白橡锯材热压干燥特性与工艺研究
作者：
谢杰;谭宏伟;郝晓峰;李贤军;熊幸阳
期刊：
林产工业 ,2018年45(2):44-48 ISSN：1001-5299
作者机构：
中南林业科技大学材料科学与工程学院;[李贤军; 谭宏伟; 郝晓峰; 熊幸阳; 谢杰] 中南林业科技大学
关键词：
热压干燥;白橡木;干燥缺陷;色差;尺寸稳定性
摘要：
以白橡锯材为研究对象,采用热压机对其进行热压干燥处理,系统研究了热压温度、热压压力和试件宽度等因素对白橡木材干燥特性、颜色、吸湿性和尺寸稳定性的影响规律,获得了优化的热压干燥工艺.研究结果表明:采用热压干燥法可以实现白橡木的快速高效干燥,随着热压温度的升高,木材干燥速度显著加快,颜色逐渐加深,热压压力和试件宽度对干燥速率和颜色的影响不明显;热压干燥可以显著减小白橡木材的平衡含水率(EMC)和湿胀率,提高其尺寸稳定性,且随着热压温度的升高,白橡木材EMC和湿胀率降低,热压压力和试件宽度对木材EMC和湿胀率无明显影响;与对照材相比,热压干燥白橡木材的EMC降低9.97％～33.67％,径向和弦向湿胀率分别降低8.54％～33.96％、11.26％～30.02％;白橡木材的优化热压干燥条件为:热压温度为140～150℃,热压压力为0.1 MPa,板材宽度为自然宽.
语种：
中文
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Investigation of drying characteristics in superheated steam drying of UF-impregnated Chinese fir
作者：
Li, Yun* ;Li, Xianjun;Quan, Peng;Cheng, Xiyi;He, Xia;...
期刊：
European Journal of Wood and Wood Products ,2018年76(2):583-589 ISSN：0018-3768
通讯作者：
Li, Yun
作者机构：
[Quan, Peng; Li, Yun; He, Xia; Cheng, Xiyi; Li, Xianjun] Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha 410004, Hunan, Peoples R China.;[Mou, Qunying] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, Yun] C;Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha 410004, Hunan, Peoples R China.
摘要：
Urea formaldehyde (UF) resin-impregnated Chinese fir (Cunninghamia lanceolata (Lamb.)Hook.) was dried at different temperatures in an atmospheric pressure superheated steam dryer. Drying characteristics, moisture content, drying rate, temperature profile, drying defects, and color change were investigated. The moisture content was reduced from 66.21 to 11.79% within 30h without causing severe drying defects; in contrast, the conventional hot air process required 7–8 days. After 25h of drying, the temperatures at both the center and the surface of wood remained stable. After 34.5h, the surface temperature gradually approached the steam temperature. The color of the superheated steam dried Chinese fir appeared slightly more intense yellow and red than the control. Investigation of the UF-impregnated Chinese fir wood by scanning electron microscopy (SEM) revealed that themajority of the lumens and voids, including the microvoids in wood structure, was filled with urea formaldehyde resin. © 2017, The Author(s).
语种：
英文
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Facile Synthesis of Highly Dispersed Ag Doped Graphene Oxide/Titanate Nanotubes as a Visible Light Photocatalytic Membrane for Water Treatment
作者：
Liu, Gonggang;Han, Kai;Zhou, Yonghua;Ye, Hongqi;Zhang, Xiang;...
期刊：
ACS SUSTAINABLE CHEMISTRY & ENGINEERING ,2018年6(5):6256-6263 ISSN：2168-0485
通讯作者：
Hu, Jinbo;Li, Xianjun
作者机构：
[Hu, Jinbo; Li, Xianjun; Hu, JB; Li, XJ; Liu, Gonggang; Zhang, Xiang] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Ye, Hongqi; Han, Kai; Zhou, Yonghua] Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;[Hu, Jinbo; Li, Xianjun; Hu, JB; Li, XJ] Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Hu, JB; Li, XJ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, Changsha 410004, Hunan, Peoples R China.
