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61.
62.
Classification of white wine aromas with an electronic nose 总被引:3,自引:0,他引:3
This paper reports the use of a tin dioxide multisensor array based electronic nose for recognition of 29 typical aromas in white wine. Headspace technique has been used to extract aroma of the wine. Multivariate analysis, including principal component analysis (PCA) as well as probabilistic neural networks (PNNs), has been used to identify the main aroma added to the wine. The results showed that in spite of the strong influence of ethanol and other majority compounds of wine, the system could discriminate correctly the aromatic compounds added to the wine with a minimum accuracy of 97.2%. 相似文献
63.
“Simple” energetic patterns, where simple means the use of parameters derived only from the stoichiometry of these species,
are relatively rarely discussed in the literature. In addition, entropy studies have been dominated by derivation of the absolute
quantity S° rather than the entropy of formation (TΔf
S
o). Relationships between the entropy of formation and different parameters such as negative value of the charge of the species,
the number of oxygen atoms, the natural logarithm of the molecular weight, the total number of atoms and the number of central
atoms that are gases were recently discussed by us for aqueous polynuclear oxyanions. As shown here hydrogen containing anions
do not follow this pattern. In this study, new approaches for the estimation of the entropy of formation of aqueous hydrogen
containing mono and polynuclear oxyanions are suggested, evaluated and recommended. 相似文献
64.
R. V. Golovnya 《Chromatographia》1979,12(8):533-538
Summary Equations modifying Rohrschneider's relationship between I and thermodynamical characteristics values are derived. Polarity in chromatography is discussed as a possibility of stationary phases or absorbents to enter into intermolecular interactions and is determined on the basis of the partial molar free energies of solution (G) of six test substances. A simple method for the calculation of stationary phase polarity in terms of G from retention indices and McReynolds constants is given. Equations are presented for the calculation of stationary phase selectivity utilizing G data tabulated for selected test substances. The thermodynamical basis of selecting a reference phase for a unified system expressing the selectivity of stationary phases which can also be applied for adsorbents is suggested. The energy equivalent to an index unit, Gi.u., is discussed. 相似文献
65.
66.
Mineral content and botanical origin of Spanish honeys 总被引:2,自引:0,他引:2
Fernández-Torres R Pérez-Bernal JL Bello-López MA Callejón-Mochón M Jiménez-Sánchez JC Guiraúm-Pérez A 《Talanta》2005,65(3):686-691
Eleven elements (Zn, P, B, Mn, Mg, Cu, Ca, Ba, Sr, Na and K) were determined by inductively plasma coupled spectrometry in 40 honey samples from different places of Spain and four different botanical origins: Eucalyptus (Eucalyptus sp.), Heather (Erica sp.), Orange-blossom (Citrus sinensis) and Rosemary (Rosmarinus officinalis). K, Ca and P show the higher levels with average concentrations ranged between 434.1-1935 mg kg−1 for K; 42.59-341.0 mg kg−1 for Ca and 51.17-154.3 mg kg−1 for P. Levels of Cu (0.531-2.117 mg kg−1), Ba (0.106-1.264 mg kg−1) and Sr (0.257-1.462 mg kg−1) are the lowest in all honey samples. Zn (1.332-7.825 mg kg−1), Mn (0.133-9.471 mg kg−1), Mg (13.26-74.38 mg kg−1) and Na (11.69-218.5 mg kg−1) concentrations were found strongly dependent on the kind of botanical origin.Results were submitted to pattern recognition procedures, unsupervised methods such as cluster and principal components analysis and supervised learning methods like linear discriminant analysis in order to evaluate the existence of data patterns and the possibility of differentiation of Spanish honeys from different botanical origins according to their mineral content. Cluster analysis shows four clusters corresponding to the four botanical origins of honey and PCA explained 71% of the variance with the first two PC variables. The best-grouped honeys were those from heather; eucalyptus honeys formed a more dispersed group and finally orange-blossom and rosemary honeys formed a less distinguishable group. 相似文献
67.
68.
Macroscopic and microscopic dissipative structural patterns formed in the course of drying the deionized aqueous colloidal
crystal suspensions of silica spheres (diameter: 103 nm) on a cover glass have been observed. Spoke-like and ring-like patterns
are formed in the macroscopic scale; the former is the crack in the sphere film and the latter is the hill accumulated with
spheres formed around the outside edge. The neighbored inter-spoke angle, thickness of the film, and other morphological parameters
have been discussed as a function of sphere concentration, concentration of sodium chloride, and the inclined angle of the
cover glass. Fractal patterns of the mud cracks are observed in the microscopic scale. Capillary forces between spheres at
the air-liquid surface and the relative rates between the water flow at the drying front and the convection flow of spheres
are important for the pattern formation.
Electronic Publication 相似文献
69.
With the accelerated accumulation of genomic sequence data, there is a pressing need to develop computational methods and advanced bioinformatics infrastructure for reliable and large-scale protein annotation and biological knowledge discovery. The Protein Information Resource (PIR) provides an integrated public resource of protein informatics to support genomic and proteomic research. PIR produces the Protein Sequence Database of functionally annotated protein sequences. The annotation problems are addressed by a classification-driven and rule-based method with evidence attribution, coupled with an integrated knowledge base system being developed. The approach allows sensitive identification, consistent and rich annotation, and systematic detection of annotation errors, as well as distinction of experimentally verified and computationally predicted features. The knowledge base consists of two new databases, sequence analysis tools, and graphical interfaces. PIR-NREF, a non-redundant reference database, provides a timely and comprehensive collection of all protein sequences, totaling more than 1,000,000 entries. iProClass, an integrated database of protein family, function, and structure information, provides extensive value-added features for about 830,000 proteins with rich links to over 50 molecular databases. This paper describes our approach to protein functional annotation with case studies and examines common identification errors. It also illustrates that data integration in PIR supports exploration of protein relationships and may reveal protein functional associations beyond sequence homology. 相似文献
70.
Tomohisa?Yamaguchi Keisuke?Kimura Akira?Tsuchida Tsuneo?OkuboEmail author Mitsuhiro?Matsumoto 《Colloid and polymer science》2005,283(10):1123-1130
Macroscopic and microscopic dissipative structural patterns formed in the course of drying the fractionated and monodisperse bentonite particles (plate-like in their shape) in aqueous deionized suspension and in the presence of NaCl have been studied on a cover glass. The patterns coexisted with the broad ring of the hill accumulated with the particles and with the round hills are formed around the outside edges of the film and in the center, respectively, in the macroscopic scale. By the addition of NaCl the pattern shifts from the broad ring to the round hill in the center. The spoke-like cracks, which have been observed for the suspensions of the spherical particles so often hitherto, are not observed at all for the bentonite suspensions. The characteristic convection flow of the particles and the interactions among the particles and substrate are important for the macroscopic pattern formation. Wrinkled, branch-like and/or star-like fractal patterns are observed in the microscopic scale. These patterns are determined mainly by the electrostatic and polar interactions between the particles and/or between the particle and the substrate in the course of drying. 相似文献