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61.
热处理过程中杉木压缩木材的材色及红外光谱 总被引:18,自引:1,他引:18
为了探讨热处理过程中杉木压缩木材的材色变化规律 ,以及材色和木材化学主成分变化之间的关系 ,该研究测定了空气介质和真空中热处理杉木压缩木材 (热处理温度范围 140~ 2 2 0℃ ,时间范围 0~ 36h)的明度 (L )、色差 (ΔE )以及红外光谱 .同时测定了杉木压缩木材的回复率 ,无压缩对照试材的重量损失率和抗收缩率 .该研究的结论为 :①在相同条件下 ,随着热处理时间延长 ,木材明度减小 ,色差增大 ;空气介质中热处理和真空中热处理相比 ,在处理温度和时间相同的情况下 ,前一种方法处理后的木材明度更小 ,色差更大 .②就热处理过程中木材明度、色差与回复率之间的关系而言 ,两种热处理方式之间的差异不大 ;热处理中木材变定的固定程度与木材颜色的变化程度有关 .③就热处理过程中杉木压缩木材的明度、色差与对照试材的重量损失率、抗收缩率之间的关系而言 ,重量损失率或抗收缩率越大 ,对应的杉木压缩木材的明度越小 ,色差越大 .④红外吸收光谱表明 ,在热处理过程中波数在 1743,16 6 0和 16 0 5cm-1附近的羰基 (C =O)峰的变化趋势最为明显 ,说明在热处理固定杉木压缩木材的过程中 ,至少半纤维素 ,甚至木素发生了化学变化 . 相似文献
62.
63.
Nagai A Taira O Ishikawa M Hiramatsu K Hohdatsu T Koyama H Arai S Sato H Nakano K Maehara N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(6):725-728
Mammalian interferon (IFN)-alpha consists of a 23-amino acid signal peptide and a 166-amino acid mature protein. Feline (Fe) IFN-alpha has an extra unique molecule consisting of a 171-amino acid mature protein with a 5-amino acid insertion. We cloned eight new subtypes of cDNA encoding FeIFN- alpha from a feline epithelial cell line. Among all the FeIFN-alpha subtypes, including six that have previously been reported, the variations were found to be far less than those of IFN-alphas of other animals. 相似文献
64.
Jianjun Zhu Tatsuo Nakano Morihiko Tokumoto Takashi Takeda 《Journal of Wood Science》2000,46(4):284-288
To examine the effectiveness of long rotation forestry and the potential of complete utilization of Japanese larch (Larix kaempferi Carriere), we designed a tensile test using the lumber from six 87-year-old sample trees. Results showed that strength properties of lumber varied greatly in the radial direction within trees, but all sample trees showed a similar trend. There was little difference in dynamic Young's modulus but a large difference in tensile strength (TS) between the lumber and small clear specimens from undestroyed parts of the lumber. These differences decreased with an increase in ring number and became constant after 30 years. The presence and distribution of knots markedly affected the TS; and among the knot indices, the knot number (Kn) and knot area ratio of a maximum single knot (Km) proved to be effective for explaining the effect of knots. The distribution of Kn and Km in the radial direction agreed with the variation of TS in the radial direction. By investigating the variation patterns of lumber and small clear specimens in the radial direction, it was found that the strength properties of both required a long time, about 30 years, to reach a relatively constant state.Part of this report was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999 相似文献
65.
Effects of radial growth rate on selected indices for juvenile and mature wood of the Japanese larch 总被引:1,自引:0,他引:1
To examine the differences between juvenile and mature wood, 12 aged sample trees from two areas of Nagano Prefecture were harvested; and the radial development of tracheid length, the ring density, and the relation of the radial growth rate (observed by ring width) with some selected indices of ring structure were investigated. The results proved that the radial variation of tracheid length with ring number can be described by a logarithmic formula, and both plantations reached the demarcation of juvenile and mature wood at age 18. With the segmented regression method, we also analyzed radial variation of mean density and found that the demarcation of juvenile and mature wood was at age 15 for sample trees from Saku and at age 21 for those from Yabuhara. By using the results of estimates from juvenile and mature wood based on ring density, we found that high growth rates resulted when producing lower-density wood during the juvenile period, but these rates did not occur during the mature period. The basic reason for this phenomenon is the variation in patterns of earlywood and latewood in juvenile and mature wood, respectively. This result advised us that when managing plantations of Japanese larch it is necessary to take different measurements at different growth periods. 相似文献
66.
We quantitatively examined changes in the morphological features of wood cells treated with aqueous NaOH and their relationship to changes in the micro-structure of wood components. Wood samples were treated with aqueous 0.00–0.20 (w/w) NaOH ([NaOH] = 0.00–0.20). Cross-sectional planes of samples were observed using confocal laser-scanning microscopy and the circularity index of cell lumens in cross-section was evaluated using digital image analysis. At [NaOH] < 0.11, the circularity index was unrelated to crystallinity, while at [NaOH] > 0.12 it was closely related to a decrease in crystallinity, as indicated by X-ray diffraction. Force balance analysis based on a cell model supported experimental results at higher concentrations. We concluded that cells appear circular in cross-section after treatment with NaOH because a decrease in crystallinity results in contraction along microfibrils, resulting in distribution of the central force of the three layers, S1, S2, and S3, in the secondary wall at the corners of cells in cross-section. 相似文献
67.
