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落羽杉种源木材微纤丝角和纤维形态的变异 总被引：1，自引：1，他引：1
对16个落羽杉种源的14年生人工林木材微纤丝角和木材纤维形态进行测定.结果表明:1)16个种源落羽杉木材微纤丝角存在显著差异,微纤丝角变化在29.9～35.8°之间.从径向变化看,落羽杉胸径处木材微纤丝角在髓心处最大,由髓心向外逐渐减小;从纵向变化看,微纤丝角在基干处最大,随树木高度的增加而逐渐减小.2)16个落羽杉种源木材的纤维长度和宽度均存在显著差异,纤维长度的变化在1 764.84～2 900.08 μm之间,纤维宽度的变化在28.48～51.21 μm之间,纤维长宽比的变化在42.79～82.12之间.落羽杉胸径处木材纤维形态的径向变化为纤维长度和纤维宽度从髓心到树皮逐渐增加,纵向变化规律为纤维长度和纤维宽度在树干基部较小,随树高的增加而逐渐增加.3)落羽杉木材微纤丝角与木材纤维长度呈极显著的负相关关系,与木材的纤维宽度和纤维长宽比呈一定的负相关,木材纤维长度与木材纤维宽度呈显著的正相关.4)16个落羽杉种源依据木材微纤丝角和木材纤维长度2个木材材性指标可以分为4类:第Ⅰ类,木材的微纤丝角较大,木材纤维长度中等;第Ⅱ类,微纤丝角和木材纤维长度均处于中等水平;第Ⅲ类,微纤丝角较小,木材纤维长度较长;第Ⅳ类,木材纤维长度较短,微纤丝角中等.综合考虑微纤丝角和木材纤维长度,2号和30号种源可作为纤维工业原料用材的优良种源. 相似文献
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方文彬 《中南林业科技大学学报(自然科学版)》1995,(2)
采用碘溶液和氢氧化钠两种溶液的混合液处理针叶树材管胞弦壁切片，并用干燥法脱除切片胞壁水，对碘结晶法测量木材微纤丝角的方法进行改良．结果表明，切片的木素脱除干净彻底，次生壁微纤丝之间易形成空隙，有利于碘离子进入其中形成碘结晶，可清晰地观察到微纤丝的走向，有利于有效而准确地测量微纤丝角，与改良前进行比较，具有省时省力，节约经费的优点． 相似文献
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管胞S_2层微纤丝角的大小为评定针叶材材质或纸张强度的重要因子,同时直接关系到木材加工与利用,以及良材培育的预测预报。一般认为,纤丝角小,木材和纸张的强度大,纵向胀缩也小。所以,国内外都比较重视管胞微纤丝角的测定。国内自八十年代开始才有这方面报导。测定微纤丝角的主要方法有:碘染色法;X射线衍射法;汞浸法:偏光显微镜观察法。本试验用碘 相似文献
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木材微纤丝角两种测试方法的对比研究 总被引：1，自引：0，他引：1
木材微纤丝角是木材各项性质中最重要的指标之一,它的大小对木材的解剖、物理、力学性能和化学性能有着很大的影响。笔者使用两种方法测定分析了杉木的微纤丝角,为研究者选择合适的实验方法提供依据。分别利用X射线衍射法和偏振光显微镜法得到杉木的木材微纤丝角及其变异规律,并对这两种方法进行分析比较,结果表明：（1）X射线衍射法测定速度快,代表性强,适用于大量试样的变异研究,但对实验仪器要求高。（2）偏振光显微镜法测定速度较慢,但实验仪器成本相对较低,适合实验室试样的少数测定。 相似文献
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杨树微纤丝角的变异及其与木材性质的相关关系 总被引：6，自引：0，他引：6
微纤丝角为细胞次生壁S2层微纤丝排列方向与细胞主轴所形成的夹角,与木材的物理性质、力学性质和化学性质都有着直接的关系。应用x射线衍射法测定了7个杨树无性系(14株样木)胸径处各年轮的微纤丝角,并对应分析和测定了各年轮的木材基本密度、纤维长度、纤维宽度和纤维素含量。研究结果表明,杨树微纤丝角在年轮间存在显著差异,其径向变异规律为从髓心向外以微纤丝角逐渐降低,年轮间的平均微纤丝角在7.8旱?8褐洌荒静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾吭谀曷旨湟泊嬖谙灾钜臁O喙胤治霰砻鳎⑾怂拷怯肽静幕久芏取⑾宋ざ取⑾宋矶群拖宋睾看嬖谙灾母合喙毓叵??0.01),相关系数分别为-0.450、-0.586、-0.516和-0.660。回归分析结果表明,多项式方程可较好地描述杨树微纤丝角与所测定的木材性质的关系,相关系数均在-0.45以上(n=125)。本文的研究结果认为,在今后针对杨树材性改良的育种计划中,微纤丝角是一个重要的选育和改良指标。图3表3参34。 相似文献
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泡桐属木材的微纤丝角和结晶度 总被引：5，自引：0，他引：5
8种泡桐木材纤维次生壁S_2层的微纤丝角平均为12.52°;纤维素相对结晶度平均为46.4%。从这两项指标来看,南方泡桐和泡桐(白花泡桐)木材具有较为优良的材质。12年生毛泡桐木材的S_2层微纤丝角由髓往外,随着树龄的增加而角度增大,而纤维素相对结晶度则减少。 相似文献
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对10个10年生日本落叶松无性系的早材和晚材微纤丝角进行了测定,结果表明:早、晚材微纤丝角无性系间差异极显著,同一年轮内早材微纤丝角大于晚材.日本落叶松微纤丝角的径向变异规律为:在髓心处最大,以后逐渐减小.早、晚材微纤丝角与树木年轮间的变异模式(径向变异)以对数和乘幂式方程拟合效果较好,R2(R为相关系数)均在0.8以上.早、晚材微纤丝角同树高、形率、树皮厚度、主枝粗、枝干比、主枝夹角、主枝长的相关关系不显著,早、晚材微纤丝角同胸径、冠幅的相关关系达到显著水平;早材与晚材的微纤丝角也相关显著.早材和晚材的微纤丝角受中到强度遗传控制,广义遗传力分别为0.767 4、0.804 3.按照20%的选择率,早材和晚材的微纤丝角的遗传增益分别为21.82%和29.75%. 相似文献
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As a newly current advanced analysis technology,the near-infrared(NIR)spectroscopy possesses advantages of easy operation,fast and accurate detection,low cost and non-destructive test, has been widely used in the fields including pulp manufacturing and paper-making,wood properties estimation,wood progressing,wood composites producing and wood protection.In present work, based on introduction of the basic principles of NIR and its main characteristics,an overview was conducted focusing on the research status of wood anatomical characteristics(including cellulose crystallinity,microfibril angle and fiber morphology) estimation by using NIR spectroscopy.Moreover, the application trends were prospected. 相似文献
