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51.
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
52.
Summary Stability constants of 2-mercaptohistamine (2-MH) with a number of transition metal ions were determined by a potentiometric titration method and the coordination mode of (2-MH) metal complexes were thereby characterized. With MnII, Fell, CoII, and NiII, coordination occurred through both the imidazole-nitrogen and amino groups, while with ZnII, CdII, PbII, and HgII, both thiolate and amino groups, contribute to the coordination. in the 2-MH copper complex, polymer formation is suggested on the basis of visible absorption and e.p.r. spectra. 相似文献
53.
Masato Sakaguchi Hiromu Kinpara Yasuro Hori Shigetaka Shimada Hisatsugu Kashiwabara 《Journal of Polymer Science.Polymer Physics》1988,26(6):1307-1312
When poly(vinylidene fluoride) (PVDF) was ground with tetracyanoethylene (TCNE) powder in a vibration glass ball mill in vacuum in the dark at 77 K, the TCNE anion radical (TCNE-) was detected in the mixture by ESR spectroscopy. The TCNE.- is formed by the abstraction of electrons by TCNE from the anion that is produced by a heterogeneous bond scission of carbon-carbon bonds in the polymer main chain. The assignment of TCNE.- was carried out by the ESR spectral simulation on the basis of an anisotropic effective hyperfine tensor that includes a forbidden transition term. At least 85% of the bond scission of the PVDF main chain is induced by a heterogeneous process to produce ionic products. The yield of these mechanions seems to increase with the polarity of carbon-carbon bond owing to a substituent group bonded to the carbon in the polymer main chain. 相似文献
54.
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56.
Hiromu Saito Mamoru Takahashi Takashi Inoue 《Journal of Polymer Science.Polymer Physics》1988,26(8):1761-1768
Orientation relaxation of dissimilar chains in the molten miscible blends, poly(methyl methacrylate)/poly(vinylidene fluoride) and poly(methyl methacrylate)/poly(vinylidene fluoride-co-trifluoroethylene), were investigated by measuring (1) the change of infrared dichroic ratio with time after the uniaxial stretching of film specimens, (2) the shear stress relaxation spectrum, and (3) birefringence relaxation in shear. The dissimilar polymers showed an identical time variation of the normalized Hermans orientation function. The blend showed a relaxation spectrum with a single characteristic relaxation time τc, depending on the blend composition. The birefringence relaxed monotonically, remaining positive. These results suggest that the dissimilar polymers do not relax independently but cooperatively. This behavior may be induced by a constraint due to the specific interactions between the dissimilar polymers, e.g., weak hydrogen bonding. For the cooperative chain relaxation, a third power relationship was found; τc/τe vprop; (M/Me),3 where τe and Me are the relaxation time and molecular weight of entanglement strand, respectively, and M is the number average molecular weight in the blend. 相似文献
57.
Mitiko Miura Hitoshi Arimori Hiromu Murata Akiko Kida Kazuaki Iishi 《Journal of Physics and Chemistry of Solids》1983,44(7):627-631
The effect of the electronic extension on the electrostatic potential was first taken into account functionally by Birman. We have applied his model to the lattice dynamics of CaO, where the degree of the electronic extension w was defined and determined with the use of the electronic charge density distribution obtained from analysis of X-ray data. Our treatment shown here not only gives a physically meaningful model including the feature of the electronic extension, but also involves essentially the same very simple process as the conventional point-charge model but with fewer adjustable parameters. Good reproduction of calculated phonon dispersion curves was obtained by taking into account the electronic extension, although the degree of the electronic extension, w, used to fit the curve was a little larger than that derived from the observed data owing to the first rough approximation for the potential energy arising from the electronic extension. 相似文献
58.
Photolysis of acyclic monothioimides gave β-lactams and thioamides via Type II reaction involving γ-hydrogen abstraction by thiocarbonyl group. 相似文献
59.
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