Legierungen

Measurements of magnetization, X-ray studies and volumetric investigations show that ferromagnetic nickel-chrome alloys (2 to 7% Cr) absorb hydrogen in high concentrations (β-phase). Caused by the interstitial hydrogen atoms NiCr looses its ferromagnetism, combined with reversibly enlarged lattice constants of some percent (decreasing with increasing Cr-content). The variation of lattice expansionΔ a with Cr-content is in some way similar to the recently found proportionality ofΔ a with the mean magnetic moment in the case of NiCu and NiCu-hydrogen-alloys but deviating in a characteristic manner. — X-ray studies also showed an additional increase ofΔ a by supersaturation of the β-phase, and the occurrance of a second phase with very low values ofΔ a.     

Exactly solvable model with two conductor-insulator transitions driven by impurities

We present an exact analysis of two conductor-insulator transitions in the random graph model where low connectivity means high impurity concentration. The adjacency matrix of the random graph is used as a hopping Hamiltonian. We compute the height of the delta peak at zero energy in its spectrum exactly and describe analytically the structure and contribution of localized eigenvectors. The system is a conductor for average connectivities between 1.421 529ellipsis and 3.154 985ellipsis but an insulator in the other regimes. We explain the spectral singularity at average connectivity e = 2.718 281ellipsis and relate it to other enumerative problems in random graph theory.     

Hybridization gap in heavy fermion compounds

We report the results of optical studies of new heavy fermion compounds YbFe(4)Sb(12) and CeRu(4)Sb(12). We show that these compounds, as well as several other heavy fermion materials with a nonmagnetic ground state, obey a universal scaling relationship between the quasiparticle effective mass m(*) and the magnitude of the energy gap Delta in the excitation spectrum. This result is in accord with the picture of hybridization of localized f-electron and free carrier states.     

Search for neutral supersymmetric Higgs bosons in pp collisions at sqrt[s] = 1.8TeV

We present the results of a search for neutral Higgs bosons produced in association with b quarks in pp-->bb(phi)-->bbb final states with 91+/-7 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model. With basic parameter choices for the supersymmetric scale and the stop-quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for tan(beta) values in excess of 35.     

Quasi-model-independent search for new high p(T) physics at D0

We apply a quasi-model-independent strategy ("Sleuth") to search for new high p(T) physics in approximately 100 pb(-1) of pp collisions at square root of (s) = 1.8 TeV collected by the D0 experiment during 1992-1996 at the Fermilab Tevatron. We systematically analyze many exclusive final states and demonstrate sensitivity to a variety of models predicting new phenomena at the electroweak scale. No evidence of new high p(T) physics is observed.     

Hilbert-Schmidt Hankel operators on the Segal-Bargmann space

This paper considers Hankel operators on the Segal-Bargmann space of holomorphic functions on that are square integrable with respect to the Gaussian measure. It is shown that in the case of a bounded symbol the Hankel operator is of the Hilbert-Schmidt class if and only if is Hilbert-Schmidt. In the case where the symbol is square integrable with respect to the Lebesgue measure it is known that the Hilbert-Schmidt norms of the Hankel operators and coincide. But, in general, if we deal with bounded symbols, only the inequality can be proved. The results have a close connection with the well-known fact that for bounded symbols the compactness of implies the compactness of .