【作者】 王羽涵；

【导师】 刘渝；

【作者基本信息】 北京林业大学 ， 木材科学与技术， 2009， 硕士

【摘要】 本文借鉴组织光学技术在生物医学上的传输机理和研究方法,将相关技术导入木材分析领域,主要包括两方面内容:一方面,采集不同树种木材的近红外透射光谱,明确最佳透射波长。另一方面,构建双积分球系统,并对不同树种木材的光学参数进行了测量。运用逆倍增程序计算木材组织的吸收系数、散射系数。本研究得出以下几点主要结论:1.本研究选取了具有典型性的人工速生林树种杉木、杨木、泡桐,加工为不同厚度的木材组织试件用于近红外透射光谱的分析。在对采集的近红外透射光谱平均化、归一化处理后,明确了木材组织近红外光学透射的最佳波段为1310nm。2.介绍了浑浊介质的光学参数测量技术,详细说明了双积分球系统的优势和测量原理。从整体上叙述了所要搭建的系统的设计思路,然后针对木材组织近红外透射特性,LD光源选择发射波长1310nm的近红外光,搭建了以锁相放大器为核心部件的双分球系统。实验证明,构建的双积分球系统信噪比合理,可以应用于数据采集。3.吸收系数和木材化学物质的种类、含量直接相关,散射系数则与木材组织散射粒子的尺寸大小直接相关。实验数据显示:杉木吸收系数平均为0.053,散射系数平均4.75;杨木吸收系数平均0.055,散射系数平均5.94;泡桐吸收系数平均0.053,散射系数平均5.41。更多还原

【Abstract】 In this paper,the transmission mechanism and analysis method in biomedical study has been conducted into the field of wood analysis.The study include two aspects mainly:on one hand,the near-infrared transmission spectra of different species of wood have been collected to clarify the best transmission wavelength.On the other hand,a double-integrating-sphere system has been established to measuring optical parameters of different species of wood.Then the absorption coefficient and scattering coefficient have been calculated by using Inverse Adding Doubling program.Following main conclusions are obtained:1.The study has selected the typical species of plantation timber to collect the NITS of different thickness samples for analysis.The processed spectra data shows that the best wavelength of near-infrared transmission in wood tissue is 1310nm.2.The paper has introduced the technology of measuring optical parameters of turbid media and detailed the advantages and the measuring principle of the double-integrating-sphere system and described the design ideas of the system generally.A double-integrating sphere system based on lock-in amplifier has been set up.Experiments show that the double-integrating sphere system performing a reasonable signal to noise ratio,can be applied to data collection.3.Absorption coefficient correlates closely with the type and content of chemistry material in wood;scattering coefficient correlates closely with the size of scattering particles in wood.The experimental datum has demonstrated:The absorption coefficient of Cunninghamia lanceolate is 0.053 equally while the scattering coefficient on average is 4.75;The absorption coefficient of Populus is 0.055 equally while the scattering coefficient on average is 5.94;The absorption coefficient of Paulownia is 0.053 equally while the scattering coefficient on average is 5.41.更多还原