添加剂对聚氨酯仿木材料发泡效果的影响

研究了催化剂、发泡剂、稳定剂、阻燃剂、增强剂等主要添加剂对木粉增强聚氨酯仿木材料生产时发泡反应效果的影响.试验结果表明,A-33和PC-35两种催化剂对发泡工艺都具有显著影响;发泡剂HCFC-141b的用量对组合聚醚体系具有显著的降粘作用;泡沫稳定剂L-6950用量越大,泡孔越细,但用量过多反而易导致泡孔塌陷;复合阻燃剂TCEP与DMMP对组合聚醚体系具有较好的降黏效果;为保证组合聚醚体系黏度,木粉添加量和粒度应分别控制在7pphp左右和80～100目.     

竹材液化树脂发泡材料的性能与技术要求

根据生产性试验,对竹材液化树脂发泡材料及复合发泡材料的制备工艺进行修正和完善,并对其性能和技术要求进行探讨.分析结果表明:竹材液化树脂发泡材料及复合发泡材料的制备工艺成熟,可实现重复性生产;参考或借鉴相应的国家标准测试方法,可全面测试材料的性能;产品规格尺寸能够满足装配式建筑工程要求.     

竹材液化树脂发泡材料的性能测试及应用评价

对竹材液化树脂发泡材料及人造板覆面的复合发泡材料的性能进行测试.结果显示:树脂发泡材料的性能优良,表现密度为0.128 g/cm3,压缩强度为0.22 MPa,导热系数为0.032 W/(m·K),氧指数最小值为41.7.制成的水泥纤维板覆面复合发泡材料,隔声效果良好,隔声量为37 dB;竹帘板覆面复合发泡材料达到B1级难燃材料的要求,为市场提供一种全新的建筑墙体材料.     

室内大厅立体绿化的植物材料及基质的选择

以花叶蔓长春花、毛鹃、散尾葵、桃叶珊瑚为植物材料,"轻型营养基质"为栽培基质,营造了室内大厅3个楼层立体花坛,进行了4种植物在不同位置、不同的光照环境下成活率测定以及生长状况观察。结果表明:4种植物耐阴性大小顺序为:桃叶珊瑚,散尾葵毛鹃花叶蔓长春花,成为室内立体绿化的植物和基质选择的一个样本。     

竹材液化树脂发泡材料的降解性能和热老化性能评价

将竹材液化树脂发泡材料分别置于土壤微生物侵蚀、干(湿)热老化、氙光辐照条件下一定时间,采用热重、红外及电镜扫描法,对比分析处理前后材料的性能变化.结果表明,该材料易于被微生物降解;经干热、湿热老化处理后,材料的质量降低,压缩强度反而提升;经氙光辐照处理后,其质量和压缩强度下降.在实际应用中,该材料经覆面处理后,可作为芯材,用作建筑外墙保温材料.     

竹塑微发泡复合材料的制备及其性能的初步研究

竹塑微发泡复合材料是一种新型的环保材料,其产业化有利于资源综合利用和循环经济的发展.初步确定了竹塑微发泡复合材料产业化生产的配方、设备及工艺流程,并在此基础上制备了复合材料,测试了复合材料的物理力学性能.结果表明:本文采用的配方、设备及工艺流程是基本可行的,复合材料的有关性能指标均已达到相关标准的要求.该研究对竹塑微发泡复合材料的产业化生产具有一定的指导意义.     

