基于IAWA针叶树材显微特征在线检索系统的开发

针对目前缺乏通用的针叶树材在线检索系统的现状,基于国际木材解剖学家协会(IAWA)《针叶树材显微特征一览表》,借鉴InsideWood阔叶树材在线检索系统,设计并搭建了国产针叶树材显微特征在线检索系统,该系统收录140余种国产针叶树材的解剖特征及显微构造图像;试用结果表明,用户可以使用该系统快速、准确检索针叶树材。     

木材树种检索方法现状与智能检索初探

回顾人工对比法、对分检索法和穿孔卡检索法三种传统木材树种检索方法,总结计算机数据库程序检索法的发展现状。以实现在线智能检索针叶树材为例,笔者开发了融入计算机视觉技术的木材树种智能检索系统,介绍该系统的体系结构和程序流程,并提出今后的研究方向。     

IAWA针叶树材显微特征一览表

《针叶树材显微特征一览表》由国际木材解剖学家协会(IAWA)委员会于2004年3月第一次正式出版发行，其初稿于1999年第16届国际植物学大会上讨论完成，后经委员会协调员Jorgo(H．G．)Richter教授广泛听取意见，并修改和编辑；于2003年在IAWA学术会上形成出版稿。该表包括了针叶树材主要识别特征(地理分布、物理性质、生长轮、管     

国产重要树种木材特征及其出现频率的研究

研究了国产（包括引种的）６６９个重要树种的木材特征及其出现的频率。涉及裸子植物木材（或针叶树材）１６９种、木材特征１３８个，被子植物木材（阔叶树材）５００种、木材特征１７８个，并列出具有特殊木材特征的树种。     

中国裸子植物木材管胞瘤状层的电镜观察

本文对中国裸子植物11科、41属、99种木材管胞瘤状层进行了系统观察。瘤状层的有无及形态特征是区分裸子植物材的重要标志。此外并对5种针叶树材在一个年轮内,瘤状层从早材到晚材大小、分布密度的变化做了观察;12种针叶树材的切片,用0.5％次氯酸钠溶液处理后,瘤状物减小、以至消失;在另6个树种的管胞内,观察到瘤状层被白腐菌或软腐菌溶解。     

针叶树材管胞气体渗透流阻及其渗透系数

针对树材气体渗透性与气体在管胞中的流动特性和规律紧密相关，研究管胞的气体渗透流阻，可以获得关于针叶树材气体渗透性更深入的认识。本文从针叶树材管胞解剖结构出发，运用流体力学理论，导出了管胞3个纹理方向渗透气体流阻的数学表达式，并由此计算了针叶树材管胞的气体渗透系数。计算结果表明，管胞流阻可以描述气体渗透阻力的分布情况，反映气体渗透性在3个纹理方向的差异，在木材细胞层次揭示针叶树材气体渗透性的机制。     

15种阔叶树木材密度与切削阻力关系的研究

继１１种针叶树材之后，对１５种阔叶树木材密度与切削阻力的关系进行了研究。针叶树材试验中发现的主要规律在此得到进一步证实。     

桉材造纸的展望

长期以来,国内外造纸部门都喜用针叶树材为造纸原料,因针叶树材容易制成化学纸浆及机械纸浆.目前,我国纸张的用量与日俱增,而可利用制作纸浆的针叶树材又日渐短缺,完全依靠用针叶树材造纸已不能满足当前的需要.因此研究应用阔叶树材造纸,开拓纸浆的资源,成了急待解决的问     

松科杉科和柏科树种的木材显微构造比较

从建筑应用和工业用材方面来说,松科、杉科、柏科的木材,是我国针叶树材3个重要的科。本文选择了松科的马尾松(Pinusmassoniana)、柔毛冷杉(Abies faxoniana),杉科的杉木(Cunninghamia lanceolata),柏科的柏木(Cupressus funebris),作为3科木材的代表,就其木材的显微构造特征方面进行比较。     