关键词：
Graphene oxide membranes;Membrane fouling;Visible light;Photocatalytic degradation;Ag;Titanate nanotubes
摘要：
Graphene oxide (GO) membranes have attracted extensive interest due to their ultrathin thickness, high flux, pore size tunability, superior flexibility, and energy-efficient properties for transporting ions and molecules through the unique 2D channels. Nevertheless, membrane fouling leading to membrane blocking and poor water flux of GO membranes during long-term use are major obstacles for water treatment or desalination applications. In this work, Ag doped GO/titanate nanotube (Ag/GO/TNT) membranes with enhanced visible light degradation ability were fabricated by a single-step procedure to resolve the fouling problem via integration of photocatalysis with membrane filtration. The results show that the Ag nanoparticles could be highly dispersed on the surface of GO and TNTs. And, the as-prepared Ag/GO/TNT membranes exhibited reasonable ability on photocatalytic degradation of Methylene Blue under visible light. We found that 90% of MB could be effectively degraded after 120 min irradiation with 8 mg of photocatalyst. More importantly, the membrane fouling could be effectively alleviated with visible light irradiation. In coupling the photocatalysis and membrane separation processes, the flux of Ag/GO/TNT membranes with the GO and TNT ratio at 1:3 and Ag content of 6% could be maintained at 34.7 L/m2 h which doubles that of membrane filtration without visible light irradiation. In addition, Ag/GO/TNT membranes possess high acid-alkali resistance stability and good compressive strength. These results have provided a simple preparation strategy to obtain highly dispersed nanoparticles and valuable insight into endowing membranes with visible light degradation ability for solving the problem of GO based membrane fouling. © 2018 American Chemical Society.
语种：
英文
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浸渍后处理及干燥处理对木材树脂浸渍改性效果的影响
作者：
徐康;吕建雄;刘君良;吴义强;李贤军
期刊：
林业科学 ,2018年54(4):84-92 ISSN：1001-7488
通讯作者：
Lü, J.
作者机构：
[徐康; 吕建雄; 刘君良] 中国林业科学研究院木材工业研究所;[徐康] 浙江省林业科学研究院;[吕建雄; 吴义强; 李贤军] 中南林业科技大学材料科学与工程学院;[吕建雄; 吴义强; 李贤军] 中南林业科技大学
关键词：
低分子质量树脂;扩散;水溶性;增重率;尺寸稳定性
摘要：
