Continuous liquid-phase valorization of bio-ethanol towards bio-butanol over metal modified alumina

Commercial mixed-phase aluminum oxide was used as a heterogeneous catalyst support, providing slightly basic properties which are well-suited for the condensation of bio-ethanol to C₄ hydrocarbons, such as 1-butanol. Different metals (Cu, Ni and Co), at various metal loadings were deposited on the support. Consequently, the catalytic reactions were carried out in a continuous laboratory-scale fixed bed reactor operated at 240 °C and 70 bar. The catalysts were characterized by means of XRD, TEM, FT-IR, XPS and ICP-OES. Different metals were found to give entirely different product distributions. With the best catalysts, the selectivities towards 1-butanol close to 70% were reached, while the ethanol conversion typically varied between 10 and 30% – strongly depending on the metal applied. It was observed that low loading of copper and high loading of nickel were responsible for the formation of 1-butanol, whereas cobalt and high loading of copper resulted in the production of ethyl acetate. The reaction was found to be extremely sensitive to catalyst preparation conditions and procedures such as metal loading, calcination/reduction temperature and, thereby, to the formation of corresponding crystallite structure.     

制冷系统液体冷媒融霜与电热融霜的对比研究

对冷库冷风机液体冷媒融霜和电热融霜过程中,库温的升高状况和能耗大小进行了实验研究。介绍了液体冷媒融霜实验原理和自动控制操作过程,电热融霜和液体冷媒融霜库温升高实验的装置和方法。对比分析实验结果,重点对库温升高状况和融霜能耗进行了分析研究,结果表明：液体冷媒融霜过程比电热融霜过程的库温升高约少10℃,在库房无负荷的条件下,液体冷媒融霜过程各工况库温平均升高几乎为零;液体冷媒融霜比电热融霜时间约长25 min ,能耗降低9％。     

脂肽生物表面活性剂在微生物采油中的应用

对从大庆油田分离到的一株枯草芽孢杆菌(Bacillus subtilis)ZW-3代谢的脂肽生物表面活性剂的理化性质(CMC值、乳化活性、对温度、矿化度的稳定性、降低油水界面张力能力)进行了测定,同时进行了物理模拟实验。研究结果表明,该脂肽表面活性剂具有优良的乳化和降低油水界面张力的能力,并可以适应油藏中复杂的环境,可提高采收率9.2%。在微生物采油中具有较好的应用前景。     

An experimental study on bubble growth within a narrow space under an interference‐piece

An experimental study was performed on the nucleate boiling of water in the narrow space formed between an interference piece and the heating surface of heat‐proof glass. A past study analyzed the bubble growth due to the conduction of heat through the thinner liquid layer under a growing bubble; however, the thickness of the liquid layer was not shown experimentally. This study investigates the thickness of this thinner layer by the interference method. Almost no change was found on the thickness of the liquid layer under both the interference‐piece and on the heating surface. The experimental results indicate the great contribution of superheating of the test liquid to bubble growth. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(2): 165–177, 2006; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/htj.20100     

多效回热降膜蒸发式太阳能液体除湿空调溶液再生器的稳态实验

设计了一种具有多效回热可用于太阳能液体除湿空调系统的溶液再生器,用碘钨灯作为模拟太阳光源对系统进行了稳态实验,得到出口浓度与光辐射强度、溶液流量、强迫对流风速和入口溶液浓度的关系曲线,给出了系统性能系数与太阳光强度的关系,并对装置的传热传质关系作了简化计算,对影响系统性能的其他因素也进行了分析。实验结果表明,由于系统采用了多效回热措施,系统的回热率相对太阳辐射能来说达到32%。由实验结果估计,在晴好天气条件下,该系统每天每平方米集热器可处理LiBr溶液量(47%～52%)约86kg。     

Computational modelling of unsaturated flow of liquid in heap leaching—using the results of column tests to calibrate the model

Unsaturated flow of liquid in a bed of uniform and spherical ore particles is studied numerically and experimentally. An unsteady and two-dimensional model is developed based on the mass conservation equations of liquid phase in the bed and in the particles. The model equations are solved using a fully implicit finite difference method giving the distribution of the degree of saturation in the particles and in the bed and the vertical velocity of flow in the bed, as well as, the effect of periodic infiltration on the above distributions. To calibrate the computational model, several column tests are performed using periodic infiltration of water on 40 cm high columns composed of ore having particles smaller than 25 mm. The numerical analysis shows that (a) the results obtained from numerical modelling under the same operating conditions as used for column tests, are in good agreement with those from experimental procedure, (b) the degree of saturation of the bed and the time required to reach steady state conditions depend on the inflow of water and intrinsic permeability of the bed and (c) the velocity fluctuations and the fluctuations of the degree of saturation in the bed depend on the inflow of water, period of infiltration, height and intrinsic permeability of the bed.     

Microwave assisted synthesis of ZnO nanoparticles in ionic liquid [Bmim]cl and their photocatalytic investigation

In this study, ZnO nanoparticles were synthesized based on the chemical reaction of zinc acetate and NaOH in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) under microwave irradiation. The prepared ZnO were characterized by utilizing various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy, FT-IR spectroscopy, and BET method. XRD pattern reveals the produced ZnO has hexagonal structure and the images of SEM and TEM also reveal it consists of nanoparticles with an average size between 15 and 25 nm. The role of the ionic liquid on morphology of ZnO was investigated. For this purpose, a control ZnO sample was prepared without using any [Bmim]Cl. Photocatalytic properties of the synthesized ZnO on degradation of malachite green dye as model pollutant was investigated. The effect of various parameters such as pH, concentration of the dye and catalyst on the degradation of malachite green was investigated. In order to explore the mechanism of photocatalytic degradation of malachite green, scavenger addition method has been employed. It is found that hydroxide radicals are main reactive species for the degradation.     

一种共价键结构的高稳定性自组装光控取向膜

通过两次光照法制备了一种基于共价键结构的自组装光控取向膜。首先采用重氮树脂与聚(4-丙烯酰氧基肉桂酸(4′-磺酸钠)苯酚酯)在水溶液状态下通过静电离子沉积法制备了layer-by-layer型的自组装多层膜,制备过程的紫外-可见光谱表明薄膜为逐层、均匀沉积。第一次光照将膜层间的重氮磺酸盐离子键转化为共价键结构,然后采用线性偏振紫外光进行第二次光照,获得具有各向异性的光控取向膜。紫外-可见光谱法证实了薄膜辐照过程中的光化学反应方式。这种液晶光控取向膜可以水平均匀取向向列相液晶,而且具有良好的热稳定性,可达到150℃。     

聚合物结构对PDLC性能的影响

用光聚合诱导相分离法制备了3种不同聚合物基体的聚合物分散液晶(PDLC)膜,研究了液晶含量和固化时间对PDLC透光率及膜形态的影响,考察了不同聚合物基体对PDLC电光性能的影响。结果表明,聚合物单体反应活性越高,达到关态下最低透过率所需的固化时间越短,丙烯酸仅需10 s,而甲基丙烯酸甲酯却需360 s;聚合物与液晶颗粒之间的相互作用越强,PDLC膜的阈值电压越高,丙烯酸的阈值电压至少是其他两者的5倍。     

MSP430在液晶显示上的应用

介绍了MSP430如何实现液晶显示，并具体给出了单CPU系统和双CPU系统的接线方案，比较了设计上的异同，突出了双CPU系统的优点。针对LM12864FBC内置驱动芯片的指令表，介绍了显示程序的流程。说明了多功能复用和模块化是新器件的发展方向。