共查询到19条相似文献，搜索用时 312 毫秒
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采用UniSpec-SC光谱分析仪对毛竹叶片反射光谱进行测定,并对叶片色素含量与反射光谱参数的相关性进行分析,研究缓释肥(Tr1)、毛竹专用肥(Tr2)、混合配方肥(Tr3)对毛竹叶片色素含量的影响。结果表明:3种施肥处理对毛竹叶片色素含量均有明显的影响,其中Tr1处理叶绿素a、叶绿素b含量呈极显著增加(P<0.01),分别比对照增加15.7%、13.8%。3种施肥处理的毛竹叶片可见光区525～605 nm波长的反射光谱都明显降低,在550 nm波长处Tr1、Tr2、Tr3处理的光谱反射率分别比对照降低11.4%(P<0.01)、8.1%、7.8%,并使红边位置向长波方向移动;与对照相比3种施肥处理均使毛竹叶片PSSRb、PSSRc、PSNDb、PSNDc、CRI1、CRI2、SIPI和PRI等反射光谱参数升高;相关分析表明,毛竹叶片叶绿素a、叶绿素b、叶绿素总量、类胡萝卜素含量与光谱参数PSSRc、PSNDc、NPCI、CRI1、CRI2、SIPI和PRI之间存在显著的相关性(P<0.05),其中PSSRc、PSNDb、PSNDc、NPCI、CRI、SIPI和mSR705等反射光谱参数值与施肥种类相关。说明毛竹对缓释肥的利用率更高,毛竹叶片反射光谱对毛竹叶片色素含量和营养状况有良好的估测效果。 相似文献
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通过设立标准地对毛竹低产商品林地下茎进行调查，了解其结构、生长规律以及空间分布格局。总结了改善毛竹低产商品林地下茎结构的生长发育规律和提高毛竹生物量的方法，为毛竹丰产林培育技术研究提供科学的理论依据。 相似文献
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近红外光谱法测定毛竹综纤维素的含量研究 总被引：5，自引：0，他引：5
研究了用近红外光谱(NIR)结合多变量统计分析技术对毛竹综纤维素含量的快速测定。用常规实验室方法测定了54个竹材样品的综纤维素含量,用近红外光谱仪采集相应样品的光谱,对原始光谱进行二阶导数和25点平滑预处理后,从54个竹材样品中挑选41个代表性的样品建模,选择1011~1675nm和1930~2488nm波段区间,用偏最小二乘法(PLS1)和完全交互验证方式建立毛竹综纤维素含量的预测模型。结果表明,毛竹综纤维素含量和近红外光谱之间存在非常好的相关性,预测模型的相关系数(RP)为0.95,预测模型的标准偏差(SEP)为0.76%。 相似文献
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杉木叶绿素含量高光谱遥感模型研究 总被引：2，自引：0，他引：2
《中南林业科技大学学报(自然科学版)》2010,(11)
利用高光谱技术,探索杉木成熟林反射光谱与其叶绿素含量之间的相关关系。以湖南省攸县黄丰桥国有林场杉木成熟林为对象,采用美国ASD公司生产的手持式野外光谱仪(波长325~1 075 nm)进行地面和空中的杉木冠层波谱观测,采集到有效观测数据44条,并同步展开叶绿素总量分析。采用ViewSpec Proversion 4.02、SPSS17.0统计软件、MATLAB软件、EXCEL数据分析工具对波谱数据进行处理和生化成分相关性分析,建立了叶绿素总量与反射光谱关系模型,通过模型检验,得到杉木叶绿素总量的高光谱模型为:y=0.291x395+20.172x521+0.758。 相似文献
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一定剂量的Co~(60)γ辐照对毛竹种子的萌发和幼苗有促进作用。用7KR照射后,种子的发芽率比对照高40%。 相似文献
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本文分析和讨论了碱处理对苦竹试样自由基的影响,探讨了经水洗使碱性减弱后试样自由基浓度的变化,并对紫外光照射、温度变化导致的自由基浓度的改变作了测定。结果表明,碱处理对试样自由基浓度有明显降低作用;水洗对减弱碱性对于自由基浓度的影响有一定作用,但不显著;紫外光照射对竹材自由基有微弱作用,但对毛竹、杨木自由基有明显影响;温度对自由基浓度有较大影响,但若试样形态不同,温度与自由基浓度变化关系图也有差异。 相似文献
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桃江县毛竹低产林改造 总被引：2，自引：2，他引：0
桃江县毛竹资源丰富,经营历史悠久。由于培育技术相对滞后,竹材供应满足不了加工的需求。因此,掌握毛竹生长规律和丰产栽培技术,因地制宜,大力营建丰产、优质的毛竹基地,开展综合利用,对加快毛竹发展,促进农村经济建设具有十分重要意义。 相似文献
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Summary Photodegradation of wood surfaces in the presence of oxygen was studied. ESR studies revealed that free radicals were formed at the wood surface during photoirradiation. These wood free radicals readily interacted with oxygen molecules to form peroxide radicals. Iodometry UV absorption studies showed that hydroperoxide was formed in the photoirradiated wood. The hydroperoxide concentration increased when wood was irradiated in the presence of singlet oxygen generators such as Rose Bengal and Methylene Blue. Hydroperoxide concentration decreased when wood was irradiated in the presence of