Vibrational properties of Sitka spruce heat-treated in nitrogen gas

结晶度 材料科学 微晶 复合材料 剪切模量 结晶 切线模量 模数 杨氏模量 氮气 体积模量 矿物学 化学 有机化学 冶金
作者
Yoshitaka Kubojima,Takeshi Okano,Masamitsu Ohta
出处
期刊:Journal of Wood Science [Springer Science+Business Media]
卷期号:44 (1): 73-77 被引量:62
标识
DOI:10.1007/bf00521878
摘要

Sitka spruce (Picea sitchensis Carr.) wood was heated for 0.5–16.Oh at temperatures of 120°–200°C in nitrogen gas or air. The values for Young's modulus, shear modulus, and loss tangent were measured by free-free flexural vibration tests. X-ray diffractometry was carried out to estimate the crystallinity index and crystallite width. The results obtained are as follows: (1) Density decreased at higher temperatures and longer heating times. The specific Young's modulus, specific shear modulus, crystallinity index, and crystallite width increased during the initial stage and were constant after this stage at 120°C and 160°C, whereas they increased during the initial stage and decreased later when the temperature was high. Loss tangent in the longitudinal direction increased under all conditions, whereas that in the radial direction increased at 120°C and decreased at 160°C and 200°C. (2) From the relation between Young's modulus and moisture content, it can be safely said that Young's modulus is increased by the crystallization and the decrement in equilibrium moisture content, and that crystallization (rather than degradation) is predominant at the initial stage of the heat treatment, whereas the latter is predominant as the heating time increases. (3) It is implied that the specific Young's modulus, specific shear modulus, crystallinity index, and crystallite width decreased more in air than in nitrogen gas because of oxidation in air.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
刚刚
完美世界应助科研通管家采纳,获得10
1秒前
脑洞疼应助科研通管家采纳,获得30
1秒前
领导范儿应助科研通管家采纳,获得10
1秒前
香蕉觅云应助科研通管家采纳,获得10
1秒前
情怀应助bofu采纳,获得10
1秒前
华仔应助科研通管家采纳,获得10
1秒前
慕青应助科研通管家采纳,获得10
1秒前
大模型应助科研通管家采纳,获得10
1秒前
1秒前
1秒前
1秒前
1秒前
阔达靖琪发布了新的文献求助10
2秒前
蓑衣客应助猫南北采纳,获得50
2秒前
3秒前
3秒前
樊小胖完成签到,获得积分10
5秒前
丘比特应助糊涂的猎豹采纳,获得10
7秒前
8秒前
9秒前
10秒前
GEeZiii完成签到,获得积分10
11秒前
Hanayu完成签到 ,获得积分10
11秒前
imzmy发布了新的文献求助10
12秒前
在水一方应助含蓄康采纳,获得10
15秒前
bofu发布了新的文献求助10
18秒前
充电宝应助狂奔的蜗牛采纳,获得10
18秒前
philospipi完成签到,获得积分10
20秒前
yang发布了新的文献求助10
21秒前
21秒前
科目三应助该换手机采纳,获得10
22秒前
23秒前
24秒前
24秒前
bofu发布了新的文献求助10
24秒前
不甜完成签到,获得积分10
24秒前
包宇发布了新的文献求助10
27秒前
27秒前
27秒前
高分求助中
A new approach to the extrapolation of accelerated life test data 1000
Picture Books with Same-sex Parented Families: Unintentional Censorship 700
ACSM’s Guidelines for Exercise Testing and Prescription, 12th edition 500
Nucleophilic substitution in azasydnone-modified dinitroanisoles 500
不知道标题是什么 500
Indomethacinのヒトにおける経皮吸収 400
Phylogenetic study of the order Polydesmida (Myriapoda: Diplopoda) 370
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 3975722
求助须知:如何正确求助?哪些是违规求助? 3520056
关于积分的说明 11200719
捐赠科研通 3256455
什么是DOI,文献DOI怎么找? 1798271
邀请新用户注册赠送积分活动 877490
科研通“疑难数据库(出版商)”最低求助积分说明 806390