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1.
Triazines are widely used in agriculture around the world as selective pre‐ and post‐emergence herbicides for the control of broad leaf and grassy weeds. With high toxicity and persistence, triazines can contaminate the environment and crops, so the development of rapid and sensitive methods for the determination of different triazines is necessary. Capillary electrophoresis comprises a group of techniques used to separate chemical mixtures. Analytical separation is based on different electrophoretic mobilities. This review focuses on the analysis of triazine herbicides with different modes of capillary electrophoresis, including capillary zone electrophoresis, micellar electrokinetic capillary electrophoresis, capillary electrochromatography and nonaqueous capillary electrophoresis. Determinations of triazines in various matrices such as surface water, groundwater, vegetables, soil and grains are emphasized. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
2.
In this context, we introduce and investigate the properties of the nonlinear negative binomial state (the state which interpolates between the nonlinear coherent and the number states). Mainly we concentrate on the statistical properties for such state where we have discussed two different cases of squeezing phenomenon. The first case is the normal squeezing while the second is the amplitude squared squeezing, further the second order correlation function is also considered. Our discussion have been extended to include the quasi-probability distribution functions (W-Wigner and Q-functions). The quadrature distribution and the phase properties in Pegg-Barnett formalism besides the phase variances are considered. Examination of the resonance fluorescence against the present state is given (single atom and thermodynamic limit). It has been shown that the atomic inversion is sensitive to any variation in the nonlinear negative binomial number m. 相似文献
3.
4.
The two-dimensional non-linear model on a Riemannian symmetric spaceM=G/H is coupled to fermions with quartic self-interactions. The resulting hybrid model is presented in a gauge-dependent formulation, with a bosonic field taking values inG and a fermionic field transforming under a given representation of the gauge groupH. General criteria for classical integrability are presented: they essentially fix the Lagrangian of the model but leave the fermion representation completely arbitrary. It is shown that by a special choice for the fermion representation (derived from the adjoint representation ofG by an appropriate reduction) one arrives naturally at the supersymmetric non-linear model onM=G/H. The issue of quantum integrability is also discussed, though with less stringent results.Work partially supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), Brazil, and KFA Jülich, Federal Republic of GermanyOn leave of absence from Fakultät für Physik der Universität Freiburg, Federal Republic of Germany 相似文献
5.
R. Shabana S. M. Khalifa S. Abdalla H. F. Aly 《Journal of Radioanalytical and Nuclear Chemistry》1986,106(1):55-63
Extraction of WO
4
2–
and ReO
4
–
by Adogen-381, tricaprylmethylammonium chloride, Hyamine 10-X, trioctylphosphine oxide or dibenzylsulphoxide in xylene from HNO3, HCl or H2SO4 acid medium was investigated. Based on the separation factors obtained, the separation of ReO
4
–
from WO
4
2–
was elucidated. ReO
4
–
was separated from WO
4
2–
in high radiochemical purity: >99.9% by three successive extractions and strippings using Adogen-381 from HCl or HNO3 acid medium. 相似文献
6.
The preparation of a variety of 8-cyano-1,4-dihydro-7-phenyl-4-oxopyrrolo[1,2-a]pyrimidine-3-carboxylicacids and 8-cyano-1,4-dihydro-7-p-fluorophenyl-4-oxopyrrolo[1,2-a]pyrimidine-3-carboxylic acids is described. 相似文献
7.
F. H. A. Abdalla G. A. El-Shobaky N. A. Hassan 《Journal of Thermal Analysis and Calorimetry》1996,47(6):1777-1785
A V2O5/Al2O3 mixed solids sample was prepared with a molar ratio of 0.41 Na2O (4 and 10 mol%) was added in the form of sodium nitrate prior to calcination in air in the temperature range 500–1000C. Solid-solid interactions between V2O5 and Al2O3 were studied using DTA and TG curves and their derivatives together with XRD techniques.The results obtained showed that Na2O interacted with V2O5 at temperatures starting from 500C to yield a sodium/vanadium compound, Na0.3V2O5 which remained stable and decomposed in part by heating at 1000C. V2O5 exists in orthorhombic and monoclinic forms in the case of pure mixed solids and those containing 4 mol% of Na2O and preheated at 500C, and in monoclinic form in the case of the mixed solid doped with 10 mol% of Na2O.Heating of pure and doped mixed oxide solids at 650C resulted in the conversion of most of the V2O5 into AlVO4. Doping with sodium oxide enhanced the solid-solid interaction between V2O5 and Al2O3 at 650C to produce AlVO4. The produced AlVO4 decomposed completely on heating at 700C to form -Al2O3 and V2O5, (orthorhombic and monoclinic forms).The presence of Na2O was found to decrease the relative intensity of the diffraction lines of -Al2O3 (corundum) produced at 750C which indicated some kind of hindrance of the crystallization process.Heating of pure and doped mixed solids at 1000C resulted in a further crystallization of acorundum together with V2O5 and sodium vanadate, Na0.3V2O5. However, the intensities of diffraction lines relative to those of the sodium vanadium compound were found to decrease markedly by heating at 1000C, indicating partial thermal decomposition into vanadium and aluminium oxides. 相似文献
8.
9.
Solid-phase extraction coupled with reversed-phase high-performance liquid chromatography and UV detection was employed for the analysis of the antibiotic vancomycin in patient plasma, bone, atrial appendage, and pericardial fluid. Vancomycin was quantitated in samples from patients undergoing cardiac surgery. Calibrations were linear in the range 3-100 micrograms/ml vancomycin; the lower limit of detection was approximately 3 micrograms/ml in fluids with an absolute limit of detection in bone samples of 0.75 microgram per injection. 相似文献
10.
Mohamed R. Mahmoud Ahmed A. Abdel Gaber Ahmed A. Boraei Elham M. Abdalla 《Transition Metal Chemistry》1994,19(4):435-438
Summary Mixed ligand metal complexes of CoII, NiII and CuII with dicarboxylic aliphatic acids, H2L (succinic, malic and tartaric) as primary ligands and with imidazoles, L (imidazole and 2-methylimidazole) as secondary ligands were prepared and characterized. MLL2 and ML4 molecular formulae were suggested for these complexes were Formation constants of the different complexes were determined pH-metrically at T = 25 ± 0.1°C and = 0.1 mol dm–3 (NaClO4). The stability of the mixed ligand complexes increased as the effective basicity of the dicarboxylic aliphatic acid anion increased, namely, tartarate < malate < succinate acid. 相似文献