singlet oxygen quenchers such as 1,4-diazobicyclo (2,2,2) octane, -carotene and triethylamine. These findings imply the participation of singlet oxygen in the photodegradation of wood surfaces. The mechanisms of formation of singlet oxygen and hydroperoxide during photoirradiation are proposed. The consequence of hydroperoxide decomposition reactions on the discoloration and degradation of wood surface is discussed.This study was supported by cooperative research funds provided by the US Forest Products Laboratory, Madison, Wisoonsin. The authors (DNSH and STC) wish to acknowledge this support 相似文献
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对机械加工不同程度、不同部位苦竹的自由基浓度进行了比较,并研究了胶粘剂的施加对自由基浓度的影响。结果表明,加工程度愈深,比表面积愈大,试样的自由基浓度愈大,竹棒试样的自由基浓度只有粉状试样的1/3～1/10;竹肉自由基浓度为竹青的两倍、竹黄的八倍;酚醛胶与脲醛胶的施加均使竹材试样的自由基浓度降低,说明胶与自由基产生了作用,但二者在ESR谱线上有明显不同。 相似文献
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The effect of ultraviolet-visible light irradiation on changes in surface chemistry and morphology of moso bamboo (Phyllostachys pubescens Mazel) was investigated. Fourier transform infrared (FT-IR) and FT-Raman spectroscopy were used in combination to study chemical
changes induced by exposure to artificial sunlight (xenon lamp) for up to 160 h, and the resulting physical changes of cell
walls of bamboo surfaces were examined by scanning electron microscopy (SEM). FT-IR results showed that significant changes
occurred in the lignin component as indicated by considerable decreases in the intensities of the characteristic aromatic
lignin peak at 1512 cm−1 and other associated bands. This was accompanied by formation of new carbonyl groups at 1735 cm−1, resulting in photooxidation of bamboo surfaces. The photosensitive nature of bamboo lignin was also demonstrated by FT-Raman
analysis, in which obvious decreases in intensities of Raman bands at 1604 and 1630 cm−1 mainly derived from lignin and free and esterified p-coumaric and ferulic acids were observed. SEM micrographs of the irradiated cross sections of bamboo revealed that significant
damage occurred to the fiber walls, whereas the parenchyma cells exhibited slight distortion and some cracks occurred in the
cell walls. The structures of cell corners and middle lamellae were nearly intact after irradiation. 相似文献
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竹席/竹碎料新型建筑模板制备工艺研究 总被引：1，自引：0，他引：1
将小径竹及竹材加工剩余物加工成一定规格的竹碎料。以竹碎料为芯层,以竹席为表层组成板坯,通过热压制备竹席/竹碎料新型建筑模板。采用正交试验,选取热压时间、热压温度和施胶量作为工艺因素,对竹席/竹碎料复合新型建筑模板制备工艺进行了研究。研究发现,施胶量对产品的各项性能指标的影响最显著,其次是热压时间和热压温度。通过分析得出优化工艺:热压时间70 s.mm-1,热压温度为170℃,施胶量为10%。 相似文献
