Stochastic stability of quasi-integrable and non-resonant Hamiltonian systems under parametric excitations of combined Gaussian and Poisson white noises

A procedure for calculating the largest Lyapunov exponent and determining the asymptotic Lyapunov stability with probability one of multi-degree-of-freedom (MDOF) quasi-integrable and non-resonant Hamiltonian systems under parametric excitations of combined Gaussian and Poisson white noises is proposed. The averaged stochastic differential equations (SDEs) of quasi-integrable and non-resonant Hamiltonian systems subject to parametric excitations of combined Gaussian and Poisson white noises are first derived by using the stochastic averaging method for quasi-Hamiltonian systems and the stochastic jump-diffusion chain rule. Then, the expression for the largest Lyapunov exponent is obtained by generalizing Khasminskii's procedure to the averaged SDEs and the stochastic stability of the original systems is determined approximately. An example is given to illustrate the application of the proposed procedure and its effectiveness is verified by comparing with the results from Monte Carlo simulation.     

Potential oscillations during the electrochemical treatment of white liquor

Potential oscillations during the electrochemical treatment of white liquor are reported on. White liquor in the kraft process is composed mainly of sodium sulfide, sodium hydroxide, and sodium carbonate. Cyclic voltammetry, linear galvanic voltammetry, and galvanostatic techniques are used to characterize the behavior of the potential oscillations. The amplitude of the harmonic potential oscillations is between −150 and 750 mV (SCE). The behavior of the potential oscillations strongly depends on the applied current density, temperature, and mass transfer. Electrochemical impedance spectroscopy is employed to study the origin of the oscillations during the electrochemical treatment of the white liquor on the Ti/Ta₂O₅-IrO₂ electrodes. Negative faradaic impedance is observed in the potential range of the potential oscillation amplitudes, and equivalent circuits are designed to fit the experimental impedance spectra. The potential oscillations are caused by the synergic effect of sulfur formation/removal and oxygen evolution in the high-potential range. Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 5, pp. 617–626. The text was submitted by the authors in English.     

用迈克尔逊干涉仪测量全息干板膜厚度

全息干板膜的厚度是全息干板的重要参数之一。使用迈克尔逊干涉仪和白光光源对2种全息干板膜厚度进行测量，并对测量结果误差进行分析，给出了测量误差与膜厚及折射率之间的关系以及此方法的适用范围。研究结果表明：在膜厚从8μm增至41μm的过程中，测量结果的绝对误差≤2μm且变化很小，相对误差则从14.1%降到了2.2%。随着膜厚的增加，相对误差明显降低；折射率n也参与了误差传递，其值与测量误差呈类似反比关系；当n值在1.5附近时，为保证测量的准确性，所测膜厚≥40μm。最后指出，迈克尔逊干涉仪在测量全息干板膜等较厚的薄膜时，具有测量范围大，结果较准确等优点。     

白光再现全息照相

简述了激光全息照相的原理,设计出全息照相的拍摄光路,探索出能成功拍出全息图的方法以及能实现白光再现的实验参数。总结出拍摄反射全息的条件,并能了解全息照相与普通照相的区别,以及全息照相的应用及开拓。     

Composition and analysis of colloidal matter along wine-making. Exploitation of its antioxidant activity in final stabilisation residues

Colloidal matter formed along vinification has been characterized for two consecutive vintages in order to a better understanding of the final solid residues obtained by freezing stabilisation. The polyphenolic content, metal concentrations and antioxidant activity of these residues have been determined. Vintage 2003 of a Vitis vinifera (Tempranillo variety) yielded a concentration of 19.018 ± 0.226 mg g^− 1 of total anthocyanins (TA) and 13.258 ± 0.158 mg g^− 1 of total flavonoids (TF) in fresh deposits. It has been found that ca. 50% of initially present Fe is eliminated along wine-making, only 6% of Cu ends up in final wine and all Mn present at the beginning of the process remains in commercial wine. Antioxidant activity in the residues is found to be related to total polyphenol concentration irrespective of polymerisation degree. An EC₅₀ of 0.130 ± 0.007 g L^− 1 (g of lyophilised dreg per L of buffered solution) was obtained for vintage 2004. Antioxidant capacity of different fractions of wine was not seen to depend upon addition of metals.     

Eu3+掺杂的α-Gd2(MoO4)3荧光粉合成与表征

采用固相反应法合成了Eu³⁺掺杂的α-Gd₂(MoO₄)₃荧光粉。通过XRD、SEM以及激发和发射光谱对样品进行了研究,结果发现助熔剂为3%时样品的结晶较好,样品的发光强度最强,并且样品粉末不团聚。光谱测量的结果表明该荧光粉与其他商品荧光粉不同,其最有效的激发波长不在电荷迁移带范围,其f-f跃迁的465,395nm吸收更强,这就意味着该类荧光粉可作为目前已商品化的白光LED的红色补偿荧光粉,也可作为近紫外LED和三基色荧光粉组合型白光器件的红色荧光粉的候选材料。     

Color tunability in non‐doped single‐layer PLEDs from a carbazole‐based electroluminescent polymer

A conjugated polymer with a carbazole moiety, poly(3,6‐divinylene‐N‐octyl‐carbazole‐p‐phenylene), was synthesized by Wittig reaction. The polymer can be dissolved in common organic solvents such as THF, chloroform, etc. Using this polymer as an active layer, single‐layer non‐doped PLEDs with different thicknesses were fabricated by a spin‐coating approach. The results suggested that electroluminescence spectra are changed with the film thickness of the polymer emitter. Fortunately, CIE 1931 coordinate values are moved to the white‐light region only by changing the film thickness. Copyright © 2008 John Wiley & Sons, Ltd.     

Electrochemical phosphorylation of unsaturated hydrocarbons

It is shown that phosphine derivatives, first of all, primary phosphines, can be produced on the basis of reaction of cathodic reduction of white phosphorus in the aqueous media under mild conditions.     

Novel high-efficiency ecologically safe electrocatalytic techniques for preparing organophosphorus compounds

Major advances and modern tendencies in electrosynthesis of organophosphorus compounds from available raw materials (mainly white phosphorus) are perused, systematized, and generalized. Potential synthetic possibilities and advantages of this intensely developing direction of elementoorganic chemistry are demonstrated.     

Empirical bayesian test of the smoothness

In the context of adaptive nonparametric curve estimation a common assumption is that a function (signal) to estimate belongs to a nested family of functional classes. These classes are often parametrized by a quantity representing the smoothness of the signal. It has already been realized by many that the problem of estimating the smoothness is not sensible. What can then be inferred about the smoothness? The paper attempts to answer this question. We consider implications of our results to hypothesis testing about the smoothness and smoothness classification problem. The test statistic is based on the empirical Bayes approach, i.e., it is the marginalized maximum likelihood estimator of the smoothness parameter for an appropriate prior distribution on the unknown signal.