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1.
云南4种典型材用丛生竹的化学成分   总被引:8,自引:0,他引:8  
对竹材的10种化学成分分析的结果认为:云南龙竹,甜龙竹,黄竹和油勒竹这4种典型材用丛生竹种间的化学成分无显著差异,且不因竹段位置不同而存在显著差异;4种丛生竹的各项抽提物含量,蜡含量和二氧化硅含量较一般木材高。  相似文献   

2.
研究了两种产自云南的丛生竹的化学组成和纤维特性。结果表明:从木材加工的角度出发,黄竹因其比重大,纤维形态好,纤维的分布规律好和细胞壁腔比较大等优点,以及它含有较多的有机溶剂抽出物,说明其耐腐蚀性也较强。总体上看,黄竹比龙竹的材料性能更好。  相似文献   

3.
云南4种典型材用丛生竹的化学成分   总被引:1,自引:0,他引:1  
对竹材的10种化学成分分析的结果认为:云南龙竹、甜龙竹、黄竹和油勒竹这4种典型材用丛生竹种间的化学成分无显著差异,且不因竹段位置不同而存在显著差异;4种丛生竹的各项抽提物含量、蜡含量和二氧化硅含量较一般木材高。表明:这4种丛生竹材的各部位都可作竹人造板,特别是重组型竹人造板的原料;但须从化学成分角度上考虑相应的工艺措施  相似文献   

4.
自1978年始,历时十年多次从广东、广西、福建、四川等丛生竹集生区引进丛生竹73种400余丛,进行存活力、冻害情况、出笋成竹能力、生长量及主物候期等引种指标的多年系统观察测定,并辅之以扩大栽培试验.综合考评结果表明,吊丝单、吊丝球、青皮竹,撑麻25号及本地绿竹在渐南地区较有推广和开发价值.  相似文献   

5.
选择我国重要经济竹种龙竹、云南甜龙竹、版纳甜龙竹和黄金碧玉竹4种大型丛生竹种,研究了这些竹种的发笋情况、笋高生长规律以及施肥对竹笋生长的影响。结果显示:4个竹种的竹笋形态均呈锥形,笋体颜色深浅不一,个体大小不一,龙竹笋体最大,黄金碧玉竹笋体最小;在相同环境条件下,黄金碧玉竹退笋率最低(17%),其他依次为版纳甜龙竹(19%)、云南甜龙竹(22%)、龙竹(25%);黄金碧玉竹的出笋期最长(222 d),其他依次为龙竹(170 d)、云南甜龙竹(153 d)、版纳甜龙竹(100 d);4个竹种的竹笋生长均呈现出慢—快—慢的生长规律,各竹种竹笋出土后30 d内高生长缓慢,30~80 d高生长较快,80 d以后高生长趋缓直至停止生长;4个竹种的竹笋生长与降雨量密切相关,年降雨量大的地区,竹笋的各项生长指标均表现最好;施肥能明显降低退笋率,延长发笋期,增加笋直径;不同肥料种类对竹笋生长的影响不同,各竹种均表现为施用尿素的竹笋生长效果最好,其次为施用复合肥,施用过磷酸钙的效果不明显。  相似文献   

6.
以长宁县硬头黄竹为研究对象,分别在龙头镇、竹海镇样地设置长度均为60 m,宽度为3 m、6 m、9 m皆伐带;3 m^6 m、6 m^9 m皆伐带间设置保留带,保留带宽度均为6 m;另外在样地附近设置一个6 m×60 m对照带。采用机械式带状皆伐1年后,通过调查和数据处理,分析其生长状况,显著性特征、生物量(地上部分)。结果表明:(1)两个样地中均发萌枝,且萌枝面积均为9 m皆伐带>6 m皆伐带>3 m皆伐带。从龙头镇来看,各皆伐带和保留带的发笋量均明显高于对照带,最大为6 m^9 m保留带,达到4 976±97株·hm-2;从竹海镇来看,3 m皆伐带、3 m^6 m保留带、6 m^9 m保留带发笋数高于对照带,6 m^9 m保留带发笋数最高,达到11583株·hm-2。(2)单因素方差分析(ANOVA)和多重比较表明,龙头镇和竹海镇竹笋平均胸径除6 m皆伐带和9 m皆伐带间差异不显著外(p>0.05),其他每个带之间差异均显著(p<0.05);龙头镇竹笋平均高除3m皆伐带和6m皆伐带之间、6 m皆伐带和9m皆伐带之间差异不显著外(p>0.05),其余各带之间差异均显著(p>0.05),竹海镇竹笋平均高除6 m皆伐带和9 m皆伐带之间差异不显著外(p>0.05),其余各带之间差异均显著(p<0.05)。(3)根据张鹏等在长宁县对硬头黄竹胸径与生物量拟合的指数回归模型,可以计算出经过带状皆伐改造试验后,龙头镇3 m^6 m保留带、 6 m^9 m保留带1 a生竹每公顷产量分别比对照提高了92.76%、175.21%。竹海镇3 m^6 m保留带、 6 m^9 m保留带1a生竹每公顷产量分别比对照提高了111.89%、161.58%。(4)通过本试验对该地硬头黄竹进行带状皆伐改造,发现6 m^9 m保留带竹林长势最好,生物量最高,改造效果最好。  相似文献   

