Adsorption of mercury by sugi wood carbonized at 1000°C     

Lilibeth Pulido-Novicio  Yasuji Kurimoto  Masakazu Aoyama  Kazuto Seki  Shuichi Doi  Toshimitsu Hata  Shigehisa Ishihara  Yuji Imamura 《Journal of Wood Science》2001,47(2):159-162

The ability of sugi wood carbonized at 1000°C to adsorb mercury was examined using aqueous solutions of mercuric chloride. Parameters studied include contact time, pH, adsorption temperature, and initial concentration of mercury in solution. Results showed that sugi wood carbonized at 1000°C could effectively remove mercury from aqueous solutions. The carbonized wood showed high adsorption ability for mercury at a wide pH range (pH 3–9), but its ability drastically decreased at pH 11. Adsorption decreased with increases in adsorption temperatures, indicating that the processes were exothermic in nature. Adsorption was found to follow the Freundlich isotherm model. The adsorption capacity of carbonized sugi wood was comparable to that of commercial activated carbon.  相似文献   

Erratum to: Mechanical properties of wood in an unstable state due to temperature changes,and analysis of the relevant mechanism III: Effect of quenching on stress relaxation of chemically modified woods     

Yue Wang  Kazuya Minato  Ikuho Iida 《Journal of Wood Science》2007,53(2):178-99

In order to understand the mechanism of destabilization occurring when wood is quenched, we applied chemical modifications, and controlled the number of moisture adsorption sites in wood. The degree of destabilization was evaluated according to the fluidity (1-E _t/E ₀), increase in fluidity, and relative fluidity in relation to the nonmodified wood, and was discussed by comparing these quantities with the hygroscopicity or swelling of wood. We found that destabilization of chemically modified wood was lower than that in nonmodified wood, and the amount of adsorbed water controlled the magnitude of flow of wood. Moreover, according to the analysis of water state by the Hailwood-Horrobin equation, it was shown that the function of dissolved water to the fluidity is almost identical for both chemical modifications, whereas hydrated water has more effect on acetylated wood than on formaldehydetreated wood. We speculate that the motion of water molecules due to quenching accompanied with the redistribution of energy resulting from the exchange of their potential energy and movement to attain a new balance, and the introduced acetyl groups and cross-linking restrict the water molecule movement. An erratum to this article is available at .  相似文献   

三通道刨花干燥机刨花干燥过程自动控制系统初探     

王志同 《木材工业》1993,7(2):23-28,50

文中对三通道刨花干燥机刨花干燥中被控对象的特性、过程控制的方法、检测仪表、调节控制器与调速系统进行了探索与研究。干燥机的热效率高、刨花终含水率均匀、形态好。  相似文献   

竹单板锯制工艺技术     

李黎  杨永福  郭建方 《竹子研究汇刊》2003,22(4):49-55

该文介绍了竹单板的锯制工艺技术、以及锯制竹单板的设备——小型精密框锯机的基本结构、传动系统等，比较了锯制工艺加工方法与其他加工方法的优缺点后，认为以复合竹集成材为基材、应用精密框锯机锯制技术生产竹单板是一种比较理想的工艺方法，它既简化了工艺程序、提高了单板质量，又降低了原料消耗、提高了竹材工业化加工的利用率。  相似文献   

Preliminary Accounting on Economic Value of Bamboo Resource in China     

LI Zhongkui LI ZhiyongInstitute of Forestrv Policy  Information Chinese Academy of Forestry. Beiiine. P.R. China 《中国林业科技(英文版)》2003,(4)

The current area of bamboo resource in China is 7.21 million ha, 4.21 million ha of which is the pure bamboo forest The stock value of the bamboo resource is 30.312 billion Renminbi (RMB) yuan, the present value of actual output from bamboo wood and shoot is 149.062 billion RMB yuan. The bamboo forest land is valuated as much as 8.133 billion RMB yuan. It is raised to improve the production and management conditions of the 2nd and 3rd type bamboo forests to raise production capacity of wood and shoot and output of processed products from bamboo.  相似文献   

美洲黑杨×青杨F₂代基本材性性状遗传变异研究   总被引：4，自引：0，他引：4       下载免费PDF全文

黄秦军  苏晓华 《林业科学研究》2003,16(2):141-145

利用美洲黑杨×青杨杂交三代谱系探索了木材密度、纤维长、纤维宽、纤维长宽比和微纤丝角等性状的遗传变异规律.结果表明基本密度与纤维长受主基因的控制,表现为"质量- 数量性状",其杂种优势明显且在F  相似文献   

