木质剩余物复合材料老化问题的分析

论述和分析木质剩余物复合材料老化的原因,主要有木质剩余物的老化、胶粘剂的老化、木质剩余物的回弹和膨胀—收缩应力。综合论述木质剩余物复合材料加速老化试验方法,指出木质剩余物复合材料在加速老化试验方面的研究,适宜采用ASTM D1037六循环加速老化法和老化仪检侧法。分析木质剩余物复合材料老化的影响因素,如温度、湿度、试件尺寸等。     

松材线虫病防治技术存在问题及建议

就松材线虫病的防治技术所存在的问题以及相应的措施作详细的探讨,使松林资源得到有效的保护。     

Association of brook trout and Oncorhynchus spp. with large wood jams in a Lake Superior tributary in a northern old‐growth watershed

Wood in streams functions as fish habitat, but relationships between fish abundance (or size) and large wood in streams are not consistent. One possible reason for variable relationships between fish and wood in streams is that the association of fish with wood habitat may depend on ecological context such as large‐scale geomorphology. We studied the relationship between salmonid assemblages and large wood jams (LWJ) in four settings that differed geomorphically at the scale of the stream corridor along a tributary to Lake Superior in old‐growth conifer–hardwood forest in northern Michigan. The focal fish species of this study were brook trout (Salvelinus fontinalis), which were wild in the stream. Relocation efforts for coaster brook trout (an adfluvial life history variant of brook trout) were ongoing in the study stream. We measured fish abundance and length in pairs of pools of similar size and substrate, but varying in the presence of LWJ; this allowed us to evaluate associations of fish simply with the presence of LWJ rather than with other channel or flow‐shaping functions of LWJ. The length of Oncorhynchus spp. and young introduced brook trout was not strongly correlated with LWJ presence; however, the presence of LWJ in pools was positively correlated with larger wild brook trout. We also found that the correspondence of LWJ with the abundance of salmonids appears to be moderated by the presence of alternative habitat in this relatively natural, old‐growth forest stream.     

Tree Diversity,Carbon Storage,and Soil Nutrient in an Old‐Growth Forest at Changbai Mountain,Northeast China

Abstract

The study of plant diversity and its role in ecosystem functioning is becoming a central issue in ecology. The relationships between carbon storage and tree diversity of natural forest at small scale are still unclear. This research investigated these relationships in an old‐growth forest at Changbai Mountain, Northeast China. It was found that at small scale, tree carbon storage generally increases with increasing tree species richness, but for stands with same species richness, tree carbon storage varies dramatically. At the small scale, tree species evenness has a significantly linear relationship with nature logarithm of total tree carbon storage. The stand carbon storage of trees is mainly controlled by stand tree composition. Fraxinus mandshurica, Pinus koraiensis, Quercus mongolica, Tilia amurensis, and Acer mono contribute more than 85% of stand carbon storage of trees. Stands with similar tree composition at small scale have different soil organic carbon storage and nutrient contents. Tree species evenness has great impact on soil N content at the soil horizon less than 30 cm deep, but its impacts on C/N, P, K, and S contents are small. Tree density has a negative linear relationship with soil organic C and C∶N ratio at the soil horizon is less than 30 cm deep. The implication of our findings here for carbon sequestration in the Kyoto Protocol is also discussed.     

木材流体渗透理论与研究方法

为较全面系统地了解木材流体渗透理论研究现状,从流体在多孔介质内的主要类型与流动理论、流体在木材内的主要流通通道及木材流体渗透性研究的主要理论与试验方法等几方面进行综合概述,提出木材流体渗透性理论研究的主要发展方向.试验观察应采取更先进的手段,动态观察流体尤其是液体渗透木材的整个连续过程,并构筑更合理的木材流体简化结构渗透模型,以较少的参数反映更完整的流体渗透途径;理论研究应借鉴木材干燥过程中应用较成熟的传质传热模型,建筑多孔材料如水泥、石、砖等的渗透性研究,土壤流体渗透性及地下石油流体渗透性研究方面应用较成熟的理论和方法,并拓宽木材渗透性的研究对象,建立符合木材非稳态渗透实际过程的二维或三维理论模型,以更逼真地模拟木材流体渗透过程;2种方法结合起来,定性和定量完整描述木材流体渗透机制.     

云南松直干、弯干材木材结构比较观察

利用光学显微镜对云南松直干、弯干材木材构造进行解剖学观察，结果表明：弯干材在解剖结构上跟直干材基本保持一致。与直干材相比，弯干材的早材比直干材的早材窄，树脂道多；早、晚材管胞的长度、壁厚、弦向直径差幅分别为：0．14、0．63、4．4、13．56、-0．46、0．81；最大交叉场纹孔数和最大单列射线细胞个数比直干材分别多1个和2个；纺锤形射线高度超出直干材的51．73％。弯干材具有右旋扭转纹。另外，两种材料都是较好的造纸原料，且以弯干材为优。     

木粉/PVC复合材料挤出流动性的影响因素

研究木粉的粒径、添加剂的种类及配比等因素,对木塑复合材料挤出流动性的影响.结果表明:木粉粒径越小,复合物料在挤出过程中的流动性能越差,所制备的木塑复合材料色差越大,且产品材色越深.综合考虑加工特性和制品材色,宜选用木粉粒径45～60目；并添加稀土热稳定剂及铝酸酯偶联剂,可以提高物料的挤出流动性.     

气相色谱-电子捕获检测器测定电子废弃物处理场地底泥中的四溴双酚-A

通过优化分析仪器的条件设置，建立了使用气相色谱-电子捕获检测器技术分析四溴双酚-A（TBBP—A）的仪器分析方法。样品采用正己烷索氏提取、硅胶柱分离纯化、外标法定量，结果表明，测定方法在测量范围内具有良好的线性关系，测定的平均回收率为86．8％，检出限为5．0ng／ml，相对标准偏差为3．26％～8．77％：     

Soil CO2 evolution from Korean pine virgin forest at Changbai Mountain

The soil CO₂ evolution rate was measured in a virgin Korean pine forest. The results in June showed that the lowest value of evolution rate was 220 mg/(m²·h) and appeared at 6:00 a.m. The highest value was 460 mg/(m²·h) at 18:00. The rates of CO₂ evolution were related with soil temperature. On the basis of the constructed regression equation and the monthly average values of temperature, the magnitude of CO₂ evolution from Korean pine forest soil was 10.4 t/hm² during a growing season. This project was funded by the Opened Research Station of Changbai Mountain Forest Ecosystem, Chinese Academy of Sciences. Responsible editor: Zhu Hong     

无（微）损检测技术在木结构古建筑中的应用及发展

介绍了古建筑木构件勘查中常用的无（微）损检测技术,阐述了各种仪器工作原理、检测方法及其优缺点,其中包括皮罗钉、阻力仪、应力波和超声波检测设备。基于以上技术,结合古建筑木构件特点,提出仪器结合使用、构件分类检测、设备便携化以及以树种鉴定为基础的木结构古建筑无损评估体系。

Abstract：

Commonly used nondestructive inspection technologies involved in the survey of the wood structures of ancient buildings are introduced and the inspection methods,working principle,advantages and disadvantages of various instruments,including of pilodyn,re