Conversion of acids to benzimidazoles with transition metal/zeolites

Transition metal/Y zeolites were prepared using microwave solid state and aqueous solution ion exchange methods. The activity of these zeolites was investigated in a conversion of acids to benzimidazoles reaction between 4-methyl-1, 2-phenylenediamine and 3-nitrobenzoic acid. The yield of these reactions increased in order of CuY < Fe²⁺Y < NiY < CoY < NaY < CrY < MnY < ZnY for both methods. The solid state ion-exchanged zeolites showed higher activity in comparison to the aqueous solution exchange. Yields of products in the presence of the ZnY zeolite were of the order of 69–83%. It seems that the Lewis sites are better sites compared to the Bronsted sites for this reaction.     

Multi-nozzle electrospray system for gas cleaning processes

A multi-nozzle electrospray system was developed as a charged droplet source for cleaning a gas contaminated with fine particles. The efficiency of removal of fine particles from the gas can be significantly increased, as compared to uncharged sprays, when the droplets are electrically charged. In the presented experiments, the spray of the droplets of size lower than 100 μm was charged either positively or negatively. Cigarette smoke was used as a source of submicrometer particles. The suppression of the particle concentration was determined after different time intervals of spraying of water. Further improvement in gas cleaning was obtained after charging the smoke particles using a specially designed corona charger. The efficiency of the cleaning process was similar to that obtained for droplets generated by mechanical atomisers with induction charging, but the electrospraying allowed decreasing the water consumption up to about three times.     

Control of adiabatic two-phase dielectric fluid flow distribution with EHD conduction pumping

Electrohydrodynamic (EHD) conduction pumping is associated with the heterocharge layers of finite thickness in the vicinity of the electrodes, which are based on the process of dissociation of the neutral electrolytic species and recombination of the generated ions. This paper presents the successful control of dielectric liquid/vapor flow distribution between two parallel branch lines utilizing an EHD conduction pump at a select mass flux level under adiabatic condition.     

Couette flow in ferrofluids with magnetic field

Instability of a viscous, incompressible ferrofluid flow in an annular space between two coaxially rotating cylinders in the presence of axial magnetic field has been investigated numerically. The magnetic field perturbations in fluid in the gap between the cylinders have been taken into consideration and these have been observed to stabilize the Couette flow.     

Iodine‐Catalyzed Friedlander Quinoline Synthesis under Solvent‐Free Conditions

Polyfunctional quinolines were synthesized using Friedlander method catalyzed by molecular iodine in high yields at 60 °C under solvent‐free conditions.     

Self-assembled dahlia-like cadmium hydrogen phosphate hydrate nanostructures as templates for cadmium hydroxyapatite hexagonal prisms

Cadmium hydroxyapatite (Cd-Hap, Cd₁₀(PO₄)₆(OH)₂) and cadmium hydrogen phosphate hydrate (Cd₅H₂(PO₄)₄·4H₂O) nanostructures with average crystallite sizes of about 38 and 44 nm, respectively, were prepared through a simple chemical process. The formation mechanism and characteristics of the Cd₅H₂(PO₄)₄·4H₂O precipitates prior to the hydrothermal process and Cd-Hap during the hydrothermal treatment were investigated with XRD, SEM, TEM and BET analyses. It was found that self-assembled dahlia-like Cd₅H₂(PO₄)₄·4H₂O nanostructure precipitates were formed due to interlace of preliminary nanosheets prior to the hydrothermal process, while nanostructure Cd-Hap hexagonal prisms were prepared after 15 h of hydrothermal treatment.     

Anisotropies in soft magnetic nanocrystalline alloys

The article reviews and updates the understanding of the soft magnetic properties of nanocrystalline Fe-based alloys. In optimized compositions the random magneto-crystalline anisotropy of the structural phases is largely averaged out. The soft magnetic properties are then controlled by magneto-elastic and induced anisotropies which are uniform on a scale much larger than the exchange length. But unlike to the case of soft magnetic amorphous alloys, there is still a competition between the random and the more uniform anisotropy contributions. The experimental findings are complemented by theoretical results.     

Entanglement Degree of Parasupersymmetric Coherent States of Harmonic Oscillator

We study the boson–parafermion entanglement of the parasupersymmetric coherent states of the harmonic oscillator and derive the degree of entanglement in terms of the concurrence. The conditions for obtaining the maximal entanglement is also examined, and it is shown that in the usual supersymmetry situation we can obtain maximally entangled Bell states. PACS numbers: 03.67.Ud 03.67.Mn     

超模的同构定理

本文利用模论导出超模的三个同构定理,同时,给出超模的Jordan-Holder定理,最后,探讨了超模的基本关系∈~*,并研究其性质．