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m0DUCYIONCunninghaniahaceolataisoneofmalnusedwoodspeciesinSouthernChina.ItPOs-sessesthecharactenshcsofhighadaPabilityandwideuhlity.WoodscienhstshavedonemorereaearchingworkonthegrOwingcharac-tenshcsandwoodPhysicalPropeniesofPlantedCunninghamiaboceolata,butlessonthewoodPropeniesvanahonpatternofnatUralCunninghtzmiahaceolata.ThewoodpropeniesandtheircorrelahonofCunn~oriahaceolatainnatUralforestwerestudiedinordertoProviderelevamtech-mqueparametersofitsPeffochonanduhliza-tion.nsThunSAunare… 相似文献
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Use of near infrared spectroscopy to measure the chemical and mechanical properties of solid wood 总被引：13，自引：1，他引：13
Near infrared (NIR) spectroscopy (500 nm–2400 nm), coupled with multivariate analytic (MVA) statistical techniques, have been used to predict the chemical and mechanical properties of solid loblolly pine wood. The samples were selected from different radial locations and heights of three loblolly pine trees grown in Arkansas. The chemical composition and mechanical properties were measured with traditional wet chemical techniques and three point bending tests, respectively. The microfibril angle was measured with x-ray scattering. These chemical and mechanical properties were correlated with the NIR spectra using projection to latent structures (PLS) models. The correlations were very strong, with the correlation coefficients generally above 0.80. The mechanical properties could also be predicted using a reduced spectral range (650 nm–1150 nm) that should allow for field measurements of these properties using handheld NIR spectrometers. 相似文献
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We investigated clonal and site variations in wood fiber length, microfibril angle, and specific gravity of seven natural
hybrid clones of Acacia (Acacia mangium × Acacia auriculiformis) grown in northern and southern Vietnam. Fiber length did not differ between clones or between sites. The microfibril angle
of the S2 layer did not significantly differ between clones but significantly differed between sites. Clone and site significantly
affected specific gravity. The significant effects of genetic × environmental interactions on wood properties indicated the
difference in the response of clones to different growing conditions. The trends of changes in fiber length, microfibril angle,
and specific gravity from the vicinity of the pith to near the bark were similar for all clones at each site; however, variations
in fiber length, microfibril angle, and specific gravity were more visible in northern Vietnam than in southern Vietnam, with
a significant effect of genetic factors. This difference may be attributable to winter, which is experienced in northern Vietnam
but not in southern Vietnam. For clone selection for plantation in the northern region, combining growth rate with wood properties
was recommended. On the other hand, for plantation in the southern region, clone selection depends mainly on the growth rate,
taking into consideration the specific gravity. 相似文献
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Guo Mnghui 《林业研究》1996,7(2):56-59
In this paper, the variation pattern of wood properties was studied for naturalCunninghamia lanceolata. The mathematical models of property parameters were obtained on tracheid length, microfibril angle, late wood percentage,