Shoko Fukuda Tetsuya Kobayashi Ian D. Robertson Fukiko Oshima Eri Fukazawa Yuko Nakano Shin Ono Donald E. Thrall 《Veterinary radiology & ultrasound》2014,55(4):374-379
The purpose of this retrospective study was to describe pre‐ and postcontrast computed tomographic (CT) characteristics of confirmed nonparenchymal hemangiosarcoma in a group of dogs. Medical records were searched during the period of July 2003 and October 2011 and dogs with histologically confirmed nonparenchymal hemangiosarcoma and pre‐ and postcontrast CT images were recruited. Two observers recorded a consensus opinion for the following CT characteristics for each dog: largest transverse tumor diameter, number of masses, general tumor shape, character of the tumor margin, precontrast appearance, presence of dystrophic calcification, presence of postcontrast enhancement, pattern of postcontrast enhancement, presence of regional lymphadenopathy, and presence of associated cavitary fluid. A total of 17 dogs met inclusion criteria. Tumors were located in the nasal cavity, muscle, mandible, mesentery, subcutaneous tissue, and retroperitoneal space. Computed tomographic features of nonparenchymal hemangiosarcoma were similar to those of other soft tissue sarcomas, with most tumors being heterogeneous in precontrast images, invasive into adjacent tissue, and heterogeneously contrast enhancing. One unexpected finding was the presence of intense foci of contrast enhancement in 13 of the 17 tumors (76%). This appearance, which is not typical of other soft tissue sarcomas, was consistent with contrast medium residing in vascular channels. Findings indicated that there were no unique distinguishing CT characteristics for nonparenchymal hemangiosarcoma in dogs; however, the presence of highly attenuating foci of contrast enhancement may warrant further investigation in prospective diagnostic sensitivity and treatment outcome studies. 相似文献
68.
Miyoshi K Saijo K Kuryu Y Oshima Y Nakano M Kawai H 《Science (New York, N.Y.)》1968,159(3816):736-737
Human metmyoglobin was separated electrophoretically into four subfractions: Mb(1), Mb(2), Mb(3), and Mb(4), which divide into at least two biochemically independent groups: Mb(1) and Mb(2), and Mb(3), and Mb(4). In normal subjects, Mb(1) constituted the predominant component; Mb(2), Mb(3), and Mb(4) were the minor components in this descending order. In the Duchenne type of progressive muscular dystrophy, on the contrary, a remarkable decrease in Mb(1) and a concomitant increase in Mb(3) were observed. This unique abnormality in the relative distribution of myoglobin subfractions was recognized only in the Duchenne type and not in other types of progressive muscular dystrophy or in other myopathies. 相似文献
69.
E Miyamoto F Watanabe S Ebara S Takenaka H Takenaka Y Yamaguchi N Tanaka H Inui Y Nakano 《Journal of agricultural and food chemistry》2001,49(7):3486-3489
A unicellular coccolithophorid alga, Pleurochrysis carterae, contained 125.4 +/- 1.2 microg of vitamin B12 per 100 g dry cell weight of the lyophilized algal cells. A vitamin B12 compound was purified from the lyophilized algal cells and partially characterized. The silica gel 60 TLC and reversed-phase HPLC patterns of the purified pink-colored compound were identical to those of authentic vitamin B12, but not those of vitamin B12 analogues inactive for humans. When 22-week-old B12-deficient rats which excreted substantial amounts of methylmalonic acid (75.5 +/- 12.3 mg/day) in urine were fed the P. carterae (10 g per kg diet)-supplemented diet for 12 d, urinary methylmalonic acid excretion (as an index of vitamin B12 deficiency) of the rats became undetectable and hepatic vitamin B12 level of the rats was significantly increased. 相似文献
70.
Takanori Nakano Seo-Ryong Jeon Junko Shindo Tamon Fumoto Naoki Okada Jun Shimada 《Water, air, and soil pollution》2001,130(1-4):769-774
The 87Sr/86Sr ratios in rain at three sites in Japan were about 0.706 to 0.712, whereas those at one site in central Korea were higher (0.711 to 0.716), reflecting the difference in geology between the two countries. Because the 87Sr/86Sr ratios of exchangeable sites in soil minerals are indistinguishable from those of associated plants, aerosol Sr originating from both can be grouped together as plant-derived Sr. Spatial and temporal variations in 87Sr/86Sr and Sr/Ca ratios in the rain suggest the presence of plant-derived Sr and Ca in addition to Sr and Ca derived from sea-salt, acid-soluble aeolian carbonate from China, and cement-derived carbonate. However, systematic data on the 87Sr/86Sr ratios and elemental concentrations of soils, plants, fly-ash, and road dust are required to put reliable constraints on the provenance of atmospheric Ca. 相似文献