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991.
Hidematsu Suzuki Yoichiro Muraoka Hiroshi Inagaki 《Journal of Polymer Science.Polymer Physics》1981,19(2):189-196
Light scattering measurements were carried out on a linear polyethylene sample NBS 1475 in 1-chloronaphthalene at 135 and 115°C to determine the weight-average molecular weight, the second virial coefficient A2, and the z-average mean-square radius of gyration. By use of these results, the system is analyzed in terms of the interpenetration function Ψ for A2. Observed values of A2 are rather large but the excluded volume is nevertheless relatively small. Such behavior seem to be similar to that of semiflexible polymers. The characteristic ratio Cn,LS as determined by light scattering is found to be almost twice the literature value of 6.7, which was obtained from viscosity measurements. This discrepancy is explained by comparing the theoretical value of the Flory viscosity parameter Φ at the nondraining limit with values calculated from the light scattering results. 相似文献
992.
993.
The 15NMR chemical shifts were measured of a number of N-substituted formamides and acetamides at the natural abundance level. The ratios of the cis and trans isomers for several N-alkylformamides were also determined. Substituent effects on the 15N chemical shifts of formamides are compared with those of some other nitrogen-containing compounds. There is a consistent pattern of behavior of the one bond spin–spin coupling constants [1J(15NH)] wherein the trans isomers of N-alkylformamides are larger than those of the cis isomers. 相似文献
994.
995.
We present solutions of seven graph equations involving the line graph, complement and n-th power operations. One such equation generalizes a result of M. Aigner. In addition, some comments are made about graphs satisfying . 相似文献
996.
Hiroshi Narushima 《Journal of Combinatorial Theory, Series A》1974,17(2):196-203
We introduce an enumeration theorem under lattice action. Let L be a finite semilattice and Ω be a nonempty set. Let be a map satisfying f(x ? y) ? f(x) ∩ f(y), where ? and (Ω) mean “join” and the power set of Ω, respectively. Then , where C is the set of all chains in L and l(c) denotes the length of a chain c. Also the theorem can be dualized. Furthermore, we describe two applications of the theorem to a Boolean lattice of sets and a partition lattice of a set. 相似文献
997.
998.
999.
Takasuke Matsuo Yoshio Kume Hiroshi Suga SyûzÔ Seki 《Journal of Physics and Chemistry of Solids》1976,37(5):499-506
The heat capacities of copper(II) formate tetrahydrate and tetradeuterate have been measured from 12 to 300 K with an adiabatic calorimeter. They have sigmoidal temperature dependence except near the antiferroelectric-paraelectric transition temperatures, 235.78 ± 0.05 K and 245.64 ± 0.05 K, respectively. The corresponding enthalpy changes are 836.0 ± 1.0 J mol?1 and 936.9 ± 0.5 J mor?1. The entropy changes are 3.546 ± 0.005 JK?1mol?1 and 3.814 ± 0.002 JK?1 mol?1. The heat capacities are larger in the high temperature phase than in the low temperature phase, the difference amounting to 5.74 JK?1 mol?1 and 7.15 JK?1 mol?1 for the hydrate and the deuterate, respectively. The heat capacity anomaly is compared with those in tin(II) chloride dihydrate and potassium hexacyanoferrate trihydrate and discussed in relation to the structure of the hydrogen bond networks in these substances. The discussion is extended to include possible properties of the hydrogen bond frameworks in ices Ih and II. 相似文献
1000.