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71.
Steam distilled oil from the shoots, separated leaves, and stem, as well as from the flower of laurel (Laurus nobilis), grown in Montenegro, were analyzed by GC and GC/MS. The yield of essential oil was as follow: 1.4% in young shoots, 1.5%
in the separated leaves, and 0.7% in separated stems. The main constituents of all investigated oils were 1,8-cineole, methyleugenol,
and α-terpinyl acetate. Besides, α-pinene, β-pinene, sabinene, and linalool were also present. It was interesting and important for commercial samples of laurel essential
oil that there was no significant difference among the essential oil obtained from young shoots and those obtained from leaves
and stem. The main constituents of the flower oil were 1,8-cineole (15.7%), β-caryophyllene (9.5%), γ-muurolene (7.1%), α-terpinyl acetate (6.5%), and methyleugenol (3.9%).
Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 337–339, July–August, 2007. 相似文献
72.
Sumiko Suzuki Mika Shirao Momoyo Aizawa Hiroyuki Nakazawa Katsushi Sasa Hideo Sasagawa 《Journal of chromatography. A》1994,680(2):541-547
A method for the determination of synthetic tar dyes used as food additives using capillary electrophoresis with photodiode-array detection was investigated. The dyes Erythrosine (R-3), Phloxine (R-104), Rose Bengal (R-105), Acid Red (R-106), Amaranth (R-2), New Coccine (R-102) and Allura Red AC (R-40) were separated on a capillary column (50 cm × 75 μm I.D.) and identified from the absorbance spectra of each peak. The electrophoresis buffer used was a mixture of 25 mM sodium phosphate buffer and 25 mM sodium borate buffer (1:1) (pH 8.0) containing 10 mM sodium dodecyl sulfate (SDS). Substitution of β-cyclodextrin for SDS in the electrolyte buffer was effective for the separation of R-2 and R-102. This modified method could be employed as an additional assay method for these two dyes. 相似文献
73.
Lesar A Prebil S Hodoscek M 《Journal of chemical information and computer sciences》2002,42(4):853-857
Various highly accurate ab initio composite methods of Gaussian-n (G1, G2, G3), their variations (G2(MP2), G3(MP2), G3//B3LYP, G3(MP2)//B3LYP), and complete basis set (CBS-Q, CBS-Q//B3LYP) series of models were applied to compute reaction enthalpies of the ground-state reaction of CO2 with Mg. All model chemistries predict highly endothermic reactions, with DeltaH(298) = 63.6-69.7 kcal x mol(-1). The difference between the calculated reaction enthalpies and the experimental value, evaluated with recommended experimental standard enthalpies of formation for products and reactants, is more than 20 kcal x mol(-1) for all methods. This difference originates in the incorrect experimental enthalpy of formation of gaseous MgO given in thermochemical databases. When the theoretical formation enthalpy for MgO calculated by a particular method is used, the deviation is reduced to 1.3 kcal x mol(-1). The performance of the methodologies used to calculate the heat of this particular reaction and the enthalpy of formation of MgO are discussed. 相似文献
74.
Raman study of structural relaxation and boson peak in amorphous films of adamantane 总被引:1,自引:0,他引:1
Bistricić L Baranović G Ilijić S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(7):1537-1546
Low-frequency Raman scattering was used to study amorphous solid films of adamantane, a globular non-polar hydrocarbon molecule. As evidenced by its spectral characteristics this type of disorder is different from the orientational disorder found in the room temperature plastic phase by the absence of the translational order as well. This gives rise to the boson peak related to acoustic phonons which gradually disappears upon heating with simultaneous emerging of the phonon line at 50 cm-1 which characterizes the low-temperature ordered phase of adamantane. Adamantane dynamics resembles that of C60 fullerene although not in the same temperature range. All this makes adamantane an attractive system that could serve as a practical reference in molecular simulation studies of the glassy phase of model fluids. 相似文献
75.
76.
The adsorption of Zn2+ ions on amorphous Fe(OH)3 and -Fe2O3, as a function of pH, has been investigated. In the pH region corresponding to the formation of positively charged Zn-hydroxy complexes, an abrupt increase in adsorption was observed. The influence of EDTA and glycine on the adsorption of Zn2+ by -Fe2O3 has also been investigated. Strong suppression of the adsorption of Zn2+ was observed for high [EDTA or Gly]/[Zn2+] concentration ratios. The results of the adsorption of Zn2+ in the presence of an organic ligand were explained by the formation of Zn-EDTA or Zn-glycine complexes and also by the occupation of adsorption sites by the free organic ligand. 相似文献
77.
78.
79.
Alexander J. Turinske Scott A. Nelson Nenad Stojilovic Sulaiman B. Ali Sasa V. Dordevic Edward A. Evans 《Journal of Sol-Gel Science and Technology》2013,65(2):283-286
In the process of fiber production from Zinc acetate and Polyvinylpyrrolidone using the electrospinning method, ZnO forms at temperature as low as 120 °C. The fibers were characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and ultraviolet–visible (UV–Vis) spectroscopy. Upon heating at 120 °C for 12 h some fibers shrink in diameter down to about 100 nm while others remain in the 400–900 nm range. Within the hybrid fibers, ZnO crystallizes in the wurtzite structure with a bang gap of 3.3 eV. The hybrid fibers exhibit the flexibility of polymer component and optical properties of ZnO phase, and promise to be very useful in various applications. 相似文献
80.
Journal of Statistical Physics - The emergence of deterministic and irreversible macroscopic behavior from deterministic and reversible microscopic dynamics is understood as a result of the law of... 相似文献