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31.
Simard P Lace N Gowans S Quintana-Rizzo E Kuczaj SA Wells RS Mann DA 《The Journal of the Acoustical Society of America》2011,130(5):3068-3076
Dolphins routinely use sound for social purposes, foraging and navigating. These sounds are most commonly classified as whistles (tonal, frequency modulated, typical frequencies 5-10 kHz) or clicks (impulsed and mostly ultrasonic). However, some low frequency sounds have been documented in several species of dolphins. Low frequency sounds produced by bottlenose dolphins (Tursiops truncatus) were recorded in three locations along the Gulf of Mexico. Sounds were characterized as being tonal with low peak frequencies (mean?=?990 Hz), short duration (mean?=?0.069 s), highly harmonic, and being produced in trains. Sound duration, peak frequency and number of sounds in trains were not significantly different between Mississippi and the two West Florida sites, however, the time interval between sounds within trains in West Florida was significantly shorter than in Mississippi (t?=?-3.001, p?=?0.011). The sounds were significantly correlated with groups engaging in social activity (F=8.323, p=0.005). The peak frequencies of these sounds were below what is normally thought of as the range of good hearing in bottlenose dolphins, and are likely subject to masking by boat noise. 相似文献
32.
Algirdas Ambrazevičius Alicija Eismontaitė 《Central European Journal of Mathematics》2013,11(6):1129-1139
A mathematical model of dissociative adsorption and associative desorption for diatomic molecules is generalized. The model is described by a coupled system of parabolic and ordinary differential equations. The existence and uniqueness theorem of the classical solution is proved. 相似文献
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34.
E. Mazėtis 《Lithuanian Mathematical Journal》1990,30(3):250-259
Vilnius Pedagigic Institute. Translated from Litovskii Matematicheskii Sbornik (Lietuvos Matematikos Rinkinys), Vol. 30, No. 3, pp. 536–547, July–September, 1990. 相似文献
35.
Institute of Mathematics and Informatics, Akademijos 4, 2600 Vilnius, Lithuania. Published in Lietuvos Matematikos Rinkinys, Vol. 32, No. 3, pp. 417–425, July–September, 1992. 相似文献
36.
A. Laurinčikas R. Macaitienė 《Proceedings of the Steklov Institute of Mathematics》2017,299(1):143-156
The Selberg class S consists of functions L(s) that are defined by Dirichlet series and satisfy four axioms (Ramanujan conjecture, analytic continuation, functional equation, and Euler product). It has been known that functions in S that satisfy the mean value condition on primes are universal in the sense of Voronin, i.e., every function in a sufficiently wide class of analytic functions can be approximated by the shifts L(s + iτ ), τ ∈ R. In this paper we show that every function in the same class of analytic functions can be approximated by the discrete shifts L(s + ikh), k = 0, 1,..., where h > 0 is an arbitrary fixed number. 相似文献
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38.
Orentienė A Olšauskaitė V Vičkačkaitė V Padarauskas A 《Journal of chromatography. A》2011,1218(39):6884-6891
The potential of 1.7 μm ethylene bridged hybrid silica phase was investigated for the separation of twelve imidazolium-based ionic liquid cations. U-shaped retention profile was observed for all solutes with an increase in retention at both low and high acetonitrile content. Chromatographic behaviour of imidazolium cations in both hydrophilic interaction chromatography (HILIC) and per aqueous liquid chromatography (PALC) modes was studied by varying key parameters such as buffer concentration and pH, acid additive, organic modifier and column temperature. Experimental data provided some evidences that under PALC conditions cationic solutes are retained predominantly by mixed hydrophobic/ion-exchange interactions. In the HILIC mode, both partitioning and ion-exchange interactions are responsible for the retention of solutes. Compared to PALC, HILIC provided significantly higher efficiencies with less or even no peak tailing, better separation selectivity and greater resistance to overload. In PALC mode gradient elution was required to achieve adequate retentivity of all solutes but selectivity was not sufficient to distinguish between solutes with very similar hydrophobicity. In contrast, under HILIC conditions twelve solutes were almost completely resolved in less than 4 min by using isocratic elution. Summarizing, it could be concluded that ethylene bridged hybrid silica column providing a dual retention mechanism offers the possibility of selecting between the two retention modes with opposite separation selectivity, just by changing the composition of the mobile phase. 相似文献
39.
Mažeikienė R Niaura G Eicher-Lorka O Malinauskas A 《Journal of colloid and interface science》2011,357(1):189-197
Surface-enhanced Raman spectroscopy (SERS) was used to probe the structure of adsorbed and electropolymerized Meldola blue (MB) films on roughened gold surfaces in solutions with pH 1.0 and 7.0 by using 785 nm excitation wavelength. Spectral bands were assigned based on density functional theory (DFT) calculations at B3LYP/6-311+G(2d, p) level. The most characteristic band of the oxidized MB form was found to be the breathing vibration of the central ring containing heteroatoms at 596 cm(-1). Based on a red shift of bands assigned to vibrations of double C=N(C(2)H(6)) bonds and adjacent ring C=C bonds in surface spectra as compared with solution 1 it was suggested that polymerization and interaction with an electrode surface proceed through these moieties. The presence of out-of-plane bands in SERS spectra was attributed to "flat" or slightly "tilted" orientation of aromatic rings at the interface. Potential-dependent spectral changes were followed by SERS spectroscopy. Raman spectra of the reduced MB form were obtained in both pH 1.0 and pH 7.0 solutions by analysis of the potential-difference SERS spectra. Reduced MB form can be recognized by characteristic bands near 1620, 1574, 1374, and 1234 cm(-1). By comparing the intensities of 1637 cm(-1) (oxidized MB form) and 1374 cm(-1) (reduced MB form) bands in experimental spectra of polymerized MB in pH 1.0 solution, a reduction-induced decrease by factor of 7 was estimated. A similar tendency in intensity changes showed calculations indicating that this effect is associated with reduction-induced changes in the molecular structure of the dye. 相似文献
40.