From PCA's to equilibrium systems and back

Stationary measures for probabilistic cellular automata (PCA's) ind dimensions give rise to space-time histories whose statistics may naturally be described by Gibbs states ind+1 dimensions for an interaction energy ? obtained from the PCA. In this note we study the converse question: Do all Gibbs states for this ? correspond to statistical space-time histories for the PCA? Our main result states that the answer is yes, at least for translation invariant or periodic Gibbs states. Thus ergodicity questions for PCA's can, at least partially, be formulated as questions of uniqueness of Gibbs states.     

Possible excitation of a fast sodium beam by laser irradiation

We present results of model calculations concerning the fraction of excited atoms obtained by laser irradiation of a fast sodium atom beam (100–400 eV kinetic energy). We calculated relative absorption probabilities as a function of the intersection angle between the two beams, the atom-beam energy, the atom-beam energy spread and the atom-beam divergence. The fraction of excited atoms that can be obtained at 300 eV is at least a factor of 5 smaller than in the case of a thermal beam, due to the divergence and energy spread of the fast atom beam giving rise to a large Doppler broadening.     

CW laser spectroscopy of autoionising 6p 3/2 nl states of Barium

6pnl states of Ba with l ≥ 5, excited with two narrowband, tunable CW lasers have been studied. In the first excitation step 6snl states were populated from metastable states of the 5d ² configuration: to 6s40h (l = 5) states in the absence, and to parabolic 6pnk (n = 30, 35, 40) states in the presence of an electric field. The atomic motion was used to adiabatically reduce this field to zero before applying the second excitation step to high-l 6p _3/2 nl states (Stark-switching). A slow decrease in the autoionisation rate for increasing value of l and, in case of 6pnh, a dependence on the fine-structure state was measured. The narrowest autoionisation linewidth observed is 113(11) MHz, relatively close to the 20 MHz linewidth corresponding to the radiative lifetime of the 6p state of the Ba⁺-ion.     

Energy spectra for decaying 2D turbulence in a bounded domain

We use results derived in the framework of the replica approach to study the liquid-glass thermodynamic transition. The main results are derived without using replicas and applied to the study of the Lennard-Jones binary mixture introduced by Kob and Andersen. We find that there is a phase transition due to the entropy crisis. We compute both analytically and numerically the value of the phase transition point T(K) and the specific heat in the low temperature phase.     

491—Linear dependence of polarographic catalytic current on the numeber of SH groups in the molecule for haemoglobins of different origin

Polarographic catalytic currents for solutions containing bovine, ovine, dog, human, rabbit, porcine or pigeon haemoglobins, and bovine or human methaemoglobins at several NH₃ and CoCl₂ concentrations were studied. At earlier elaborated conditions [9], for isomolar solutions of five haemoglobins of known amino-acid composition, a linear correlation between the current of the first catalytic wave and the number of SH groups in the molecule was obtained, this being confirmed by a very high value of the correlation coefficient. No correlation could be stated using solutions of lower ammonia concentrations for the first and, under all conditions studied, for the second catalytic wave. On the basis of the linear dependence obtained, a number of SH groups in tetramers—and hence in the ß-chain of dog haemoglobin and the α-chain of porcine haemoglobin—were found. The fact that the straight lines obtained do not intersect with the origin of coordinates is briefly discussed. Values of the standard deviation pointed to the use of low cobaltous chloride concentrations in the solution. It has also been stated that the magnitude of the catalytic current of haemoglobins depends on their methaemoglobin content, which should be connected with structural differences in these two species.     

A single-period inventory placement problem for a supply system with the satisficing objective

Consider the inventory placement problem in an N-stage supply system facing a stochastic demand for a single planning period. Each stage is a stocking point holding some form of inventory (e.g., raw materials, subassemblies, product returns or finished products) that after a suitable transformation can satisfy demand. Stocking decisions are made before demand occurs. Unsatisfied demands are lost. The revenue, salvage value, ordering, transformation, and lost sales costs are proportional. There are fixed costs for utilizing stages for stock storage. The objective is to maximize the probability of achieving a given target profit level.     

Formation of intramolecular hydrogen bonds in heterodisubstituted ferrocene diamides with a secondary and a tertiary amido group: X-ray structure of 1′-(N′-butyl-carbamoyl)-morpholino ferrocenecarboxamide

Various unsymmetrically substituted ferrocene 1,1′-diamides have been synthesized via homogeneous catalytic carbonylation starting from 1,1′-diiodoferrocene. The unique features observed in the ¹H NMR and IR spectra of the compounds bearing a secondary and a tertiary amido group are explained by the formation of an internal hydrogen bond between the substituents. Addition of chloride ions (as a tetrabutylammonium salt) into the solutions of these compounds results in spectroscopic changes due to the formation of intermolecular hydrogen bonds between the ferrocene diamide and the anion. The solid state structure of 1′-(N′-butyl-carbamoyl)-morpholino ferrocenecarboxamide (1a) has also been determined by X-ray crystallography. A strong intramolecular H-bond between the NH group of the N′-butyl-carbamoyl moiety and the CO of the tertiary amido group was observed.