Study on Balance between Supply and Demand for Timber and Timber Products in China

INTRODUCTION Because China is deficient in forest resources, and the forest has the characteristics of low quality, uneven distribution, slow growth and severe situation of ecological environment, the ecology construction has become the first requirement in society and with the implementation of the “Natural Forest Conservation Program”, Chinese forestry is in the historic transition from timber production to ecological construction. Therefore, the timber production in China increases…     

用CONE法研究木材阻燃剂FRW的阻燃机理

采用锥形量热仪(CONE)法对复合木材阻燃剂FRW处理紫椴木材(FZ)、FRW的组分磷酸脒基脲(GUP)处理紫椴木材(GZ)、硼酸处理紫椴木材(BZ)和未处理的紫椴木材(UZ)的燃烧性进行了系统的测定，通过对上述试样在燃烧时的热释放、质量变化、烟气产生以及尾气成分等实验数据的综合对比分析，讨论了阻燃剂的作用机理。结果表明：1)FRW阻燃剂显著降低了木材的热释放速率(RHR)、总热释放量(1FHR)、有效燃烧热(EHC)、质量损失速率(MLR)、烟比率(SR)、比消光面积(SEA)、CO2的浓度及产率(Yco2)；2)GUP与硼酸之间存在显著的阻燃协同效应；3)FRW阻燃木材的MLR曲线与RHR曲线相似，失重和热释放主要发生在有焰燃烧阶段；4)FRW阻燃处理能显著提高木材燃烧时的成炭率，说明催化成炭是FRW阻燃机理的主要方面。     

Sawing patterns for large-diameter sugi (Cryptomeria japonica D. Don) sawlogs: Current status and future outlook

Abstract

A survey was conducted at nine sawmills in Japan to evaluate and compare the sawing of sugi (Cryptomeria japonica D. Don) logs of 30 cm and more in diameter. The purpose was fourfold: (1) to document sawing patterns appropriate to the large-diameter logs; (2) to examine the composition of wood components (structural, nonstructural, and fixtures) produced from those patterns; (3) to investigate log and product prices; and (4) to ascertain distances to the log supplier and product markets. Impetus for the study arose from a forecasted shift in the diameter distribution of plantation trees in Japan; from small and medium-sized logs to large-diameter logs. With an overabundance of large-diameter domestic logs forecasted within the next decade, the need to understand how to best utilize and effectively process the large-diameter resource is of utmost importance.     

Effect of high temperature heat treatment on pH value of Masson Pine wood

Heat-treated wood has good dimensional stability,corrosion resistance and visual quality,but it is prone to mold,which limits its application.Based on the pH value of heat-treated wood,this study examines the factors affecting the pathogenesis causing heat-treated wood mold.Normally,the pH value of the heat-treated wood is between 4.38 and 5.10,which is suitable for the growth of mold.However,the pH of the heat-treated copper-containing material is between 6.63 and 7.12,which deviates the treated wood from the comfortable growth conditions for the mold,thereby reducing the occurrence of mold.     

速生杨木改性研究进展

论述了近年来杨木改性优化的研究进展。对速生杨木材进行优化处理可使其在性能上接近或超过天然林木材,这对充分利用速生杨木资源、缓解木材供应紧张局面、促进林业经济良性发展等具有重要意义。目前对杨木改性研究主要集中在依靠物质填充处理和非填充处理两方面,主要包括浸注有机物、无机物的改性处理,压密化处理,高温热处理以及多种方法联合改性处理等。     

数字图像处理技术在木材微观结构研究中的应用概况

对木材微观结构的研究始终是木质材料学发展的难点,数字图像处理技术的引入不仅带来了对此问题的高效解决方案,更展示出了广阔的研究前景,分析并总结了国内外该项技术在木材微观结构研究中的进展和应用。     

海口地区的木材平衡含水率

海口地区的木材平衡含水率蔡则谟（中国林业科学研究院热带林业研究所广州５１０５２０）关键词木材平衡含水率，海口研究各气候区的木材平衡含水率（Ｗｅ）对木材干燥有重要意义，自５０年代以来，华东、华北、东北、西南、西北及中南等地区的有关单位在这方面做了许多工...     

No “Gadgil effect”: Temperate tree roots and soil lithology are effective predictors of wood decomposition

The “Gadgil effect” hypothesizes that root associations may slow down decomposition through pre‐emptive competition. In the context of recalcitrant litter decomposition, specifically coarse wood debris, it is uncertain as to what is the relative importance of soil communities associated with living roots when compared to those without roots. Here, it is hypothesized that the presence of live roots and active photosynthates will enhance wood decomposition. To test this hypothesis, the presence or absence of temperate tree roots was used in this study. Sugar maple (Acer saccharum) and white oak (Quercus alba) roots were manipulated at three sites of either limestone or shale parent rock residuum. At each site, wood substrate was placed in soils beneath the canopy of either A. saccharum or Q. alba, while in the presence of roots (root⁺). At the same time, wood substrate was placed in the same soil community, but live root exposure was eliminated by trenching (root^?). This eliminated active photosynthate supply to the soil microbial community. Results determined that live root exposure promoted faster decomposition and greater mycelial colonization of wood substrate. Also, sites of shale parent rock residuum had higher rates of decomposition in comparison with limestone parent rock residuum. Although additional work is needed to determine the extent in which roots and lithology can facilitate wood decomposition, these findings suggest that living roots impact decomposers and provide a pathway towards humus and soil organic matter formation.     

木材干燥过程中声发射信号分析

对木材在干燥过程中产生的声发射信号进行采集和特征分析,结果表明:木材干燥过程中主要采集到两种不同类型的声发射信号:一种信号来自木材内部自由水的蒸发,与木质部导管内水分空穴化过程的声发射信号一致;另一种信号与木材干燥过快时自身形变开裂相关.作为一种木材干燥质量的控制方法,测量和分析声发射信号,可为木材干燥温度和湿度的控制提供依据,实现防止木材干裂、提高木材干燥质量的目的.     

声发射检测技术及其在木质材料无损检测中应用的展望

介绍了声发射检测技术的定义、原理和特点, 回顾了声发射技术的发展历史以及它在木质材料无损检测领域中的应用; 在此基础上提出声发射检测技术在木材科学与技术领域的应用前景。