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101.
基于Web木材营销系统的设计与实现 总被引:1,自引:0,他引:1
本文从系统分析、系统实现和系统安全几个方面阐述了建立Web木材营销系统的过程。 相似文献
102.
Ernst L. Back 《Journal of Wood Science》2002,48(3):167-170
There is a general pattern of resin chemistry for parenchyma cells and secretory tissue. In sapwood the parenchyma resin is composed of fats, steryl esters, and occasionally waxes. Secretory tissue (most often resin canals) contains terpenes, terpenoids, and polyisoprenes. Other types of canal resin occur in a few hardwood families. The pattern is valid for softwoods and hardwoods. It has been defined from a comparison of available information on wood chemistry, wood anatomy, and the chemistry of oleoresin exudates from trees. This is a short overview with the most important references of two detailed reports. 相似文献
103.
主要综述了季铵盐类化合物(QAC)在用作木材防腐剂时的耐腐性、抗流失性及其与木材的结合机理等方面的研究概况,分析了实验室耐腐性和野外实验耐腐性结果不一致的原因。此外也介绍了对季铵盐进行改性处理方面的一些研究进展。 相似文献
104.
本文简要阐述了新型木材防腐剂百菌清(chlorothalonil)制剂防止木材霉菌、变色菌、木腐菌、土栖白蚁的研究近况,并对我国将来开展百菌清的研究提出了建议好的有以下几种制剂:0.50%百菌清+0.50%DDAC、1.0%百菌清乳剂,0.50%百菌清+0.10%IPBC等,防变色菌效果与1.0%五氯酚钠(NaPCP)相当[5]。2防止木腐菌2.1单一百菌清制剂对木腐菌(P.gigantea,A.vailanti等)防止效果较好的是1.0%百菌清乳剂,其次是1.0%百菌清可湿性粉剂、0.50%百菌清乳剂、0.50%百菌清+0.50%DDAC、0.50%百菌清+0.10%DITS[5]。百菌清防止木材6种褐腐菌及5种白腐菌的效果与PCP及CCA-C进行了比较;对Neolentinuslepi-deus,Trametesverscolor菌种,百菌清的抑制效果不及PCP;对Irpexlacteus,Trameteshispida菌种,百菌清的抑制效果较PCP好;对其它菌种,百菌清的抑制效果与PCP相当。对Gloeophylumtrabeum、Postiaplacenta、Coniophoraputeana、Se 相似文献
105.
DNA was extracted from wood samples of six representativeCyclobalanopsis species (Fagaceae) growing in Japan that cannot be distinguished from one another by conventional microscopy. A part of the intergenic spacer region betweentrnT andtrnT 5 exon was amplified and sequenced. The sequences obtained from wood samples were grouped into three DNA types by a single nucleotide polymorphism as reported previously in leaf samples: I (Quercus acuta, Q. sessilifolia, Q. salicina), II (Q. myrsinaefolia, Q. glauca), and III (Q. gilva). Thus,Q. gilva can be distinguished from the otherQuercus species, and the others are separated in two subgroups based on DNA polymorphism. The present findings support the possibility of wood identification based on DNA polymorphism. 相似文献
106.
湿地松与马尾松人工林木材物理力学性质的比较研究 总被引:2,自引:0,他引:2
庄奇 《中南林业调查规划》2004,23(2):58-59
通过对湿地松和马尾松人工林木材物理力学性质的测定和比较分析,结果表明:湿地松人工林木材密度、干缩系数和除冲击韧性以外的力学强度均稍大于马尾松人工林木材,而冲击韧性则恰恰相反.经差异显著性t检验表明:湿地松和马尾松木材物理力学性质指标中顺纹抗压强度、抗弯强度、弦面顺纹抗剪强度和冲击韧性差异极显著,气干密度、基本密度、径面顺纹抗剪强度和端面硬度差异显著,除此之外的其余指标差异不显著. 相似文献
107.
108.
木质复合材料研究概况 总被引:4,自引:0,他引:4
新型木质复合材料可缓解由于我国现有林木资源总量不足和森林资源质量不高而形成的资源危机,所以木质复合材料将是新世纪人们关注和研究的重点领域。 相似文献
109.
Shigeru Yamauchi Yoichi Sakai Yasuo Watanabe Michael Kenya Kubo Hideaki Matsue 《Journal of Wood Science》2007,53(4):324-331
The distributions of boron in Japanese cedar (Cryptomeria japonica D. Don) sapwood blocks treated with aqueous or methanolic boric acid [B(OH)3] solutions were explored through Raman spectroscopy and prompt gamma-ray analysis (PGA). B(OH)3 was the sole boron species observed in Raman spectra of the wood blocks treated with either solution. Plots of weight gain
of the treated wood blocks versus boron concentration in treatment solutions were found to be linear. The results indicated
that the methanolic solution makes it possible to impregnate wood with much larger amounts of boron than the aqueous solution.
PGA confirmed that B(OH)3 was highly enriched near the end grains of the treated wood blocks. Raman measurements suggested that boron content in the
bulk of the wood block is not as large as expected from the weight gain of the treated wood blocks when an ordinary air-drying
method is used. It was concluded that the aqueous solution impregnates the cell walls of wood with boron more easily than
the methanolic solution.
Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan
Wood Research Society. This article follows the previous rapid communication “Analysis of boron in wood treated with boric
acid solutions using Doppler broadening method of prompt gamma-rays.” J Wood Sci (2006) 52:279–281 相似文献
110.
Shang Deku 《林业研究》1990,1(1):79-85
An analogy between water flux and the field of temperature gradient in a column of wood fuel chips was discovered by these
experiments. The heat—mass transfer coefficient was determined by least squares method. An equation relating water flux and
temperature gradient was developed and it was demonstrated that the temperature gradient was the main driving force for water
transport. The mechanism was evaporation—condensation of water vapor through natural convection in air phase. The study gives
a theoretical explanation for analyzing the problem of water transport in wood particle material. 相似文献