【目的】探讨不同浸渍后处理方式和干燥方式对MUF树脂浸渍材增重率和尺寸稳定性的影响,为树脂浸渍改性技术提供参考和借鉴。【方法】利用5%、10%、15%和25%浓度的MUF树脂真空加压浸渍毛白杨木材,每种浓度树脂浸渍后试样首先分别进行4种方式浸渍后处理(气干处理7天、高湿度环境中平衡处理7天、树脂溶液中平衡处理7天以及不进行气干或平衡处理) ,然后分别利用2种干燥方式(直接干燥和湿干燥)进行干燥处理,干燥处理后测量不同处理条件下树脂浸渍材的增重率和容胀率,最后将素材和树脂浸渍材置于蒸馏水中常压浸渍14天,测试树脂浸渍材的抗胀率和径弦向差异湿胀程度。【结果】木材增重率与树脂浓度呈正相关关系,4种浓度树脂浸渍后试样增重率分别为9.7%、19.1%、28.4%和50.0%;不同浸渍后处理试样间的增重率差别不大;相同浸渍后处理条件下,直接干燥试样的增重率略低于湿干燥试样的增重率。树脂浸渍后,置于高湿度环境或树脂溶液中处理的试样,细胞壁容胀率较高;相同浸渍后处理条件下(除气干处理外) ,直接干燥试样的细胞壁容胀率低于湿干燥试样的细胞壁容胀率。树脂浸渍材抗胀率的变化规律与其细胞壁容胀率的变化规律基本一致。随着增重率增加,树脂浸渍材的径弦向湿胀率均降低,而其径弦向差异湿胀程度呈增加趋势,低增重率时试样的径弦向差异湿胀程度低于素材,而增重率超过30%左右时试样的径弦向差异湿胀程度高于素材。【结论】1)相同浓度树脂浸渍条件下,干燥方式对增重率的影响大于浸渍后处理方式,湿干燥处理有利于树脂在木材内部良好固着,从而获得更高的增重率; 2)细胞壁容胀率受浸渍后处理方式和干燥方式二者的共同影响,置于高湿度环境或树脂溶液中的浸渍后处理有利于树脂继续扩散到木材细胞壁,湿干燥处理有利于树脂进一步扩散到木材细胞壁中并良好固着,从而对细胞壁产生更好的容胀效应; 3)树脂浸渍材的抗胀率与细胞壁容胀率密切相关,树脂对细胞壁的容胀是树脂浸渍材尺寸稳定性提高的前提; 4)树脂浸渍材的径弦向差异湿胀程度随增重率增加而有所增加。
语种：
中文
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高温热处理对杨木PF浸渍材尺寸稳定性的影响
作者：
徐康;吕建雄;李贤军;吴义强
作者机构：
中国林业科学研究院木材工业研究所 北京100091;中南林业科技大学材料科学与工程学院 长沙410004
会议名称：
第六届全国生物质材料科学与技术学术研讨会
会议时间：
20151018
会议地点：
南京
会议论文集名称：
第六届全国生物质材料科学与技术学术研讨会论文集
关键词：
杨木材;浸渍工艺;酚醛树脂;热处理;尺寸稳定性;吸水性;吸水膨胀率;吸湿含水率
摘要：
为研究高温热处理对杨木PF浸渍材尺寸稳定性的影响,对速生杨木素材和PF浸渍材进行高温热处理,系统研究杨木素材、PF浸渍材、热处理材和PF浸渍-热处理材的吸水性、线性(径向和弦向)和体积吸水膨胀率、吸湿含水率.结果表明:高温热处理可显著降低材料的吸水性、吸水膨胀率、吸湿含水率,提高尺寸稳定性.相比于素材,浸水8d后,PF浸渍材吸水量降低了17.37％,热处理材最高降低了63.8％,PF浸渍-热处理材最高降低了74.7％;PF浸渍材径向、弦向及体积吸水膨胀率分别降低14.71％、36.93％、30.19％,热处理材最高分别降低了64.99％、74.94％、72.33,PF浸渍-热处理材最高分别降低94.4％、90.61％、91.37％;PF浸渍材吸湿含水率降低了11.14％,热处理材最高降低了55.57％,PF浸渍-热处理材最高降低了60.62％.相同热处理条件下,PF浸渍-热处理材尺寸稳定性更优异.红外光谱图中,PF浸渍材羟基、羰基和羧基吸收峰减弱、苯环碳骨架振动加强,热处理后羟基和乙酰基吸收峰减弱,表明PF浸渍处理和热处理对木材亲水性基团的减少和尺寸稳定性提高均有贡献.
语种：
中文
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Recent Progress in Flexible Fibrous Batteries
作者：
Xi, Zhaowei;Zhang, Xiang;Ma, Yuansheng;Zhou, Cui;Yang, Jing;...
期刊：
ChemElectroChem ,2018年5(21):3127-3137 ISSN：2196-0216
通讯作者：
Luo, Yongfeng;Chen, Daoyong
作者机构：
[Zhou, Cui; Luo, Yongfeng; Chen, Daoyong; Xi, Zhaowei; Wu, Yiqiang; Ma, Yuansheng; Yang, Jing; Li, Xianjun; Zhang, Xiang] Cent South Univ Forestry & Technol, Mat Sci & Engn Sch, Coll Sci, Changsha 410004, Hunan, Peoples R China.;[Xi, Zhaowei; Luo, Yongfeng] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Guangdong, Peoples R China.;[Luo, Yongfeng; Chen, Daoyong] Fudan Univ, Dept Macromol Sci, State Key Lab Mol Engn Polymers, Shanghai 200433, Peoples R China.
