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121.
Toru Sato Keisuke Mitsuhori Shinichiro Hirabayashi Paul E. Brumby Jiro Nagao Norio Temma Hideo Narita 《Transport in Porous Media》2013,96(1):153-167
The reduction in permeability of sediments due to blockages caused by the trapping of suspended particles is a common concern for the extraction processes of oil or natural gas. In this study, the effect of trapped fine particles in sand sediments is studied numerically using a three-dimensional lattice Boltzmann method. The geometrical properties of larger, immobile, sand grains are digitally extracted by the spherical harmonics series expansions of CT scans of real sand grains. The migrating fine particles are assumed to be spherical in shape with their volumes following a log-normal distribution. These fine particles, together with larger frame sands, are positioned, without overlapping, within a microscopic, cubic, domain with periodic boundaries. The remaining empty volume is filled with water and imposing a pressure gradient simulates the flow of fluid through the sediment. As a result of fine particles becoming trapped by the frame sand, the initial porosity of which is 0.589, the absolute permeability of the system is reduced by approximately 60?C90?%, corresponding to fine particle saturations of 0.15?C0.29, respectively. The permeability change due to the trapping of fine particles is also modelled theoretically using not only volume saturations but also specific surface areas of both the frame sands and the fine particles with a coefficient of proportionality. 相似文献
122.
Colloid and Polymer Science - Für die Flockung des elektronegativen Mastixsols sind zwar die Anionen nicht völlig belanglos, gewisse Anionen (Sulfosalizylsäure) wirken sogar stark... 相似文献
123.
E. Söderbäck K. Masaki O. Hirabayashi G. S. Forbes J. H. Faull A. Hemingway E. L. Arnow C. Morton W. Hiltner N. J. King H. Moser E. Raub W. Stein C. del Fresno E. Mairlot M. Abribar P. Rumpf M. Auméras J. Marcon W. A. Kargin M. I. Ussanowitsch und O. Stelling 《Fresenius' Journal of Analytical Chemistry》1934,97(5-6):195-199
Ohne Zusammenfassung 相似文献
124.
Firyon Ko Kazunori Hirabayashi Toshio Shimizu Ken-ichi Sugiura 《Tetrahedron letters》2018,59(48):4251-4254
An unexpected ketone was obtained in the synthesis of tetrabenzo[a,d,j,m]coronene having tert-butyl groups from Thiele’s hydrocarbon derivative. The structure of the product was confirmed by not only spectroscopic but also diffraction studies. This product was formed by the rearrangement reaction of one phenyl group and this reaction could be analogous to the pinacol-pinacolone rearrangement. 相似文献
125.
M. Muralidhar M. Tomita M. Jirsa N. Sakai M. Murakami I. Hirabayashi 《Physica C: Superconductivity and its Applications》2009,469(15-20):1196-1199
Flux pinning in melt-processed (Nd0.33Eu0.33Gd0.33)Ba2Cu3Oy “NEG-123” + 35 mol% Gd2BaCuO5 “NEG-211” (70 nm in size) composite doped by TiO3, MoO3 and Nb2O5 achieved record values. The optimum values of all three dopands were found to be around 0.1 mol%. Transmission electron microscope (TEM) analysis found clouds of <10 nm sized particles in the NEG-123 matrix, shifting the pinning particle size distribution to significantly lower values. TEM by energy dispersive X-ray spectroscopy (EDX) analysis clarified that these nanoparticles contained a significant amount of Nb, Mo, and Ti. Appearance of nanometer-sized defects correlated with a significantly improved flux pining at low and medium magnetic fields, which was particularly significant at high temperatures. In the Nb-doped sample, a record Jc value of 925 kA/cm2 at the secondary peak field (4.5 T) was achieved at 65 K, 640 kA/cm2 at zero field at 77 K, and 100 kA/cm2 at 90.2 K, the last value having been up to now considered as a good standard for REBa2Cu3Oy “RE-123” materials at 77 K. The greatly improved Jc–B performance in Nb/Mo/Ti doped samples can be easily translated to large-scale LRE-123 (LRE = light rare earths, Nd, Eu, Gd, Sm) blocks intended for real superconducting super-magnets applications. 相似文献
126.
We theoretically demonstrate the inclusive and semiexclusive spectra in the 3He (K ?, π ?) reactions at 600 MeV/c (4°) within a distorted-wave impulse approximation, using a coupled (2N ? Λ) + (2N ? Σ) model with a spreading potential. It is shown that a signal of a ${^3_\Sigma{\rm He}}$ quasibound state is clearly observed near the Σ threshold in the π ? spectrum, whereas a peak of a ${^3_\Sigma{\rm n}}$ quasibound state is relatively reduced in the π + spectrum. The mechanism of Σ production for these spectra is discussed. 相似文献
127.
Matrix or impurities remaining in a DNA sample solution after various sample treatment procedures may influence a subsequent DNA analysis. In this work, several matrices were investigated concerning their effects on the analysis of oligonucleotide by using an ion-trap mass spectrometer equipped with a sonic spray ionization source. Inorganic salts of sodium chloride and magnesium chloride depressed the signal intensity by about 50% when the content of the salts was about 10 microM. dNTPs and Taq showed more severe depression on the oligonucleotide. However, Tris, or (hydroxymethyl)aminomethane, intensified the signal intensity, if its content was within an appropriate range. When the content of Tris was about 500 microM, the signal intensity was enhanced by factors of 3 and 5 for the 6-mer and the 20-mer oligonucleotides, respectively. With the existence of Tris, matrix effects from the inorganic salts, dNTPs and Taq were reduced. 相似文献
128.
M. Hirabayashi 《Archiv der Mathematik》2002,79(3):175-181
We give a relative class number formula for an imaginary abelian number field by means of a determinant, which yields a generalization of Inkeris determinant. 相似文献
129.
We construct some multiple Dedekind sums and relate them to the relative class number of an imaginary abelian number field. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
130.
This paper reviews liquid crystal optical devices including tunable filters, photonic switches and spatial light modulators, and examines their application to optical communication and information processing systems. Optical processing has three major advantages: massive parallelism, high speed and broad wavebands. Compared with typical optical materials including silica, semiconductors and inorganic electrooptic crystals used in communication systems, a liquid crystal has a number of outstanding features including its large refractive index change and large polarization rotation power at a low voltage. These features make it possible to develop new optical components. 相似文献