Spin‐1 Bose Hubbard Model with Nearest Neighbour Extended Interaction

A spinor () Bose gas is studied in presence of a density‐density interaction through a mean field approach and a perturbation theory for either sign of the spin dependent interaction, namely the antiferromagnetic (AF) and the ferromagnetic cases. In the AF case, the charge density wave (CDW) phase appears to be sandwiched between the Mott insulating (MI) and the supersolid phases for small values of the extended interaction strength. But the CDW phase completely occupies the MI lobe when the extended interaction strength is larger than a certain critical value related to the width of the MI lobes and hence opens up the possibilities of spin singlet and nematic CDW insulating phases. In the ferromagnetic case, the phase diagram shows similar features as that of the AF case and are in complete agreement with a spin‐0 Bose gas. The perturbation expansion calculations nicely corroborate the mean field phase results in both these cases. Further, we extend our calculations in presence of a harmonic confinement and obtained the momentum distribution profile that is related to the absorption spectra in order to distinguish between different phases.     

Generalized fixed point theorems for compatible mappings with some types in fuzzy metric spaces

In this paper, we give some new definitions of compatible mappings of types (I) and (II) in fuzzy metric spaces and prove some common fixed point theorems for four mappings under the condition of compatible mappings of types (I) and (II) in complete fuzzy metric spaces. Our results extend, generalize and improve the corresponding results given by many authors.     

C4−H alkoxylation of 6-bromoindole and its application to the synthesis of breitfussin B

Subjecting 6-bromoindole to an iridium-catalysed triborylation-diprotodeborylation sequence followed by Chan-Evans-Lam coupling gives 6-bromo-4-methoxyindole in good overall yield. This indole C4?H alkoxylation process was used in a formal synthesis of the natural product breitfussin B.     

Adsorption behaviour of some metal ions and their oxinates on Zeokarb-226

Summary To develop a preconcentration technique for trace elements in aqueous solution, the adsorption behaviour of some metal ions and their oxinates on a weak carboxylic acid resin (Zeokarb-226) in the H⁺ form was investigated. Results indicate that under the conditions of the experiment, the resin behaves like a chelating ion-exchanger and that by selecting appropriate conditions, a group of ions such as U(VI), Th(IV), Pb(II), Hg(II), Fe(III) may be separated from many other ions.

---

Adsorptionsverhalten einiger Metallionen und ihrer Oxinate an Zeokarb-226

Zusammenfassung Das Adsorptionsverhalten einiger Metallionen und ihrer Oxinate an dem schwachen Carbonsäureharz Zeokarb-226 (H⁺-Form) wurde untersucht, um ein Anreicherungsverfahren für Spurenelemente in wäßriger Lösung zu entwickeln. Die Ergebnisse zeigen, daß sich das Harz unter den gegebenen Bedingungen als Chelataustauscher verhält und geeignet ist für die selektive Anreicherung von z.B. U(VI), Th(IV), Pb(II), Hg(II) und Fe(III).

     

Speech enhancement in dual-microphone mobile phones using Kalman filter

In this paper, a dual-microphone speech enhancement algorithm for the mobile phones is proposed. The adopted method exploits the coherence function algorithm and the Kalman filter. This algorithm has a simple implementation that does not need a prediction of interfering signals statistics. In addition, this algorithm can be used in small devices with so closely distance between the two microphones. Moreover, the use of such algorithm allows reducing multiple noise sources at many azimuths positions. Finally, the new algorithm proves its performances referring to the perceptual evaluation of speech quality and the time domain waveforms.     

Explorations on the asymmetric total synthesis of isoschizogamine

Two approaches to the synthesis of isoschizogamine were reported. Both routes utilized an efficient aza-Claisen rearrangement to establish the absolute stereochemistry of the all-carbon quaternary center in the natural product. In the first approach, a highly diastereoselective (10:1) hetero-Diels-Alder reaction was utilized to reach a densely functionalized tetrahydroquinoline derivative as an advanced intermediate to the targeted alkaloid. An acylamidine intermediate was prepared and studied in the intramolecular cyclization reaction under acidic conditions in our second approach.     

First-principle electronic, elastic, and optical study of cubic gallium nitride

The ab initio pseudopotential (PP) method within the generalized gradient approximation (GGA) has been used to investigate the electronic, elastic constants, and optical properties of zinc-blende GaN. An underestimated band gap along with higher DOS and squeezed energy bands around the fermi level is obtained. The d-band effect is briefly discussed for electronic band structure calculations. With the help of elastic constants, acoustic wave speeds are calculated in [100], [110], and [111] planes. The dielectric constant, refractive index, and its pressure coefficient are well illustrated. The effect of hydrostatic pressure is explicated for all these properties. The results of the present study are evaluated with the existing experimental and first-principle calculations.