7.
丛生竹高效育苗技术的研究   总被引:1,自引:0,他引:1  
通过对竹秆、竹节和竹枝高效育苗技术的系统研究,总结出丛生竹主要竹种经济实用的育苗方法。结果表明:正确选择苗圃地及母竹,用适当的植物生长调节剂处理,适时育苗,进行科学的抚育管理,可使育苗成活率由传统育苗方法的10%-20%提高到80%-95%,竹苗质量明显改善。造大成活率达90%以上,实现了高效育苗1hm^2,规模化造成350-900hm^2的目标。  相似文献   

8.
丛生竹的育苗包括播种育苗、埋节(秆)、竹枝扦插、分株、压条、埋蔸和组织培养等几种。其主要技术措施包括:①正确选择苗圃地;②细致整地、作床和土壤消毒;③合理施肥;④掌握育苗时间;⑤不同育苗方法的技术处理和幼苗管护。  相似文献   

9.
我国丛生竹资源价值评估及其生产力拓展   总被引:4,自引:0,他引:4  
分析了我国丛生竹资源的特点,利用现状和存在问题,然后提出了其利用价值评估,生产力拓展与开发策略。  相似文献   

10.
竹林资源属于生态经济型产业资源,丛生竹栽培利用是四川省竹林经营的特色与活力。借助国家"退耕还林工程"建设,引种推广的撑绿竹、麻竹,已深刻地影响到四川竹业资源基础,促成了竹材制浆造纸、笋竹、竹文化旅游的优势产业地位,相关的研究与推广实践推动了行业科技进步。  相似文献   

11.
选取日本落叶松为试验材料,开展不同树龄日本落叶松物理力学性质的比较研究.结果表明:43年生、30年生和17年生日本落叶松木材气干密度分别为0.607,0.567和0.507 g/cm3,气干体积干缩率分别为7.7%,7.7%和7.1%;全干到气干体积湿胀率分别为5.1%,4.9%和4.5%;抗弯弹性模量分别为17.527,16.775和12.510 GPa,抗弯强度分别为121.1,110.3和90.9 MPa,顺纹抗压强度分别为56.8,51.8和44.0 MPa.随着树龄增大,日本落叶松木材密度、顺纹抗压强度、抗弯强度和抗弯弹性模量等各项物理力学性能指标提高,差异干缩逐渐变小.日本落叶松木材的气干密度与抗弯弹性模量、抗弯强度、顺纹抗压强度呈线性正相关,相关系数分别为0.760,0.816和0.900.  相似文献   

12.
Effects of nanoclay (NC) on physical and mechanical properties of wood-plastic composite (WPC) were studied here. Virgin, recycled, and mixed (50/50% of virgin/recycled) polyvinyl chloride (PVC) were used as the matrix in the WPC. Specimens with three NC contents of 1.5%, 3%, and 5% were manufactured; they were then compared with control specimens. Totally, 12 treatments were manufactured. The physical and mechanical properties were measured in accordance with the ASTM standards. The highest properties were found in specimens made from virgin PVC. Addition of recycled PVC resulted in significant decrease in all properties. NC improved all physical and mechanical properties studied in the present research project; the highest properties were observed in specimens with 5% of NC content. The improvement in properties was as a result of formation of bonds between the hydroxyl groups of NC with the wood flour components. It was concluded that NC would significantly improve the properties in all the three PVC types of virgin, recycled, and mixed. From an industrial point of view, it was concluded that mixing virgin and recycled PVC can be recommended not only to decrease production costs, but also to partially solve the problem of PVC residue which are not bio-degradable.  相似文献   

13.
This study examines certain physical, mechanical, and anatomical characteristics of coconut palm wood. The results show a correlation between the anatomical characteristics and density as well as lengthwise compression. All properties (density, frequency of vascular bundles (VBs), and mechanical properties) increase with the transverse distance from the center of the trunk. The study also tests VBs from different radial sections of the coconut palm tree (Cocos nucifera) for diameter, ultimate tensile strength, and modulus of elasticity. The influence of the VBs on the overall properties of the wood is discussed.  相似文献   

