制备方法对BaNi0.2Mn0.8Al11O19－δ催化燃烧二甲醚的催化活性的影响

Catalytic combustion of dimethyl ether （DME） over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated. The catalysts were prepared with the sol-gel method and reverse microemulsion method respectively and characterized by thermogravimetry-differential thermal analysis, X-ray diffraction and transimission electron microscope. It was found that the formation of Mn, Ni modified hexaaluminate was a relatively slow process via two solid state reactions and spinel structure was a transition phase. At the same calcined temperature and time, the catalyst prepared with the reverse microemulsion method could form the hexaaluminate phase more easily than that prepared with the sol-gel method. The catalyst BaNi0.2Mn0.8Al11O19-δ prepared with the reverse micro-emulsion method appeared a plate-like morphology, while it appeared a needle-like morphology when using the sol-gel method. The catalytic activities of catalysts BaNi0.2Mn0.8Al11O19-δ prepared with two different methods for DME combustion were tested. It showed that catalyst prepared with the reverse microemulsion method had better catalytic activity, i.e. T10% of DME had decreased by 45℃, about 90% conversion of diemthyl ether at 380℃.     

4,4'-二硝基双呋咱醚的合成与表征

以3,4-二氨基呋咱(DAF)为原料,经Caro-acid氧化生成二硝基呋咱(DNF),碱性条件下DNF分子间硝基醚化后合成目标化合物4,4′-二硝基双呋咱醚(FOF-1).采用红外光谱、质谱、元素分析及核磁共振进行了结构表征;初步探讨了硝基分子间醚化合成FOF-1的反应机理;优化了氧化、分子间醚化工艺,确定了最佳合成条件:氧化反应时间为3.5 h, H2SO4的起始浓度为51.7%,醚化反应时间为2.5 h,水质量分数小于0.03%.总收率达到42%,纯度为99.6%.     

硝基芳香族化合物密度、爆速和撞击感度的量子化学及QSPR研究

运用Gaussian98等程序对32种描述符进行了计算,采用Cerius2程序包中的QSPR方法建立了硝基芳香族化合物密度、爆速和撞击感度与32种描述符之间的构效关系式,相关系数R分别为0.951、0.992和0.92,预测值与实验值之间的平均误差分别为1.92%、0.93%和5.10%;与Kamlet方法计算的爆速值相比,用QSPR方法计算的爆速值准确性较高.此外,还找到了影响硝基芳香族化合物密度、爆速和撞击感度的主要因素,以及可以同时使密度和爆速增大而撞击感度降低的因素.     

AlxCrFeNiCuVTi系高熵合金的组织和力学性能研究

采用真空电弧熔炼制备AlxCrFeNiCuVTi(摩尔比x=0,0.5,1,1.5)高熵合金.利用XRD、SEM和万能材料试验机等方法对该合金进行研究.结果表明:铸态合金由枝晶相,菊花状共晶组织以及枝晶间富Cu相共同组成;随着Al元素的增加,合金的组织结构逐渐由多种bcc相和fcc相共存逐渐变为单一的bcc相,合金硬度和抗压缩性能整体呈上升趋势;Al1CrFeNiCuVTi合金的最高抗压缩强度达到1810.4 MPa,压缩率为23％.     

改性膨润土的吸附性能研究

用NaOH改性、微波改性、焙烧改性膨润土,以亚甲基蓝溶液模拟污染物对原土和改性膨润土的吸附性能进行考查.实验结果表明,膨润土经改性后,其吸附性能与原土相比有明显改善.经NaOH改性、微波改性、400℃下焙烧2 h改性后的膨润土对25 mg/L的亚甲基蓝溶液的脱除率分别为75.64％、74.36％、68.17％.     

