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41.
Tumarkin E Nie Z Park JI Abolhasani M Greener J Sherwood-Lollar B Günther A Kumacheva E 《Lab on a chip》2011,11(20):3545-3550
We report a microfluidic (MF) approach to studies of temperature mediated carbon dioxide (CO(2)) transfer between the gas and the liquid phases. Micrometre-diameter CO(2) bubbles with a narrow size distribution were generated in an aqueous or organic liquid and subsequently were subjected to temperature changes in the downstream channel. In response to the cooling-heating-cooling cycle the bubbles underwent corresponding contraction-expansion-contraction transitions, which we term 'bubble breathing'. We examined temperature-controlled dissolution of CO(2) in four exemplary liquid systems: deionized water, a 0.7 M aqueous solution of NaCl, ocean water extracted from Bermuda coastal waters, and dimethyl ether of poly(ethylene glycol), a solvent used in industry for absorption of CO(2). The MF approach can be extended to studies of other gases with a distinct, temperature-dependent solubility in liquids. 相似文献
42.
Complete photonic band gaps (PBGs) are found in one-dimensional ternary photonic crystals (1D TPCs) composed of an ordinary dielectric and single negative metamaterials. The proposed TPC gives omni directional PBG completely independent of polarizations dependent weekly on angle of incidence. Here the choice of different parameters of TPC is done in such a way so that it eliminates the Brewster's-angle transmission resonance, thus allowing a complete 3D PBG. It exhibits a photonic band or gap near frequencies where either the magnetic permeability or the electric permittivity of the metamaterial changes sign, whose width increases with the increasing angle of incidence. These result from the dispersive properties of the metamaterials and disappear for the particular case of propagation along the stratification direction. The results are discussed in terms of incident angle, layer thickness, dielectric constant of the dielectric material for TE and TM polarizations. 相似文献
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C. Laxmi Kanth B. Appa Rao 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,90(1):97-113
Differential scanning calorimetric studies, spectroscopic studies (viz., optical absorption, ESR, infrared spectra) and thermoluminescence studies of ZnF2-MO-TeO2 (MO=ZnO, CdO and PbO) glasses doped with different concentrations of chromium ions have been investigated. Results have been analyzed in the light of different oxidation states of chromium ion. The analysis indicates chromium ions mostly exist in Cr3+ state in ZT, CT and PT glasses when Cr2O3 is present upto 0.1%, 0.2% and 0.3%, respectively; these ions seems to be present in Cr6+ state that take part network forming positions with CrO42− structural groups in all the three glasses when the concentration of Cr2O3 is greater than the above quantities. Quenching of thermoluminescence light output of the glasses has been observed with increase in Cr2O3 concentration upto 0.1%, 0.2% and 0.3%, respectively in ZT, CT and PT glasses. This has been identified due to the killing effect of Cr3+ ions. Further it has also been concluded that ZnF2-PbO-TeO2 is more favourable glass network for the presence of large concentration of laser-emitting Cr3+ ions, among the three glass series studied. 相似文献
45.
A high power electromagnetic Gaussian beam is assumed to be incident on the F region ionosphere, which causes modification in the plasma temperature and density. Subsequently the evolution of a second Gaussian em beam in such modified F region inosphere has been studied numerically. The numerical calculations are carried out in a two dimensional grid space which covers a region of 80 km horizontally and 100 km vertically. It is seen that the second wave propagating through the modified plasma gets focused in the axial regions and gets filamented near its peak intensity point. Consequently the plasma gets irregularly structured and the resulting fluctuations in plasma temperature and density give rise to a pressure gradient force. This force inturn causes the formation of more number of filamentary structures about the axis in wave intensity and also amplifies the initially formed ones. 相似文献
46.
Recently Kim has given a general method, using group-invariant orbit parameters, for determining the energy and residual symmetry of the Higgs potential minimum. In this paper we illustrate the method by working out the case of a quartic SU(5) Higgs potential with and higgsons. In this method the Gell-Mann-Slansky conjecture concerning possible little groups of the potential minimum takes a geometric form, which is verified for our case. The results are used to discuss the hierarchical symmetry breaking of SU(5) grand unification theory. We generalize our results to the SU(N) adjoint + vector models, which are all closely related. 相似文献
47.
Schiff base derivatives of the type Ph3Si? O? Sb(NO)Ph3 (where NO represents the donor system of a monobasic bidentate ligand) have been synthesized. These are obtained as coloured solids; they are non-electrolytes and monomeric in nature, and have been characterized by elemental analysis, IR and 1H NMR. Spectral studies suggest that silicon and antimony atoms are in tetra- and hexa-coordinated states, respectively. 相似文献
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It has been a general opinion that the Clausius-Mossotti dielectric theory is not capable of explaining the observed photoelastic behaviour of partially ionic crystals.However in the present communication we show that by making account of the variation of polarizabilities under compressive stress within the framework of the Clausius-Mossotti theory it is possible to obtain a reasonable agreement with experimental data on the photoelastic behaviour of ZnO, ZnS and CdS crystals. 相似文献