Structural,mechanical, and gas barrier properties of poly(ethylene terephthalate) nanohybrid using nanotalc

Amorphous poly(ethylene terephthalate) (PET)/nanotalc nanohybrids have been prepared through solution casting route. The fine dispersion of nanotalc clay in the polymer matrix has been examined through transmission electron microscopy (TEM). The intercalation and interaction of nanoclay have further been confirmed using X-ray diffraction, ultraviolet, and Fourier transform infrared techniques. The thermal stability has been tested via thermogravimetric analysis and nanohybrids have been found thermally stable. The glass-transition temperature has been further confirmed through DTA and differential scanning calorimetry analysis which has been increased in the presence of nanotalc arising from greater interaction. The nanohybrids have been tested for their mechanical performances and have been found to have improved mechanical responses for nanotalc-filled nanohybrids. The modulus has been increased whereas toughness has been compromised meagerly. The modulus values have been theoretically predicted using various micromechanical models. The microhardness of the nanohybrids has been examined through Vicker hardness test. The theoretical prediction of the hardness values has been done using different micromechanical models. The structural development upon uniaxial stretching of the samples has been studied using small-angle X-ray scattering and wide-angle ray diffraction. The stretched samples have found to have short-range ordering as well as increased blob size and better coherency in the presence of nanotalc. The aspect ratio has been increased upon stretching. The inclusion of nanotalc has induced high barrier for gas permeation as compared to pure PET. The oxygen transmission rate has been found to decrease up to 64% for 8 wt % of filler concentration. The prediction of the permeability data has been done using different models considering different aspect ratios. The permeability values have been predicted very closely and nanohybrids have been found suitable for practical applications such as packaging. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48607.     

Transition of Cs3C60 crystals with Rb impurity to the superconducting state

The statistical theory of phase transition in fullerides of alkali metals to the superconducting state has been elaborated. The calculation of the free energy of crystals has been performed on the basis of molecular-kinetics and the equilibrium equations have been examined. The critical temperature of superconductivity has been estimated, and its concentration dependence has been ascertained. The calculation results have been compared with experimental data. The numerical estimation for energetic parameters of pairing of Cooper pairs electrons has been performed.     

油田含油污水过滤器滤料原位清洗再生

通过分析发现滤料污染物主要成分为原油、硫化物等。针对污染物成分研制了有效的滤料再生剂,很好地解决了致密的混合污染物层难以清除的问题。研制了加药装置,确定了滤料原位再生工艺,现场应用取得了良好的效果。     

电力电缆用膨胀型防火涂料的研制

依照电力电缆的特点和膨胀型防火涂料的膨胀防火机理,筛选涂料各组分原料。通过实验, 确定出合理的涂料配方。所生产的涂料经检测,各项理化指标均达到要求,防火性能达到了一级。     

Third-order optical nonlinearity in single-wall carbon nanotubes

The third-order optical nonlinearity in carbon nanotubes (CNT) exposed to an intensive external electromagnetic field has been investigated. The analysis is based on the quantum kinetic equations for the density matrix of π-electrons in CNT. In the regime of weak driving field, the kinetic equations have been solved by the perturbation method and the third-order nonlinear polarizability of different achiral CNTs has been calculated. The theory elaborated has been used for the evaluation of nonlinear susceptibility of CNT-based composites. Comparison with available experimental data has been presented. In the case of high intensive driving field a nonperturbative numerical simulation of the process has been carried out in the time domain. The axial current density in CNT has been calculated. Excitation of π-plasmons in CNTs has been analyzed.     

