图像分析方法在混凝土孔结构测试中的应用

根据定量体视学的原理,应用光学显微镜和计算机图像处理软件(Image-pro Plus)获取了孔隙率、孔径及其分布等孔结构参数,并详细介绍了混凝土孔结构图像分析方法的过程。结果表明,建立的光学显微图像分析法可以准确量化表征混凝土细观孔隙率、孔径及其分布等孔结构参数,该方法可望为水泥基材料或其他多孔材料孔结构调控以及建立孔结构与性能关系奠定基础。     

干熄炉焦炭床层换热的实验和理论研究

干法熄焦工艺的技术核心是干熄炉内焦炭与循环气体的热交换.本文根据干熄炉内焦炭床层换热的特点,建立了固定床干熄炉传热模拟实验装置,针对焦炭粒度、冷却气体流量等关键参数进行了实验研究.为了有效地处理实验数据,重新定义、推导了平均换热系数的计算公式,得到了干熄炉冷却段平均换热系数及其相关准则数关系;并利用导热反问题原理得到了焦炭床层的局部换热系数.研究结果表明,局部换热系数和平均换热系数的变化规律相似,冷却气体流量的增加有利于提高换热系数;换热系数对焦炭的粒度较敏感,焦炭粒度变小时,换热系数增加.     

纳米ZnO的形貌对光催化降解焦炭废水效果的研究

制备了片状多孔、花状、球状、棒状和菱形的纳米ZnO粒子,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)进行表征,并研究了片状多孔、花状、球状、棒状和菱形的纳米ZnO颗粒对焦炭废水的降解以及其不同形貌对光催化处理焦炭废水效果的影响。结果表明,不同形貌纳米ZnO的光催化降解焦炭废水能力大小顺序为:片状多孔>花状>球状>棒状>菱形,当片状多孔纳米ZnO的加入量为焦炭废水质量的2%,降解时间为0.5 h,其吸附性能与催化效果达到最佳。     

纳米ZnO的形貌对光催化降解焦炭废水效果的研究

制备了片状多孔、花状、球状、棒状和菱形的纳米ZnO粒子,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)进行表征,并研究了片状多孔、花状、球状、棒状和菱形的纳米ZnO颗粒对焦炭废水的降解以及其不同形貌对光催化处理焦炭废水效果的影响。结果表明,不同形貌纳米ZnO的光催化降解焦炭废水能力大小顺序为:片状多孔>花状>球状>棒状>菱形,当片状多孔纳米ZnO的加入量为焦炭废水质量的2%,降解时间为0.5 h,其吸附性能与催化效果达到最佳。     

纳米多孔配位聚合物的研究进展

纳米多孔材料可用作催化剂、气体储存材料和光电子器件,是目前新型多孔材料的研究热点之一.借助自组装技术,选择羧酸类、联吡啶类和吡啶羧酸类化合物作为桥联配体,可获得一维、二维和三维的多孔配位聚合物.简要综述了该类纳米多孔配位聚合物的设计原理、合成路线和应用前景,评价了其合成方法的优缺点.由于其特殊的结构和性质,纳米多孔配位聚合物将发展成为具有光、电、磁等性质的多功能材料.     

基于TRIZ理论的一种减少已破裂烧杯内溶液损失的方法研究

文章运用TRIZ理论,在分析己发生破裂的烧杯与减少烧杯内溶液损失所存在的技术矛盾的基础上,通过查找矛盾矩阵表,得到推荐的发明原理,并对被推荐的发明原理进行分析,找到了两种基于虹吸原理和多孔材料的解决该问题的方法.     