竹材液化树脂发泡材料发泡工艺的研究

利用竹材液化产物树脂发泡,制备新型墙体材料。在已进行竹化液化和树脂化优化工艺试验的基础上,通过单因素试验,筛选出发泡剂为正戊烷;再通过正交试验,分析发泡剂、填料和固化剂等用量,对发泡材料表观密度和压缩强度的影响。在试验得出优化工艺的条件下,制得发泡材料的表观密度约0.14g/cm3,压缩强度达454.5kPa。     

小径竹液化制备轻质高强度墙体工程材料研究与示范取得重大科技创新成果

由浙江省林业科学研究院承担的省重大科技专项"小径竹液化发泡制备轻质高强度墙体工程材料研究与示范"日前通过项目验收。该项目历时3年,取得了重大科技创新成果。     

质量填充系数对竹材液化树脂发泡材料性能的影响

以苯酚和聚乙-醇-400为液化剂合成竹材液化树脂,并加入表面活性剂、固化剂、发泡剂、交联剂等,制备竹材液化树脂发泡材料,分析质量填充系数对发泡材料性能的影响.结果表明:质量填充系数从1.73增至2.73,发泡材料的压缩强度增强,热稳定性能良好,阻燃性能略有下降.当质量填充系数为2.27时,发泡材料的压缩强度为0.15 MPa,临界氧指数为31％,可满足外墙泡沫保温材料的性能要求.     

Microscopic structure and properties of wood-based foaming composites

In order to reduce the density of wood-based composites without causing a deterioration of their mechanical properties, we studied the process of manufacturing wood-based composites. A combination of polymer foaming technology and flat hot-pressing technology was used. The microscopic structure of the various wood-based composites was analyzed with a scanning electron microscope (SEM). Modulus of rupture (MOR), modulus of elasticity (MOE), impact strength, and thickness expansion rate of water sorption (TS) were all measured. The results showed that fibers loosely interweave, and fibers had been connected by micropore. They also showed that spaces between fibers had big micropore structure. MOR, MOE and impact strength were the highest among three levels of ratio. When the total content of resin and foaming agent were 20% by weight, TS was higher. A hot-pressing temperature of 120°C was optimal. At the low temperatures of 80°C, the foaming process was uncompleted. At a higher temperature, micropores burst at a certain pressure. Based on the variance analysis and maximum difference analysis, a significance test shows that the optimum conditions for the total content of resin and foaming agent is 20% by weight, with a hot pressing temperature of 120°C for 15 min. Under these conditions, the properties of wood-based foaming composites all achieved the industry standard. __________ Translated from Journal of Beijing Forestry University, 2007, 29(3): 154–158 [译自: 北京林业大学学报]     

不同轻基质配比对核桃楸容器苗根系形态和养分累积的影响

为探究不同轻基质组成和配比对核桃楸容器苗根系的影响,为核桃楸优质苗木培育提供依据,以当年生核桃楸幼苗为研究对象,选用泥炭土、蛭石、珍珠岩、废弃木耳菌棒和锯末进行不同比例组合,设置12种不同轻基质配比,比较不同处理下核桃楸幼苗根系发育和养分累积的差异.结果表明,S9(泥炭土︰珍珠岩︰木耳菌棒=3︰3︰4)处理下的土壤毛管...     

Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban Sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of ...     

薜荔及其生长的土壤营养元素含量特征

对城市垂直绿化和水土保持新材料——薜荔进行了研究,结果表明:(1)土壤pH值为4.61;有机质含量为33.23 g.kg-1;全N、全P含量分别为1.021、0.27 g.kg-1,且有效率低,分别为4.29%和3.15%;全K含量为4.26g.kg-1,属缺K型土壤;全Ca、全Mg含量分别为0.59、8.51 g.kg-1。(2)土壤微量元素含量依次排序为FeMnZnCuPbNiCoCd,全Pb、全Zn、全Cu含量均未超过我国土壤环境质量标准(GB15618-1995)中的3级标准,可以作为林地使用。(3)薜荔体内不同营养含量差异较大,N、K、Ca元素含量在10 g.kg-1以上,P、Mg、S元素含量在10g.kg-1以下;Fe、Mn元素含量在50 mg.kg-1以上,Cu、Zn、Pb、B元素含量为5~10 mg.kg-1,Cd、Ni、Co元素含量在10 mg.kg-1以下。(4)土壤有机碳含量为15.19~23.98 g.kg-1,薜荔体内有机碳含量为411.11~510.80 g.kg-1。研究结果可为薜荔的深入研究提供理论依据。     