通讯机构：
[Luo, YF; Chen, DY] C;[Luo, Yongfeng; Luo, YF; Chen, DY] F;Cent South Univ Forestry & Technol, Mat Sci & Engn Sch, Coll Sci, Changsha 410004, Hunan, Peoples R China.;Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Guangdong, Peoples R China.;Fudan Univ, Dept Macromol Sci, State Key Lab Mol Engn Polymers, Shanghai 200433, Peoples R China.
关键词：
flexible fibrous batteries;lithium-ion batteries;metal-air batteries;lithium-sulfur batteries;wearable devices
摘要：
Flexible fibrous batteries have attracted unprecedented attention, owing to the development of wearable electronic devices, which have the advantages of flexibility, weavability, and miniaturization compared with conventional bulky batteries. In this Minireview, we summarize the latest developments in flexible fibrous batteries, including lithium-ion batteries, lithium–sulfur batteries, sodium-ion batteries, and so forth. We also discuss the future directions and challenges of flexible fibrous batteries. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
语种：
英文
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三聚氰胺/纳米TiO2联合改性脲醛树脂胶粘剂研究
作者：
刘文杰;刘明;李新功;李贤军;吴义强;...
期刊：
中国胶粘剂 ,2018年27(10):10-14 ISSN：1004-2849
作者机构：
中南林业科技大学材料科学与工程学院,湖南长沙,410004;[李贤军; 卿彦; 刘文杰; 吴义强; 李新功; 刘明; 左迎峰] 中南林业科技大学
关键词：
三聚氰胺;纳米TiO2;脲醛树脂;游离甲醛;热性能
摘要：
以甲醛、尿素为原料,纳米TiO2和三聚氰胺为改性剂,采用“碱-酸-碱”的合成工艺合成脲醛树脂,并对三聚氰胺/纳米TiO2联合改性脲醛树脂工艺进行优化。研究结果表明：当纳米TiO2用量不变,脲醛树脂的黏度、固含量、胶合强度随三聚氰胺加入量增加而增大,而固化时间和游离甲醛含量则呈现出相反的变化趋势;添加w（三聚氰胺）=1.5%（相对于尿素添加质量而言）改性后的脲醛树脂游离甲醛含量为0.41%,耐水胶合强度为1.25 MPa,对不同配比的甲醛/尿素（F/U）脲醛树脂,三聚氰胺/纳米TiO2联合改性性能相似;改性后的脲醛树脂及纳米TiO2能够均匀分布于木材表面,以保证较好的胶合强度和联合改性效果。
语种：
中文
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初含水率对白橡锯材热压干燥特性的影响
作者：
谢杰;谭宏伟;郝晓峰;李贤军;熊幸阳;...
期刊：
中南林业科技大学学报 ,2018年38(9):120-125 ISSN：1673-923X
作者机构：
中南林业科技大学材料科学与工程学院, 湖南, 长沙, 410004;大自然家居(中国)有限公司, 广东, 佛山, 528000;[谢杰; 郝晓峰; 李贤军; 熊幸阳; 全鹏] 中南林业科技大学材料科学与工程学院, 湖南, 长沙, 410004;[谭宏伟; 郑敏] 大自然家居(中国)有限公司, 广东, 佛山, 528000
关键词：
热压干燥;白橡;干燥速率;干燥缺陷
摘要：
以白橡锯材为研究对象,采用平板热压机对其进行干燥处理,系统研究了初含水率对木材温变特性、干燥速率、干缩特性、干燥缺陷和微观构造的影响规律,探明白橡锯材的热压干燥特性.结果表明:热压干燥是一种高效快速的干燥方法,将初含水率为14% ~ 75%的木材在温度为140℃、压力为0.1MPa的条件下干燥到2%以下终了含水率仅需120 ~ 210 min,木材干燥速率随着初含水率的增加而增加;初含水率较高的木材在热压后会产生严重内裂和皱缩缺陷,当木材初含水率降至15%以下时,热压后无内裂缺陷产生,截面变形也明显减小;随着初含水率的增加,木材厚度干缩系数呈增加趋势,而宽度干缩系数则呈下降趋势.通过观察木材的横切面微观结构发现,高初含水率试件的内裂沿木射线生成,其早材大管孔部位可观察到明显压缩.