Physical and mechanical properties of wood after moisture conditioning   总被引：1，自引：0，他引：1  

Yutaka Ishimaru  Kazutoshi Arai  Masato Mizutani  Katsuhito Oshima  Ikuho Iida 《Journal of Wood Science》2001,47(3):185-191

Some properties of wood (hinoki:Chamaecyparis obtusa) moisture-conditioned by an adsorption process from a dry state and by two desorption processes (from a water-saturated state and from a state with a moisture content slightly below the fiber saturation point) were investigated. The moisture contents of wood conditioned by the adsorption process and by the desorption process continued to approach to one another for the moisture-conditioning period of over 50 weeks. Accordingly, sorption hysteresis should be regarded as a transitional phenomenon that occurs during the process of approaching the true equilibrium, which requires a long time. The wood conditioned by the desorption process beginning from a water-saturated state showed slightly smaller dimensions than those conditioned by the adsorption process with the same moisture content; however, the wood conditioned by the desorption process from a moisture content below the fiber saturation point showed slightly larger dimensions than those conditioned by the adsorption process. The wood conditioned by the adsorption process from a dry state showed a higher modulus of elasticity and modulus of rupture than did the wood conditioned from a water-saturated state with the same moisture content. The mechanical properties of the wood also varied based on the states at which the desorption process was started. This is a notable characteristic of the relation between the drying condition and the mechanical properties of wood.  相似文献   

栽培措施对短周期工业材材性影响规律的研究     

方文彬  徐永吉  罗建举 《中南林业科技大学学报(自然科学版)》1997,(4)

对4种不同栽培措施的日本落叶松、湿地松、马尾松和杉木等多种短周期工业材309株样木的材性进行了全面测试分析研究，结果表明．立地指数大，木材生长率和纤维宽度大．但纤维长度、纤维长宽比、木材基本密度、顺纹抗压强度和抗弯弹性模量减小；立地指数相差两级，木材的年龄宽度、纤维宽度、长度和微纤线角度的差异达到显著或极显著水平栽植密度小，木材的年轮宽度和干缩比增大但纤维长宽比及体积全干缩率减小；栽植密度增大，杉木和昭林6号杨木材的力学强度提高，但尾叶桉和I－69杨降低；不同栽植密度的木材pH值及酸碱总缓冲容量，都是心材大于边材，但木材的脲醛树脂胶凝速度，则是边材快于心材.与未间伐林分的木材比较，随着间伐强度的增大、年轮宽度增大．但纤维长宽比和微纤丝角度减小；间伐强度增大，针叶树村的力学强度降低，阔叶树树则提高．但将强度间伐材（间代40％）与未间伐材比较，结果完全相反；北京杨木材心材的pH值、酸碱缓冲容量及总容量，均随间伐强度的增大而增大，但边材却减小．施肥措施能够增大纤维直径，但将导致纤维长宽比、木材密度和力学强度的降低施肥可以使树木速生，但会降低木材密度和质量，在培育建筑结构材的林分应慎用．  相似文献   

Abrasive wear properties of compressed sugi wood     

Tadashi Ohtani  Akira Inoue  Chiaki Tanaka 《Journal of Wood Science》2002,48(6):473-478

We examined the abrasive wear properties and the effect of abrasive grain size on the rate of wear when sugi wood (Cryptomeria japonica D.Don), compressed to various densities, was rubbed with abrasive paper. The results showed that the wear resistance of compressed wood increased linearly with the increased compression ratio; and under the condition of a low compression ratio it tended to be higher in comparison with the strength of compressed wood. The critical grain size effect, which can be witnessed during the abrasive wear of metals and plastics, was seen when low pressure was applied to the abrasive material. At higher pressures, the wear rate of the compressed wood increased with grain size, but the critical grain size effect was not observed. The pressure required to create the critical grain size effect was found to be higher than that needed for other types of uncompressed wood with the same yield properties.Part of this report was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000  相似文献   

橡胶木制造薄片刨花板的研究     

余德新  赵悦藩 《木材工业》1991,5(4):12-16

本文论述了橡胶木小径材和枝桠材制造薄片刨花板的可行性,并通过正交试验对脲醛胶刨花板制造工艺进行了优化选择,同时也对酚醛树脂胶粘剂制造薄片刨花板和薄型刨花板进行了探索。试验表明,橡胶木可以制造出质地良好的刨花板。  相似文献