14.
对江汉平原水杉、池杉、落羽杉人工林物理力学性能进行了研究,结果表明:落羽杉的密度和硬度最大;落羽杉、水杉、池杉的抗弯强度差异不大;水杉的弹性模量最大,约为落羽杉的2.3倍,落羽杉的弹性模量与池杉的比较接近。南北方向对水杉、池杉、落羽杉的密度、顺纹抗压强度在5%水平上差异均不显著,对池杉、水杉抗弯强度在5%水平上差异不显著,对落羽杉抗弯强度在1%水平上差异显著,对落羽杉、池杉的弹性模量在1%水平上差异显著,对水杉的弹性模量在5%水平上差异不显著。三杉南北面近树皮处木材的密度、抗弯强度、弹性模量、顺纹抗压强度均大于髓心处。对水杉、池杉、落羽杉物理力学性能比较研究,旨在为其培育及合理利用提供依据。  相似文献   

15.
杨村新无性系木材物理力学性质的研究   总被引:4,自引:0,他引:4  
研究了7个杨树新无性系和I-69杨的木材物理力学性质。结果表明,杨木新无性系的物理力学性质等主要指标均属于小至甚小级,无性系间物理力学性质差异显著,据此可用木材物理力学性质因子选育优良无性系。尽管新无性系的生长速度超过I-69杨,但由于其某些强度指标低于I-69杨,8年生的速生材尚不能完全替代11年生的I-69杨使用,因此不能作为建筑结构材使用。  相似文献   

16.
Wood modification, of which thermal modification is one of the best-known methods, offers possible improvement in wood properties without imposing undue strain on the environment. This study investigates improvement of the properties of heat-treated solid wood. Scots pine (Pinus sylvestris) was modified in two stages: impregnation with modifiers followed by heat treatment at different temperatures. The impregnation was done with water glass, melamine, silicone, and tall oil. The heat treatment was performed at the temperatures of 180°C and 212°C for three hours. The modified samples were analyzed using performance indicators and scanning electron microscope micrographs. The mechanical and physical properties were determined with water absorption, swelling, bending strength, and impact strength tests. All the modifiers penetrated better into sapwood than hardwood; however, there were significant differences in the impregnation behavior of the modifiers. As regards the effect of heat treatment, generally the moisture properties were improved and mechanical strengths impaired with increasing treatment temperature. In contrast to previous studies, the bending strength increased after melamine impregnation and mild heat treatment. It is concluded that the properties of impregnated wood can be enhanced by moderate heat treatment.  相似文献   

17.
以强化木地板、中密度纤维板、高密度纤维板、浸渍胶膜纸饰面人造板等5类人造板为试材,研究标准、模拟夏季、模拟冬季等不同温湿度平衡处理条件对上述人造板内结合强度、吸水厚度膨胀率和表面结合强度值等理化性能检测指标结果的影响。结果表明,高温高湿平衡处理使人造板的力学强度增加,吸水厚度膨胀率降低;低温低湿平衡处理使人造板力学强度降低,吸水厚度膨胀率增加;不同平衡处理条件下强化木地板吸水厚度膨胀率差异较大;对饰面板表面结合强度的影响大于素板。  相似文献   

18.
We studied the effects of nanoparticles of organo-silane(NOS) compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption(WA) and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix:the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.  相似文献   

19.
不同植被类型对沙地土壤理化性质的影响   总被引:3,自引:0,他引:3  
为探讨不同植被类型与沙地土壤理化性质的影响,对我国辽西北沙地不同植被类型下土壤容重、土壤养分、水分含量进行了测定和分析。结果表明:辽西北沙地8种典型植被类型土壤容重大小依次为荒草地〉油松纯林〉弃耕地〉樟子松林〉山杏林〉榆树疏林〉松杨混交林〉杨树纯林;沙地经过人工固定后土壤的养分含量发生了变化,土壤有机质含量和全氮含量有不同程度的提高,全磷、全钾则有不同程度的下降。在雨季,针叶树林地土壤含水量高于其他植被类型,农业弃耕地在7月份和10月份中土壤表层含水量较高,山杏林地在不同时期含水量均表现为最低。  相似文献   

20.
外生菌根菌对巨桉人工林土壤理化性质的影响   总被引:1,自引:0,他引:1  
该文调查了四川乐山沙湾、眉山丹棱巨桉人工林下外生菌根菌土,测定了土壤养分情况。结果表明:两地所采集的菌根土的理化指标与对照相比有明显变化,样地Ⅰ菌根土pH值显著高于对照土,有机质含量与对照相比并不显著,样地ⅡpH值显著低于对照,而有机质含量明显高于对照;两样地菌根土的全N、水解N、全P和有效P含量均显著高于对照;大孢硬皮马勃的菌根土全K含量与对照相比并不显著,彩色豆马勃和马勃状硬皮马勃的菌根土全K含量均显著低于对照(P〈0.05);样地Ⅰ菌根土速效K含量与对照差异不显著,样地Ⅱ菌根土速效K含量显著低于对照。由此可见,巨桉外生菌根真菌对提高巨桉人工林的土壤肥力,维护人工林地力具有一定作用。  相似文献   

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