洋葱色素的提取及抗氧化活性的测定

分别用芬顿（Fenton）反应法和1,1-二苯-2-苦肼基（DPPH）法测定了洋葱色素的抗氧化作用。结果表明,洋葱色素对羟自由基和DPPH自由基均有一定的清除作用,其清除率大小依次为42．4％,58．2％。洋葱色素是十分具有开发利用价值的天然色素。     

Optical Hilbert transform using polarization filters

Using a combination of linear polarization filters, a new method to generate the optical Hilbert transform (OHT) is described. Linear polarizers, acting as knife-edge filters in the spatial frequency plane and together with an image plane analyzer, can produce at the output, the input signal, its analytical function and its OHT. Both one and two dimensional, also angularly anisotropic and isotropic, OHTs are discussed. With a white light source, this method also produces a white light HT (WHT).     

Surface-enhanced Raman scattering of silicon evaporated on Ag island films

Enhanced Raman scattering of Si films from 1 to 25 Å thick deposited on Ag island films is presented. It is found that Raman spectra of Si deposits have a spectral shape similar to those of amorphous Si.     

Random-field induced memory effects in inhomogeneously diluted antiferromagnets K2NixZn1−xF4

Using neutron diffraction a random-field generated memory is observed in K₂Ni_xZn_1−xF₄ with x = 0.96, 0.85, and 0.75. The intensities and profiles of magnetic Bragg reflections are found to follow unique trajectories determined by switching the external magnetic field on and off while cooling. The effect, associated with a inhomogeneous spread in T_N on a microscopic scale, is a direct manifestation of freezing in of multi-domain states at the ordering temperature.     

Parametres thermodynamiques des defauts ponctuels dans le chlorure de strontium pur ou dope par des cations monovalents ou trivalents

The electrical conductivity of a great number of SrCl₂ crystals, either purified or doped with Na⁺, K⁺, Rb⁺, Gd³⁺ and Ce³⁺, has been studied. The microscopic models used for the interpretation of the results have been justified by dielectric loss measurements, ITC and EPR (for Gd³⁺). The thermodynamic parameters of point defects have been derived, over the temperature range 420–860 K, from the fitting of experimental data to the equations of the Lidiard-Debye-Hückel theory. The values of the enthalpies of Cl vacancy mobility (0.30 eV) and Cl interstitial mobility (0.76eV), association of Cl vacancy with Na⁺ (0.53 eV), K⁺ (0.42 eV), Rb⁺ (0.40 eV) and ionic Frenkel defects formation (2.20 ± 0.11 eV) have been used in the interpretation of the experimental results over a large concentration range. The solubility enthalpy of Na ⁺ is 1.2 ± 0.1 eV; the solubility of the rare earths is very small at low temperature. The thennodynamic parameters which have been found have been compared with other known experimental values and with theoretical results.     

RKR potentials and radial wave equation

A RKR-Kaiser potential is obtained for the X¹Σ⁺CO state. This potential is tested through radial wave equation integration. In the application to the A ⁶LiH state there is not self-consistence. To improve it we present a mixed potential that is consistent. This is a Huffaker-RKR-van der Waals potential. This procedure is applicated to X′Σ⁺⁶LiH, A¹Σ⁺⁶LiH and A′Σ⁺⁶LiD states.     

On possibilistic linear programming

The problem of processing and combining possibilistic information in the scope of linear programming is approached. As apparatus to cope with this problem, we use the concepts of ‘more possible value’, ‘α-possibly feasible action’ and ‘α-possibly efficient action’.Issues regarding the feasibility of the resulting deterministic programs as well as the characterization of their optimal solutions are also discussed.