An integrated purification and production of hydrogen with a palladium membrane-catalytic reactor

In this paper, we presented an integrated production and purification process of hydrogen by the use of a defect-free palladium membrane. Hydrogen could be purified from a variety of mixtures providing the purity of 3–7 N depending on the feeding stream. The permeation parameters are accurately predicted by a separation model as established. The membrane is prepared by electroless plating and is stable among 300–400°C. Using an active catalyst, the rate of steam reforming of methanol was found to be significantly faster than that without a membrane module. In the steam reforming of methane, the reaction temperature was lowered to 500°C to achieve a conversion of 45%, which is 15% higher than the thermodynamic equilibrium conversion.     

Total reflection in the time domain

Contents Time domain solution for total reflection of a Dirac shaped incident electromagnetic wave is calculated analytically. The impulse responses of the reflected and evanescent waves are discussed with special regard to causality. Finally the energy flow of the evanescent wave for a bell shaped incident wave is analyzed.

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Totalreflexion im Zeitbereich

Übersicht Die Zeitbereichslösung für die Totalreflexion einer einfallenden Dirac-förmigen elektromagnetischen Welle wird analytisch berechnet. Die Impulsantworten der reflektierten und der evaneszenten Welle werden unter besonderer Berücksichtigung der Kausalität diskutiert. Des weiteren wird der Energiefluß für eine glockenförmige einfallende Welle analysiert.

     

分散染料在共混纤维上的分布状态研究

用少量的烯烃类高聚物加入到聚丙烯中,制成分散染料可染丙纶,对共混丙纶的结构和分散染料染色后染料分子在纤维上的状态与反射光谱的关系进行了研究.结果表明,共混纤维内部存在大量的相界面,分散染料部分缔合在这些界面上,从而引起反射光谱的变化.染料分子在纤维上的状态直接影响被染织物的K/S值和艳度.     

Direct Catalyst Monitoring by Electrical Means: An Overview on Promising Novel Principles

By measuring the electrical properties of the catalyst coating itself, one can observe directly and in situ the state of TWC, LNT, and SCR catalysts. Two principles are possible: a contact method, for which the coating is applied to planar electrodes and the electrical impedance is measured, and a non-contact method, in which the coating material is penetrated by radio frequency waves. In either case, the catalyst state is directly correlated with the measured transmission or reflection characteristics of the electrical sensors.     

Synthesis and Stretching of Rolling Circle Amplification Products in a Flow‐Through System

Enzymatic isothermal rolling circle amplification (RCA) produces long concatemeric single‐stranded DNA (ssDNA) molecules if a small circular ssDNA molecule is applied as the template. A method is presented here in which the RCA reaction is carried out in a flow‐through system, starting from isolated surface‐tethered DNA primers. This approach combines gentle fluidic handling of the single‐stranded RCA products, such as staining or stretching via a receding meniscus, with the option of simultaneous (fluorescence) microscopic observation. It is shown that the stretched and surface‐attached RCA products are accessible for hybridization of complementary oligonucleotides, which demonstrates their addressability by complementary base pairing. The long RCA products should be well suited to bridge the gap between biomolecular nanoscale building‐blocks and structures at the micro‐ and macroscale, especially at the single‐molecule level presented here.     

造纸白水封闭与阴离子垃圾捕集剂PDE

当前环境危机十分突出，造纸白水封闭循环是节能、降耗、减排的重要措施，也是能否生存的当务之急，白水封闭后，各种阴离子垃圾（AT）在白水中积累使纸机无法正常进行，纸品质量降低。而使用阴离子垃圾捕集剂（ATC）是重要措施之一，它可有效克服AT的干扰，提高白水封闭率，降低水耗、减少助剂和施胶剂用量，提高纸质，降低成本。     

Crosswise ridge micromixers with split and recombination helical flows

This study presents a novel crosswise ridge micromixer (CRM) with a series of microstructures placed on the top and bottom floors of channels. Passive micromixers fabricated by Micro Electro-Mechanical Systems (MEMS) technologies with slanted ridges are investigated. Numerical simulations and experimental investigations are undertaken to determine the effects of various microstructure patterns on mixing efficiency with Reynolds numbers (Re) of 0.05–50. The confocal images at the cross-sections along the channel with ridges on both the channel top and bottom are first investigated in our study. A significant amount of split and recombination (SAR) helical flows is produced by the slanted ridges embedded on the two floors of the channels. The effects of non-dimensional parameters, such as the Re, as well as geometrical parameters on mixing performance are presented in terms of the mixing index. When the Re exceeds 1, the mixing index of the micromixer with slanted ridges increases as the Re increases further. Simulation results are presented and compared with experimental data. The trends of the experimental results and numerical data are very similar. Finally, various numbers of slanted ridges in the same orientation in one channel cycle are investigated to determine mixing performance in microchannels. The mixing performance achieves an optimum value in case where the number of ridges per cycle is equal to 8.     

Characterization of vacuum-annealed TiNb2O7 as high potential anode material for lithium-ion battery

Electrochemical properties of mixed titanium-niobium oxide TiNb₂O₇ (TNO) synthesized via vacuum annealing as high potential anode material for lithium-ion batteries were investigated. Crystal structure, size, and morphology are nearly independent of the annealing atmosphere for starting materials but the color of vacuum-annealed TNO (TNO-V) is dark blue while white for the air-annealed one (TNO-A). X-ray photoelectron spectroscopy analysis also indicated that Ti⁴⁺ and Nb⁵⁺ in TNO are partially reduced into Ti³⁺ and Nb⁴⁺ due to the introduction of oxygen vacancy. Electronic conductivity for TNO-V was around 10⁻³ S cm⁻¹ at room temperature and much higher than that for TNO-A (=10⁻¹¹ S cm⁻¹). In electrochemical testing, both TNO-A and TNO-V electrodes showed reversible capacity of 260-270 mAh g⁻¹ at low current density of 0.5 mA cm⁻², while at higher current density of 5.0 mA cm⁻², TNO-V electrode retained higher reversible capacity of 140 mAh g⁻¹ than that for TNO-A electrode (=80 mAh g⁻¹). The enhancement of intrinsic electronic conductivity greatly contributes to improve the rate performance of TNO.     

Equations of State for Rare Gas Solids under Strong Compression

Experimental data on equations of state for rare gas solids are analysed within an extended Mie-Grüneisen approach, which uses a Modified Debye-Einstein model, MoDE2 for the quasiharmonic phonon contribution to the thermal pressure with additional corrections for intrinsic anharmonicities. The static lattice pressure is represented thereby with an Adapted Polynomial expansion of 3^rd order, AP3, which uses as adjustable parameters the atomic number Z, the atomic volume V_sl0, the bulk modulus K_s10, and its first and second pressure derivatives K_s10, and K_s10 at zero pressure. Within this model, not only the data for selected p(V,T) isotherms, but also for the specific heat capacities C_po andC_vo, the volume V₀(T), and the bulk modulus K₀(T), at ambient pressure, are analysed in detail. Good agreement of the model with the experimental data is found for Ar, Kr, and Xe. The data for Ne, however, point to significant anharmonicity and vacancy contributions at ambient pressure, which go beyond the limits of the present model.     

一种可控的直方图均衡算法

本文提出一种在传统直方图中利用细节信息的可调的直方图均衡算法.该算法不但能够有效的提高图像的对比度,而且还能增强图像的细节.这种算法可以采用各种不同的边缘信息如Laplacian、Sobel等.实验证明该方法对增强图像是很有效的.