TiO2改性的镁基中温吸附剂及其CO2吸附性能的研究

采用沉淀法合成一系列TiO₂改性的镁基吸附剂,利用XRD、SEM和氮气吸附等方法对吸附剂进行表征,通过变温吸附-脱附动态循环实验考察其CO₂吸附性能。随着TiO₂含量的增加,样品的结晶度逐渐下降,同时由于焙烧后生成钛酸镁,样品比表面积逐渐减小。当TiO₂添加量为2%(质量分数),此时吸附剂呈直径为4.0~5.0μm的球形,局部为纳米片状结构,该吸附剂自第二次循环开始吸附能力无明显变化;经过50次变温吸附脱附循环实验后,动态吸附容量可达6.64%(质量分数),这是由于TiO₂改性后生成的钛酸镁为该吸附剂提供了刚性骨架,促进了活性组分的分散,并提高了吸附剂的稳定性。     

Shockwave Visualization Using Holographic Interferometer

High-speed holographic interferometry was employed to visualize and record Shockwave phenomena. We performed three kinds of holographic interferometry for visualization and recording of the propagation of a Shockwave: a real-time holographic interferometer with a high-speed framing camera, a real-time holographic interferometer with a high-speed streak camera and a double-pulse laser holographic interferometer with a dual-reference-beam module. The experimental results were compared and their advantages and disadvantages are discussed. The experimental results clearly show the high-speed Shockwave propagation and give the feasibility of quantitative interpretation of high-speed gas-dynamics.     

稀土氧化物修饰的富勒烯-二氧化钛复合材料光催化降解亚甲基蓝(英文)

Rare earth oxide-treated fullerene and titania composites (Y-fullerene/TiO2) were prepared by the sol-gel method. The products had interesting surface compositions. X-ray diffraction patterns of the composites showed that the Y-fullerene/TiO2 composites contained a single and clear anatase phase. The surface properties were observed by scanning electron microscopy, which gave a characterization of the texture on the Y-fullerene/TiO2 composites and showed a homogenous distribution of titanium particles. The ...     

Regioselective Bridging Calix[6]arenes: Synthesis and X-ray Structure of Trisbridged Calix[6]arene

The preparation and characterization of gold nanoparticles (～6 nm in diameter) modified with mono-6-thio-β-cyclodextrin (II) is described. The resulting monolayer-protected gold nanoparticles are water-soluble and more stable. The concentration of II plays a crucial role for the distribution of the modified nanoparticles. When the ratio of concentration of II to HAuCl₄,[II]/[HAuCl₄] ≥ 0.93, a stable gold nanoparticle with uniform distribution and diameter of 6.0 ± 0.9 nm will be obtained. The recognition of modified gold nanoparticles to organic guest molecule is researched. The modified gold nanoparticles can make the electrochemical reduction current of nitrobenzene decrease and can be self-assembled in three-dimensional to form spherical clusters with ligand of methylene green.     

Iterative Deconvolution Algorithm for Improving Range Resolution of a CO2-Laser Based Lidar System

An iterative deconvolution algorithm for improving range resolution of long-pulse lidars is proposed, and can be applied to the lidar data obtained with the typical pulse of a CO₂-laser which consists of a gain-switching peak and a long tail. The lidar signal itself with certain temporal shift is set to be the start profile for the unknown maximally resolved profile in the proposed technique, and then is corrected in proportion to the difference between the lidar return calculated with the assumption and the real one. The same process is repeated until the correction is smaller than tolerance. Simulations are made to test the performance of the proposed algorithm. We investigate the errors in the vicinity of data boundary in the retrieved profile when a part of lidar data is absent. The sensitivity of the iteration algorithm to noise in the lidar signals and the laser pulse profile is also numerically determined.     

超声辅助法合成的石墨烯-TiO2复合材料声催化降解罗丹明B（英文）

A series of graphene-TiO2 composites was fabricated from graphene oxide and titanium n-butoxide(TNB) by an ultrasonic-assisted method.The structure and composition of the nanocomposites were characterized by Raman spectroscopy,BET surface area measurements,X-ray diffraction,transmission electron microscopy,and ultraviolet-visible absorption spectroscopy.The average size of the TiO2 nanoparticles on the graphene nanosheets was controlled at around 10-15 nm without using surfactant,which is attributed to the pyrolysis and condensation of dissolved TNB into TiO2 by ultrasonic irradiation.The catalytic activity of the composites under ultrasonic irradiation was determined using a rhodamine B(RhB) solution.The graphene-TiO2 composites possessed a high specific surface area,which increased the decolorization rate for RhB solution.This is because the graphene and TiO2 nanoparticles in the composites interact strongly,which enhances the photoelectric conversion of TiO2 by reducing the recombination of photogenerated electron-hole pairs.     

交联型聚乙烯亚胺智能基因载体的制备及PEG化影响

使用胱胺双丙烯酰胺(CBA)对低分子量聚乙烯亚胺(PEI)进行交联反应制备智能降解型聚阳离子基因载体.通过与聚乙二醇(PEG)反应得到不同程度PEG化的聚阳离子载体.利用核磁、黏度测试、粒度仪、zeta电位仪和凝胶电泳对聚阳离子载体及其与DNA的复合物进行了表征.研究表明随着PEG含量的增加,聚阳离子载体/DNA复合物颗粒粒径变小、表面正电荷降低,PEG具有明显的屏蔽作用,但过多的PEG也使载体与DNA复合能力下降.通过MTT细胞毒性测试和荧光素酶质粒转染实验得出,含二硫键的交联型阳离子聚合物在测试范围内显示了非常低的细胞毒性,最佳转染效率是PEI25k的4倍,PEG化后其细胞毒性得到进一步改善,转染效率却明显降低.     

Performance of successively complex rules for locational decision-making

The relative performance of five simple rules for selecting facility locations are compared with two heuristic location-allocation algorithms in the context of a real region. It is hypothesized that the performance of a rule is likely to be systematically related to the spatial structure of the region in which it is used. In the Iowa settlement system, known to have predictable structural regularity, some rules performed over 95 percent of the level achieved by the algorithms (the greedy add and the modified vertex exchange algorithms) on a range of commonly used criteria for evaluating locational efficiency. Under certain circumstances, these rules may be recommended as alternatives to more formal algorithms.