Critical phenomena in isoelectronic diatomic sequences—the 14-electron sequence

A theory of isoelectronic molecules which describes stable and metastable members of a sequence has been developed. To achieve this synthesis, it has been necessary to require that the total electronic energy surface E(R,Z,Z') for the sequence contain critical points—that is, values of the nuclear charges Z and Z' at which energy minimum, maximum [at R_e(min) and R_e(max)], and horizontal inflection points occur. For ground state sequences a primary physical source of these extreme points is the screened, coulombic repulsion of like-charged atomic centers in the diatomics. With this realization, we can write analytical forms that have the correct scaling behavior and which properly model the screened, coulombic repulsion for E along certain straight-line trajectories in the (Z,Z') plane. This leads to the observation that R_e(max) values diverge logarithmically in λ-like transitions wherever the screened coulombic repulsion becomes small as the nuclear charges vary along those trajectories. At the horizontal inflection points the E surface contains A₂ folds, as required by Thom's theorem for analytical surfaces containing one control parameter. Within the isoelectronic sequence molecular subgroups have been noted and explained in terms of the underlying atomic shell structures of the molecules' constituent atoms. Using input data for seven stable molecules together with the analytical surface selected for study, we have estimated the equilibrium bond distances R_e(min), dissociation energies D_e(min), and harmonic force constants E⁽²⁾(min) for 18 other neutral and charged species.     

Isotope shift studies in UV lines of Sm I on FTS: level isotope shifts and configuration assignments of the energy levels of neutral samarium atom

Isotope shifts in 200 spectral lines of neutral samarium atom (Sm I) in the region of 355-455 nm (28160-21970 cm^-1) have been measured using a Fourier Transform Spectrometer. Isotope shift data in 187 spectral lines of Sm I are being reported for the first time. Level isotope shifts, of 119 high odd- and 7 low even-parity energy levels have been evaluated using present isotope shift data combined with the earlier available data. These values have enabled us to check the assignments to 4f ⁶6s6p and 4f ⁵5d6s ² configurations of the odd-parity levels made earlier on the basis of parametric calculations. For several levels, the reported compositions of the mixed configuration of type [4f ⁵(⁶H⁰, ⁶F⁰) 5d6s ² + 4f ⁶(⁷F) 6s6p(³P⁰)] have been interpreted with the help of our values. 20 unassigned energy levels have been uniquely assigned to 4f ⁵5d6s ² configuration. The present study provides values of the levels, which were tentatively assigned to 4f ⁵5d ²6s and 4f ⁶5d6p configurations. We could also identify 4f ⁶5d6p configuration for 12 unassigned levels.Received: 16 December 2004, Published online: 7 September 2004PACS: 31.30.Gs Hyperfine interactions and isotope effects, Jahn-Teller effect     

Bosonic loops and gluon condensate

Contributions to the vacuum polarisation inQCD are calculated separately with fermion as well as boson loops to have an idea of results expected for possible supersymmetric extension. It is found that the results are not altered in any significant way.     

An experimental investigation of the effect of waves on vapour side heat and mass transfer in filmwise condensation inside a vertical tube

The effect of liquid Reynolds number in condensation of a single vapour from a non-condensing gas has been investigated experimentally. It is apparent that there is no significant enhancement of the heat and mass transfer coefficients on the vapour side up to a liquid film Reynolds number of 200 and a gas Reynolds number of 14,000 in a vertical tube of length 1 metre.     

Translationsdeckel für geschlossene Kurven

Ohne Zusammenfassung     

Free actions of finite groups on products of symmetric powers of even spheres

This paper answers a question on the existence of free actions on products of symmetric powers of even-spheres. The main objective is to show that a finite group acts freely on a finite product of symmetric powers of even-dimensional spheres iff it can act freely on a suitable product of even-dimensional spheres themselves.

     

Linear Wirelength of Folded Hypercubes

Manuel et al. (Discret. Appl. Math. 157(7):1486–1495, 2009) obtained the exact wirelength of an r-dimensional hypercube into a path as well as a 2^?r/2?×2^ér/2ù{2^{lfloor r/2rfloor}times 2^{lceil r/2rceil}} grid and conjectured the same for a folded hypercube. In this paper we solve the edge isoperimetric problem for folded hypercubes and thereby obtain the exact wirelength of folded hypercubes into paths. Further we compute the exact wirelength of the r-dimensional folded hypercubes into 2 ^k × 2 ^r−k grids.     

Catalytic reduction of 4-nitrophenol using synthesized and characterized CoS@MorphcdtH/CoS@4-MPipzcdtH nanoparticles

CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were synthesized by precipitation method involving three mechanisms: inclusion, occlusion, and adsorption. The synthesized NPs were characterized with the help of UV-Vis spectroscopy, FESEM-EDAX, powder x-ray diffraction, TEM, ESIMS, TG/DSC analysis. The morphology of the CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were hexagonal and rectangular, and the particles were in the range 7–12 nm. UV–visible spectral measurements showed surface plasmon resonance at 320 nm–340 nm with band gap of 3.65 eV–3.86 eV. The catalytically active CoSNPs called were investigated for the reduction of 4-nitrophenol (4-NP) via hydrogenation using sodium borohydride (NaBH₄) as a reducing agent. Both the CoS NPs successfully reduced 4-NP to 4- aminophenol (4-AP) in a short time, catalytic performances are almost unchanged for the first five cycles. Herein, we report the preparation and characterizations of efficient active CoS NPs consisting carbodithioic acid framework as a support/capping material, along with catalytic property.