多孔无机材料的性质及用途

对各种多孔无机材料的制备工艺原理和性质进行了论述，并分析了影响多孔无机材料孔径的因素，介绍了多孔无机材料在国民经济生产中的各种用途，指出了以往研究发展中存在的问题。     

硫磺还原分解磷石膏制硫酸节能减排新工艺

对近年来化学法处理磷石膏的研究状况、提出的研究方案和内容进行了分析,提出了用硫磺代替部分焦炭还原磷石膏的新方法。该新方法具有可降低反应温度、提高SO_2含量、减少CO_2排放等优点,可望降低成本、提高产品的竞争力、顺利实现工业化。     

多尺度特征对纳米多孔材料辐射特性的影响

基于辐射等效介质理论,建立了纳米多孔材料的光学和辐射特性参数理论模型,计算了纳米多孔材料的有效热辐射特性参数。基于非灰体各向异性的Rosseland近似,建立了纳米多孔材料辐射换热模型,计算了纳米多孔材料的辐射热导率,分析了含不同遮光剂纳米多孔材料的辐射热导率与颗粒体积份额、颗粒平均直径的关系,揭示了纳米多孔材料内部辐射换热与多尺度结构特征和材料属性间的本构关系,为纳米多孔材料结构参数优化设计提供了依据。     

影响换热器用多孔表面管沸腾换热的主要因素

综述了换热器用多孔表面管沸腾传热的各种影响因素,既介绍了如孔穴直径、多孔层厚度及孔隙率等多孔层的特征参数的特性;也介绍了材料物性、加工工艺、工质物性、压力与温度等对沸腾传热的影响.同时对各种因素对沸腾换热的具体影响进行了分析归纳,对今后多孔表面强化沸腾传热的研究提出了一些自己的建议.     

Comparison of fractal properties of porous structures during coal devolatilization

This paper investigates fractal property changes of pore structures during coal devolatilization. Similar to char pores, coal pores can also be classified as micro pores and macro pores based on their fractal dimensions. The specific surface area and fractal dimension of micro pores in coal particles are basically unchanged after devolatilization. However, the specific surface area and fractal dimension of macro pores, which are key factors in char combustion, are increased after devolatilization. In fact, the fractal dimensions are basically doubled. These parameters will affect another fractal geometrical factor β in char pores that is correlated to char combustion rate. Since the rate of char combustion can be predicted from their fractal pore properties, it may be possible to predict char combustion directly from the properties of their parent coal pores in the future. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

热解温度对生物质和煤成焦特性的影响

以麦秆、橡树木屑和华亭烟煤为原料,研究热解产物的理化特性并讨论燃料种类和热解温度对其的影响.采用BET、SEM-EDS、XRD和TGA对其进行分析表征.结果表明:在600~1 000 ℃的温度范围内,煤焦的比表面积和孔隙容积随热解温度增加而增大,而木屑焦的变化不明显,麦秆焦在800 ℃时比表面积和孔隙容积最大,更高温度则发生烧结;焦样中C元素含量随热解温度升高而增加,而H元素和O元素随之降低,麦秆焦的着火特性优于木屑焦和煤焦.木屑焦和煤焦的着火特性随热解温度升高而变差,而麦秆焦在800 ℃具有最佳的着火特性.     

淮南煤焦颗粒内部孔隙结构在燃烧过程中的变化

用氮气等温吸附/脱附（77 K）方法测量了淮南低变质煤及其在850℃条件下燃烧得到半焦的内部孔隙结构.通过分析得到有关煤焦颗粒内部孔隙结构的参数及其与燃尽率之间的关系.由吸附/脱附曲线判断煤焦孔洞的形状呈多样性.结合吸附理论,认为分形BET和分形Freundlich方程回归得到的分形维数分别表征颗粒内部大中孔表面分形维数和微孔体积分形维数.发现在燃烧过程中煤焦的表面分形维数及体积分形维数具有不同的变化趋势.     

