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三聚氰胺浸渍纸是人造板行业用量最大的饰面材料之一。为拓展三聚氰胺浸渍纸边角废料的利用途径,以杂木刨花和回收的原态浸渍纸边角废料为原料制备复合刨花板。采用正交试验方案,探究了浸渍纸边角废料纸添加量、施胶量和热压参数等因素对板材物理力学性能的影响。结果表明:在三聚氰胺浸渍纸边角废料添加量为20%、脲醛树脂胶黏剂(UF)施胶量13%、热压温度190℃和热压时间9 min工艺条件下,制备的复合刨花板物理力学性能符合GB 4897—2015中P2型刨花板指标要求。 相似文献
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水泥刨花板快速固化工艺的初步研究 总被引:1,自引:0,他引:1
为缩短水泥刨花板的压制时间,提高生产效率,探讨了通过施加一种添加剂使得水泥刨花板快速固化的工艺。主要研究了快速压制工艺因素及其对制品性能的影响。结果表明,该法可大幅度降低水泥刨花板的压制时间,板材具有较高的脱模强度。 相似文献
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以废旧建筑模板和家具为原料,使用环保型无机胶黏剂制备刨花板。利用扫描电子显微镜(SEM)观察刨花板的微观形貌,同时利用量热仪、氧指数测定仪、同步热分析仪等评价板材的阻燃性及热稳定性。结果表明:当板材密度为0.95g/cm^3时,除24h吸水厚度膨胀率外,其余物理力学性能均符合国标中的P3型刨花板要求;SEM观察到无机胶黏剂包覆刨花,填充板材孔隙,使板材物理力学强度大幅提高;选择氯化镁为固化剂,当表层/芯层刨花的固化剂用量为4.5%/5.0%时,压制的密度为0.95g/cm^3的刨花板,其氧指数为31%,具有较好阻燃性能。 相似文献
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聚醋酸乙烯酯(PVAc)具有固化速度快、初粘性好的优点,可作为胶黏剂或增稠剂应用于人造板工业。研究以醋酸乙烯酯(VAc)为单体、聚乙烯醇(PVA)为保护胶体,采用半连续乳液聚合法制备低黏度、高固含量聚醋酸乙烯酯乳液,并考察了PVA种类及其他聚合工艺因素对乳液性能的影响。结果表明:PVA种类对乳液性能影响较大。采用激光粒度分析仪、差示扫描量热仪(DSC)等对不同种类PVA合成的乳液进行表征表明:粒径随PVA醇解度增加而明显增大;PVA聚合度对乳液的玻璃化转变温度(Tg)影响较大。以PVA0599为保护胶体制备的PVAc乳液作为木材胶黏剂时,其拉伸剪切强度达8.62 MPa。 相似文献
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研究了不同的阻燃剂及不同施加方法对刨花板阻燃性能的影响。试验结果表明:①单独使用硼系阻燃剂或磷-氮系阻燃剂(P-N),当其添加量在≤9刨花板的阻燃性会随着阻燃剂添加量的增加而提高。板也具有较好的物理力学性能。当阻燃剂的添加量>12%时,板阻燃性的提高不明显,板的物理力学性能却明显降低。②同样,当混合阻燃剂在适当的范围内,刨花板具有高的阻燃性和好的物理力学性能。③阻燃剂的添加方法对刨花板的阻燃性和物理力学性能也有一定的影响。本试验中添加方法1和2制的板具有好的阻燃性和高的物理力学性能。方法4的板具有较低的胶合性能是由于胶粘剂中的大分子阻燃剂影响脲醛树脂胶的胶合。 相似文献
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水泥刨花板用作内外墙板、隔墙板、地板、铁路或公路两旁的声屏障材料等正在逐步扩大。这种板材一般由水泥、木材刨花、粉煤灰以及各种添加剂制备而成,板材具有强度高、防火阻燃性好、耐水性和隔音保温性能好的特点。但为了保证水泥刨花板的强度以及物理力学性能等,通常要求粉煤灰的含钙量低于8%。 相似文献
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平面抗拉强度是衡量刨花板胶合力的一项重要指标。目前,国内测试这项指标按国标(GE4902—85)规定是用木卡头。胶粘试件和木卡头的胶粘剂多数是聚醋酸乙烯酯乳液胶(简称乳白胶或PVAC乳液)和动物蛋白胶。我们在试验中发现,用木卡头和乳白胶有一定弊端,影响测试的准确性和效率。1、测试准确性差。使用木卡头,每次测试后卡头需要重新刨切胶粘面以去掉残余 相似文献
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城市公园作为重要的生态系统 )具备雨洪管理的巨大潜力 )但在雨水资源利用方面还有待提升 。 以武汉市园林 科普公园为例 )对公园现状进行调查和分析 )对该园雨水利用潜力进行估算 )以此为基础 )提出了基于雨水利用潜力提升的 绿地提质设计思路 )以.渗、蓄、净,为主 )旨在从经济性、实用性和有效性多方面对城市公园绿地雨洪功能提质改造 )给予更 可具有实际意义的指导意见。 相似文献
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A new method of simultaneous determining Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography
was developed. The experiment condition was studied and the results show that the optimum base solution is that the residue
got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1.0 mol/L ammonia-ammonium chloride, 5.0
mL 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL with water. Under the condition of this base
solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution,
Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) in synthetic samples were determined with relative errors 0.4–9.4% and relative
standard deviations 0.8%-12.2%. Under this experiment condition, one fold of Pb(II), Cr(VI) and Mo(VI) do not interfere with
the determination for Cu(II). This method has been used to the simultaneous determination of the amount of the six cations