镁在有机合成中的应用研究进展

综述了镁在有机合成中的应用研究,从镁在元素周期表的位置和电子构型详细讲述了镁作为催化剂和格氏试剂对有机合成的影响。催化剂从催化活性物质,催化剂载体,助催化剂的角度进行论述,格氏试剂主要论述了典型的反应类型,最后对镁在有机合成中的应用进行了展望。     

Evaluation of Amberlite IRC‐718 Chelating Ion Exchange Resin in Loading‐Elution‐Regeneration Cycles for the Separation and Recovery of Strontium from Alkaline Radioactive Waste

The separation and recovery of radiostrontium from simulated alkaline reprocessing waste solution has been studied using Amberlite IRC‐718, a chelating resin containing iminodiacetic acid groups. The breakthrough behavior of strontium has been determined by conducting an extended column run. The column loading performance has been correlated with batch equilibration results. Efficient elution of loaded strontium has been achieved using dilute nitric acid. Satisfactory column performance has been demonstrated in repeated loading‐elution‐regeneration cycles. Finally, the characteristics of used resin have been determined to ascertain its efficacy for further use.     

Retarding behaviour of organic solvents in permanganate-sulphite-initiated polymerization of acrylamide

Redox polymerization of acrylamide initiated by a new redox couple, potassium permanganate-sodium sulphite, has been studied under atmospheric oxygen at 35 ± 0.2° C. The rate of polymerization has been found to vary with the half power of the redox components and the first power of the monomer concentration. The energy of activation has been calculated to be 8.29 kcal/(deg. mol.). The effect of various additives such as neutral salts and surface-active agents has been studied qualitatively. The retarding effect of organic solvents on the rate of polymerization has also been studied both qualitatively and quantitatively. An interpretation of the observed results has been proposed.     

复杂断块油田特高含水期实现持续稳产的做法

胜利油田临盘采油厂目前开发动用临盘、商河、临南三个油田,区域构造位于渤海湾盆地济阳坳陷惠民凹陷中央隆起带。“九五”末期由于油田相继进入特高含水期,剩余油分布复杂、断块破碎、油水井套损严重、注采完善程度低,造成油田产量连续三年下降。针对严峻的开发形势,进入“十五”以后,通过深化油藏构造、储层、剩余油潜力的研究,强化注采井网的完善。提高了水驱控制程度,增强油田稳产基础,提高采收率。全厂连续三年原油年产量连续稳定在163×104t,取得较好的开发效果和经济效益。     

Modeling Hydrodynamic Cavitation

A simplified and unified model has been proposed to study the cavitation phenomena in hydraulic devices, with emphasis on the venturi tube and high-speed homogenizer. A turbulence model analogous to the acoustic cavitation has been developed and the dynamics of the cavities as a cluster has been considered. The prediction of the cavitation inception number has been made for various operating conditions and has been compared with the experimental observations. The effect of operating parameters, such as inlet pressure and fully recovered downstream pressure, has been studied numerically and compared with the data in the literature for the case of the venturi. The predicted cavitation intensities were compared indirectly with the experimental results. It has been found that optimum operating conditions do exist at which the observable cavitational effect is maximum. In the case of the high-speed homogenizer, the predicted effects as a function of rotational speed have been compared with the results of the aqueous KI decomposition reaction and have been found to match well. The study concludes with the recommendations and methods for possibly optimizing hydrodynamic cavitation phenomena for maximum effect.     

Potassium persulphate-malonic acid redox pair initiated polymerization of methacrylamide

Summary The kinetics of aqueous polymerization of methacrylamide initiated by potassium persulphate-malonic acid redox pair has been investigated at 50±1°C under nitrogen atmosphere. The initial rate of polymerization has been found to be square root dependence to the initial concentration of potassium persulphate and malonic acid. The order of reaction with respect to monomer has been found to be unity. The overall energy of activation has been found to be 66±1 KJ/mol. The effect of addition of manganous sulphate and sulphuric acid has been investigated. On the basis of experimental results a suitable mechanism has been proposed.     