语种：
中文
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高温热处理对UF树脂改性杉木吸湿性和耐湿尺寸稳定性的影响
作者：
全鹏;李芸;牟玉姝;刘元;胡进波;...
期刊：
中南林业科技大学学报 ,2018年38(9):126-130 ISSN：1673-923X
作者机构：
[全鹏; 李芸; 牟玉姝; 刘元; 胡进波; 李贤军] 中南林业科技大学材料科学与工程学院, 湖南, 长沙, 410004
关键词：
杉木;UF树脂改性;热处理;吸湿性;耐湿尺寸稳定性
摘要：
以脲醛（UF）树脂改性杉木为研究对象,采用高温过热蒸汽对其进行热处理,系统研究了热处理温度和时间对UF树脂改性杉木吸湿性和耐湿尺寸稳定性的影响规律。结果表明：与杉木对照材相比,UF树脂改性杉木吸湿性降低,耐湿尺寸稳定性提高;高温热处理能降低UF树脂改性杉木的吸湿性,提高其耐湿尺寸稳定性;与热处理时间相比,高温热处理温度对UF树脂改性杉木的吸湿性和耐湿尺寸稳定性的影响更大,随着热处理温度的升高,UF树脂改性杉木的平衡含水率、弦向湿胀率、径向湿胀率和体积湿胀率均呈先下降后升高的趋势;与杉木对照材相比,热处理UF树脂改性杉木的平衡含水率、弦向、径向湿胀率和体积湿胀率最大分别降低了39.00%、62.02%、69.89%、59.99%;与未经热处理的UF树脂改性杉木相比,热处理UF树脂改性杉木的平衡含水率、弦向、径向湿胀率和体积湿胀率最大分别降低了28.71%、53.42%、65.85%、54.32%。
语种：
中文
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Cellulose nanofibrils aerogel cross-linked by poly(vinyl alcohol) and acrylic acid for efficient and recycled adsorption with heavy metal ions
作者：
She, Jiarong;Tian, Cuihua;Wu, Yiqiang* ;Li, Xianjun;Luo, Sha;...
期刊：
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY ,2018年18(6):4167-4175 ISSN：1533-4880
通讯作者：
Wu, Yiqiang;Qing, Yan
作者机构：
[Wu, Yiqiang; Tian, Cuihua; Luo, Sha; Qing, Yan; Li, Xianjun; She, Jiarong; Jiang, Zheng] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Wu, Yiqiang; Qing, Yan; Li, Xianjun] Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, Changsha 410004, Hunan, Peoples R China.;[Luo, Sha; She, Jiarong] Hunan Qual Inspect & Testing Ctr Forestry Prod, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wu, YQ; Qing, Y] C;Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, Changsha 410004, Hunan, Peoples R China.
关键词：
Cellulose Nanofibrils;Cross-Linked Porous Structure;Adsorption;Reusability;Wastewater Purification
摘要：
Cellulose nanofibrils (CNFs), disintegrated from natural fibers, are promising alternatives in wastewater purification for the porous structure and numerous hydroxyls. The pristine CNFs aerogel has limited mechanical strength and are vulnerable to collapse when exposed to water. In this work, eco-friendly and recycled CNFs aerogel adsorbents were successfully prepared using cellulose nanofibrils (CNFs), which cross-linked by poly(vinyl alcohol) (PVA) and acrylic acid (AA). The combination of PVA and AA endowed CNFs aerogel strong three-dimensional porous structure and desirable adsorption properties. The heavy metal ions were adsorbed on the CNFs-PVA-AA (CPA) adsorbents efficiently and the maximum adsorption capacities for Cu2+ and Pb2+ approached 30.0 mg/g and 131.5 mg/g, respectively. The CPA adsorbent also showed excellent reusability and their adsorption capacities maintained 89% and 88% for Cu2+ and Pb2+ after 5 repeated uses. The adsorption of these heavy metal ions were confirmed to follow pseudo-second-order kinetic and Langmuir isotherm model. The functions of C = O and -OH were the major adsorption sites. Chemical adsorption combined with the porous physical adsorption made the CPA to be excellent adsorbent for the removal of heavy metal ions in wastewater.