growth ring width and growth ring density in the radial direction. The interrelation were analyzed between tracheid length
and microfibril angle. The result can provide scientific theory basis for wood utilization and early prediction of wood properties. 相似文献
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I. D. Cave 《Wood Science and Technology》1997,31(3):143-152
Summary The property of fibre symmetry as exhibited by wood cellulose can be used to derive an explicit relationship between the orientation of a cellulose microfibril and the orientation of the X-ray beam diffracted by any of its crystallographic planes. The solution applies to a microfibril of any orientation and so is well suited to evaluating the microfibril angle distribution in wood containing cells of any cross-sectional shape. The (002) and (040) reflections of cellulose have complementary properties that could be exploited to enable current problems associated with the use of each individually for evaluating the mean microfibril angle of the S2 layer to be overcome. It is expected that it will be possible to measure the microfibril angle distribution throughout the whole cell wall and also measure the average cell cross-section of a wood sample, by analysing (002) and (040) diffraction profiles in conjunction with each other.This work is supported by the NZ Foundation for Research, Science and Technology under contract # UOC 401 相似文献
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B. A. Meylan 《Wood Science and Technology》1981,15(2):81-92
Summary Inclined branches of Pseudowintera colorata exhibit pronounced growth promotion to the lower (abaxial) side similar to that found in gymnosperms. The only other significant difference between the anatomy of the upper and lower regions is that the tracheids on the lower side have a larger microfibril angle. Other microscopic features normally associated with compression wood or tension wood are completely absent. The longitudinal shrinkage of samples from the upper and lower regions is shown to be related to the mean microfibril angle in a highly non-linear way, and a relatively small change in microfibril angle is associated with a large change in longitudinal shrinkage. This result is in agreement with the hypothesis that compression wood force generation arises during the lignification phase of secondary wall deposition and is critically dependent on mean microfibril angle.The author is indebted to Mr R. R. Exley of this laboratory who prepared the samples and made all the measurements in this project 相似文献
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Microfibril angle variability in Masson Pine (Pinus massoniana Lamb.) using X-ray diffraction 总被引：1，自引：0，他引：1
Zhang Bo Fei Ben-hua Yu Yan Zhao Rong-jun 《中国林学(英文版)》2007,9(1):33-38
The microfibril angle of fiber walls is an ultra-microscopic feature affecting the performance of wood products. It is there-fore essential to get more definitive information to improve selection and utilization. X-ray diffraction is a rapid method for measur-ing microfibril angles. In this paper, the variability of microfibril angle in plantation-grown Masson pine was investigated by peak-fitting method. This method was compared with the traditional hand-drawn method, 40% peak height method and half peak h... 相似文献