A New Method for Separation of Hydrophobic Au Nanoparticles in the Reversal Micelle

In this article, a new method which not only can separate hydrophobic Au nanoparticles (NPs), but also obtain highly monodisperse NPs is discussed. A self‐made device of two same burettes, one of which was inserted into the other, was used for separating the nanoparticles by washing the reversal micelle. The effects of separation were characterized and analyzed by micrograph of transmission electron microscope (TEM), UV‐vis spectra, quartz crystal microbalance (QCM), and energy dispersive x‐ray analysis (EDX). It has been shown that, the smaller nanoparticles are, the easier they are to stay at the reversal micelle and the narrower the sizes are. This method can be applied to synthesize highly monodisperse Au NPs.     

Development of novel backwash cleaning technique for reverse osmosis in reclamation of secondary effluent

The objective of the study was to further develop a novel cleaning technique for reverse osmosis in reclamation of municipal secondary effluent. This technique is a new backwash method via direct osmosis (DO) by intermittent injection of the high salinity (HS) solution without stopping of high pressure pump and it is environment and membrane friendly technique. In the study, DO-HS trials were carried out with a UF-RO pilot system which was operated on site with the secondary treated effluent as the raw feed. Different operating conditions for DO-HS treatment in the actual process were investigated. It was found that the operation for implementation of the DO-HS cleaning technique developed was easy. For the first time, the actual profiles of HS concentration, DO backwash flow rate, brine flow rate and permeate pressure during DO-HS treatment have been demonstrated. It was observed that turbidity of the brine stream during DO-HS treatment at 3 NTU was 5 times higher than that before DO-HS treatment. The results from this study have confirmed the previous hypothesis with DO-HS treatment that there would be a strong driving force for DO backwash to lift and sweep the foulants from the membrane surface which would be carried over to the brine. The optimal plant operating conditions in terms of RO feed flow rate, HS concentration and HS injection time are ready for the DO-HS method to be adopted and validated in a long-term continuous plant operation.     

Ammonium Ion Optical Sensor Formation and Characterization of a Self‐Assembled Thiazole Containing Dibenzo‐18‐Crown‐6 Monolayer toward Developing Ammonium Ion‐Sensing Interface

Abstract

This letter demonstrates a selective NH₄ ⁺ detection using a synthesized thiazole benzo crownether ethylamine‐lipoic acid conjugate (1) monolayer. A self‐assembled monolayer (SAM) of 1 was formed on Au surface and well characterized by atomic‐force microscopy, Fourier transform infrared reflection absorption spectroscopy and cyclic voltammetry (CV). A good selectivity for NH₄ ⁺ sensing was observed in a range of 1.0×10^?1 to 1.0×10^?6 M by surface plasmon resonance.     

预试环中H_2及掺杂甲烷的辉光放电清洗

本文给出了在预试环中产生和维持辉光放电的基本参数、氢气(H_2)及氢气掺杂甲烷(H_2/CH_4)辉光放电清洗过程中的质谱分析结果以及氢气辉光放电清洗处理后的样品表面SIMS(二次离子质谱)结果,并进行了讨论。     

A version of Stöber synthesis enabling the facile prediction of silica nanospheres size for the fabrication of opal photonic crystals

A sol-gel synthesis procedure based on the method proposed by Stöber et al. (J Colloid Interface Sci 26:302–315, 1968) has been adopted for the one-step preparation of mono-dispersed silica nanospheres. An excellent control of the particle diameter over a wide range is obtained by varying the amount of silicon alkoxide only, while the concentration of all other components is kept fixed: this allows the fabrication of artificial opals with a finely tuned and precisely predictable lattice parameter.     

Underwater and water-assisted laser processing: Part 1—general features, steam cleaning and shock processing

Water is always present in laser processing in air: as vapor, condensate or adsorbate. Water is the working environment in underwater processing—but it can also be added on purpose to gain better results: to avoid redeposition of debris, to cool the material, to increase plasma pressure or to conduct light. Water can also act as a chemical reagent. The first part of the article will review the advantages and disadvantages of laser processing in the presence of water, light transmission by water, and the two most mature methods of water-assisted laser processing: steam cleaning and shock processing.     

Multispectrum fits for line mixing in the ν3 band Q branch of methane

First-order line-mixing coefficients and model relaxation matrix element scaling factors have been obtained for allowed transitions in the ν₃ band Q branch of CH₄ broadened by H₂, He, N₂, O₂, Ar, and CH₄. The broadening, shifting, Dicke-narrowing, and line-mixing parameters are determined by simultaneous least-squares fitting of spectra at pressures from 0.014 to 66.66 kPa recorded with a high-resolution difference-frequency laser. These results confirm, improve, and extend a previous analysis of the lower pressure (?13.3 kPa) data [A.S. Pine, J. Chem. Phys. 97 (1992) 773] which yielded averaged coefficients of individually fit spectra where adjacent broadened lines are still partially resolved.     

Quantum electrodynamic effects in atomic structure

Summary In high-Z atoms, quantum electrodynamic (QED) corrections are an important component in the theoretical prediction of atomic energy levels. The main QED effects in electronic atoms are the one-electron self-energy and vacuum-polarization corrections which are well known. At the next level of precision, estimates of the effect of electron interactions on the self energy and higher-order effects in two exchanged photon corrections are necessary. These corrections can be evaluated within the framework of QED in the bound interaction picture. For high-Z few-electron atoms, this approach provides a rapidly converging series in 1/Z for the corrections, which is the generalization of the well-known relativistic 1/Z expansion methods. This paper describes recent work on the effect of electron interactions on the self energy. The QED effects are particularly important for the theory for lithiumlike uranium where an accurate measurement of the Lamb shift has been made, as well as for numerous other cases where systematic differences appear between theory that does not include these QED effects and experiment.     

Ultraviolet laser removal of small metallic particles from silicon wafers

Laser removal of small 1 μm sized copper, gold and tungsten particles from silicon wafer surfaces was carried out using ultraviolet radiation at 266 nm generated by Nd:YAG harmonic generation. Successful removal of both copper and gold particles from the surface was achieved whereas tungsten particles proved to be difficult to remove. The cleaning efficiency was increased with an increase of laser fluence. The optimum processing window for safe cleaning of the surface without any substrate damage was determined by measuring the damage threshold laser fluence on the silicon substrate and the required fluence for complete removal of the particles. The different cleaning efficiencies with particle type are discussed by considering the adhesion force of the particle on the surface and the laser-induced cleaning force for the three different particles.     

磷酰化氨基酸自聚成肽的FTIR研究

本文通过对傅里叶变换红外光谱（ＦＴＩＲ）技术研究证明了磷酰化氨基酸可以知聚成肽，并由此说明了在仿生化成肽反应过程中，磷（酰化）起着十分重要的作用，同时了说明了ＦＴＩＲ技术为仿生化的过程研究提供了新的研究方法。