The packing structure of side chains of liquid-crystalline side-chain polymers before and during heat treatment

Six varieties of liquid-crystalline side-chain polymers, poly (cholesteryl ω-(methacryloyloxy)alkanoates) (p-ChMO-n, n = 1,2,3,4,5,7, the carbon number of the alkyl chain), were studied by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). On and after the first cooling run from the isotropic state, these polymethacrylates gave the same smectic phase. However, on the first heating run for virgin samples, unique phenomena were observed, similar to those frequently observed on the first heating run for thermotropic liquidcrystalline polymers. The thermal properties of the first heating run for these six polymers showed different tendencies between pChMO-n (n-1-3) and pChMO-n (4-7). Although the DSC curve of pChMO-n (n = 4, 5 and 7) exhibited the melting and clearing points on the first heating run, the DSC curve of pChMO-n (n = 1,2 and 3) exhibited an exothermal peak between the glass transition and the clearing point on the first heating run. This difference, probably due to the difference in the spacer length of these polymers, was investigated quantitatively by small-angle X-ray scattering by which the micro-change of the packing structure of the side chains of the polymers was traced.     

Polymerisation von makro cyclischen Formalen

Ohne Zusammenfassung     

Kaehler manifolds satisfying the axiom of anti-invariant 2-spheres

A Kaehler manifold with the axiom of anti-invariant 2-spheres is a complex space form.     

A statistical theory for road traffic noise based on the composition of component response waves and its experimental confirmation

None of the existing standards, which express the needs of engineers, consider correlation properties of traffic noise. But the correlation properties of traffic noise often seem to have a fundamental importance in certain engineering fields of noise control, such as the design of barriers for sound insulation and the detection of voices in noisy out-of-doors situations. In this paper, firstly, the correlation properties in the time domain and the frequency characteristics of the sound intensity at an observation point are discussed in the general case: i.e., for arbitrary values of quantities such as the propagation characteristics of the traffic sound energy, the numbers of lanes of road and of types of vehicles, the mixture ratios of vehicle types, the average number and respective acoustic power distributions of vehicles travelling with specific velocities on each lane of the road, the lengths of the straight sections of the road and the distance from the observation point. Next, the equivalence problem of replacing the several lanes of the road by a representative single lane is also discussed in detail, as an application of the statistical method. Finally, the values obtained from the theoretical expressions for several kinds of correlation functions of lower and higher orders are compared with experimental values, as obtained by use of the digital simulation technique.