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211.
A conjugate problem of natural convection between two horizontal concentric, isothermal cylinders filled with a fluid-saturated porous medium is studied. The flow field and energy equations are solved under the conditions of equality in temperature but with jump in heat flux at the fluid-solid interface. Numerical results by a finite-difference technique are presented for a large variation in the parameters entering the problem. A comparison of the solution with non-conjugate problem is also given.Das konjugierte Problem der freien Konvektion zwischen zwei horizontalen, konzentrischen, isothermen Zylindern, die mit einem fluid-gesättigten porösen Medium gefüllt sind, wurde hier untersucht.Das Strömungsfeld und die Energiegleichung sind unter den Bedingungen gelöst worden, daß die Temperatur gleich ist, aber ein Wärmeflußsprung am Übergang von der Flüssigkeits- zur Festphase stattfindet. Die numerischen Ergebnisse werden mit dem Finite-Differenzen-Verfahren für viele Parametervariationen dargestellt. Zudem wurde ein Lösungsvergleich mit einem nicht konjugierten Problem gegeben. 相似文献
212.
The combination of Pd catalyst and Xantphos ligand in the presence of Et(3)B nicely promotes the allylation of aldehydes with conjugated dienes to provide dienyl homoallyl alcohols in excellent yields. The reaction occurs selectively at the C-C double bond bearing higher electron density. 相似文献
213.
Enthalpies of mixing of ethanol solution of R- and S-enantiomers of limonene in large concentration have been measured at 298.15 K. The enthalpies of mixing were negligibly small
for all concentrations. Enthalpies of mixing showed negative in less than 30 mol%, but positive in more than the high concentration
of limonenes. The heterochiral solutions were more stable than each of the homochiral solutions in dilute solutions. The concentration
dependence on enthalpies of mixing in dilute concentration of less than 10 mol% was much sharper in inclination than the dense
solutions limonene. 相似文献
214.
Hongli Liu Tomoko Yamashita Tadashi Kamiyama Masao Fujisawa Takayoshi Kimura 《Journal of Thermal Analysis and Calorimetry》2010,99(1):95-103
The excess molar enthalpies of 8 binary mixtures for the o-, m-, and p-isomers of fluoroiodobenzene, fluoromethoxybenzene, bromofluorobenzene, chlorofluoro-benzene, difluorobenzene, fluoromethylbenzene,
fluoronitrobenzene, and aminofluoro-benzene were measured at 298.15 K. The changes of the measured enthalpies were very small.
The experimental results revealed that the isomers containing two electron-acceptor groups showed the most positive excess
enthalpy change, while isomers containing both one electron donor and one electron acceptor group, such as aminofluorobenzene,
showed more stable and always the most negative results. 相似文献
215.
We report the construction of a molecular recognition layer composed of polyelectrolyte brushes and metal complexes on the surface of a quartz crystal microbalance (QCM) and the sensing abilities for various volatile organic compounds (VOCs). Atom‐transfer radical polymerization of 2‐(dimethylamino)ethyl acrylate from an initiator‐terminated self‐assembled monolayer yielded polyelectrolyte brushes on the surface of a weight‐detectable quartz crystal microbalance. One end of a poly[(2‐dimethylamino)ethyl methacrylate] brush was covalently attached onto the surface of a sensor. We found that metallophthalocyanines with four bulky pentaphenylbenzene substituents could adsorb volatile organic compounds selectively into their cavities. Macromolecular metal complexes were prepared by immersing polymer‐brush‐modified QCMs into an aqueous solution of sterically protected cobalt phthalocyanine. Anionic cobalt phthalocyanine was trapped in the polymer brushes and acted as a molecular receptor for the sensing of VOC molecules. 相似文献
216.
217.
Matsuda H Nakamura S Fujimoto K Moriuchi R Kimura Y Ikoma N Hata Y Muraoka O Yoshikawa M 《Chemical & pharmaceutical bulletin》2010,58(12):1617-1621
The methanolic extract and its 1-butanol-soluble fraction from the flower buds of Camellia sasanqua THUNB. were found to show inhibitory activities on the release of β-hexosaminidase from rat basophile leukemia (RBL-2H3) cells. From the 1-butanol-soluble fraction, five new acylated oleanane-type triterpene saponins, sasanquasaponins I-V, were isolated together with a known saponin and their chemical structures were elucidated on the basis of chemical and physicochemical evidence. The principal saponin constituents, sasanquasaponins I-III, with an acyl group at the 22-position of the aglycon part showed the inhibitory effects on the release of β-hexosaminidase and some structure-activity relationships were reported. 相似文献
218.
Velocity dispersion and attenuation in granular marine sediments: comparison of measurements with predictions using acoustic models 总被引:1,自引:0,他引:1
Kimura M 《The Journal of the Acoustical Society of America》2011,129(6):3544-3561
The large velocity dispersion recently reported could be explained by a gap stiffness model incorporated into the Biot model (the BIMGS model) proposed by the author. However, at high frequencies, some measured results have been reported for negative velocity dispersion and attenuation proportional to the first to fourth power of frequency. In this study, first, it is shown that the results of velocity dispersion and attenuation calculated using the BIMGS model are consistent with the results measured in two kinds of water-saturated sands with different grain sizes, except in the high-frequency range. Then, the velocity dispersion and attenuation in six kinds of water-saturated glass beads and four kinds of water-saturated silica sands with different grain sizes are measured in the frequency ranges of 80-140 and 300-700 kHz. The measured results are compared with those calculated using the BIMGS model plus some acoustic models. It is shown that the velocity dispersion and attenuation are well predicted by using the BIMGS model in the range of kd ≤ 0.5 (k: wavenumber in water, d: grain diameter) and by using the BIMGS model plus multiple scattering effects in the range of kd ≥ 0.5 in which negative velocity dispersion appears. 相似文献
219.
Fang YongDe Zhang YuHu Oshima M. Toh Y. Xu FuRong Shi Yue Zhou XiaoHong Liu MinLiang Guo YingXiang Koizumi M. Kimura A. Hatsukawa Y. Morikawa T. Nakamura M. Sugaware M. Kusakari H. 《中国科学:物理学 力学 天文学(英文版)》2011,54(1):98-102
A new rotational band has been identified and assigned to 188Au for the first time using the 173Yb(19F,4nγ) reaction at the beam energies of 86 and 90 MeV. This band is proposed to be built on the πh 9/2 ⊗ νi 13/2 configuration by comparing the band properties with known bands in neighboring nuclei. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around 188Au for the ηh 9/2 ⊗ νi 13/2 bands in odd-odd Au isotopes on the basis of total Routhian surface (TRS) calculations.
相似文献220.
We have investigated the heat generation from gold nanoparticles resulting from their local plasma resonance. We have demonstrated the self-assembly of Au nanoparticle arrays/dielectric layer/Ag mirror sandwiches, i.e., a local plasmon resonator, using a dynamic oblique deposition technique. The thicknesses of the Au and dielectric layers were changed combinatorially on a single substrate. As a result, local plasmon resonator chips were successfully fabricated. Because of strong interference, their optical absorption can be controlled between 0.0% and 97% in the near-IR region, depending on the thickness of the dielectric layer. We evaluated the heat generation from Au nanoparticles by measuring the temperature of water with which a cell prepared on a chip is filled under laser illumination. The change in the water temperature is proportional to the optical absorption of the local plasmon resonator chips. This suggests that the photothermal conversion efficiency can be controlled by interference. These features make the application of the local plasmon resonator to nanoheaters, which can spatiotemporally control heat generation, suitable. 相似文献