Optimization of solvent crystallization process in obtaining high purity anthracene and carbazole from crude anthracene

Solvent crystallization is the main method used for preparing anthracene and carbazole from the crude anthracene. The key to the optimization of this method is improving the solubility selectivity of the solvent by means of solvent modulating and process optimization. In this study, the solubility of anthracene, phenanthrene, and carbazole in xylene, dimethylformamide (DMF), DMF with amine/amide, isopropanolamine, and chlorobenzene is examined and the solid‐liquid ternary anthracene–carbazole–DMF/(DMF+19.96% isopropanolamine) system phase diagram is determined and applied in the solvent crystallization process. The results showed that the solubility selectivity of xylene increases with increased temperature. Also, selectivity increases with an increase of the amount of isopropanolamine in the mixture of DMF and isopropanolamine, while decreases with increased temperature. Through multiple washings of crude anthracene with xylene, DMF+19.96% isopropanolamine, and chlorobenzene, it was possible to obtain anthracene and carbazole of purity higher than 98 wt %. © 2013 American Institute of Chemical Engineers AIChE J, 60: 275–281, 2014     

Microstructure,martensitic transformation and shape memory effect of polycrystalline Cu-Al-Mn-Fe alloys

In this study, two Cu-Al-Mn-Fe polycrystalline alloys were prepared, and their microstructure, reversible martensitic transformation, mechanical properties and shape memory effects were investigated. The results show that the reversible martensitic transformation temperatures of the studied alloys are between room temperature and 373 K, which are suitable for practical applications. Two typed martensites of 18R and 2H coexist both in two alloys. The bcc β(FeAl) nanoparticles are Fe-rich, Mnrich and Cu-poor, whereas the martensite is Cu-rich, Fe-poor and Mn-poor. The size of nanoparticles ranges from tens to hundreds of nanometers. Full shape recovery property is displayed in Cu-12.9Al-4.5Mn-2.6Fe alloy all the time while applying different deformation from 5% to 8%. The maximum recoverable strain is up to 4.4% with a recovery rate of 100%.     

异形铸件斜孔加工工装的设计及应用

铸件油泵体属于异形件,使用普通车床对其上的斜孔加工时,油泵体的定位、装夹很麻烦,需要大量的辅助时间。通过设计一种工装夹具,实现了方便定位,大大缩短了辅助时间。     

Biogas recovery from microwave heated sludge by anaerobic digestion

Biogas generated from sewage sludge,livestock waste,and food waste by anaerobic digestion is a valuable renewable energy resource.However,conventional anaerobic digestion is not an efficient process.A long hydraulic retention time and low biogas recovery rate hinder the applications of those resources.An effective pretreatment method to destroy sludge microbial cells has been one of the major concerns regarding improvement of the biogas production.This article focuses on the effects of microwave heating on ...     

多智能体系统开发工具和运行平台研究综述

多智能体系统技术在实际工程中的广泛应用,使人们对能够支持快速设计和实现多智能体系统的开发工具和运行平台提出了迫切的需求。文章首先对多种具有代表性的通用开发工具和运行平台的实现方法及表现出来的优缺点做了详细分析和探讨,随后对该技术的发展进行了展望。     

B样条小波基自适应无网格迦辽金法应用于刚塑性成形模拟

无网格方法适合大变形计算和自适应分析,是进行刚塑性成形过程仿真的比较有潜力的方法。利用样条小波的多分辨分析特性,基于刚塑性变形的特点,通过实现刚塑性场量的两尺度分解技术,将场变量分解成低尺度成分和高尺度成分,利用高尺度成分判断求解高梯度区域;利用基于局部Delaunay三角化的细分方案实现高梯度区域节点的自适应细分,最终实现一个应用于刚塑性成形仿真的样条小波基自适应无网格迦辽金法,并用实例验证算法的稳定性和有效性。     

液压启闭机双缸同步问题的探讨

阐述了同步回路选择的重要性。从液压启闭机设计、制造、安装等方面分析了影响双缸同步的因素，着重介绍了同步回路及工程应用情况。     

Estimation of methane and nitrous oxide emissions from biomass waste in China:A case study in Hebei Province

Crop residue,animal manure and MSW are selected as representative biomass waste.Greenhouse gas emissions from treatment and disposal process of biomass waste in Hebei province are estimated for the period from 2002 to 2007,using the methodologies recommended by the Intergovernmental Panel on Climate Change.Greenhouse gas emission was about 10 Mt CO2-equivalent annually.About 6% of greenhouse gas emission came from open burning of crop residue,74% from management system of animal manure,and 20% from MSW disp...     

Two-phase flow in anode flow field of a small direct methanol fuel cell in different gravities

An in-situ visualization of two-phase flow inside anode flow bed of a small liquid fed direct methanol fuel cells in normal and reduced gravity has been conducted in a drop tower. The anode flow bed consists of 11 parallel straight channels. The length, width and depth of single channel, which had rectangular cross section, are 48.0, 2.5 and 2.0 mm, respectively. The rib width was 2.0 mm. The experimental results indicated that when the fuel cell orientation is vertical, two-phase flow pattern in anode channels can evolve from bubbly flow in normal gravity into slug flow in microgravity. The size of bubbles in the reduced gravity is also bigger. In microgravity, the bubbles rising speed in vertical channels is obviously slower than that in normal gravity. When the fuel cell orientation is horizontal, the slug flow in the reduced gravity has almost the same characteristic with that in normal gravity. It implies that the effect of gravity on two-phase flow is small and the bubbles removal is governed by viscous drag. When the gas slugs or gas columns occupy channels, the performance of liquid fed direct methanol fuel cells is failing rapidly. It infers that in long-term microgravity, flow bed and operating condition should be optimized to avoid concentration polarization of fuel cells. Supported by the National Natural Science Foundation of China (Grant No. 50406010) and Excellent Talents Programme of Beijing Municipality (Grant No. 20081D0501500167)     

锤片粉碎机气力输送系统的试验研究

设计的锤片粉碎机气力输送系统试验台,在粉碎机机壳的四个不同位置设置了进风口,采用孔径为0.7 mm(开孔率5.15%)和1 mm(开孔率7.92%)筛板,用玉米进行粉碎试验的结果表明,根据粉碎机机型设计合适的机壳进风口和可调节进风口面积的结构,并且在气力输送系统中安装参数检测装置,使锤片粉碎机的气力输送系统能够适应饲料原料多品种和不同粉碎成品粒度的要求。