Novel polymeric potassium complex: Its synthesis,structural characterization,photoluminescence and electrochemical properties

In this paper, we obtained a novel poly(vanillinato potassium) complex (PVP) as a single crystal and characterized by analytical and spectroscopic methods. A single crystal of the PVP was obtained from the acetone solution. X-ray structural data show that crystals contain polymeric K⁺ complex of vanillin. Each potassium ion in the polymeric structure is identical and seven-coordinate, bonded to two methoxy, two phenoxy and three aldehyde oxygen atoms from four vaniline molecules. Two aldehyde oxygen atoms are bridging between potassium ions. It crystallizes in the monoclinic system, space group P2₁/c, with lattice parameters a=9.6215(10) Å, b=17.4139(19) Å, c=9.6119(10) Å, β=100.457(2)° and Z=4. Thermal properties of the PVP were investigated by TGA, DTA and DSC methods. The electrochemical properties of the complex were studied in different solvents and at various scan rates. The luminescence properties of the complex in different solvents and at different pH values have been investigated. The results show that the complex exhibits more efficient luminescence property in CH₃CN and n-butanol.     

Compton scattering of 59.5 keV gamma rays from p-Si sample in an external electric field

This study is related to Compton scattering of photons from a p-Si sample whose surface charge density distributions are changed by an external electric field. The external electric field intensity in the range 0-75 kV/m was used to change the surface charge density distributions of the sample. The sample surface perpendicular to the electric field was selected as the scattering surface. The p-Si sample was bombarded by 59.5 keV γ-photons emitting from an Am-241 point source. The Compton scattered photons at an angle of 90^o were detected by an Si(Li) detector. The Compton scattering intensity suddenly increased with the application of the electric field since the applied electric field distorts both the negatively charged scattering center (free electron, bound electron, ionized acceptor) and the positively charged scattering center (hole) and their momentum distribution in the sample. There is a good third-order polynominal relation between the Compton scattering intensity and the increasing (or decreasing) electric field intensity. The results show that the positively charged scattering centers behave like negatively charged scattering centers, but the latter are slightly more effective than the former in the Compton scattering of γ-rays from the sample in the electric field.     

对机读卡民文信息采集系统的探讨

针对当前新疆维吾尔自治区招生考务管理工作中急待解决的一个问题，即万卡通数据录入系统（ＧＤＲＳ）只能识别英文，汉文而无法识别民文的问题，设计出在无民文ＤＯＳ系统的支持下也可以采集民文信息的新方案，本项目１９９６年在自治区教委立项并研制成功，填补了新疆计算机考务管理工作的空白，在１９９７年的普通高校招生统一考试，录取工作中推广实用，效果很理想。     

A green synthesis of new 3-aryl-4-phenylsulfonyl-5-aminoisoxazoles

The present work describes a new protocol for the synthesis of 5-aminoisoxazoles using α-chlorooximes and 2-phenylsulfonyl acetonitrile via green chemistry routes. The titled 5-aminoisoxazoles 3 were further reacted with 4-nitrobenzoyl chloride to obtain 5-amidoisoxazoles with moderate yields. These heterocyclic compounds were tested in vitro MTT study to investigate inhibitive abilities to some cancer cell lines (C3a, L929, T98g and Mcf-7) and compounds 3a, 3c, 3e and 3h showed noticeable cytotoxic property against four cancer cell lines.     

Theoretical prediction of ionization/oxidation potentials in conjugated polymers

Various density functional theory (DFT) functionals and semiempirical techniques were used to predict the ionization potentials of selected conjugated polymers. Ionization potentials at infinite chain lengths were estimated using Meier fit on oligomer data. Calculated gas-phase ionization potentials with BHandH functional showed good correlation with the experimental data. The results from the semiempirical techniques do not compare as favorably as the ones obtained from DFT methods. The data fitting allowed us to estimate the size of “effective ionization length”, which spanned over 20–30 double bonds in the conjugated backbone of the polymer in question.     

Effect of variable thermal conductivity and viscosity on single phase convective heat transfer in slip flow

For a variety of fields in which micro-mechanical systems and electronic components are used, fluid flow and heat transfer at the microscale needs to be understood and modeled with an acceptable reliability. In general, models are prepared by making some extensions to the conventional theories by including the scaling effects that become important for microscale. Some of these effects are; axial conduction, viscous dissipation, and rarefaction. In addition to these effects, temperature variable thermal conductivity and viscosity may become important in microscale gas flows due to the high temperature gradients that may exist in the fluid. For this purpose, simultaneously developing, single phase, laminar and incompressible air flow in a microtube and in the micro gap between parallel plates is numerically analyzed. Navier–Stokes and energy equations are solved and the variation of Nusselt number along the channel is presented in tabular and graphical forms as a function of Knudsen, Peclet, and Brinkman numbers, including temperature variable thermal conductivity and viscosity.     

Spectroscopic Application of Realgar Using X-ray Fluorescence and Raman Spectroscopy

ABSTRACT

Samples of realgar ore were collected from the hydrothermal products of the Eocene volcanic material of the Erzurum region in Turkey. The prepared samples were analyzed by polarized energy dispersive X-ray fluorescence (PEDXRF) and by confocal Raman spectroscopy (CRS). The goal of this study was to figure out the chemical composition of realgar and its properties through PEDXRF and CRS and the optical characteristic features under the polarized microscope. The result of the XRF analysis shows the collected realgar samples are mainly composed of As, S, Si, and Mg in different proportions. The contents of As in realgar change from 36.55% through 31.49% to 5.97% in the analyzed samples. The strong peak of the realgar samples is at 352 cm^?1, and a weaker peak exists around 190 cm^?1. The accuracy and precision of the technique for chemical analysis is demonstrated by analyzing CRM 2126-81. The realgar ores were studied by use of CRS and polarized microscopy.     

New analysis and application of fractional order Schrödinger equation using with Atangana–Batogna numerical scheme

In this work, an analytical approximation to the solution of Schrodinger equation has been provided. The fractional derivative used in this equation is the Caputo derivative. The existence and uniqueness conditions of solutions for the proposed model are derived based on the power law. While solving the fractional order Schrodinger equation, Atangana–Batogna numerical method is presented for fractional order equation. We obtain an efficient recurrence relation for solving these kinds of equations. To illustrate the usefulness of the numerical scheme, the numerical simulations are presented. The results show that the numerical scheme is very effective and simple.     

The metal complexes of new Schiff bases containing phosphonate groups and catalytic properties for alkane oxidation

In this study, two new salicylidene phosphonate ligands (HL¹ and HL²) and their metal complexes (Cu²⁺, VO²⁺ and La³⁺) were synthesized and characterized by spectroscopic and analytical methods. The molecular structure of the ligand HL¹ was determined by single‐crystal X‐ray diffraction study. In the structure of the ligand, there is an intramolecular phenol‐imine hydrogen bond. The synthesized compounds exhibit only one emission maximum upon excitation at 270–295  nm range. Complexation of the Schiff base ligands with metal ions did not cause a considerable quenching effect. Finally, the complexes prepared were used as catalysts in cyclohexane oxidation under microwave irradiation. The complexes showed high conversion rates (> 90%) for cyclohexane oxidation; however, poor selectivity was observed for all complexes. The La³⁺ complexes showed better selectivity for cyclohexane → cyclohexanol transformation with about 45% selectivity.