Kinetic Relationships of Liquid-Phase Oxidation of Styrene with Hydrogen Peroxide in the Presence of Polyoxotungstate Modified with Cerium Cations

Russian Journal of Applied Chemistry - Liquid-phase oxidation of styrene with hydrogen peroxide in the presence of a catalytic system based on (NH4)10W12O41 + Ce(NO3)3 + H3PO4, supported on a...     

Impurity-related optical response in a 2D and 3D quantum dot with Gaussian confinement under intense laser field

ABSTRACT

Using the two-dimensional (2D) diagonalisation method, the impurity-related electronic states and optical response in a 2D quantum dot with Gaussian confinement potential under nonresonant intense laser field are investigated. The effects of a hydrogenic impurity on the energy spectrum and binding energy of the electron and also intersubband optical absorption are calculated. The obtained numerical results show that the degeneracies of the excited electron states are broken and the absorption spectrum exhibits a redshift with the values of the laser field. The findings indicate a new degree of freedom to tune the performance of novel optoelectronic devices, based on the quantum dots and to control their specific properties by means of intense laser field and hydrogenic donor impurity. Using the same Gaussian confinement model, the electronic properties of a confined electron in the region of a spherical quantum dot are studied under the combined effects of on-centre donor impurity and a linearly polarised intense laser radiation. The three-dimensional problem is used to theoretically model, with very good agreement, some experimental findings reported in the literature related to the photoluminescence peak energy transition.     

Dynamic and buckling analysis of polymer hybrid composite beam with variable thickness

This work deals with a study of the dynamic and buckling analysis of polymer hybrid composite(PHC) beam. The beam has variable thickness and is reinforced by carbon nanotubes(CNTs) and nanoclay(NC) simultaneously. The governing equations are derived based on the first shear deformation theory(FSDT). A three-phase HalpinTsai approach is used to predict the mechanical properties of the PHC. We focus our attention on the effect of the simultaneous addition of NC and CNT on the vibration and buckling analysis of the PHC beam with variable thickness. Also a comparison study is done on the sensation of three impressive parameters including CNT, NC weight fractions, and the shape factor of fillers on the mechanical properties of PHC beams,as well as fundamental frequencies of free vibrations and critical buckling load. The results show that the increase of shape factor value, NC, and CNT weight fractions leads to considerable reinforcement in mechanical properties as well as increase of the dimensionless fundamental frequency and buckling load. The variation of CNT weight fraction on elastic modulus is more sensitive rather than shear modulus but the effect of NC weight fraction on elastic and shear moduli is fairly the same. The shape factor values more than the medium level do not affect the mechanical properties.     

Dielectrophoretically Modulated Optical Spectroscopy of Colloidal Nanoparticle Solutions in Microfluidic Channels

Optical spectroscopic techniques (e.g., extinction, scattering, and fluorescence spectroscopies) are important for the analysis of colloidal solutions of nanoparticles (NPs). They are routinely applied to plasmonic and quantum-dot NP samples assuming that these contain a single population of particles with modest size and shape dispersity. However, these spectroscopic techniques become less effective when the sample is a mixture of particles with different sizes, shapes, or composition. Here, an original microfluidic method is proposed for the optical spectroscopic analysis of colloidal NP solutions that combines periodic trapping of NPs by dielectrophoresis (DEP) with in situ optical extinction spectroscopy. The periodic trapping leads to modulation of the continuously monitored optical spectrum depending on the DEP properties of the NPs. DEP-modulated spectroscopy is demonstrated using colloidal gold NPs as small as 40 nm diameter. It is found that the DEP modulation is significantly enhanced when employing suitable microfluidic flow over a multielectrode array. Finally, it is shown that the method can identify and characterize the NP species simultaneously present in a mixture of 40 and 80 nm gold NPs, opening the way toward optical spectroscopic analysis of higher complexity NP mixtures through the combination of the DEP-modulated spectroscopy with chemometric methods.     

A facile approach for synthesis of thiazines-, thiazoles- and triazoles-annulated 6-styryl-2-thiouracil derivative

Journal of the Iranian Chemical Society - Utility of 4-oxo-6-styryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 1 in synthesis of a new series of fused pyrimidines was described....     

Synthesis and Some Transformations of 5-(1,4-Benzodioxan-2-yl)-4-phenyl-4H-1,2,4-triazole-3-thiol

Russian Journal of Organic Chemistry - The title compound was synthesized by reaction of 1,4-benzodioxane-2-carbohydrazide with phenyl isothiocyanate, followed by cyclization of the...     

Click Synthesis of 1,2,3-Triazole Nucleosides Based on Functionalized Nicotinonitriles

Russian Journal of Organic Chemistry - A facile synthesis of a new series of 1,2,3-triazolyl nucleosides via one-pot click reaction is described. Acetylenic nicotinonitriles synthesized previously...     

Review of highly charged ion production with ECR ion source and the future opportunities for HCI physics

In recent years, there is very intense worldwide research and development work on electron cyclotron resonance ion source (ECRIS). Remarkable progress represented by the third generation superconducting ECRIS has been made with regards of intense highly charged ion beam production such as >600 eμA Ar¹⁶⁺, >10 eμA Ar¹⁸⁺, and hundreds of enA He-like Kr³⁴⁺. A low energy heavy ion platform named Low Energy heavy ion Accelerator Facility (LEAF) that features a next generation 45 GHz ECRIS, a 300 kV high voltage platform, a 0.5 MeV/u radio-frequency quadrupole, and several multidisciplinary experimental terminals is under construction at the Institute of Modern Physics (IMP). This paper will report on the recent progress with ECRIS dedicated to highly charged ions and the status of LEAF at IMP that will provide new opportunities for highly charged ion physics in the near future.     

Optimized spacer layer thickness for plasmonic-induced enhancement of photocurrent in a-Si:H

Journal of Nanoparticle Research - Plasmonic interfaces consisting of silver nanoparticles of different sizes (50–100&;nbsp;nm) have been processed by the self-assembled dewetting...