语种：
英文
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一种电子式全量程木材含水率测试仪
作者：
全鹏;贺霞;程曦依;李芸;李贤军
期刊：
林产工业 ,2017年44(8):23-26 ISSN：1001-5299
作者机构：
中南林业科技大学材料科学与工程学院;[李贤军; 全鹏; 程曦依; 贺霞; 李芸] 中南林业科技大学
关键词：
含水率测试仪;木材;全量程;电子式;称重法
摘要：
介绍了一种新研制的电子式全量程木材含水率测试仪的基本结构、测试原理与使用方法,并对其测量精度和测量误差进行了系统分析.结果表明:新研制的含水率测试仪可以实现全量程木材含水率的快速测量,并具有较高的测量精度;与现有电阻式和感应式含水率测试仪相比,新含水率测试仪具有更高的测量精度和更小的测量误差,特别是对于含水率40％以上木材的检测,新含水率测试仪更具有优势;在0～140％的含水率变化范围内,其测试结果的绝对偏差范围为2％～5％,且绝对偏差波动小;新含水率测试仪测量误差是由木材的非均质特性造成的,在实际生产过程中,可以通过合理取样有效减少测量误差,提高测量精度.
语种：
中文
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高温热处理对UF树脂改性杉木力学强度的影响
作者：
全鹏;李芸;曹敏;姜成宇;刘元;...
期刊：
中南林业科技大学学报 ,2017年37(12):153-158 ISSN：1673-923X
作者机构：
[全鹏; 李芸; 曹敏; 姜成宇; 刘元; 胡进波; 李贤军] 中南林业科技大学材料科学与工程学院, 湖南, 长沙, 410004
关键词：
杉木;UF树脂改性;热处理;力学性能
摘要：
本研究以脲醛(UF)树脂改性杉木为研究对象,采用高温过热蒸汽对其进行热处理,系统研究了热处理温度和时间对UF树脂改性杉木力学强度的影响规律。结果表明:与杉木对照材相比,UF树脂改性杉木力学强度显著提高;高温热处理使杉木浸渍材的力学强度降低;随着温度升高和时间延长,杉木浸渍材的抗弯弹性模量和强度、顺纹抗压强度和横纹抗压比例极限应力均呈明显下降趋势;经热处理后,UF改性杉木抗弯弹性模量、抗弯强度、顺纹抗压强度最大分别可降低11.4%、65.1%和17.3%,横纹全部弦向和径向抗压比例极限应力最大分别可降低60.9%和59.6%,横纹局部弦向和径向抗压比例极限应力最大分别可降低36.5%和56.5%。
语种：
中文
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Effect of microwave pretreatment on permeability and drying properties of wood
作者：
He, Xia;Xiong, Xingyang;Xie, Jie;Li, Yunyan;Wei, Yanqiang;...
期刊：
BIORESOURCES ,2017年12(2):3850-3863 ISSN：1930-2126
通讯作者：
Li, Xianjun
作者机构：
[Wei, Yanqiang; Quan, Peng; Xie, Jie; Li, Yunyan; Li, Xianjun; Xiong, Xingyang] Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha 410004, Hunan, Peoples R China.;[Mou, Qunying] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, Xianjun] C;Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha 410004, Hunan, Peoples R China.
关键词：
Drying properties;Eucalyptus;Microwave pretreatment;Permeability
摘要：
A microwave (MW) treatment of plantation eucalyptus (Eucalyptus urophylla) wood was investigated by applying MW treatments with varying conditions, such as radiation power, irradiation time, and initial moisture content of the wood. The wood permeability and drying properties were investigated. Results show that the permeability (both along the transverse and longitudinal directions) increased with the radiation power and the irradiation time. The permeability was considerably enhanced by the MW pretreatments, which effectively decreased the moisture content within the wood. A MW pretreatment can greatly accelerate the drying rate and shorten the wood drying time. Under atmospheric pressure the stain uptake along the transverse and longitudinal directions, with respect to the wood fibers, increased to 58% and 135%, respectively, compared to reference samples. Meanwhile, the drying rate increased to 171% and the drying time was cut by 65%. The MW pretreatment was found to generate a high-pressure internal steam that resulted in the rupture of wood cell pore membranes and ray cells. Therefore, a remarkable permeability increase and drying time reduction was achieved, which created favorable conditions for the fabrication of high value-added functional wood-based composites materials.