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采用滑动弧冷等离子体对竹条和圆竹筒进行处理,并将处理后的样品进行复合型防护药剂加压浸渍处理。采用质量增加率、平衡含水率、湿胀率以及竹条和竹筒的抗压强度等指标来考察防护药剂处理后对竹材性能的影响,并观察竹条和圆竹筒防护处理后的发霉情况。实验结果表明,竹条和圆竹筒表面在加压条件下对二羟甲基二羟乙基乙烯脲(2D树脂)+戊唑醇与丙环唑(PT)+碘代丙炔基氨基甲酸丁酯(IPBC)复合型树脂防护剂的渗透性和附着性得以提升,表现为竹条和圆竹筒经滑动弧冷等离子体和防护药剂加压浸渍处理后质量增加率提高,而平衡含水率和湿胀率下降。对竹条和圆竹筒的质量增加率、平衡含水率、湿胀率和抗压强度产生积极影响的顺序为:冷等离子体处理+加压浸渍防护药剂>加压浸渍防护药剂>未经任何处理的竹条和圆竹筒。此外,竹节的多少也对竹材的质量增加率、平衡含水率和湿胀率产生影响,影响顺序为:无节>单节>双节。处理后,竹条和圆竹筒具有优异的防霉特性,存放半年后,圆竹筒仍能保持原来的物理特征,竹条和圆竹筒表面和端部均无发霉、腐朽和开裂现象。 相似文献
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Oil production from the seeds of Camellia oleifera Abel. causes a great waste of shells which contain a lot of bioactive components. The aim of this research was to isolate flavonoid from the shells of C. oleifera Abel. and evaluate its uses. The shells were extracted by 70% methanol, hydrolyzed by 2 M hydrochloric acid, and further crystallized in acetone, the corresponding yield of flavonoid was up to 2.1% (purity: 93.8%). The procedure is concise, quick and proper for industrial utilization of the shells. Flavonoid was identified as bimolecular kaempferol structure by UV, MS, 1H NMR and 13C NMR spectra, which is a new biflavonoid and first found in C. oleifera Abel. It showed stronger scavenging activity of DPPH and ABTS radicals than kaempferol. MDA decreased, and SOD and GSH-Px activities increased significantly in serum (P < 0.01) and brain tissue (P < 0.05) of mice after intragastric administration of biflavonoid at 200 mg/kg/d for 30 d. Its effects in vivo are superior to vitamin C and similar to kaempferol. Thus biflavonoid can be used as a prospective antioxidant to protect brain cells against damage from free radicals. 相似文献
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MuJun UeharaTohru LiJianzhang FurunoTakeshi 《中国林学(英文版)》2004,6(2):1-5
The antioxidant activity of solvent extracts from two main bamboo species, moso bamboo (Phyllostachys pubescens) and madake bamboo (P bambusoides) in Japan, was first evaluated by scavenging free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH), the inhibition activity for peroxidation of linoleic acid, and the reduction power. The methanol-extracts of moso bamboo culms and madake bamboo leaves presented stronger antioxidant activity compared with DPPH scavenging activity. Methanol-extract of moso bamboo culms was further fractionated by different solvents and n-butanol soluble fraction exhibited the most significant activity in the DPPH scavenging assay. The fractionation of n-butanol soluble extract was isolated by silica gel column with gradient mixture solvent of chloroform and methanol. The isolated fractions were directed by the antioxidant activity measured by scavenging the stable DPPH free radical. It was observed that most of the eluted fractions showed the antioxidative activity. Fractions acquired from elution with the mixture solvent of chloroform and methanol (10:1-5:1) showed stronger antioxidant activity than the other fractions. 相似文献