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Using soft X-ray photography, two-dimensional observations were made of the water distribution within the green stem ofCryptomeria japonica D. Don. Variations in the distribution pattern of the wet area in the horizontal plane of the lower stem were described. The distribution patterns showed extreme variation among individual trees, with broad wet-area distribution types appearing, namely, the regularly distributed wet area and the irregularly distributed wet area. We defined five basic types of wet-area distribution patterns on the basis of their regularity or irregularity. It was concluded that the between-tree variation in the wet-area distribution causes the between-tree variation in the mean moisture content of the heartwood. The distribution patterns of the wet area were similar for individual trees within each plus-tree clone.Part of this paper was presented at 46th annual meeting of the Japan Wood Research Society at Kumamoto, April 1996 相似文献
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Hisashi Ohsaki Yoshitaka Kubojima Mario Tonosaki Masamitsu Ohta 《Journal of Wood Science》2007,53(2):134-138
The object of this study was to understand precisely the drying characteristics of wetwood of todomatsu (Abies sachalinensis Mast.). For this purpose, the vibrational properties of wetwood of todomatsu at high temperature were compared with those
of normal parts that had lower green moisture content than the wetwood. Specimens were cut respectively from the wetwood and
normal parts, and matched in the radial direction. The specimens and the measuring systems were placed in an electric drying
oven and free-free vibration tests were conducted in the oven under absolutely dry conditions. The wetwood and the normal
parts were tested separately. The temperature was raised from room temperature to 200°C and then lowered to 50°C in steps
of 25°C. The specific Young’s modulus decreased with an increase in temperature during the heating process while it increased
with the decreasing temperature during the cooling process. There was no significant difference in the specific Young’s modulus
between the wetwood and the normal part at all tested temperatures. The loss tangent took a minimum value at about 100°C in
both the heating and cooling processes. There was no significant difference in the loss tangent between the wetwood and the
normal part. Thus, the elastic and viscoelastic behaviors of the wetwood appear to be similar to those of the normal part
in the temperature range of an actual kiln-drying process. 相似文献
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引起杨树湿心材的一种病原真菌--Fusarium proliferatum (Matsushima) Nirenberg 总被引:4,自引:0,他引:4
在我国,杨树湿心材是一种分布广危害严重的病害。1995~1996年从湖北、山东、河北、辽宁等省及北京地区的20多种杨树的根、干部取样,分离到一种真菌,此菌在杨树的根、干部都有广泛的分布,依据其形态特征和培养形状,据Nelson,T.M.(1983)《FusariumSpecies》,此菌被鉴定为Fusariumproliferatum(Matsushima)Nirenberg。室内和田间的多次接种结果表明,F.proliferatum致病力强,能产生典型的湿心材症状,是引起我国杨树湿心材的主要病原之一,这在国内外还是首次报道。电镜观察表明,此菌能破坏杨树导管—射线间纹孔膜,与国内外有关纹孔膜的报道一致。本文还讨论了细菌及生理因素在湿心材形成过程中的可能作用。 相似文献
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Der pH-Wert und das Vorkommen niedermolekularer Fettsäuren im Naßkern der Buche (Fagus sylvatica L.)
M. Von Walter 《Forest Pathology》1993,23(1):1-10
The pH-value and the occurrence of fatty acids in wetwood of European Beech (Fagus sylvatica L.). At the border of the wetwood area pH-value of the capillary liquid was altered from acid to neutral conditions. Fatty acids frequently occurred in wetwood. Probes with pH-values higher than 6.8 often were deeply black stained. 相似文献
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R.?NakadaEmail author Y.?Fujisawa K.?Yamashita Y.?Hirakawa 《Journal of Wood Science》2003,49(2):107-115
Three-dimensional distribution of water in the heartwood of Cryptomeria japonica D. Don was observed by soft X-ray photography. The within-tree variation in the distribution of “wet areas” (water-accumulated
areas in heartwood) was enormous, as was the variation among trees. Although we found no universal pattern of changes in wet
area distributions along the stem axes of all trees, similarities among individual trees within each cultivar and clone were
observed. The difference between the two kinds of wetwood in C. japonica – genetically defined wetwood and secondarily induced wetwood – is discussed, as is the use of soft X-ray photography in Japanese
tree breeding programs.
Received: December 21, 2001 / Accepted: May 1, 2002
Part of this paper was presented at the 46th Annual Meeting of the Japan Wood Research Society, Kumamoto, Japan, April 1996
Correspondence to:R. Nakada 相似文献
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