Structural mechanics of wood composite materials I: Ultrasonic evaluation of internal bond strength during an accelerated aging test

This research attempts to observe indirectly the variation of internal bond characteristics for wood composite materials during accelerated aging test treatment using ultrasonic pulse-transmission techniques. Particleboard (PB) and oriented strandboard (OSB) were the representative specimens. The transit time of the ultrasonic wave propagating through the samples along the nominal length and thickness directions was recorded using an apparatus called PUNDIT (C.N.S. Electronic, London). The transit times were measured in the samples under an oven-dried condition after treating them with boiling water at different treating time stages, and the velocity was then calculated based on the transit time. Examination of the internal bond strength conducted on the same samples was done according to JIS A 5908. A study of the relations among springback, internal bond strength, and velocity indicated that a high correlation existed between ultrasonic velocity measured in the length or thickness direction and the internal bond strength for the PB specimen, but no significant correlation was observed between the velocity measured in the length direction and the internal bond strength for the OSB specimen. The results of this research suggested that ultrasound techniques can be applied to predict or evaluate the internal bond state of some wood-composite materials made of relatively small particles, such as PB especially, during accelerated aging test treatment processes.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, April 1997     

木材微生物变色与调控研究现状和展望

木材变色是一种木材材性的缺陷,木材调色是木材变色现象的逆利用。利用微生物调控木材材色环保无污染,具有较好的发展前景。综述了易变色的木材种类、易使木材变色的菌种、微生物控制木材变色和腐朽以及微生物诱导木材调色的研究现状,并对今后木材微生物变色与调控的发展提出建议。     

木材工业用胶粘剂的现状及发展趋势

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。     

我国人造板用胶粘剂发展浅议

胶粘剂在我国木材工业中占有举足轻重的作用，人造板行业胶粘剂的消耗量是十分可观的。针对当前我国胶粘剂行业存在的一些问题，提出了一些意见及建议，并对胶粘剂的发展趋势进行了探讨。     

Wood identification of JapaneseCyclobalanopsis species (Fagaceae) based on DNA polymorphism of the intergenic spacer betweentrnT andtrnL 5′ exon

DNA was extracted from wood samples of six representativeCyclobalanopsis species (Fagaceae) growing in Japan that cannot be distinguished from one another by conventional microscopy. A part of the intergenic spacer region betweentrnT andtrnT 5 exon was amplified and sequenced. The sequences obtained from wood samples were grouped into three DNA types by a single nucleotide polymorphism as reported previously in leaf samples: I (Quercus acuta, Q. sessilifolia, Q. salicina), II (Q. myrsinaefolia, Q. glauca), and III (Q. gilva). Thus,Q. gilva can be distinguished from the otherQuercus species, and the others are separated in two subgroups based on DNA polymorphism. The present findings support the possibility of wood identification based on DNA polymorphism.     

木材工业和可持续发展──世界木材工业的发展趋势

进入80年代以来,世界经济已开始由工业化社会向生态化社会发展,林业和木材工业的目标也开始由传统的以生产木材和木材制品为主向可持续经营,实现森林的生态、环境、社会和木材等多方面效益发展。木材工业的进一步发展面临木材资源紧缺、环境保护压力增加等重大问题的挑战。遵循可持续发展原则,加强工业人工林的培育和利用,发展环境协调技术和产品,改进林业和木材工业的竟争地位,更好地适应市场的需求,实现林业和木材工业的协调发展,是木材工业通向未来之路。     

Coarse woody debris in late-successional Picea abies forests in northern Europe: Variability in quantities and models of decay class dynamics

Coarse woody debris pools and their decay class dynamics were studied in three areas of unmanaged boreal forest in northern Finland, and in the Murmansk and Arkhangelsk provinces in northwestern Russia. The study areas had varying climatic and edaphic conditions, and disturbance histories. Living and dead trees (diameter at 1.3 m height ≥10 cm) were measured in five late-successional Picea abies-dominated stands in each of the three areas. Wood density and time since death were determined from randomly sampled dead P. abies, and their decay class dynamics were modeled using stage-based matrix models.     

基于GC-MS顶空进样法鉴别瘿木降香黄檀与大果紫檀

分别对两个批次含瘿瘤的降香黄檀和大果紫檀木材,采用GC-MS技术顶空进样方式,获取其总离子流图并进行相关系数、系统聚类和特征性化学成分分析。结果表明:两种木材之间总离子流图差别大,无相关性,而同种木材不同批次间相似度高,均含有相同的特征峰,相关系数高(R>0.900);系统聚类分析进一步验证了该试验结果;两种含瘿瘤木材主要特征化学成分种类和含量也完全不同;相关性分析、聚类分析和特征性成分分析均可鉴别区分这两种含瘿瘤木材,解决了含瘿瘤木材传统方法难以鉴别的难题。     

木质材料系列阻燃技术的研究

ＷＦＲ木质材料系列阻民括多功能系列阻燃剂诼阻燃型木材、胶合板、刨花析和中密度纤维板的生产工艺。ＷＦＲ系列阻燃剂阻燃效果好，流失性小，低毒、防腐。用ＷＦＲ生产的板材阻燃性能和物理力学性能好。人造板板材甲醛释放量低。     

西北地区木材市场现状及前景分析

西北地区木材总量供需矛盾仍然突出,结构性供需矛盾仍然存在,价格稳中看涨,未来木材供求形势将更加严峻。本文介绍了中国木材市场供需和进口现状及发展趋势。解决木材供需缺口不可能长期依赖进口,扩大国内商品材的生产是根本途径。主张通过木材产业发展促进西北地区产业结构调整从而达到林业资源的充分利用。