优材更替生态公益林水土保持效益研究

以湖南省洞口县月溪国有林场生态公益林为研究对象,对其成熟林优材更替前后水土保持效益进行了研究.结果表明:1#更替模式(新造杉木纯林)和2#更替模式(新造杉木+樟树混交林)的地表径流量、泥沙流失量都比3#更替模式(CK,未砍伐杉木过熟林)大2～3倍;前者实施了挖穴造林,破坏了地表土壤结构,但水土流失系数没有超出允许浸蚀量...     

保定市不同绿地土壤动物群落与土壤理化性质的关系

对保定市4种绿地类型：苗圃绿地（Nursery Greenland）、道路绿地（Road Greenland）、防护林绿地（Shelterforest Greenland）、公园绿地（Park Greenland）中的土壤动物群落组成和数量进行了调查,并分析了4种绿地的环境要素与土壤动物群落的关系。结果表明：4种绿地类型中的土壤动物个体数表现为苗圃绿地（526头）〉公园绿地（431头）〉道路绿地（326头）〉防护林绿地（179头）,但土壤动物类群数相差不大。土壤理化性质对土壤动物的影响不同。土壤动物群落的个体数在一定范围内与土壤含水量的变化呈正相关关系;pH值对土壤动物的分布关系不密切;0～10cm土层和10～15cm土层的土壤动物的数量与有机质都呈正相关关系。     

Preparation of liquefied wood-based resins and their application in molding material

To investigate value in use of liquefied wood-based resin applications in molding material, Chinese fir （Cunninghamia lanceolata） and poplar （Populus tomentosa） wood meal were liquefied in phenol. The reactant was co-condensed with formaldehyde to obtain liquefied wood-based resin. For this paper, we investigated the characterization of the resin and its application in molding material. The result shows that the basic properties of liquefied wood-based resin were satisfactory; the bonding strength of plywood prepared with liquefied Chinese fir and liquefied poplar resin can reach 1.54 and 1.00 MPa, respectively. The compression strengths of the molding material prepared with two kinds of liquefied wood resin were 73.01 and 73.58 MPa, almost the same as that of PF resin molding material. The limiting volume swelling of molding material made with liquefied Chinese resin and liquefied poplar resin were 8.5% and 8.3%, thickness swelling rates of water absorption were 3.3% and 4.2%, and the maximum weight ratios of water absorption were 25.9% and 26.2%, respectively. The soil burial test result shows that the weight loss rate of the molding materials made with liquefied Chinese resin and liquefied poplar resin were 8.3% and 9.1% and that of the PF resin molding material was 7.9%. After the soil internment test, the reduction ratio of compression strength of the two kinds of molding material achieved 16.9% and 17.7%, while that of the PF resin molding material was 15.4%. The test results of wood fungi inoculation on the three surfaces of the molding material indicate the breeding rate of molding material prepared with liquefied Chinese resin and liquefied poplar resin were at level 4 and that of PF resin molding material was at level 1 of the ISO standard.     

Connection of growth and wood density with wood anatomy in downy birch grown in two different soil types

Soil affects the anatomy of downy birch wood (Betula pubescens), which raises the question whether the growth of this species differs between mineral and peat soils. The aim of this study was to compare growth, density and structure of xylem of B. pubescens between trees grown in different soils. Both growth and density differed between trees grown in different soils. All measured anatomical characteristics, except double thickness of fibre walls, percentage vessel area and ray number, showed differences between the soil types: the cell dimensions were larger and numbers smaller in trees grown in mineral soil. In peat, high growth rates decreased the wall:lumen ratio of fibres in maturing wood, while no such correlation was observed in trees grown in mineral soil at any studied cambial age. In addition, axial parenchyma may have a different role in trees grown in different soils, as the rapid growth decreased and increased axial parenchyma in mineral and peat soil, respectively. The characteristics affecting wood strength were more similar between trees grown in different soils than those affecting water conductance. The observed differences between trees grown in different soils emphasise rapid growth particularly at young ages and shorter reasonable rotation period in mineral soil.     

