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51.
Michael Stavola J.M. Friedman R.A. Stepnoski Mark G. Sceats 《Chemical physics letters》1981,80(1):192-194
Cooperative vibronic spectra involving Gd3+ electronic transitions and the vibrational transitions of nearby water molecules are used to determine the stretching spectrum for isotopically dilute OH in a solution of GdCl3 in D2O. The OH stretching spectrum of water molecules in the first hydration sphere is shifted to lower energy than that of the bulk liquid. 相似文献
52.
Thirteen phosphorus-containing flame retardants were synthesized in this work. The solubilities of flame retardant [(6-oxide-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)-methyl]-butanedioic acid (DDP) in selected solvents are measured. TGA measurements of the 13 phosphorus-containing flame retardants were carried out and thermal stabilities of three flame-resistant PET (FRPET) resins were investigated. A FRPET incorporated by DDP with terephthalic acid and ethylene glycol reported in literature was also discussed and compared. The thermal stability of the FRPET is improved by the incorporation of phosphorus-containing flame retardants. The LOI values of all phosphorus-containing polyesters are higher than 27%. The improvement of the flame-resistant ability is due to the formation of the char that is not only caused by the existence of phosphorus elements in the resin but also by the relative large number of carbon atoms of the phenyl group in the flame retardants. 相似文献
53.
Geometries and electronic structures of W4 and W clusters were studied by use of density functional methods B3LYP, B3P86, B3PW91, BHLYP, BLYP, and MPW1PW91. The calculated results indicate that the three‐dimensional structure of singlet state with either D2d symmetry (B3LYP, B3P86, B3PW91, BLYP, and MPW1PW91) or C2v symmetry (BHLYP) is the ground state for the W4 cluster. For the W cluster, the doublet state is preferred, and the most stable structure is also 3D with either D2d symmetry (B3LYP, B3PW91, BHLYP, BLYP) or C2v symmetry (B3P86 and MPW1PW91). The calculated electron affinity at B3P86 gives the best performance compared with experiment. For the dissociation channel, W + W3 is suggested to be the possible route for the W4 cluster. For the W cluster, W + W is the most likely route for dissociation, in agreement with experiment. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 相似文献
54.
55.
应用火焰原子吸收光谱(FAAS)法测定了钮扣电池中铅和镉的含量,对测定条件作了较详细的研究。用在线双毛细管标准加入法消除了基体的干扰。按所述方法测定电池样品中铅和镉,测定结果的RSD依次为3.58%和5.87%,铅和镉的浓度水平分别为5.4×10-3%和2.3×10-4%(质量分数),回收率结果为93.0%~100.1%(铅)和95.0%~101.0%(镉)。 相似文献
56.
A novel modification of a hydrogen-atmosphere flamo ionization detector (HAFID) is presented which attenuates response to hydrocarbon compounds, significantly enhancing selectivity towards organometallic compounds by more than an order of magnitude. Chromatograms of an organometallic compound test mixture and regular leaded gasoline are presented to depict the specificity of the response. 相似文献
57.
Barontini F. Marsanich K. Cozzani V. 《Journal of Thermal Analysis and Calorimetry》2004,78(2):599-619
The TG-FTIR technique was used in the present study to investigate the thermal degradation behaviour of materials containing
brominated flame retardants under fire conditions. Time-temperature profiles and oxygen concentrations typical of selected
fire scenarios were reproduced in the thermogravimetric analyzer, while the characterization of the gaseous products generated
was performed by the simultaneous FTIR analysis. FTIR analysis combined with the use of specific calibration procedures allowed
the quantitative estimation of the gaseous products evolved as a function of experimental conditions. The results obtained
allowed the straightforward assessment and the comparison of the quantities of hydrogen bromide formed in the oxidation and
thermal degradation of pure brominated flame retardants and of flame retarded materials of industrial interest. Hydrogen bromide
yields resulted dependent on the experimental conditions used, such as oxygen concentration and heating rate. Although TG-FTIR
experiments only provide a representation of the actual heterogeneous combustion products in real fire conditions, the coupled
TG-FTIR technique proved to be a straightforward experimental methodology allowing one to obtain reference data on the nature
and quantities of the macropollutants generated in a fire.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
58.
The gauging of free differential algebras (FDA's) produces gauge field theories containing antisymmetric tensors. The FDA's extend the Cartan-Maurer equations of ordinary Lie algebras by incorporating p-form potentials (p>1). We study here the algebra of FDA transformations. To every p-form in the FDA, we associate an extended Lie derivative l generating a corresponding gauge transformation. The field theory based on the FDA is invariant under these new transformations. This gives geometrical meaning to the antisymmetric tensors. The algebra of Lie derivatives is shown to close and provides the dual formulation of FDA's. 相似文献
59.
The quantum group IGL
q
(N), the inhomogenization of GL
q
(N), is formulated with
-matrices. Theq-deformed universal enveloping algebra is constructed as the algebra of regular functionals in this formulation and contains the partial derivatives of the covariant differential calculus on the quantum space. 相似文献
60.
We use a quite concrete and simple realization of sl
q
(2, ) involving finite difference operators. We interpret them as derivations (in the noncommutative sense) on a suitable graded algebra, which gives rise to the noncommutative scheme 1 II 1* as the counterpart of the standard 1 = Sl(2, )/B. 相似文献