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1.
Christiane Albrecht 《Analytical and bioanalytical chemistry》2008,390(5):1223-1224
2.
Harry Biron Christiane Grller-Walrand Stephan De Jaegere 《Chemical physics letters》1973,20(6):581-585
A quantitative comparison between the excitation and absorption spectra of Eu3+ in aqueous solution is given which leads to the conclusion that fluorescence quantum yields are independent of the excitation wavelength. Use is made therefore of the series of homologous lines 5D3, 5D2, 5D1, 5D0 → 7F1. 相似文献
3.
Various methods of radiochemical separation were tested for the determination of phosphorus in metals and alloys by neutron
activation analysis. Classical methods of separation revealed some defects when they were applied to this problem. Methods
using liquid extraction gave low yields and were not reproducible. Methods based on precipitation gave better results, but
were not selective enough in most of the cases. Retention on alumina was not possible without preliminary separations We studied
a new radiochemical separation based on the extraction of elemental phosphorus in the gaseous phase after reduction at high
temperature with carbon. Measurements with radioactive phosphorus showed that the extraction yield is better than 99%. 相似文献
4.
S. Zouad C. Loos-Neskovic M. Fedoroff 《Journal of Radioanalytical and Nuclear Chemistry》1987,111(2):337-349
The fixation mechanisms of strontium on polyantimonic acid (PAA) were studied in order to choose the best recovery conditions from nuclear wastes. This was performed through the determination of the composition and structure, the kinetics and capacity involving the use of different methods: radioactive tracers, X-ray diffraction, potentiometric measurements. The composition of PAA corresponds to H2Sb2O6·1.5H2O with a cubic pyrochlore type structure. A total exchange leading to SrSb2O6·nH2O is achieved in basic medium, while the capacity is lower in acid and neutral media. The kinetics can be divided into two stages: the first one may be due to a surface phenomenon and the second can be interpreted by a diffusion mechanism into the particle. These results were confirmed by potentiometric measurements. Owing to the rapidity of the first stage of fixation and to the high distribution coefficient, PAA offers a good alternative for column separation from dilute radioactive solutions. 相似文献
5.
6.
We consider a class of indecomposable modules over the Virasoro Lie algebra that we call bounded admissible modules. We get results concerning the center and the dimensions of the weight spaces. We prove that these modules always contain a submodule with one-dimensional weight spaces. From this follows the proof of a conjecture of V. Kac concerning the classification of simple admissible modules.Preprint Université de Bourgogne-mai 1990 相似文献
7.
Christiane Quesne 《Czechoslovak Journal of Physics》1996,46(2-3):249-254
A few years ago, Matsuo and Cherednik proved that from some solutions of the Knizhnik-Zamolodchikov (KZ) equations, which first appeared in conformal field theory, one can obtain wave functions for the Calogero integrable system. In the present communication, it is shown that from some solutions of generalized KZ equations, one can construct wave functions, characterized by any given permutational symmetry, for some Calogero-Sutherland-Moser integrable models with exchange terms. Such models include the spin generalizations of the original Calogero and Sutherland ones, as well as that with -function interaction.Presented at the 4th Colloquium Quantum Groups and Integrable Systems, Prague, 22–24 June 1995 相似文献
8.
Christiane Tretter 《Integral Equations and Operator Theory》1996,26(2):222-248
We study nonselfadjoint spectral problems for ordinary differential equationsN(y)–P(y)=0 with -linear boundary conditions where the orderp of the differential operatorP is less than the ordern ofN. The present paper addresses the question of the completeness of the eigenfunctions and associated functions in the Sobolev spacesW
2
k
(0,1) fork=0,1,...,n. To this end we associate a pencil
– of operators acting fromL
2(0,1) to the larger spaceL
2x(0,1)
n
with the given problem. We establish completeness results for normal problems in certain finite codimensional subspaces ofW
2
k
(0,1) which are characterized by means of Jordan chains in 0 of the adjoint of the compact operator
=
–1.Dedicated to Professor Heinz Langer on the occasion of his 60th birthday 相似文献
9.
FT-IR spectroscopy and SFM were used to investigate the growth of thin films of the organic semiconductor 3,4,9,10-perylenetetracarboxylicdianhydride (PTCDA) deposited by vacuum sublimation onto various substrates, i.e. Ag(111) layers on mica, KBr(100), mica, oxidized Si, and TiO2 nanoparticles on Si. Layer thicknesses of PTCDA varied from 10 to 1500 nm.The anhydride vibrations of PTCDA differ for the used substrates, which can be connected to the orientation of the molecules relative to the substrate surface and the film morphology as detected in the SFM pictures. 相似文献
10.
The representation theory of the generalized deformed oscillator algebras (GDOA's) is developed. GDOA's are generated by the four operators {1, a, a
, N}. Their commutators and Hermiticity properties are those of the boson oscillator algebra, except for [a, a
]
q
= G(N), where [a, b]
q
= ab – q ba and G(N) is a Hermitian, analytic function. The unitary irreductible representations are obtained by means of a Casimir operator C and the semi-positive operator a
a. They may belong to one out of four classes: bounded from below (BFB), bounded from above (BFA), finite-dimentional (FD), unbounded (UB). Some examples of these different types of unirreps are given. 相似文献