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961.
962.
A monatomic simple liquid in two dimensions, where atoms interact isotropically through the Lennard-Jones-Gauss potential
[M. Engel, H.-R. Trebin, Phys. Rev. Lett. 98, 225505 (2007)], is vitrified by the use of a rapid cooling technique in a molecular
dynamics simulation. Transformation to a crystalline state is investigated at various temperatures and the time-temperature-transformation
(TTT) curve is determined. It is found that the transformation time to a crystalline state is the shortest at a temerature
14% below the melting temperature T
m
and that at temperatures below T
v
≡ 0:6T
m
the transformation time is much longer than the available CPU time. This indicates that a long-lived glassy state is realized
for T ≤ T
v
.
相似文献
963.
964.
Takashi Mino Hiroaki Shindo Tomoko Kaneda Tomoko Koizumi Yoshio Kasashima Masami Sakamoto Tsutomu Fujita 《Tetrahedron letters》2009,50(38):5358-432
Palladium-catalyzed Mizoroki-Heck reaction of allyl aryl ethers with aryl iodides gave aryl cinnamyl ethers using a catalytic amount of Pd(OAc)2 in DMF at 50 °C with phosphine-free hydrazone as a ligand in good yields. 相似文献
965.
966.
Hideaki Ichiba Tomoko Ogawa Takehiko Yajima Takeshi Fukushima 《Biomedical chromatography : BMC》2009,23(10):1051-1058
Structural modification of a polypeptide hormone, glucagon, by a hydroxyl radical in vitro was investigated by reversed‐phase high‐performance liquid chromatography (RP‐HPLC), and the oxidized site of glucagon was detected by electrospray ionization tandem mass spectrometry (ESI‐MS/MS). It was shown that 27methionine (Met) was oxidized to 27Met sulfoxide by hydroxyl radical, and the production rate of 27Met sulfoxide was faster than that by hydrogen peroxide. In addition, production of 27Met sulfoxide enantiomer was confirmed by RP‐HPLC analysis. cAMP production in a HepG2 cell induced by 27Met sulfoxide glucagon was reduced to approximately 75% as compared with that induced by the native form of glucagon. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
967.
Takashi Sasaki Tadashi Uchida Kensuke Sakurai 《Journal of Polymer Science.Polymer Physics》2006,44(14):1958-1966
The characteristic length of the glass transition temperature was evaluated for crosslinked bulk polystyrenes and poly(methyl methacrylate)s by differential scanning calorimetry. The characteristic length, which corresponds to a length scale of the cooperative rearrangement due to polymer segmental relaxation, was revealed to decrease with increase in the degree of crosslink. The relative values of configurational entropy for crosslinked polymers were evaluated based on a simple polymer network model on a cubic lattice. As a result, the configurational entropy of the smallest cooperatively rearranging region was revealed to decrease with increase in the degree of crosslink, which is responsible for the above behavior of the characteristic length. The effects of crosslink on the characteristic length and the glass transition temperature were found to be stronger for crosslinked poly(methyl methacrylate)s than for crosslinked polystyrenes, which reflects the difference in the structure of crosslink segment. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1958–1966, 2006 相似文献
968.
969.
970.
To increase recording density in an optical disk system, a two-lens system which enlarge its numerical aperture (NA) has been developed. When NA becomes larger, however, the spherical aberration due to disk thickness error increases. We propose an optical pickup with a spherical aberration compensator using nematic liquid crystal (LC). Our LC device is composed of two LC cells each of which has X and Y stripe electrodes, respectively. We discussed how the spherical aberration due to the disk thickness error can be compensated by combination of two crossed cylindrical phase distributions induced by the LC cells, and confirmed the compensation effect in a design example by simulation. We have also fabricated the crossed stripe LC device actually, and have obtained the experimental result which shows that amount sufficient to compensate the aberration is achieved. 相似文献