甲苯液相氧化制苯甲醛工艺的产品质量控制

简述了甲苯液相氧化制苯甲醛的工艺过程,详细介绍了苯甲醛在生产过程中存在的产品质量问题、影响因素,并提出了解决方案及优化过程,从而使苯甲醛产品纯度从99%提高到99.5%,优级品率达到95%以上。     

Modeling of Separation of Granular Materials on Multiple-Deck Classifiers Using the Theory of Stochastic Processes

The mathematical model of the separation of granular materials on multiple-deck sieve classifiers has been constructed using the theory of Poisson processes and the model has been identified. The problem of the optimal implementation of the process in multicriterial setting has been formulated and solved; the engineering simulation of the classifier has been performed using this solution.     

露天矿连续工艺系统设备可靠性分析

针对黑岱沟露天煤矿第一套连续工艺系统长期达不到设计生产能力的问题,对系统中的设备进行了可靠性数据的收集与分析,计算了各台设备的可靠性指标,找出了系统的薄弱环节,并提出了提高设备可靠性的措施.     

基于ANSYS的复合材料旋翼桨叶动力分析

首次应用APDL语言建立复合材料旋翼桨叶三维有限元模型。计入空气动力和离心力,应用ANSYS软件对旋翼桨叶的动力特性和静强度进行分析,给出桨叶共振图。依据本文动力分析后设计的复合材料旋翼桨叶已成功应用于某型号的无人直升机。     

Modification of the glass surface by titanium dioxide films synthesized through the sol–gel method

The glass surface has been modified by titanium dioxide films synthesized using the sol-gel method. The sol-gel synthesis has been optimized by the experimental design with the use of the Latin square method. The film composition has been evaluated using X-ray powder diffraction analysis and optical measurements. The photoinduced hydrophilicity of the modified glass has been investigated.     

硝基苯精馏再沸器爆炸事故分析

介绍了硝基苯精馏再沸器爆炸发生的主要经过，根据硝基苯的有关物性以及爆炸理论，对硝基苯精馏再沸器爆炸事故的过程进行了分析，找出可能产生的原因，并对爆炸的机理进行了探讨，最后提出相关安全措施。     

Optical and electrochemical study of underpotential deposition of bismuth on gold electrode

The underpotential deposition of Bi on Au has been investigated by specular reflectance spectroscopy and linear sweep voltammetry. The spectral dependance of ΔR/R caused by Bi adatoms has been determined and compared with the calculated spectrum. A satisfactory agreement between experimental and calculated spectra was found. ΔR/R values have been used to determine the surface concentration of Bi_ad which then has been used to calculate the electrosorption valence of Bi_ad. It has been found that γ_Bi = 2.6. The optical evidence of interaction of Bi ions with gold oxide has been obtained.     

Combined use of sepiolite and a hyperbranched polyester in the modification of epoxy/anhydride coatings: A study of the curing process and the final properties

The curing reaction of formulations of diglycidyl ether of bisphenol A (DGEBA) and tetrahydrophthalic anhydride (THPA) catalyzed with a tertiary amine and containing sepiolite and/or hyperbranched poly(ester) has been studied by means of DSC, and the effect of each additive has been evaluated. The resulting coatings have been characterized by DMTA, TGA and also the shrinkage during the curing process has been determined. The influence of the additives in the toughness of the resulting coatings has been determined by performing standardized impact tests and observing the fracture surfaces by SEM. The values of impact strength have been correlated to the morphology of the samples by means of TEM. Also microhardness of the cured materials has been measured.     

Phase diagram of poly(vinyl chloride) and solution chlorinated polyethylene

The behaviour of mixtures of poly(vinyl chloride) (PVC) and solution chlorinated polyethylene (SCPE) has been investigated as a function of temperature. These polymers have been found to be compatible over some ranges of composition and exhibit the phenomenon of a lower critical solution temperature (LCST). The thermally-induced phase separation has been investigated by optical, dynamic mechanical, and electron microscope techniques. The single phase mixture has been investigated by scanning analytical electron microscopy. Some investigation of the thermodynamics of the mixture has been made and the heat of mixing term has been found to be negative and small, i.e. favouring mixing. It has been shown that the technique of in situ polymerization overcomes many of the problems of preparing these polymer mixtures in the solid state.