Highly Porous Zirconia Ceramic Foams with Low Thermal Conductivity from Particle‐Stabilized Foams

Zirconia ceramic foams with ultra‐high porosity of 96%–98% have been fabricated using sodium dodecyl sulfate (SDS) as the particle stabilizer of zirconia particles for the first time. The wet foams stabilized by zirconia particles are ultra‐stable due to partially hydrophobic zirconia particles modified by SDS. Zirconia foams exhibit close cells with thin cell wall and small grain size. Increasing SDS concentration favors the foamability of the suspension, and further increases the porosity of ceramic foams. Zirconia ceramic foams with porosity of 98.1% have compressive strength of 0.26 ± 0.05 MPa. Decreasing solid loading leads to the porosity of ceramic foams. The compressive strength could be improved significantly by increasing the sintering temperature. Zirconia ceramic foams with porosity of 97.9% has low thermal conductivity of 0.027 ± 0.004 W·(m·K)^?1, which could be used as thermal insulation and refractory material.     

Mass transfer simulation on pervaporation dehydration of ethanol through hollow fiber NaA zeolite membranes

A multi‐layer series‐resistance mass transfer model was developed to simulate mass transfer behaviors of water/ethanol mixture through hollow fiber NaA zeolite membranes. The mass transfer through zeolite layer was described by Maxwell‐Stefan mechanism based on adsorption and diffusion parameters obtained from molecular simulation. The mass transfer through asymmetric hollow fiber support was described by dusty gas model involving Knudsen diffusion and viscous flow. It was found that the sponge‐like layer of support besides of zeolite layer made an important contribution to overall membrane transfer resistance while the finger‐like layer had less effect. When permeate pressure shifted from 0.2 to 7.5 kPa, the mass transfer resistance contribution of sponge‐like layer varied from 27.1 to 17.8%. Effects of microstructure parameters of support on mass transfer through membrane were investigated extensively. Large pore size and thin thickness for sponge‐like layer of support were beneficial to improve water permeation flux. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2468–2478, 2016     

国产开放式电石炉导电颚板的改进

在考察分析了国产开放式电石炉导电颚权的消耗情况后，针对其存在的问题改进了导电颚板的设计，从而提高了导电颚板的使用寿命，延长了电石炉的运行周期。     

聚氨酯/乙烯基酯树脂互穿聚合物网络结构与性能的研究

通过同步法制备了一系列聚氨酯／乙烯基酯树脂互穿聚合物（ＰＵ／ＶＥＲ－ＩＰＮ）,研究了ＰＵ／ＶＥＲＩＰＮ性能的影响因素。结果表明：随着ＰＵ含量的增加,ＩＰＮ的热稳定性能有一定程度的提高;而ＶＥＲ的含量增加,ＰＵ／ＶＥＲ－ＩＰＮ的剪切强度提高。实验还发现：当ＰＵ／ＶＥＲ－ＩＰＮ为部分相容的多相微区结构时,对增加ＩＰＮ的力学损耗更有利     

磷细菌突变株生理特性的研究

本文对经过筛选培育出的一株解磷能力较强的磷细菌突变株Ｄ０１７Ｐ的生理特性进行了研究。其中,最佳氮源为麦麸汁,与出发菌株所用马铃薯汁相比,生物量增加９．８倍,解磷能力提高７１．４％,最佳碳源为蔗糖,与出发菌株所用碳源葡萄糖比较,解磷能力提高２８．８％,金属离子,培养温度,ｐＨ,气／液比等也对突变株的生长有一定影响,其结果可作为选定工业化条件的参考。     

添加剂对非离子表面活性剂DYNOL-604浊点的影响

Dynol -604是一种新型的亲油性非离子表面活性剂 ,本文测定了一系列极性不同的有机醇(甲醇、乙醇、丙醇、正丁醇、丙二醇、丙三醇)、离子表面活性剂(SDS、CTAB)等添加剂对Dynol-604浊点的影响 ,结果表明 :有机醇对浊点的影响较复杂 ,一般表现为先升高再降低 ,而且影响幅度不大 ;SDS、CTAB可使Dynol-604的浊点大幅度升高。并对原因进行了探讨。我们认为醇对Dynol-604浊点的影响规律较复杂,是和Dynol -604特殊的结构有关的。Dynol-604在形成胶束时 ,其分子是平躺着排列在界面上的 ,而不象其它直链表面活性剂分子是竖直排列的 ;另外不同的平躺着的Dynol-604分子具有可压缩性 ,因此其截面积大小是可以变化的 ,同一种醇在Dynol-604分子形成的胶束中的增溶位置随醇浓度的变化而发生变化 ,从而出现拐点 ,另外我们还利用束缚因子对其进行了解释。离子表面活性剂的加入使Dynol-604浊点升高是因为离子表面活性剂和非离子表面活性剂形成了混合胶束(Dynol-604的cmc的质量分数为0 03 %) ,离子表面活性剂的带电离子极性头使混合胶束的表面带有了电荷 ,增加了胶束之间的排斥力 ,阻碍了胶束之间的聚集 ,使Dynol-604浊点升高。     

多孔介质气体流动模型在垫片密封中的应用

气体通过非金属垫片的泄漏可以用多孔介质模型来描述,由流动方程得到的垫片材料常数可以作为密封设计的基本参数。这一工作有可能使现行规范中的密封设计由主要依据连接结构强度的设计方法发展成以最大允许泄漏率为设计准则的“紧密性设计”方法。     

非金属垫片螺栓法兰连接寿命评价

分析非金属垫片密封的时效特性,考虑高温条件下材料退化和垫片载荷松弛过程对密封性能的影响,依据多孔介质理论,建立非金属垫片密封的时效泄漏模型.将螺栓法兰连接系统寿命划分为密封寿命和部件寿命.提出密封寿命试验方法,在考虑垫片泄漏特性变化的基础上,基于指标泄漏率分析螺栓法兰连接系统密封寿命;基于蠕变和疲劳损伤准则分析高温螺栓的剩余寿命,探讨螺栓法兰连接系统的密封寿命和各部件寿命之间的关系.建立螺栓法兰连接系统的寿命预测最弱环模型,将垫片的变形特性和泄漏特性统一于螺栓法兰连接系统中进行研究,提出基于指标泄漏率和结构完整性的螺栓法兰连接系统寿命评价方法.     

耐火材料中氮的测定

介绍利用样品预处理来抑制高浓度氧对氮的干扰，从而准确测定耐火材料中的氮含量。