美洲黑杨×青杨F2代基本材性性状遗传变异研究

利用美洲黑杨×青杨杂交三代谱系探索了木材密度、纤维长、纤维宽、纤维长宽比和微纤丝角等性状的遗传变异规律.结果表明基本密度与纤维长受主基因的控制,表现为"质量- 数量性状",其杂种优势明显且在F     

Physical and mechanical properties of wood after moisture conditioning

Some properties of wood (hinoki:Chamaecyparis obtusa) moisture-conditioned by an adsorption process from a dry state and by two desorption processes (from a water-saturated state and from a state with a moisture content slightly below the fiber saturation point) were investigated. The moisture contents of wood conditioned by the adsorption process and by the desorption process continued to approach to one another for the moisture-conditioning period of over 50 weeks. Accordingly, sorption hysteresis should be regarded as a transitional phenomenon that occurs during the process of approaching the true equilibrium, which requires a long time. The wood conditioned by the desorption process beginning from a water-saturated state showed slightly smaller dimensions than those conditioned by the adsorption process with the same moisture content; however, the wood conditioned by the desorption process from a moisture content below the fiber saturation point showed slightly larger dimensions than those conditioned by the adsorption process. The wood conditioned by the adsorption process from a dry state showed a higher modulus of elasticity and modulus of rupture than did the wood conditioned from a water-saturated state with the same moisture content. The mechanical properties of the wood also varied based on the states at which the desorption process was started. This is a notable characteristic of the relation between the drying condition and the mechanical properties of wood.     

栽培措施对短周期工业材材性影响规律的研究

对4种不同栽培措施的日本落叶松、湿地松、马尾松和杉木等多种短周期工业材309株样木的材性进行了全面测试分析研究，结果表明．立地指数大，木材生长率和纤维宽度大．但纤维长度、纤维长宽比、木材基本密度、顺纹抗压强度和抗弯弹性模量减小；立地指数相差两级，木材的年龄宽度、纤维宽度、长度和微纤线角度的差异达到显著或极显著水平栽植密度小，木材的年轮宽度和干缩比增大但纤维长宽比及体积全干缩率减小；栽植密度增大，杉木和昭林6号杨木材的力学强度提高，但尾叶桉和I－69杨降低；不同栽植密度的木材pH值及酸碱总缓冲容量，都是心材大于边材，但木材的脲醛树脂胶凝速度，则是边材快于心材.与未间伐林分的木材比较，随着间伐强度的增大、年轮宽度增大．但纤维长宽比和微纤丝角度减小；间伐强度增大，针叶树村的力学强度降低，阔叶树树则提高．但将强度间伐材（间代40％）与未间伐材比较，结果完全相反；北京杨木材心材的pH值、酸碱缓冲容量及总容量，均随间伐强度的增大而增大，但边材却减小．施肥措施能够增大纤维直径，但将导致纤维长宽比、木材密度和力学强度的降低施肥可以使树木速生，但会降低木材密度和质量，在培育建筑结构材的林分应慎用．     

Abrasive wear properties of compressed sugi wood

We examined the abrasive wear properties and the effect of abrasive grain size on the rate of wear when sugi wood (Cryptomeria japonica D.Don), compressed to various densities, was rubbed with abrasive paper. The results showed that the wear resistance of compressed wood increased linearly with the increased compression ratio; and under the condition of a low compression ratio it tended to be higher in comparison with the strength of compressed wood. The critical grain size effect, which can be witnessed during the abrasive wear of metals and plastics, was seen when low pressure was applied to the abrasive material. At higher pressures, the wear rate of the compressed wood increased with grain size, but the critical grain size effect was not observed. The pressure required to create the critical grain size effect was found to be higher than that needed for other types of uncompressed wood with the same yield properties.Part of this report was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000     

橡胶木制造薄片刨花板的研究

本文论述了橡胶木小径材和枝桠材制造薄片刨花板的可行性,并通过正交试验对脲醛胶刨花板制造工艺进行了优化选择,同时也对酚醛树脂胶粘剂制造薄片刨花板和薄型刨花板进行了探索。试验表明,橡胶木可以制造出质地良好的刨花板。     

Magnetic resonance imaging used for the evaluation of water presence in wood plastic composite boards exposed to exterior conditions

