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大叶相思人工林木材理化特性及利用方式的研究 被引量:8
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作者 林秀兰 《林业科学》 EI CAS CSCD 北大核心 2002年第5期121-127,共7页
对同林龄不同林分大叶相思人工林木材试验地的生长量调查、化学组成测定及相关部位利用的研究 ,结果表明 :萌生林分比实生林分的材积和生物量分别提高 14 8%和 4 3 4 % ,证实速生树种形成次生林的幼树具有早期速生的特点 ;不同林分材... 对同林龄不同林分大叶相思人工林木材试验地的生长量调查、化学组成测定及相关部位利用的研究 ,结果表明 :萌生林分比实生林分的材积和生物量分别提高 14 8%和 4 3 4 % ,证实速生树种形成次生林的幼树具有早期速生的特点 ;不同林分材性变化不明显 ,木材基本密度均≤ 0 .6 0g·cm- 3,纤维长度为 898~ 916μm ,壁腔比 0 5 6~ 0 6 0 (<1) ,纤维柔性系数 5 9 3~ 6 8 5 ,在 75~ 5 0范围内。采用KP法制浆 ,细浆得率达 4 4 %以上 ,木浆物理性能均达本色硫酸盐阔叶木浆标准 ;萌生林分鲜原胶产量大于实生林分 ,单株平均净增产鲜原胶 1 4 2kg ;挂胶与否对木材化学组成无影响而对树皮有影响 ,但不论挂胶与否 ,其树皮含单宁量高达 9 97%~ 11 4 0 % (>8% ) ,用于制备栲胶 ,产品质量及鞣革性能均优于国产一级木麻黄栲胶标准 ;木材、枝丫材作培养基栽培香菇等食用菌 ,其产量和生物效率与木屑对照组比较 ,均值差异达极显著 (F <F0 .0 5)。以各产品所产生的经济效益为依据 ,进行最佳利用方式的研究 ,结果得出大叶相思人工林以 3a生萌生林挂放紫胶虫、采收后砍伐、剥皮 ,然后将去皮材和枝丫材做食用菌生产原料 ,树皮做栲胶生产原料的利用组合方式 。 展开更多
关键词 人工林 木材理化特性 大叶相思 利用方式 生长量
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Study of Brazilian Woods Using Gamma-Ray Sources
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作者 Gilberto Carvalho Leonardo Gondim de Andrade e Silva 《Journal of Physical Science and Application》 2014年第5期304-309,共6页
Due to the availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw-material for paper and cellulose manufacturing; in indust... Due to the availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw-material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instruments; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere as to the growth of trees. This behavior explains why the average of physical chemical properties is important in wood study.Most of the researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties in wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: "Freijo", "Jequitiba", "Muiracatiara" and "Ipe". For wood density determination by non-conventional method, ^241Am, ^133Ba and ^137Cs gamma-ray sources, a NaI scintillation detector and a counter were used. The results demonstrated that this technique is quick and accurate. Considering the nuclear parameters obtained as half-value layers and linear absorption coefficients,^ 137Cs demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. 展开更多
关键词 Brazilian woods DENSITY gamma-ray.
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