in the samples of soil and Beiqi Tea. The relative standard deviations were 0. l%-2.1% and recoveries were 93.5%-99.0 %. 相似文献
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An attempt was made to examine the possible connection between the various ratios of calcium/aluminum (Ca/Al) in the nutrient
solution of plant cultures and the active oxygen scavenging system of hinoki cypress (Chamaecyparis obtusa) seedlings. The hinoki cypress seedlings were transferred to nutrient solutions containing 5 mM AlCl3 together with various concentrations of Ca(NO3)2 in pots containing glass beads and Teflon tips. The activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase
(APX) and glutathione reductase (GR) in the needles were estimated at several stages during the 7-day treatment. The samples
treated with the lower Ca/Al solutions show the highest SOD activities. The activities of APX and GR, both of them involved
in the ascorbate-glutathione cycle, showed the same tendency with decrease to higher Ca/Al ratio. These results indicate that
rhizospheric Ca might compete with Al and ameliorate Al toxicity on and in the roots, the Al stress is not transformed to
the needles after a few days, and the ascorbate-glutathione cycle in the hinoki cypress needles might fluctuate and be suppressed
by the rhizospheric Al stress during the 7 days.
This work was supported in part by funding from the Japan Science & Technology Corporation, the CREST program 1996–2001, and
the Center for Forest Decline Studies. 相似文献
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应用灰色系统与方法,以松溪县渭田镇森林资源调查统计数据为基础,建立灰色预测GM(1,1)模型,对松溪县渭田镇森林资源主要指标(森林覆盖率、有林地面积、活立木蓄积量、用材林蓄积量、近成过熟林蓄积量)的发展趋势进行预测。预测结果经检验,预测精度好,可信度高,可为福建省松溪县渭田镇森林资源研究提供切实可靠的分析工具。 相似文献
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This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin
Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based
on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites,
a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect,
vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems.
The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.
Foundation item: This paper was supported by Chinese Academy of Sciences “100 people” project and the Open Research Station of Changbai Mountain
Forest Ecosystem.
Biography: XIAO Bao-ying (1974-), female, postgraduate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
P. R. China
Responsible editor: Zhu Hong 相似文献
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本文对乌鞘岭地区天然分布的中国沙棘和西藏沙棘果实生长与成熟期间维生素C,PP,E等含量的动态变化进行了系统的调查和分析测定。结果表明:V_C主要存在于果肉中,且随果实发育而增加,果实变色期(花后107—110天)达到最高值,随后急速下降。但完熟后果肉中V_C减少时种子内V_C却有所增加。中国沙棘V_C水平远较西藏沙棘为高(5倍以上)。果实发育前期果肉中V_(PP)含量很高,以后逐渐下降,完熟期中国沙棘果实内V_(PP)再度升高,其变化与呼吸速率的变化表现出相同的消长规律。V_E主要存在于种子里,总趋势是随成熟而增加。种子变色期V_E上升至第一高峰值,随后下降,果实完熟后达到第二高峰值。西藏沙棘V_E含量高于中国沙棘。本文对不同维生素可能起的生理作用也进行了讨论。 相似文献
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中国西南干旱河谷区植物多样性边界影响域的两种判定方法 总被引:4,自引:0,他引:4
研究了中国西南岷江上游干旱河谷区不同类型景观边界的影响域.共选取三种类型的边界.以植物多样性为基础,分别采用主成分分析法和移动窗口法对边界的影响域进行分析.结果表明, 5条样带中,主成分分析法可以判定3条样带的影响域,而移动窗口法可以判定4条.两种方法均可判定边界的影响域,并且影响域均在距边界50m内.在林地样带两种方法可以得出相似的结论,但在花椒地样带中所得结论不一致.两种方法比较,移动窗口法更成功些.虽然两种方法各有利弊,但它们都是刻画边界动态的有力工具. 相似文献