The carbon impurity ohmic discharges on particle transport in the HT-7 tokamak

The line-integrated optical measurement of impurity radiation profiles for the study of light impurity transport is performed in the HT-7 tokamak. The carbon impurity line emissivity is obtained by Abel inversion. The radial transport behaviours of carbon impurities at different central line averaged electron densities ne are investigated in ohmic discharges. The diffusion coefficient Dk（r）, the convection velocity Wk（r） and the total flux of the impurity ions Fk decrease with the increase of ne, which shows a reduction in the impurity particle transport at higher electron densities.     

Direct olive oil analysis by low‐temperature plasma (LTP) ambient ionization mass spectrometry

A fast, reagentless, and direct method is presented for the mass spectrometric analysis of olive oil without any sample pretreatment whatsoever. An ambient ionization technique, the low‐temperature plasma (LTP) probe, based on dielectric barrier discharge, is used to detect both minor and trace components (free fatty acids, phenolics and volatiles) in raw untreated olive oil. The method allows the measurement of free fatty acids (the main quality control parameter used to grade olive oil according to quality classes), selected bioactive phenolic compounds, and volatiles. The advantages and limitations of the direct analysis of extremely complex mixtures by the ambient ionization/tandem mass spectrometry combination are discussed and illustrated. The data presage the possible large‐scale application of direct mass spectrometric analysis methods in the characterization of olive oil and other foodstuffs. Copyright © 2009 John Wiley & Sons, Ltd.     

Solvability of F 4 Quantum Integrable Systems

It is shown that the F ₄ rational and trigonometric integrable systems are exactly solvable for arbitrary values of the coupling constants. Their spectra are found explicitly while eigenfunctions are obtained by pure algebraic means. For both systems new variables are introduced in which the Hamiltonian has an algebraic form being also (block)-triangular. These variables are a certain invariants of the F ₄ Weyl group. Both Hamiltonians preserve the same (minimal) flag of spaces of polynomials, which is found explicitly.     

Symbolic-computation construction of transformations for a more generalized nonlinear Schrödinger equation with applications in inhomogeneous plasmas,optical fibers,viscous fluids and Bose-Einstein condensates

Currently, the variable-coefficient nonlinear Schr?dinger (NLS)-typed models have attracted considerable attention in such fields as plasma physics, nonlinear optics, arterial mechanics and Bose-Einstein condensates. Motivated by the recent work of Tian et al. [Eur. Phys. J. B 47, 329 (2005)], this paper is devoted to finding all the cases for a more generalized NLS equation with time- and space-dependent coefficients to be mapped onto the standard one. With the computerized symbolic computation, three transformations and relevant constraint conditions on the coefficient functions are obtained, which turn out to be more general than those previously published in the literature. Via these transformations, the Lax pairs are also derived under the corresponding conditions. For physical applications, our transformations provide the feasibility for more currently-important inhomogeneous NLS models to be transformed into the homogeneous one. Applications of those transformations to several example models are illustrated and some soliton-like solutions are also graphically discussed.     

Speciation of Cr(VI)/Cr(III) by electrothermal atomisation AAS after electrodeposition on a L'vov platform

Summary The pyrolysed graphite L'vov platform of a tube furnace is considered as an electrode for the electrodeposition and speciation of chromium by electrothermal atomisation atomic absorption spectrometry (ETA-AAS). Firstly, a preliminary study of the Cr(VI)/Cr(III) voltammetric behavior at pH 4.70 on a glassy-carbon electrode is carried out. Secondly, the L'vov platform is used as a cathodic macro-electrode for the selective preconcentration of Cr(VI)/Cr(III) on a mercury film. Speciation of Cr(VI)/Cr(III) is carried out on the basis of the electrolysis potential (E_e): at pH 4.70 and E_e=–0.30 V, only Cr(VI) is reduced to Cr(III) and accumulated as Cr(OH)₃ by adsorption on a mercury film; at E_e=–1.80 V both Cr(VI) and Cr(III) are accumulated forming an amalgam with added mercury(II) ions. Once the film has been formed, the platform is transferred to a graphite tube to atomise the element. The reliability of the method was tested for the speciation of chromium in natural waters and it proves to be highly sensitive thanks to the electroanalytical step. In all samples, the Cr(VI) concentration was less than the detection limit (0.15 ng ml^–1), and the concentration of Cr(III) agrees with those of total chromium. The analytical recovery of Cr(VI) added to water samples [3.50 ng ml^–1 of Cr(VI)] was 105±6.2%.     

一阶导数分光光度法测定蜂胶保健品中黄酮的探导

用一阶导数分光光度法测定了蜂胶保健品中黄酮。以芦丁为对照品，测定了蜂胶保健品中总黄酮总量。芦丁浓度在0－20mg/L内，一阶导数值与其浓度具有良好的线性关系，其回归方程为y=-0.00061-0.0065x,相关系数r=0.9998。方法简便、快速、准确。     

Continuum gamma spectroscopy and order statistics

An analytical function deduced from Order Statistics is able to analytically reproduce lengthy Monte Carlo simulated Energy-Ordered Spectra obtained from heavy ion fusion-evaporation reactions in the case in which the level density is given by Constant Temperature Fermi Gas and the E1 gamma strength by the classical dipole law.     

On the validity of marcus relationship for dissociative electron transfer reactions in solution

In this paper Monte Carlo simulations of a dissociative electron transfer reaction in solution have been performed in order to test to what extent the deviation of Marcus' relationship for this kind of reactions can be attributed to the features of the solute internal potential energy. It is shown that Marcus' equation does not apply to this kind of dissociative electron transfer processes if the ab initio solute internal potential energies are used. Conversely, if a Morse curve and its repulsive part are employed to describe the solute internal potential energies, Marcus' relationship is recovered. Then, the problem is reduced to what extent the ab initio solute internal potential energies can be represented by Morse curves.     

Clement-Desormes实验之不足

通过分析实验数据发现，Clement-Desormes的测量结果接近理论值存在某种巧合，该实验所用的测量原理并不能充分解释其实验现象。