纳米纤维素基吸油气凝胶的制备及性能

以竹粉为原料制备纳米纤维素基体材料,以聚乙烯醇(PVA)为增强相,在酸性环境下采用冷冻干燥法制得PVA/CNFs(纳米纤维素)复合气凝胶;采用三甲基氯硅烷(TMCS)对其进行疏水改性处理,随后将其浸渍到还原氧化石墨烯(r GO)悬浮液中,最终制得疏水型r GO/PVA/CNFs复合气凝胶;通过扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、拉曼光谱(Raman)、接触角(CA)和吸油性能测试,对所制气凝胶的微观形貌、化学结构、疏水性能及吸油性能进行表征。结果表明:制得的复合气凝胶密度为6.78 mg/cm3,具有均匀的三维网状多孔结构,且孔洞结构表面均被石墨烯片层覆盖;经过TMCS疏水处理后,在气凝胶表面形成疏水层结构。FT-IR和Raman分析表明,TMCS疏水改性处理并未改变PVA/CNFs复合气凝胶的化学结构。经疏水处理后气凝胶与水的接触角为138°左右,吸油倍率为78 g/g左右,且吸附过程迅速,饱油后也能悬浮于溶液表面,便于回收再利用。     

晋北干旱区盐碱地柽柳形态特征及其与土壤养分的关系

【目的】研究困难立地植被地上和地下部分对环境胁迫的响应,探讨植物叶、根形态对不良环境的适应策略,是逆境生理生态学研究的有效途径,可为困难立地造林及管理提供科学依据。【方法】以30年生柽柳Tamarix chinensis人工纯林为研究对象,分析其比叶面积(SLA)、细根比根面积(SRA)和比根长(SRL),并对0~60 cm不同土壤层次的全N、全P、速效K、Na、Mg、Ca、Zn、Fe、Cu等营养元素进行含量测定,研究盐碱地植物柽柳地上及地下部分形态特征及其与盐碱地土壤养分垂直分布格局的相关性。【结果】1)在晋北干旱区重度盐碱胁迫下的柽柳SLA显著高于轻度和中度胁迫(F=3.301,P=0.041);SRA在重度盐碱胁迫下高于轻度和中度胁迫,与轻度胁迫差异显著(F=0.154,P=0.015);SRL在不同盐碱胁迫等级下无显著差异(F=0.808,P=0.632),但在重度盐碱胁迫下其值明显高于轻度和中度胁迫。2)土壤全N含量表现为浅层高于深层,且重度胁迫盐碱含量明显低于轻度胁迫,全P、Cu含量在不同盐碱胁迫及不同土壤深度差异均不显著,速效K、Fe含量在不同盐碱胁迫下表现出完全不同的分布格局,Na含量在不同盐碱胁迫下差异显著,Mg、Ca、Fe含量在15~60 cm土壤表现出重度盐碱胁迫高于轻度和中度盐碱胁迫土壤,Zn含量在不同盐碱胁迫间差异不显著。3)不同的土壤营养元素对柽柳叶、根形态特征的作用机制不同,土壤速效K与柽柳SLA、SRA和SRL均呈显著正相关关系(P<0.05),Zn与柽柳SRA、SRL呈显著负相关关系(P<0.05),土壤全P和Fe含量与SRL呈显著正相关关系(P<0.05),其中以30~45 cm土壤养分含量与柽柳形态特征的关系最为密切,此土壤深度全N含量与SLA、SRA和SRL均呈显著负相关关系(P=0.038,0.019,0.006)。【结论】研究结果可为树种立地适应性评价、该区域植被恢复以及生态环境改善提供理论参考。