HZSM－5的水蒸汽处理及其对丙烷芳构化反应的影响

采用吡啶吸附－红外光谱及探针反应，研究了水蒸汽处理的ＨＺＳＭ－５对丙烷芳构化反应的影响。结果表明，用水蒸汽处理ＨＺＳＭ－５能引起催化剂酸性的改变。在３００℃水蒸汽处理时，样品的Ｂ酸量达到最多，而Ｌ酸量最少；丙烷的转化率和芳烃的选择性均达到最高值。     

Design of an active fault tolerant control system for a simulated industrial steam turbine

An active fault tolerant control (FTC) scheme is proposed in this paper to accommodate for an industrial steam turbine faults based on integration of a data-driven fault detection and diagnosis (FDD) module and an adaptive generalized predictive control (GPC) approach. The FDD module uses a fusion-based methodology to incorporate a multi-attribute feature via a support vector machine (SVM) and adaptive neuro-fuzzy inference system (ANFIS) classifiers. In the GPC formulation, an adaptive configuration of its internal model has been devised to capture the faulty model for the set of internal steam turbine faults. To handle the most challenging faults, however, the GPC control configuration is modified via its weighting factors to demand for satisfactory control recovery with less vigorous control actions. The proposed FTC scheme is hence able to systematically maintain early FDD with efficient fault accommodation against faults jeopardizing the steam turbine availability. Extensive simulation tests are conducted to explore the effectiveness of the proposed FTC performances in response to different categories of steam turbine fault scenarios.     

从肉桂皮中提取肉桂油并鉴定其主要成分

探讨了水蒸气蒸馏法从肉桂皮中提取肉桂油的蒸馏时间、浸泡溶剂对提取效率的影响。得到最佳的提取条件:将肉桂皮粉用乙醇浸泡24h后进行水蒸气蒸馏1h。并利用官能团性质鉴定法和红外光谱法对肉桂油的主要成分进行了鉴定,发现肉桂油的主要成分是肉桂醛。     

秦岭德昌香薷不同提取方法挥发油成分分析

采用分析型超临界CO2流体萃取技术(SFE-CO2)与传统水蒸汽蒸馏法(SD)分别提取德昌香薷挥发油,并通过气相色谱-质谱联用技术测定了提取物的化学成分.从中分别鉴定出35个和50个化合物.结果显示:白苏酮、香芹酚、α-石竹烯、石竹烯、柠檬醛、芳樟醇、对薄荷烯醇等是德昌香薷挥发油的主要成分.对比两种不同方法的分析结果可知,超临界萃取法比传统水蒸气蒸馏法能得到更多的极性组分,因而其被广泛应用于中草药的分析.     

An experimental study on convective heat transfer performance of steam and air flow in V-shaped rib roughened channels

An experimental study on heat transfer characteristics of steam and air flows in a V-shaped ribbed channels was conducted. The effects of Reynolds numbers and rib angles on heat transfer of steam and air were obtained. The area-averaged Nusselt numbers of steam flow at a Reynolds number of 12,000 were 13.9%, 20.6%, 27.1%, and 27.9% higher than those of air flow for rib angles of 90°, 75°, 60°, and 45°, respectively. The correlations for Nusselt number in terms of Reynolds number and rib angle for steam and air in V-shaped ribbed channels were developed.     

花椒挥发油的定性鉴别研究

采用水蒸气蒸馏法对不同产地的花椒进行挥发油提取,薄层层析法以及气相色谱-质谱联用技术进行鉴别。通过归一化法测定已鉴定成分占挥发油中的百分含量。     

Changes in cellulose supramolecular structure and molecular weight distribution during steam explosion of aspen wood

We have studied the cellulose supramolecular structure in pulps obtainedby steam explosion of aspen wood. The pulps were bleached with hydrogenperoxidein an OQP-sequence and characterised by size exclusion chromatography and¹³C cross polarisation magic angle spinning (CP/MAS)NMR-spectroscopy. With CP/MAS-NMR-spectroscopy and chemometrics we were able toseparate the supramolecular structural changes taking place during steamexplosion into two independent processes. One process was related to the extentof processing and showed degradation and dissolution of cellulose,hemicelluloseand lignin accompanied by an increase in cellulose content. The second processwas displayed by pulps having molecular weights below approximately 100000 andwas interpreted as showing the removal of dislocations and an increase incrystalline and/or paracrystalline cellulose in the cellulose fibrils.     

水热合成介孔ZnO及Pd／m－ZnO催化剂甲醇水蒸气重整制氢性能研究

以三嵌段高聚物F-127为模板剂采用水热法合成了介孔ZnO（m—ZnO）,以甲醇水蒸气重整制氢为探针反应,在连续流动反应条件下考察了Pd／m．ZnO催化剂的性能,并利用XRD、FT—IR、H2-TPR、TEM和BET等手段对载体及催化剂进行了表征．结果表明,该法所制m-ZnO具有较大的比表面积（124．7m^2／g）,其比表面积不但高于非介孔ZnO,而且大于文献值（103．6m^2／g）．与Pd／ZnO催化剂相比,Pd／m—ZnO催化剂中活性组份Pd的分散度较高以及与m—ZnO间的相互作用较强,因此该催化剂对甲醇水蒸气重整制氢反应具有较高的催化活性、氢气产率、CO2选择性和稳定性．250℃时,Pd／m—ZnO催化剂的催化活性、氢气产率和C02选择性分别比Pd／ZnO催化剂提高了38．4％、44．4％和30．0％,170oC连续反应100h后,Pd／m-ZnO催化剂的活性仍为95％,仅下降了4．9％．     

甲醇水蒸汽重整制氢Cu/Zn/Ce/Al催化剂的XPS研究

利用XPS技术，研究了在甲醇水蒸汽重整制氢过程中，添加稀土元素Ce对Cu/Zn/Al催化剂表面结构的影响。发现，催化剂表面存在Cu^2 和Cu^ 物种；CeO2的加入促进表面Cu^ 物种的生成，提高了表面Cu^ 物种的浓度。Cu60/Zn30/Al5/Ce5催化剂表面具有较高的Cu^ 浓度，是催化剂长时间保持高活性的重要原因之一。