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Tree communities of secondary deciduous oak forests were surveyed in 13 forests (two in residential and 11 in rural areas) in the warm temperate Hokuriku District of Japan to understand the effects of fragmentation, location (residential or rural), and logging history. The rural forest logged most recently, where diameter at breast height was smallest, had a distinct canopy tree (>12 m) community due to an increase of trees from wind-dispersed seeds. The rural forest with gaps and the two residential forests also had different canopy tree communities from the other rural forests. In contrast, the tree community in the shrub layer (≤6 m) was not influenced by logging history and the existence of gaps but by location only. This was caused by an increase in evergreen trees (consequently causing poor light conditions on the forest floor) and a decrease in trees from wind-dispersed seeds in the residential forests. Among the rural forest patches, no negative effects of forest size and isolation on density of tree individuals were detected for any seed dispersal mode. This may be because many forest patches were arranged at distances of 10–50 m from neighboring patches in rural areas, which enables tree species with low dispersal ability to disperse their seeds to neighboring forests. However, as found in the residential forests, long-term abandonment and extensive fragmentation may gradually reduce tree diversity through loss of tree species with shade intolerance and low seed dispersal ability.

Microdomain structure of polyurethane elastomers (PUEs) during mechanical deformation was investigated using simultaneous small-angle X-ray scattering (SAXS)/wide-angle X-ray diffraction measurements. In the SAXS profile for the PUEs, a four-point pattern or a meridional scattering was observed during the deformation process depending on curing temperatures. The relationship between the initial microdmain structure and deformation behavior was discussed in detail.

Morphological control of poly(2,5-benzimidazole) (PBI) was examined by reaction-induced phase separation of oligomers during polymerization to prepare nanofibers. Three monomers, 3,4-diaminobenzoic acid (DABA), 3,4-diacetoamidebenzoic acid (DAcBA) and phenyl 3,4-diaminobenzoate (PDAB), were used to synthesize PBI. Polymerizations were carried out at 350 °C in a mixture of dibenzyltoluene isomers. Polymerization of DABA yielded spheres with plate-like crystals on their surface. Polymerization of DAcBA yielded almost no precipitates because of the high solubility of DAcBA oligomers. By contrast, polymerization of PDAB yielded aggregates of PBI nanofibers (of which the average diameter was ∼60 nm), which resembled nonwoven fabrics. These fibers were formed by precipitation of (2,5-benzimidazole) oligomers and their subsequent polymerization into a developing crystal structure. The structure of the monomer significantly influenced the morphology of the PBI product, and PDAB was preferable for the preparation of PBI nanofibers. The temperature of 10% N2 weight loss in these nanofibers was in the range of 634–644 °C and they were thermally stable. The network aggregates of poly(2,5-benzimidazole) nanofibers were prepared by the polymerization of phenyl 3,4-diaminobenzoate at 350 °C in a mixture of dibenzyltoluene isomers. The average diameter of the fibers was ∼60 nm. These fibers were formed by the crystallization of oligoimidazoles and the subsequent polymerization in them.