离子液体用于燃料油深度脱硫的研究进展

首先介绍了加氢催化脱硫和其他脱硫技术的特点,综述了近年来国内外利用离子液体在萃取脱硫、萃取脱硫与氧化脱硫耦合、萃取脱硫与生物脱硫耦合等方面的研究。认为离子液体萃取脱硫具有操作简便、可循环使用、无需氢气、环境友好、能深度脱硫等特点,是一项具有广阔发展前景的技术。若要实现该技术的工业化应用,还需进一步加强离子液体在合成工艺、脱硫选择性及回收再生等方面的研究。     

个性飞扬 情境使然

相IT和数码领域对而言,打印机市场已经发展得比较成熟,一个成熟的市场在一定程度上辐射出其竞争的激烈,打印机市场便是如此.     

Mass transfer kinetics of neodymium(III) extraction by calix[4]arene carboxylic acid using a constant interfacial area cell with laminar flow

BACKGROUND: Thermodynamics and kinetics data are both important to explain the extraction property. In order to develop a novel separation technology superior to current extraction systems, many promising extractants have been developed including calixarene carboxylic acids. The extraction thermodynamics behavior of calix[4]arene carboxylic acids has been reported extensively. In this study, the mass transfer kinetics of neodymium(III) and the interfacial behavior of calix[4]arene carboxylic acid were investigated. RESULTS: The rate constant (K_ao) becomes constant when the stirring speed was controlled between 250 rpm and 400 rpm. The activation energy (E_a) was calculated to be 21·41 kJ mol^?1 or 88·17 kJ mol^?1 (dependent on temperature) from the slope of log K_ao against 1000/T. The linear relationship between the specific area and the extraction rate is the characteristic of an interfacial reaction control. The minimum bulk concentration of the extractant necessary to saturate the interface (C_min) is lower than 4·19 × 10^?4 mol L^?1. CONCLUSION: The effect of stirring speed, temperature, and species concentration on the extraction rate demonstrates that the extraction regime depends on the extraction conditions. The chemical reaction control governs the extraction regime at temperatures below 303 K and a mixed control regime occurs when the temperature is between 303 K and 318 K. The probable locale for the chemical reaction is at the liquid–liquid interface and the rate equation is deduced to be: ? d[Nd³⁺]_(a)/dt = k_f[Nd³⁺]_(a)[H₄A]_(o)^0·727[H⁺]_(a)^?0·978. The rate‐controlling step was suggested by the analysis of the experimental results. Copyright © 2008 Society of Chemical Industry     

地下连续墙在太钢老厂改造工程中的应用

结合某深基坑支护施工实例 ,介绍了采用多头潜水钻成槽机进行地下连续墙施工的基本原理、工艺流程及注意事项。指出该方案对于在老厂区改造工程狭窄场地条件下 ,解决深基坑施工保护附近建 (构 )筑物安全具有独特的优势     

Novel one-step route for synthesizing sub-micrometer PSt hollow spheres via redox interfacial-initiated method in inversed emulsion

Interfacial-initiated polymerization of styrene (St) was carried out in inversed emulsion with cumene hydroperoxide (CHPO) and ferrous sulfate (FeSO₄)/disodium ethylenediaminetetraacetate (NaEDTA)/sodium formaldehyde sulfoxylate (SFS) as the redox initiation system. The water-soluble Fe²⁺-NaEDTA-SFS acted as the reducing component and the oil-soluble CHPO as the oxidant component of the redox initiation system. Therefore, the primary radicals were produced mainly at the oil/water interface to initiate the polymerization of St. Thus, sub-micrometer hollow polystyrene (PSt) spheres were obtained by one-stage polymerization, which was supported by the techniques of transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM).     

基于高抗热震性能的陶瓷刀具材料的微观结构设计

本文以现有的抗热震断裂和抗热震损伤的评价理论为基础，通过对材料中微裂纹的长度进行预测，从而实现了对陶瓷刀具材料的抗热震性能的微观结构设计。根据此理论对现有材料的抗热震性能的进行预测，预测结果与实际的测量结果相符，验证了该理论的正确性。     

《钢结构工程施工质量验收规范》修订简介

简要介绍《钢结构工程施工质量验收规范》(GB 5 0 2 0 5 - 2 0 0 1)的修订原则、方法以及对原规范进行修订中新增加的内容及要求 ,并进行了详细解释 ,以便于对新规范的理解     

天铁炼铁技术进步

近十年来，天铁集团炼铁厂通过改善原燃料条件；优化炉料结构，提高入炉品位；采用提高炉顶压力、富氧喷煤、低硅冶炼、炉顶气象系统等多项先进技术，使高炉各项经济技术指标逐年提高。     

Nanocrystalline Ni coatings strengthened with ultrafine particles

In this study, nanocrystalline Ni powders and thermally sprayed coatings, containing ultrafine AlN particles, were synthesized and characterized. The results indicated that the presence of AlN particles in the powders drastically decreased the dimension of agglomerates formed by cryomilling and increased the surface roughness of the agglomerates. The AlN phase was broken down into ultrafine particles of approximately 30 nm in size. These particles were dispersed in the Ni matrix and enhanced the development of a nanocrystalline structure in the Ni matrix during cryomilling. Selected-area diffraction patterns, obtained from transmission electron microscopy (TEM) and X-ray mapping with scanning electron microscopy (SEM), confirmed the presence of AlN particles in the coatings. The presence of AlN particles also led to an increase in the amount of NiO phase that was distributed in the coating, in the form of ultrafine, round particles. AlN particles increased the microhardness of the Ni coating by approximately 60 pct. Indentation-fracture results also indicated that the fine, dispersed AlN particles raised the apparent toughness of the Ni coating. The synthesized Ni coatings containing ultrafine AlN particles were characterized as equiaxed nanocrystalline grains with an average size of 24 nm, in which twins were observed. The increase in microhardness resulted from both grain refinement and the presence of ultrafine particles. The latter played the primary role in strengthening.     

Convergence of simultaneous perturbation stochastic approximation for nondifferentiable optimization

We consider simultaneous perturbation stochastic approximation for function minimization. The standard assumption for convergence is that the function be three times differentiable, although weaker assumptions have been used for special cases. However, all work that we are aware of at least requires differentiability. We relax the differentiability requirement and prove convergence using convex analysis.