Microwave spectrum of p-chlorostyrene

The microwave spectrum of p-chlorostyrene has been studied in the frequency region 18.0–26.5 GHz. Rotational transitions of the ground state, the first two torsionally excited states and two other vibrational states of the ³⁵Cl isotopic species have been identified. The molecule was found to be planar in the ground state. From intensity measurements, the frequency of the first torsional transition has been estimated to be 35 ± 15 cm^?1.     

The orthorhombic polymorph of diammonium trichromate(VI) decaoxide, <Emphasis Type="Italic">α</Emphasis>–(NH<Subscript>4</Subscript>)<Subscript>2</Subscript>Cr<Subscript>3</Subscript>O<Subscript>10</Subscript>

Synthesis and crystal structure of a trichromium(VI) decaoxide compound, α–(NH₄)₂Cr₃O₁₀, is reported. The crystal structure has been determined from three dimensional X-ray data collected at low temperature, 173 K. The structure is isomorphous with its Rb and Cs trichromate analogues, orthorhombic, space group Pbca, with a = 11.2558(3), b = 9.3193(3), c = 18.9819(5) ? and Z = 8. The title compound is composed of discrete [Cr₃O₁₀]^2– chains held together by the counter ion charge and a hydrogen bonding network. The different conformations adopted by trichromate anion within its ammonium, alkali and organic salts are discussed.     

Min- and Max-Entropy in Infinite Dimensions

We consider an extension of the conditional min- and max-entropies to infinite-dimensional separable Hilbert spaces. We show that these satisfy characterizing properties known from the finite-dimensional case, and retain information-theoretic operational interpretations, e.g., the min-entropy as maximum achievable quantum correlation, and the max-entropy as decoupling accuracy. We furthermore generalize the smoothed versions of these entropies and prove an infinite-dimensional quantum asymptotic equipartition property. To facilitate these generalizations we show that the min- and max-entropy can be expressed in terms of convergent sequences of finite-dimensional min- and max-entropies, which provides a convenient technique to extend proofs from the finite to the infinite-dimensional setting.     

Numerical studies of the Möbius power series

We define the Möbius power series throughf(z)= _n-1 z ⁿ ,g(z)= _n=1 (n)z ⁿ /n where (n) is the usual Möbius function. This paper presents some heuristic estimates describing the behavior off(z) andg(z) when |z| is close to 1 together with representations in terms of elementary functions for real values ofz. Function tables are also given together with zeros and a few other special values.     

Charged particle production and correlations at high transverse momentum at the CERN intersecting storage rings

We study the production of identified charged particles in pp collisions at a c.m. energy of 63 GeV in events with an identified high-p_T trigger particle. The measurements were performed at the CERN Intersecting Storage Rings using the Axial Field Spectrometer.Production ratios are presented as a function of p_T in the range 2.5 to 8 GeV/c.     

Metal Ion Coordination at the Water-Manganite (gamma-MnOOH) Interface

The local structure of Zn(II) adsorbed at the water-manganite (gamma-MnOOH) interface has been investigated by extended X-ray absorption fine structure (EXAFS) spectroscopy. Adsorption experiments were carried out within the pH range 6.17-9.87 and surface coverages of 0.9 to 9.7 μmol/m(2)cZn(II) coordination was observed to change from six to four as pH was increased. This was indicated by a change in Zn-O distance from 2.04 to 1.96 ? and by a decrease in the obtained coordination numbers. Two higher shells were detected at about 3.08 and 3.33 ?, at all pH values and surface coverage investigated. As the backscattering phase and amplitude functions of Mn and Zn are similar, we used structural and chemical considerations to assign the backscattering at 3.08 ? to Mn neighbors, and the one at 3.33 ? to Zn atoms. Indeed the size of the Zn polyhedra, especially of ZnO(4), does not quite match the structure of the manganite surface. We conclude that Zn(II) forms multinuclear hydroxo-complexes or a zinc hydroxide phase at the surface, as it might be easier for an additional Zn(II) to bond to an already sorbed Zn. These results were compared to our previous EXAFS study of Cd(II) adsorption onto manganite, where mononuclear inner-sphere complexes bound to the surface via edges were found. Copyright 2000 Academic Press.     

High spin states of 83Sr

The reactions ⁸⁰Kr(α, n)⁸³Sr and ⁸²Kr(α, 3n)⁸³Sr were used to populate excited states of high spin in ⁸³Sr. The de-excitation of these states was studied by in-beam γ-ray spectroscopy. A number of new high-spin states have been observed. The results are discussed within the framework of the Coriolis-coupling model and the cluster-core coupling model.     

A unified approach to particle-holes and rotations in the spectrum of 16O

The cranked Nilsson-Strutinsky formalism is applied to the many-faceted spectrum of ¹⁶O. The deformation parameters ?, γ and ε₄ are varied independently and many-particle-many-hole excitations are considered in the rotating system. Potential-energy surfaces are presented at different values of spin, parity and signature. Surprisingly good agreement is obtained when the different minima are compared with the measured states. Generally, it is observed that the more particles that are excited to higher shells, the larger becomes the intrinsic deformation. Rotational bands as well as pure p-h excitations, the latter sometimes constituting the termination of a rotational band, are identified. Additional high-spin states (I ? 12) are suggested. A microscopic analysis is performed of the rotational bands which emerge when ¹⁶O in its triaxial 4p-4h configuration rotates around each of its three principal axes.     

The use of bond paths for quantitatively characterizing bond strain

The concept of the bond path as a means for characterizing individual strained bonds is developed in detail and applied to a variety of molecules. A reference path is defined in terms of the superposed electronic densities of the free atoms, and a “bond deviation index” is introduced, for expressing quantitatively the difference between the actual and the reference bond paths. This difference is taken as indicating the degree of strain in the bond. It is shown that bond paths can be significantly affected by not only neighboring bonding electrons, but by lone pairs as well, as in the H₂O and NH₃ molecules.