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401.
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403.
It has been shown (J. Harant and D. Rautenbach, Domination in bipartite graphs. Discrete Math. 309:113–122, 2009) that the domination number of a graph of order n and minimum degree at least 2 that does not contain cycles of length 4, 5, 7, 10 nor 13 is at most
\frac3n8{\frac{3n}{8}}. They believed that the assumption that the graphs do not contain cycles of length 10 might be replaced by the exclusion
of finitely many exceptional graphs. In this paper, we positively answer that if G is a connected graph of order n and minimum degree at least 2 that does not contain cycles of length 4, 5 nor 7 and is not one of three exceptional graphs,
then the domination number of G is at most
\frac3n8{\frac{3n}{8}}. 相似文献
404.
Sung Hoon Kim Ik-Bu Sohn Sungho Jeong 《Applied Physics A: Materials Science & Processing》2011,103(4):1053-1057
The self-organized formation of ripples in the direction parallel to the groove during the femtosecond laser machining of
microgrooves on aluminum nitride ceramic at laser fluences much higher than the single-pulse ablation threshold is reported.
These parallel ripples are notably different from the commonly observed polarization-perpendicular ripples and are produced
in grooves having an appropriate width and depth, irrespective of laser polarization. From subsequent experiments with narrow
and wide groove widths, it could be considered that the groove walls play an important role in the formation of these parallel
ripples, possibly by confining the laser-induced plasma. 相似文献
405.
Lee DooSung Sung YongHun Lee InGun Kim JongGi Sohn Hyunchul Ko Dae-Hong 《Applied Physics A: Materials Science & Processing》2011,102(4):997-1001
The characteristics of resistive switching of TiN/HfO2/Ti/HfO2/Pt/Ti stacks on SiO2/Si substrates were investigated and compared to TiN/HfO2/Pt/Ti stacks in order to study Ti interlayer effects on resistive switching. The Ti interlayers were deposited in situ during
the reactive sputtering of HfO2 films. The current–voltage measurements showed that the Ti interlayers enhanced the memory window but reduced the endurance
of SET/RESET operations. The energy filtered images by TEM showed asymmetric oxygen accumulation at the Ti/HfO
x
interfaces. Subsequent heat treatment improved the endurance of SET/RESET operation of TiN/HfO2/Ti/HfO2/Pt/Ti stacks. 相似文献
406.
Inseon Seo Eun-Ho Sohn Jong-Chan Lee Kigook Song Fumito Araoka Ken Ishikawa 《Liquid crystals》2013,40(3):323-331
The orientation of alkyl sulfonyl side-chains on a series of polyoxyethylenes, CH3–nSE (n?=?6, 8 or 10), and the effect of annealing and rubbing on the molecular orientation of the alkyl side-chains at the substrate surface, were investigated using sum-frequency generation (SFG) vibrational spectroscopy. Based on the SFG spectra and their quantitative interpretation, we deduced that the alkyl chains of CH3–10SE are almost vertically oriented at the surface and that the terminal methyl groups of the alkyl chains are tilted from the surface normal as much as θ ≈ 40?±?5°, with a broad distribution of tilt angles. We also found that rubbing treatment induced the anisotropic orientation of the alkyl side-chains perpendicular to the rubbing direction, but their orientation was unchanged by annealing. 相似文献
407.
Daewon Park Alyssa M. Larson Alexander M. Klibanov Yadong Wang 《Applied biochemistry and biotechnology》2013,169(4):1134-1146
We have prepared and characterized a new polyurethane-based antimicrobial material, N,N-dodecyl,methyl-polyurethane (Quat-12-PU). It exhibits strong antiviral and antibacterial activities when coated (as an organic solution or an aqueous nanosuspension) onto surfaces and antibacterial activity when electrospun into nanofibers. Quat-12-PU surfaces are able to kill airborne Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, as well as inactivate the enveloped influenza virus (but not the non-enveloped poliovirus). 相似文献
408.
Jang Min Park Baek-Rock Oh Jeong-Woo Seo Won-Kyung Hong Anna Yu Jung-Hoon Sohn Chul Ho Kim 《Applied biochemistry and biotechnology》2013,170(8):1807-1814
The concentration of ethanol produced from lignocellulosic biomass should be at least 40 g l?1 [about 5 % (v/v)] to minimize the cost of distillation process. In this study, the conditions for the simultaneous saccharification and fermentation (SSF) at fed-batch mode for the production of ethanol from alkali-pretreated empty palm fruit bunch fibers (EFB) were investigated. Optimal conditions for the production of ethanol were identified as temperature, 30 °C; enzyme loading, 15 filter paper unit g?1 biomass; and yeast (Saccharomyces cerevisiae) loading, 5 g l?1 of dry cell weight. Under these conditions, an economical ethanol concentration was achieved within 17 h, which further increased up to 62.5 g l?1 after 95 h with 70.6 % of the theoretical yield. To our knowledge, this is the first report to evaluate the economic ethanol production from alkali-pretreated EFB in fed-batch SSF using S. cerevisiae. 相似文献
409.
Jeng-Hun Suh Sang-Wook Lee Yong-Sang Ryu Youngjoo Sohn 《Molecular Crystals and Liquid Crystals》2014,600(1):81-87
We present the coarsening dynamics of a liquid-ordered (Lo) domain in a supported lipid membrane under an electric field. In a relatively small nanosmooth region surrounded by geometrical walls of nanocorrugated regions, full coarsening of the Lo domain was produced while in a large nanosmooth region, an intermediate, less-ordered Lo domain was developed so that the diffusion of charged phospholipids in the liquid-disordered (Ld) domain was allowed across the geometrical walls in the presence of an electric field. No appreciable diffusion of the charged lipids into a fully coarsened Lo domain by the electric field implies that the structural ordering of the membrane components plays a significant role on the formation of lipid rafts for biological processes. 相似文献
410.
Hoon Sohn Hyung Jin Lim Martin P. DeSimio Kevin Brown Mark Derriso 《Journal of sound and vibration》2014
This study presents a fatigue crack detection technique using nonlinear ultrasonic wave modulation. Ultrasonic waves at two distinctive driving frequencies are generated and corresponding ultrasonic responses are measured using permanently installed lead zirconate titanate (PZT) transducers with a potential for continuous monitoring. Here, the input signal at the lower driving frequency is often referred to as a ‘pumping’ signal, and the higher frequency input is referred to as a ‘probing’ signal. The presence of a system nonlinearity, such as a crack formation, can provide a mechanism for nonlinear wave modulation, and create spectral sidebands around the frequency of the probing signal. A signal processing technique combining linear response subtraction (LRS) and synchronous demodulation (SD) is developed specifically to extract the crack-induced spectral sidebands. The proposed crack detection method is successfully applied to identify actual fatigue cracks grown in metallic plate and complex fitting-lug specimens. Finally, the effect of pumping and probing frequencies on the amplitude of the first spectral sideband is investigated using the first sideband spectrogram (FSS) obtained by sweeping both pumping and probing signals over specified frequency ranges. 相似文献