Review on the effect of heat exchanger tubes on flow behavior and heat/mass transfer of the bubble/slurry reactors

Bubble/Slurry bubble column reactors(BCR/SBCR) are intensively used as multiphase reactors for a wide range of application in the chemical, biochemical and petrochemical industries. Most of these applications involve complicate gas–liquid/gas–liquid–solid flow behavior and exothermic process, thus it is necessary to equip the BCR/SBCR with heat exchanger tubes to remove the heat and govern the performance of the reactor. Amounts of experimental and numerical studies have been carried out to describe the phenomena taking place in BCR/SBCRs with heat exchanger tubes. Unfortunately, little effort has been put on reviewing the experiments and simulations for examining the effect of internals on the performance and hydrodynamics of BCR/SBCR. The objective of this work is to give a state-of-the-art review of the literature on the effects of heat exchanger tubes with different types and configurations on flow behavior and heat/mass transfer, then provide adequate information and scientific basis for the design and the development of heat exchanger tubes in BCR/SBCR, ultimately provide reasonable suggestions for better comprehend the performance of different heat exchanger tubes on hydrodynamics.     

响应曲面法优化衣康酸三元共聚物制备工艺

针对咸阳某企业循环冷却水水质情况,选择衣康酸(IA)、乙酸乙烯酯(VAc)和2-丙烯酰胺-2-甲基丙磺酸(AMPS)为单体,采用水溶液自由基聚合法制备IA-VAc-AMPS共聚物阻垢剂.利用响应曲面Box-Behnken试验优化共聚物制备工艺,并建立多元回归模型.结果表明:单体摩尔比和反应温度影响最大,单体摩尔比和引发...     

乙烷-氧-水氧化裂解制乙烯反应的研究

研究了不同反应体系组成的乙烷造反然的反应性能,考究了乙烷－氧－水反应体系氧化裂解制乙烯的反应条件。结果表明,在不同反应体系中,以Ｃ２Ｈ６－Ｏ２－Ｈ２Ｏ氧化裂解制乙烯反应性能最佳,８００℃的乙烷转化率为８５．１％,乙烯选择性为６８．１％,乙烯收率可达５８％,Ｃ２Ｈ６－Ｏ２－Ｈ２Ｏ氧化裂解帛乙烯体系最佳工艺参数;反应温度为８５０℃,原料气组成为５０．５％,Ｃ２Ｈ６＋２５．２％Ｏ２＋２４．３％Ｈ２Ｏ停留     

硫铝酸盐水泥抗酸侵蚀性能与机理研究

本文研究了硫铝酸盐水泥(CSA)在盐酸和硫酸环境下的力学性能演化规律,并探究了其抗酸侵蚀机理。分别测试了水和酸溶液养护的CSA胶砂试件的抗折强度,计算了CSA的抗酸侵蚀系数。采用XRD、TGA、CT和SEM分析了酸侵蚀导致的产物种类和数量变化,表征了微观结构演化过程。结果表明:与普通硅酸盐水泥(OPC)相比,CSA在盐酸和硫酸中抗折强度损失率更低,具有更好的抗盐酸和硫酸侵蚀能力;CSA主要水化产物(钙矾石)比OPC主要水化产物(氢氧化钙和硅酸钙凝胶)更难与酸反应,因此抗酸侵蚀能力更强。盐酸与硫酸对CSA的侵蚀机制略有不同,盐酸对CSA的侵蚀过程实质上为氢离子对CSA水化产物钙矾石的酸解,硫酸对CSA的侵蚀则是氢离子和硫酸根离子的共同作用。     

纳/微异构型钙钛矿氧化物电极在固体氧化物燃料电池的研究进展

开发高效、稳定、廉价的钙钛矿氧化物电极材料是固体氧化物燃料电池(SOFC)进一步商业化发展的关键。目前,研究重点仍集中在解决阳极积碳、硫毒化以及阴极氧还原(ORR)低温性能不佳等问题。最近,有研究报道,一些易还原过渡金属元素掺杂的钙钛矿可以在还原气氛中原位析出该金属并以纳米颗粒的形式"镶嵌"在钙钛矿表面形成"纳米金属–钙钛矿"复合结构。该方法制备的材料具有性能高、抗积碳能力强、可再生性好等优点。从钙钛矿氧化物本体的选择、A/B位掺杂、缺陷调整、以及拓扑离子交换、相变诱发等方面,总结了近年来关于构建纳米(析出金属颗粒)微米(钙钛矿氧化物母体)异质结构(统称纳微异构)钙钛矿氧化物纳米纤维复合电极的研究。此外,总结了具有纳米纤维状形貌的钙钛矿氧化物电极及其结构对于SOFC性能、稳定性的影响,最后提出了该类纳微异构材料的优势、不足和展望。