A new mathematical solution for predicting char activation reactions

The differential conservation equations that describe typical gas-solid reactions, such as activation of coal chars, yield a set of coupled second-order partial differential equations. The solution of these coupled equations by exact analytical methods is impossible. In addition, an approximate or exact solution only provides predictions for either reaction- or diffusion-controlling cases. A new mathematical solution, the quantize method (QM), was applied to predict the gasification rates of coal char when both chemical reaction and diffusion through the porous char are present. Carbon conversion rates predicted by the QM were in closer agreement with the experimental data than those predicted by the random pore model and the simple particle model.     

不同变质程度的煤制活性炭孔隙结构分析

在Autosorb—lC全自动物理化学吸附仪上使用N2和CO2对宁夏太西、山西大同和内蒙古准格尔3种不同变质程度的煤为原料制备的活性炭进行孔隙结构分析，用BET方程处理N2等温吸附数据，计算比表面积；用DFT法处理CO2等温吸附数据，进行微孔分析：用BJH法计算中孔孔径分布。从得出的结果可以看出，随着原料煤变质程度的加深，所制备的活性炭微孔和比表面积增大，超微孔、中孔体积变小，平均孔径变窄。分析结果表明。原料煤的性质是影响活性炭孔隙结构的主要因素。     

A new char combustion kinetic model 1. Formulation

This paper describes the development and formulation of a novel char combustion kinetic model for pulverised coal. The chemical reaction rate was considered as a function of coal intrinsic reactivity and fuel mass for a global reaction order n. The equation for char combustion reaction rate was devised by dimensional analysis using the Rayleigh method. It shows the dependency of chemical reactivity on coal parameters, such as maceral and mineral composition; char parameters, such as specify surface area and apparent density; devolatilisation time; temperature; and activation energy. The char combustion reaction rate equation developed, unlike most models, is dimensionally homogenous and is expressed by three dimensionless numbers which have physical chemical meaning. The model also exhibit similarities with transport phenomena models described by dimensionless numbers.     

Effects of micropore development on the physicochemical properties of KOH-activated carbons

Effects of micropore development through varying the KOH/char ratio on the porous, electrochemical, electronic, and adsorptive properties for corncob-derived activated carbons (ACs) prepared by means of the KOH activation method were systematically compared. The pore properties of ACs, including BET surface area, total pore volume, micropore volume ratio, bulk density, and product yield based on the raw material were investigated to gain an understanding for the influence of KOH dosage on the pore development. Element analysis and temperature-programming desorption (TPD) were used to obtain the information of chemical composition and surface oxygen functional groups on ACs in order to propose the reaction mechanism of KOH activation. Based on the pore development, KOH-activated carbons can be classified into two groups: a combination of physical activation and chemical KOH etching at low KOH/char ratios (0.5-2) as well as chemically uniform etching at high KOH/char ratios (≥3.0). From the adsorption study for five organics with molecular weights varying from 129 to 466 g/mol, the specific adsorption capacity of ACs for organics is independent of their specific surface area. The specific capacitance of ACs reached a maximum as the KOH/char ratio was equal to 3, attributed to a compromise between the specific surface area and electronic resistance of ACs.     

PES高孔隙率多孔材料的研究

采用有机物成孔剂１２１３和骨架稳定剂ＦＡ，制得具有规则孔结构的大孔径，高孔隙率ＰＥＳ多孔材料，并探讨了ＦＡ用量及加工工艺对多孔材料结构，性能的影响。     

氮吸附法表征多孔材料的孔结构

采用低温氮吸附法表征了具有不同孔结构的碳纳米管、碳分子筛、活性炭、分子筛和石墨化炭黑等多孔材料的孔径分布。氮吸附一脱附等温线利用康塔公司NOVA3000在相对压力0．001-1范围内测定。五种材料的比表面积在100-1000m2／g之间。低压下的吸附等温线和高压下的脱附等温线分别用HK方法和BJH方法解析,结果表明:五种多孔材料既含有发达的微孔,又含有一定数量的中孔。孔径大小及其分布的细微信息在色谱采样中能够预测吸附剂的吸附性能,也是新型多孔材料开发的关键。