分形理论在木材科学与工艺学中的应用

分形是一种新兴的基础理论，将成为木材科学研究的有效手段之一。本文阐述了分形理论（ＦｒａｃｔａｌＴｈｅｏｒｙ）的基本概念、原理和应用，着重介绍分形在木材解剖学、木材物理力学和加工过程中的应用前景。

对来华留学生“讲好中国故事”的实践路径——以全英文“木材加工工艺学”课程为例

“讲好中国故事”是提高来华留学生培养质量的重要组成部分。文章以南京林业大学全英文“木材加工工艺学”课程为例,探讨了在来华留学生全英文授课课程建设中“讲好中国故事”的基本路径,明确了“讲好中国故事”的内容、主体和方式,总结了教学内容、授课方式和教学方法的相应革新策略,旨在为国际化课程建设提供借鉴与参考。

Non-isothermal Kinetics of Pyrolysis of Three Kinds of Fresh Biomass

The pyrolysis kinetics of three different kinds of fresh biomass (grass: triple A, wheat straw, corn straw) in nitrogen flow were studied by thermogravimetric analysis at five different heating rates. The kinetic parameters of the pyrolysis process were calculated using the method of Ozawa-Flynn-Wall and the mechanism of reactions were investi- gated using the method of Popescu. It was found that the values of activation energy varied in different temperature ranges. The pyrolysis processes are well described by the models of Zhuravlev (Zh) and valid for diffusion-controlled between 200 ℃ and 280 ℃, by Ginstling-Brounshtein (G-B), valid for diffusion-control between 280 ℃ and 310 ℃, for first-order chemical reaction between 310℃ and 350 ℃, by Zhuravlev (Zh) valid for diffusion-control between 350 ℃ and 430 ℃ and by the one-way transport model when temperatures are over 430 ℃.

纳米TiO_2改性涂料涂饰染色单板的光变色

利用纳米TiO2改性水性双组份聚氨脂清漆和丙烯酸清漆,将改性涂料直接涂饰染色单板并进行氙光辐射试验,探讨了纳米TiO2对染色单板光变色的抑制作用以及纳米TiO2加入量对光变色性的影响。结果表明,聚氨酯和丙烯酸清漆中纳米TiO2加入量分别为3%和5%时对染色单板光变色的抑制效果最佳。光辐射前后,涂饰改性与未改性聚氨酯清漆杨木染色单板的色差ΔEa*b分别为18.75、22.98,丙烯酸清漆的分别为11.75和16.98。改性涂料涂饰染色单板的光变色度小于未改性涂料染色单板,主要在于改性涂料能显著抑制染色单板红绿色品指数a*的变化。