针叶树材径向和弦向气体渗透的三维流阻网络

将针叶树材气体渗透的三维流阻网络理论进行了扩充 ,提出了气体径向和弦向渗透次级流阻网络的二维等效流阻网络及二维等效流阻网络流阻基元的确定和等效流阻的求解方法 ,将三维流阻网络从关于针叶树材气体纵向渗透性研究 ,扩展到针叶树材气体径向和弦向渗透性研究。提出了针叶树材径向和弦向气体渗透三维流阻网络理论 ,计算了马尾松试件径向和弦向渗透系数 ,并与测量值进行比较 ,结果表明两值相符合。将本文的针叶树材径向和弦向气体渗透三维流阻网络理论与此前关于针叶树材纵向气体渗透的三维流阻网络工作相结合 ,可以使用三维流阻网络计算针叶树材纵向、径向、弦向的气体渗透系数 ,其在木材干燥、改性、防腐有应用价值     

东南亚阔叶树材数据库查询系统

国内研究或鉴定东南亚木材较早的为中国林业科学研究院木材工业研究所。已发表的有陈嘉宝的《十二种柬埔寨重要工业木材的粗视特征及其物理力学性质》一文;1989年又编译了《马来西亚商用木材性质和用途》一书(商用木材74种)。1988年,安徽农学院林产工业研究所卫广扬等主编的《东南亚木材——识别及用途》问世,以近百种进口的马来西亚和菲律宾原木作为木材构造和材性试验的主要材料,共记载针、阔叶树材90余种;因系进口原木,所以不少没有种名;供作材性试验的木材也多为1号标本。以上这些资料各有侧重,有的只有粗视构造,有的虽有显微构造记载但不少没有种名,不利于木材识别;有的虽然作了木材物理力学试验,但试材太少,代表性不强;就已研究的树种数量看也较少,不能满足广大用材者的需求。     

一种新的针叶材自动识别方法

提出通过横切面显微图像对针叶材树种进行计算机识别的方法。该方法通过提取图像的PCA特征,生成特征树,然后采用SVM对样本进行分类。使用8种针叶材,每种12个样本,并采用留一交叉验证,对图像的分割方法、最近邻与SVM分类算法和不同范数距离下的识别效果进行试验。结果表明通过部分木材微观的纹理结构进行木材识别的可能性。     

On the fracture morphology in wood

Summary Failure forms caused by axial ultimate compression stress in three softwood and nine hardwood species and in model specimens made of wood, paper and plastics are described. Three categories of failure forms are distinguished: 1. Wood characteristic failure forms are connected with the general anisotropic structure of the wood. 2. Failure forms specific to the species are modifications of the first category arising from predominant anatomical structures. 3. Modifications of the failure forms are also induced experimentally. The interdependence among the anatomical structure, strength characteristics and failure forms of the wood specimens are examined by statistical methods. The structure cipher introduced in this paper, as a numerical characteristic of the anatomical features of the wood species, is seen to be the most important influencing factor as regards the intensity and pattern of the fracture, followed in second and third place by the geometry of the specimen and its specific gravity. Specimen volume and other factors are shown to have only a marginal influence on the fracture morphology.The strength tests were carried out as part of a diploma thesis by K. Buchmüller. Also the assistance of E. Risi in measuring and evaluating is gratefully acknowledged     

Quantitative analysis of lignin using an UV microscopic image analyser. variation within one growth increment

Summary The variation of the lignin content within one growth increment of Abies sachalinensis was investigated with the aid of an ultraviolet microscopic image analyser. The lignin content was determined continuously in each cell within a growth increment. The direct photometric scanning method of UV image is believed to give accurate results for determination of the lignin content of the cell wall, since it contains fewer assumptions. The lignin content of the earlywood was higher than that of latewood in adult wood as same as the others. It was high, however, in the terminal zone of the latewood. The trends of the juvenile wood were quite different from those of the adult wood. The lignin content increased from earlywood to latewood.This paper was presented at the Wood Anatomy Congress of IAWA, Aug. 27, 1979, Amsterdam. The authors wish to express their gratitude to Prof. Dr. J. Bauch for helpful advice     

Variation of the phenolic hydroxyl group content in wood lignins

Summary The phenolic hydroxyl group content of wood lignin has been determined in situ by a periodate oxidation method for four softwood and six hardwood species. Hardwood lignins, in contrast to softwood lignins, showed a significant variation among different species in this functional group content which decreased with an increase in the proportion of syringyl units in the wood lignin.Financial support from the Empire State Paper Research Associates is greatly appreciated     

Measurement of free shrinkage at the tissue level using an optical microscope with an immersion objective: results obtained for Douglas fir (Pseudotsuga menziesii) and spruce (Picea abies)

