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121.
人工林毛白杨木材解剖构造与染色效果相关性的研究 总被引:9,自引:0,他引:9
为探讨木材构造和木材染色效果之间的相关性变化规律,本研究测字5株34块人工林毛白杨 的解剖构造及其木材染色效果,对二者的相关性进行了多元回归分析。结果表明,毛白杨木材染色效果与解剖因子之间有一定的相关关系,各染色效果指标与木材解剖因子间的复相关系数在0.4836-0.7998之间,采用比较多元回归分析标准回归系数的方法,确定了影响毛白杨木材染色效果的主要解剖因子为导管比量、木纤维比量和木射线量等因子。 相似文献
122.
木材构造和生体节律的1/f型涨落谱 总被引:1,自引:0,他引:1
在综合现代木质环境学研究成果的基础上,就自然界中普遍存在着的涨落现象、涨落的分类、各种涨落谱的特征等做了一般性的说明。集中讨论了木材构造的涨落谱及生体节律的涨落谱特征,并就两者之间存在的共同点,即两者之间的相关性做了浅显说明,回答了为什么自古以来人们喜爱生物材料——木材及木材纹理构造这一问题的根本原因。 相似文献
123.
There is a growing desire to improve the properties and use of nonwood plant materials as supplements to wood materials for wood cement-bonded boards (WCBs). This study was conducted to determine the comparative properties of WCBs containing various amounts of discontinuous inorganic fiber materials, such as alkali-resistant glass fiber, normal glass fiber, mineral wool, and nonwood plant materials such as retted flax straw and wheat straw particles. Tested cement-bonded boards were made at wood/additive compositions of 100/0, 90/10, 80/20, 70/30, 60/40, and 50/50 (weight percentages). Seventy-eight laboratory-scale WCBs were produced. Various board properties, such as the modulus of rupture (MOR), internal bonding strength (IB), water absorption (WA), thickness swelling (TS), and linear expansion (LE), were studied. The test results showed that three types of discontinuous inorganic fiber used as reinforcing materials in composites significantly enhanced and modified the performance of WCBs. The mechanical properties and dimensional stability of cement-bonded board were significantly improved with increasing amounts of the additives. MOR and IB were increased; and WA, TS, and LE of boards were reduced by combination with the inorganic fiber materials. The results also indicated that combination with retted flax straw particles only slightly increased the MOR of boards, and wheat straw particles led to marked decreases in all the mechanical properties and the dimensional stability of WCBs.Part of this report was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000 相似文献
124.
Takaaki Fujimoto Kazuhito Kita Kazuko Uchiyama Makoto Kuromaru Hisashi Akutsu Kazuyuki Oda 《Journal of Forest Research》2006,11(3):157-163
Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion
were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F1. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations
between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained
using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of
environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age
for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66.
Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits
at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum
gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at
early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at
a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth
rate because rapid growth will result in a low-density wood product, especially in the early growth period. 相似文献
125.
木材工业用胶粘剂的现状及发展趋势 总被引:12,自引:2,他引:12
主要介绍了脲醛树脂、酚醛树脂、三聚氰胺-甲醛树脂、木质素、单宁、异氰酸酯等木材工业用胶粘剂的研制状况及世界木材资源和木材工业的发展趋势。 相似文献
126.
Withthesmallsawlogwidespreadused,theuncut-boardsandslabsarecutbythemulti-bitrippingedgerinthejhoberindustw.AfersawingripPed,theunedgedboedaccuratelyvolumeisfAnotherparametCrsaredefinitebyadrawing,theaPProimatevolumeforn1ulateofunedgedboardistx,y,~inatC,x'… 相似文献
127.
Crystallinity of wood and the size of cellulose crystallites in Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis>) 总被引:5,自引:0,他引:5
Seppo?Andersson Ritva?SerimaaEmail author Timo?Paakkari Pekka?Saranp?? Erkki?Pesonen 《Journal of Wood Science》2003,49(6):531-537
X-ray diffraction was used to study variations in the crystallinity of wood and the average thickness and length of the crystallites of cellulose as a function of the number of the year ring in Norway spruce [Picea abies (L.) Karst.]. The crystallinity increased from ring 4 to ring 10 from the pith and was constant after ring 10. The crystallinity of mature wood was about 30% ± 5%. The average thickness and average length of the crystallites were 3.2 ± 0.1nm and 28 ± 2nm, respectively; and no systematic variation of these values with the number of the year ring was observed. The mean microfibril angle decreased near the pith but was constant in the mature wood. 相似文献
128.
129.
木材材性株内径向变异模式初探──Ⅲ.种植密度对湿地松、火炬松木材密度径向变异模式的影响 总被引:3,自引:0,他引:3
对两个地区不同种植密度的湿地松、火炬松进行了微密度分析,研究了种植密度对木材密度径向变异模式的影响。主要结果是:种植密度对湿地松和火炬松各密度特征值径向变异模式的影响,主要表现在变异曲线平均水平高低的变动,而对变异曲线形状的影响并不显著。种植密度对湿地松和火炬松各年轮宽特征值径向变异模式的影响,主要表现在年轮宽度RW和早材宽度EW变异曲线平均水平高低的变动和RW、EW与晚材宽度LW变异曲线形状的变动。种植密度对年轮密度RD的影响从年轮内宽度和年轮密度变异曲线平均水平高低两个方面起作用,出现较复杂的情况,并非所有情况下都是单调的正相关。 相似文献
130.