An integrated optical coupler used in a fibre interferometry system for on-line surface measurements

In this paper, an integrated optical (IO) coupler produced using the technique of silica-on-silicon was described. A fibre interferometry system using the IO coupler was then developed and its performance was tested. The environmental noise and disturbances in this system were reduced significantly after combining a reference interferometer and an all fibre polarisation scrambler so as to produce good stability and repeatability. Furthermore, the measurement mirror was mounted on a piezoelectric transducer (PZT) and disturbances were introduced in the system in order to simulate on-line surface measurements. Both a commercial fibre and the IO couplers were compared using this method. Better experimental results were achieved when the system using the IO coupler than using the fibre one.     

Computational study on mechanisms and pathways of the atmospheric NH2 + IO reaction

ABSTRACT

The potential-energy surfaces of the amino radical (NH₂) with IO reaction have been studied at the CCSD(T)/cc-pVTZ//MP2/6-311++G(d,p) level. Two kinds of pathways are revealed, namely H-abstraction and addition/elimination. Rice–Ramsperger–Kassel–Marcus theory and transition state theory are employed to calculate the overall and individual rate constants over a wide range of temperatures and pressures. It is predicted that, at atmospheric pressure with N2 as bath gas, the formation of P1 (HI?+?HNO) is the dominant pathways at 200–700?K, while the direct H-abstraction leading to P3 (³NH?+?HOI) takes over the reaction at a temperature above 700?K. At the high-pressure limit, IM1 [IONH₂] formed by collisional stabilisation is dominant at 200–700?K; the direct H-abstraction resulting in P3 (³NH?+?HOI) plays an important role at higher temperatures. However, the total rate constants are independence on the pressure; however, the individual rate constants are sensitive to pressure. The atmospheric lifetime of NH₂ in IO is around one week. TD-DFT computations imply that IM1 [IONH₂], IM1A [IONH₂′], IM2 [IN(H₂)O], IM3 [OINH₂], IM4 [HOINH], tra-IM5 [tra-HON(H)I] and cis-IM5 [cis-HON(H)I] will photolyze under the sunlight.     

BiOIO3和Bi2(IO4)(IO3)3晶体电子结构和光学性质研究

采用基于密度泛函理论(DFT)的第一性原理方法对BiOIO3和Bi2(IO4)(IO3)3两种碘酸铋非线性光学晶体的电子结构及光学性质-折射率及双折射率进行了计算研究.结果表明:采用GGA-PBE计算两者的禁带宽度分别为2.385 eV和2.930 eV;选用optados计算BiOIO3和Bi2(IO4)(IO3)3化合物的折射率和双折射率,计算结果表明二者皆具有较大的双折射率.     

基于极值理论的EXPAR时序模型异常点诊断

本文基于极值理论给出诊断EXPAR模型异常点检验统计量的渐近分布,并依此渐近分布来选取检验的临界值。这种方法选取的临界值可保证控制在一定显著性水平下,而且可以计算渐近p值,比仿真选取的临界值更科学合理。     

Recent developments in manufacturing emulsions and particulate products using membranes

Membrane emulsification (ME) is a relatively new technique for the highly controlled production of particulates. This review focuses on the recent developments in this area, ranging from the production of simple oil-in-water (O/W) or water-in-oil (W/O) emulsions to multiple emulsions of different types, solid-in-oil-in-water (S/O/W) dispersions, coherent solids (silica particles, solid lipid microspheres, solder metal powder) and structured solids (solid lipid microcarriers, gel microbeads, polymeric microspheres, core-shell microcapsules and hollow polymeric microparticles). Other emerging technologies that extend the capabilities into different membrane materials and operation methods (such as rotating membranes, repeated membrane extrusion of coarsely pre-emulsified feeds) are introduced. The results of experimental work carried out by cited researchers in the field together with those of the current authors are presented in a tabular form in a rigorous and systematic manner. These demonstrate a wide range of products that can be manufactured using different membrane approaches. Opportunities for creation of new and novel entities are highlighted for low throughput applications (medical diagnostics, healthcare) and for large-scale productions (consumer and personal products).     

Electrochemical Behavior and Its Electrocatalytic Activity of A P—Mo Heteropolyanion Modified ITO Electrode

ITO is a versatile material in the electronic industry because of its special transparent and conductive properties. However, there are a few reports regarding the adsorption of organic or organometallic compounds on the ITO surface1-4. The heteropolyanions are interested in the field of material science, catalytics, biology, and medicine owing to their chemical, structural, and electronic versatility5-7. One of the most important properties of polyoxometalate anions is their ability to a…     

Scientific post hoc and in situ visualisation of high-order polynomial solutions from massively parallel simulations

This paper presents two recent numerical tools developed respectively to perform traditional post-processing and more advanced in situ processing of high-order polynomial data generated by massively parallel finite element codes. For post-processing and visualisation of high-order solutions, we present a new ParaView plugin that integrates Gmsh used as an external library. This plugin therefore combines respectively ParaView's scalability in parallel and Gmsh's ability to apply h-refinement of the initial mesh followed by solution interpolation on the resulting visualisation grid, thus enabling parallel visualisation of any arbitrary high-order polynomial solutions in client–server mode. In a second stage, this capacity has been extended to an in situ interface based on the Catalyst library which enables in situ analysis and visualisation of high-order solutions. These new capacities are demonstrated with the visualisation of high-order solution of the unsteady flow generated by a discontinuous Galerkin method for an unsteady turbomachinery application.     

Efficient and Convenient Oxidation of Organic Halides to Aldehydes and Ketones Catalyzed by H5IO6/V2O5 in Ionic Liquid [bmpy][PF6]

A mild, efficient, and eco‐friendly procedure for the oxidation of organic halides to aldehydes and ketones in good to high yields catalyzed by H₅IO₆/V₂O₅ in ionic liquid [bmpy][PF₆] with no trace of overoxidation to carboxylic acids has been developed. The product can be isolated by a simple extraction with organic solvent, and the catalytic system can be recycled or reused without any significant loss of catalytic activity.     

Experimental investigation of positron self-trapping near the vapour-liquid critical point of hellium-4

Positron self-trapping in helium near the vapor-liquid critical point is investigated using the positron annihilation lifetime technique. A 13% decrease in the slowing-down time for positrons to reach the self-trapped state is observed at the critical temperature 5.190 K relative to the slowing-down time at 5.200 K.     

［Cu（IO_5OH））_2］~（5－）离子配合物中~（127）I超超精细相互作

用ＥＳＲ方法研究了［Ｃｕ（ＩＯ５ＯＨ）２］５－离子配合物中１２７Ｉ核的超超精细相互作用，旨在证实在碘离子上存在未成对电子自旋和找到一种解释Ｃｕ２＋离子中电子离域的机制。根据ＥＳＲ参数的计算指出碘离子上自旋密度为０．７７％。