Shrinkage at the tissue level has been evaluated satisfactorily using relatively simple equipment, comprising an optical microscope equipped with reflected light, a standard objective, a water immersion objective of same magnification and a digital camera connected to a computer. Shrinkage is calculated from pairs of images taken at the same magnification, one collected during immersion in water and the other in air-dry state. A novel software program has been developed to determine shrinkage based on a closed chain of reference points chosen from the anatomical markers at the external part of the zone of interest. Measurements were performed on earlywood, latewood and compression wood zones from two softwood species (Douglas fir and spruce), isolated from the rest of the annual ring with the aid of a diamond wire saw. As main results, reference should be made to the low degree of shrinkage and high anisotropy factor of earlywood, the marked and practically isotropic shrinkage in latewood and the low shrinkage (with respect to cell wall thickness) and inverse anisotropy ratio in compression wood.     

闽楠嫩枝扦插繁殖技术研究

为解决多用途树种闽楠苗木快繁的问题,开展了闽楠嫩枝扦插繁殖技术研究.结果表明:闽楠3年生苗木嫩枝扦插单株间生根率有显著差异,半木质化穗条带2片叶进行扦插可显著提高穗条生根率,GGR生根剂不同浓度处理闽楠穗条对其生根率有极显著影响,不同扦插基质对闽楠插穗生根率有显著影响.     

Three-dimensional modelling of wood fracture in mode I, perpendicular to the grain direction at fibre level

A coupled experimental and numerical modelling approach was used to investigate the mechanism of softwood fracture at the fibre level. First, a three-dimensional mixed lattice-continuum fracture model was developed to investigate the mechanism of wood fracture, taking into account the porosity of its structure and its heterogeneities at the fibre level. The critical volumes in the specimen where crack propagation was more probable were modelled by a lattice that could show the alternation of earlywood and latewood fibres, and the other regions were considered as the continuum medium. The proposed model was used to investigate the mode I fracture of a small softwood sample in RL orientation. Secondly, a method was developed for microscopic observation of the crack trajectory and investigating the mechanism of initiation and propagation of cracks. This approach was used for microscopic investigation of the fracture behaviour of spruce specimens in mode I and RL orientation. The results of the numerical study were compared with the experimental results. The prepeak and postpeak behaviour of the obtained stress-displacement curve and also the crack opening trajectory in cross-section and longitudinal section in the model and experiments were in good agreement. Both the model and the microscopic observation showed that in mode I fracture and RL orientation, the main trajectory of the crack propagates in the earlywood ring.     

The use of an acoustic technique to assess wood decay in laboratory soil-bed tests

This study assesses the changes in elastic behaviour (i.e. modulus of elasticity – MOE) and mass loss of different hardwood and softwood species exposed to decay in laboratory soil-bed tests. Elasticity moduli were determined using conventional static methods as well as a dynamic method based on flexural vibration. The results obtained show a high correlation between dynamic and static bending measurements for all the timber species tested at different stages of fungal decay. Furthermore, the non-destructive MOE assessment proved to be a good tool for the early detection of wood decay. Received 5 January 1999     

中国储木及建筑木材腐朽菌(Ⅰ)

本文首次系统报道了生长在中国原木、建筑物(包括房屋、桥梁、涵洞、栅栏等木质结构材)、坑木、枕木、矿柱、电杆、薪材等上的腐朽菌107种.其中24种引起木材褐色腐朽,83种引起白色腐朽.褐色腐朽的种类主要发生在针叶树木材上,白色腐朽的种类在针叶树和阔叶树木材上都常见.在针叶树原木上常见的木材腐朽菌有黄薄孔菌、红缘拟层孔菌、深褐褶菌、硫磺绚孔菌、冷杉附毛孔菌.在阔叶树原木上常见的有紫褐多孢孔菌、黑管孔菌、一色齿毛菌、红贝俄氏孔菌、硬毛粗毛盖孔菌、皮生锐孔菌、淡黄木层孔菌、鲜红密孔菌、淡黄裂孔菌、毛栓孔菌、锗栓孔菌和云芝栓孔菌等.这些种类来自作者长期的采集、记载和鉴定,全部标本保存在中国科学院沈阳应用生态研究所生物标本馆.