Abstract

Two wood plastic composite (WPC) boards, one experimental and one commercial, were exposed to exterior conditions and evaluated non-destructively using a clinical magnetic resonance imaging (MRI) unit for moisture content (MC) and distribution. The experimental board was exposed in Vancouver, British Columbia, for more than 8 years, and the commercial board was exposed near Hilo, Hawaii, for 2 years. Both boards were characterized in terms of wood content, density, water uptake properties and voids content. The experimental board was additionally destructively analysed for water absorption of the WPC and MC calculated based on the wood content for verification of MRI results. MRI detected the presence of free water and its distribution in both of the WPC boards. Fibre saturation in the experimental board was found to be about 22–24%, in comparison to 25–30% present in most wood species. There was good correlation between the detection of free water by MRI and by destructive testing. Magnetic resonance images showed various major points of water entry in the WPC boards such as the support area, the cut ends, the dripping edge and the sides of the boards. For the experimental board, significant water entry also occurred at the upper exposed surface.     

用热分析法研究木材阻燃剂FRW的阻燃机理

采用热重(TG)、微商热重(DTG)和差热(DTA)分析法，对木材阻燃剂FRW及其主要组分硼酸和磷酸脒基脲(GUP)、硼酸处理紫椴木材(BZ)、GUP处理紫椴木材(GZ)、FRW处理紫椴木材(FZ)以及未处理紫椴木材(UZ)进行了系统的热解行为研究。TG和DTG分析结果表明，当FRW受热达到分解温度时，其组分的热分解是独立的：硼酸在95和160℃依次分解为偏硼酸和三氧化二硼，GUP在180、285和385℃依次分解为聚磷酸胍(GPP)、聚磷酸铵(APP)和多聚磷酸(PPA)。用阻燃剂FRW及其组分处理的木材，其热解均不同于传统的木材热解模式，其中，BZ在较低的温度下(约165℃)即发生明显的失重，说明硼酸的阻燃机理除了传统理论认为的物理覆盖作用以外尚存在化学催化作用(催化脱水)；GUP处理使紫椴木材的最大失重速率出现的温度从375℃(uz)降到314℃(GZ)，同时失重率也显著降低，而成炭率升高；FZ的失重率低于其他处理材。此外，与各种药剂TG曲线之间的相互关系不同，FZ曲线不等于BZ曲线与GZ曲线的简单加和，这3条曲线相互交叉，预示着GUP与硼酸之间存在阻燃协同作用。DTA分析支持了上述结果。此外，BZ的DTA曲线在约425℃产生一个放热峰，说明硼酸的分解产物可能在高温下催化木材热解产物的芳构化。     

CMC系列防腐剂对毛竹材的防霉效果

以3～4年生新伐毛竹为试材,以青霉、木霉、黑曲霉为试菌,与常用的竹材防霉剂硼酸(HBO3)、百菌清等进行比较,对壳聚糖金属配合物(CMC)系列的壳聚糖铜配合物(CCC)、壳聚糖锌配合物(CZC)的防霉性能进行测试.结果表明:CCC和百菌清对木霉、青霉、黑曲霉防治效果均优于CZC、壳聚糖和硼酸;相比之下,CCC对青霉防治效果优于百菌清,而百菌清对木霉防治效果优于CCC.     

辊压处理大青杨木材的密度和干缩系数变异

对大青杨辊压处理材(压缩率10%～50% )的密度和干缩系数进行测试和研究.结果表明,与素材相比,辊压处理材的全干、气干和基本密度均有所增加,密度变化率＜5%,其中气干密度增幅最大,密度变异与压缩方向无明显相关;气干和全干干缩系数随压缩率增大而变大,变动范围-3.448%～23.678%;弦向干缩系数变化大于径向.     

A brief review of the past, present and future of wood preservation

Wood products used in exterior applications must be protected against biodeterioration by decay fungi, insects such as termites, and other organisms. Traditionally, wood products for residential or industrial applications have been protected by treatment with chromated copper arsenate (CCA) or older inexpensive organic biocides, but environmental and disposal concerns and governmental regulations have resulted in a rapid and dramatic worldwide shift to copper-based systems. The current development trend is towards employing totally organic biocides based on relatively benign and expensive agrochemicals, with continuing research directed towards developing non-biocidal methods to protect wood.