Lignin-degrading activity of edible mushroom <Emphasis Type="Italic">Strobilurus ohshimae</Emphasis> that forms fruiting bodies on buried sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) twigs

Strobilurus ohshimae is an edible mushroom, and it specifically forms its fruiting bodies on buried sugi (Cryptomeria japonica) twigs. In this research, we studied lignindegrading activity of S. ohshimae. We isolated 18 strains of S. ohshimae from various regions of Japan, and determined their lignin degradation rates on sugi wood meal medium. All the strains of S. ohshimae degraded approximately 6%–12% of sugi lignin in 30 days, and these lignin degradation rates were 1.5–3 times higher than those of Trametes versicolor, which is a typical lignin-degrading fungus. Among the three main lignin-degrading enzymes, activity of lignin peroxidase and manganese peroxidase was not observed, while 4340U/g of laccase was produced in 30 days. To investigate the effect of wood species on lignin degradation by S. ohshimae, the lignin degradation rate and laccase productivity on sugi wood meal medium were compared with those on beech (Fagus crenata). In T. versicolor, both lignin degradation rate and laccase productivity were higher on beech than on sugi. Conversely, in S. ohshimae, lignin degradation rate and laccase productivity were higher on sugi than on beech. Therefore, it was suggested that coniferous lignin is not always difficult to degrade for the fungi that inhabit softwood. Part of this article presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004     

Contributions of Extractives and Lignin to the Fractal Geometry of Internal Wood Surfaces

Internal wood surfaces can be treated as fractals, which are between Euclidean geometry and complete randomness. The fractal dimension Dfs is very informative in investigating the roughness of the internal surfaces of wood. In this study, the water sorption isotherms, including adsorption and desorption isotherm, of untreated, benzene-alcohol extracted and delignified (after benzene-alcohol extracted) spruce (Cuninghamia lanceolata) were measured at 30℃. On the basis of these isotherms, the Dfs values were calculated by FHH equation, which is based on multimolecular sorption. The results showed that both groups of Dfs values (respectively calculated from adsorption and desorption isotherms) of untreated, benzene-alcohol extracted and delignified wood have same order, that is, untreated > benzene-alcohol extracted - delignified. Therefore, the conclusion can be made that the benzene-alcohol extractives have significant contribution to the fractal geometry of internal wood surfaces. Lignin also has influ     

心材提取物和专用木材防腐剂作为木材保护剂的相对功效

本文调查了三种耐用木材(Afzelia africana J.E. Smith; Erythrophleum suaveolens (Guill & Perr.) Brenam. Syn. E guinensis G.Don. or Milicia excelsa (Welw) C.C. Berg. Syn. Chlorophora excelsa (Welw) Benth.)的心材提取物（在60%的甲醇中风干提取）和两种专用木材防腐剂（CCA和Penta）在暴露的土壤区组设计条件下，抑制三种木材腐朽菌(Coridopsis Polyzona Klotzch; Lenzites trabea; or Trametes cingulata Fr.)对见血封喉边材的侵袭的相对潜能，并测定其阈值。提取物和防腐剂的剂量分别是8.009、24.778、48.056、96.111、144.167 kg·m-3 ，样品的暴露处理时间与ASTM D1413-72规定的一致分别是14周和18周。结果显示：在阈值范围内，任何一种心材提取物或木材防腐剂在研究中对木材腐朽菌的抑制能力在0.01的显著水平下，差异显著。这些生物杀灭剂的相对功效是取决于真菌的种类。没有任何一种心材提取物或木材防腐剂（除在用最高的存留水平处理被侵袭的非洲毒箭木的条件下）对于被处理的木材能够授予"非常持久"等级。本土树种的心材提取物相对持久力的减少的可能原因是复杂的。在最高的存留量（144.167 kg·m-3）水平下，在0.05显著水平下每种心材提取物和任一种专用木材防腐剂（CCA和Penta）之间的功效差异不显著.     

速生杨硫酸盐浆中木素的存在对纤维素水解反应性能及其产物结构的影响(英文)

对木素含量为0.9％～8.3％的速生杨硫酸盐浆进行了X-射线分析研究。利用多相水解方法测定了其反应性能。研究确定,浆中结晶纤维素含量取决于木素脱出程度并随着木素含量的降低而增加。木屑和浆中的纤维素结晶度相当高,而在脱木素过程中只呈微小变化。木素存在于多相水解反应过程中起着阻碍纤维素水解的作用,降低其反应速度常数。基于研究结果还提出了木素与纤维素结晶部分外表面联结的结论,并探讨了这种联结键的可能方式.     

国外纸业用竹近况

本文综述国外对竹子特性及其在制浆造纸工业利用的近况。包括竹子的备料、制浆、漂白和废液处理等,其中较为详细地叙述了竹子的硫酸盐法,碱性亚硫酸盐—蒽醌法制浆和硫酸盐浆的漂白研究。对于某些工厂应用的实例也有介绍。     

Sorption of Cr(VI) on the wood of Japanese larch treated with concentrated sulfuric acid

A carbonaceous sorbent was prepared from the wood of Japanese larch (Larix leptolepis) by dehydration with concentrated sulfuric acid in a 69% yield. The abilities of the sorbent to remove Cr(VI) from aqueous solutions were investigated. Research parameters included the initial solution pH, temperature, and initial concentration of Cr(VI) in solution. The removal of Cr(VI) was highly solution pH dependent and was mainly governed by physicochemical sorption under weak acidic conditions. The equilibrium data fit well in the Langmuir isotherm model. The Langmuir constants were calculated at different temperatures, and the sorption capacity increased with rising temperature, indicating the endothermic nature of the Cr(VI) sorption onto the sorbent. The desorption experiments suggest that the Cr(VI) sorption is generally irreversible, owing to strong interaction of HCrO ₄ ⁻ with the active sites of the sorbent.     

木材断口分形的初步研究

木材是一种天然的多孔性生物高分子材料,结构复杂且变异性大,所以木材断裂表面定量分析的难度很高,对于木材内部裂纹产生、发展的研究一直没有大的突破.在木材断裂力学的研究中,国内外科学家运用传统的断裂试验方法研究居多,但普遍结论是规律不明显或找不到规律(费本华,1999).木材研究者们一直在寻找一种定量描述木材断裂表面形态的新指标,并希望在此基础上预测木材强度和了解木材断裂机制(Schmitt et al.,1996;Qin et al.,1999).     

CCA木材防腐剂活性成分检测方法比较试验

文章介绍了CCA木材防腐药剂中CuO、CrO3、As2O5等活性成分的常规化学分析方法,并与仪器分析方法进行了比较。结果表明,常规化学分析与仪器分析的结果相接近,两者之间的偏差很小,不需做修正便可应用于工业生产上。     

Ecological Wood Adaptation and Horizontal Variations of Vessel Element and Fibre Length of Calligonum mongolicum

INTRODUCTION The larger genus in Polygonaceae is Calligonum, which includes about 100 species of shrubs that grow in central Asia. It is well suited to arid climates with drought resistance, and grows more on clay, sandy and gravel grounds. These plants are often cultivated as ornamentals and a stabilizer of mobile sand dunes. There was published information on the wood anatomy of all the examined genera in Polygonaceae (Ma 1994), but the selected species have not yet been described. Ad…