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31.
Miyuki Harada Kentaro Aoyama Mitsukazu Ochi 《Journal of Polymer Science.Polymer Physics》2005,43(11):1296-1302
The fracture toughness of liquid‐crystalline epoxy systems, which had a nematic polydomain structure (domain size about 40 μm), with an increasing loading rate was evaluated. In this system, the fracture toughness dramatically decreased from 1.96 to 0.22 MN/m3/2 with an increasing loading rate (0.1–5 mm/min). The network orientation near the fracture surface of different loading rate systems was investigated with polarized optical microscopy and polarized infrared spectroscopy. As a result, a large oriented region of mesogenic groups was observed near the fracture surface in the relatively low loading rate (0.1 and 0.5 mm/min) systems, but such a phenomenon was not observed in the high loading rate (2 and 5 mm/min) systems. These results showed that the high fracture toughness of the system at the low loading rate was due to the magnitude and region of the reorientation of the mesogenic groups in the fracture process and that high toughness could not be achieved at a high loading rate because the loading rate was too fast to allow orientation of the networks containing the mesogenic groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1296–1302, 2005 相似文献
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Based on the dispersionless KP (dKP) theory, we study a topological Landau-Ginzburg (LG) theory characterized by a rational
potential. Writing the dKP hierarchy in a general form treating all the primaries in an equal basis, we find that the hierarchy
naturally includes the dispersionless (continuous) limit of Toda hierarchy and its generalizations having a finite number
of primaries. Several flat solutions of the topological LG theory are obtained in this formulation, and are identified with
those discussed by Dubrovin. We explicitly construct gravitational descendants for all the primary fields. Giving a residue
formulae for the 3-point functions of the fields, we show that these 3-point functions satisfy the topological recursion relation.
The string equation is obtained as the generalized hodograph solutions of the dKP hierarchy, which show that all the gravitational
effects to the constitutive equations (2-point functions) can be renormalized into the coupling constants in the small phase
space.
Supported in part by NSF grant DMS-9403597. 相似文献
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Photolysis of acyclic monothioimides gave β-lactams and thioamides via Type II reaction involving γ-hydrogen abstraction by thiocarbonyl group. 相似文献
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Takashi Takeo Tomohiko Kanie Katsuhiro Satoh Shigeyuki Aoyama Haruhiko Itoh Hajime Hattori 《Optical Review》1995,2(5):366-370
In lightwave community antena television (CATV) systems as well as other optical fiber communication networks, a transmitted optical signal is known to be degraded by an intensity noise produced within the fiber due to the interference between the signal and doubly reflected light. We report on the improvements to the signal degradation due to the double Rayleigh backscattering by inserting optical isolators in the trunk lines of the systems. A carrier-to-noise ratio (CNR) has been calculated as a function of the number and the insertion loss of the isolators. The calculated results indicate that there is an optimum number of isolators, and if the insertion loss is less than 0.3 dB, the CNR degradation can be restored by more than 60%. To test the calculated results, we conducted experiments for the specific case of employing one isolator, and obtained good agreements between the two. 相似文献
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