语种：
英文
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马尾松锯材常压过热蒸汽干燥脱脂特性研究
作者：
程曦依;李芸;全鹏;韦妍蔷;李昀彦;...
期刊：
中南林业科技大学学报 ,2017年37(6):108-113 ISSN：1673-923X
作者机构：
[程曦依; 李芸; 全鹏; 韦妍蔷; 李昀彦; 熊幸阳; 谢杰; 李贤军] 中南林业科技大学材料学院, 湖南, 长沙, 410004
关键词：
马尾松;锯材;过热蒸汽;干燥;脱脂
摘要：
以速生马尾松锯材为研究对象,采用常压过热蒸汽对其进行干燥脱脂一体化处理,系统研究了干燥脱脂过程中马尾松木材内部温度及含水率变化规律,讨论了过热蒸汽温度对锯材干燥速率、干燥质量、颜色、表面溢脂及微观构造的影响规律。结果表明:过热蒸汽干燥脱脂过程中,锯材内部温度及含水率变化可分为快速升温加速干燥段、恒温恒速干燥段和升温减速干燥段三个阶段,干燥速率介于0.14~0.26 %/min,过热蒸汽温度对干燥速率影响非常显著;过热蒸汽干燥脱脂材可达到锯材干燥质量指标二级以上标准,与常规干燥材相比,发生的表裂缺陷少,140℃时出现内裂缺陷;过热蒸汽干燥脱脂处理对木材颜色的影响不显著;过热蒸汽干燥材表面不发生溢脂,达到一级脱脂松木锯材标准;过热蒸汽干燥处理破坏了树脂道内的薄壁细胞,处理后的树脂道内残存有固态松香。
语种：
中文
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Theoretical investigation of temperature distribution uniformity in wood during microwave drying in three-port feeding circular resonant cavity
作者：
Zhang, Jianxiong;Luo, Yongfeng* ;Liao, Chunrong;Xiong, Feng;Li, Xi;...
期刊：
Drying Technology ,2017年35(4):409-416 ISSN：0737-3937
通讯作者：
Luo, Yongfeng;Li, Xianjun
作者机构：
[Zhang, Jianxiong; Sun, Lilu; Xiong, Feng; Luo, Yongfeng; Liao, Chunrong; Li, Xi] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410018, Hunan, Peoples R China.;[Li, Xianjun] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410018, Hunan, Peoples R China.
通讯机构：
[Luo, Yongfeng; Li, Xianjun] C;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410018, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410018, Hunan, Peoples R China.
关键词：
Finite element analysis;microwave drying;moisture content;temperature distribution;uniform heating of wood
摘要：
The temperature distribution within wood samples during microwave drying is significantly influenced by the dimensions of the wood sample, microwave frequency, heating time, and moisture content of the wood. Here, the temperature distribution inside the wood during microwave drying has been studied by finite element analysis in a three-port feeding circular resonant cavity. With an increasing radius of the wood, the calculated temperature variation coefficient decreased from 54.3 to 23.5% and the energy efficiency increased from 18 to 95%. When the radius of the wood was 0.8 times that of the circular cavity, the drying process was optimal. The theoretical calculations indicated that the length of the wood also affects the temperature variation coefficient. When the length of wood was more than the height of waveguide, the temperature variation coefficient was less than 40.5% and the energy efficiency was more than 90%. Other factors such as microwave frequency, heating time, and moisture content also influenced the uniformity of temperature distribution. This study helps to better understand the microwave drying process to facilitate its further applications for wood drying. © 2017 Taylor & Francis.
语种：
英文
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Determination of moisture content and moisture content profiles in wood during drying by low-field nuclear magnetic resonance
作者：
Xu, Kang;Lu, Jianxiong* ;Gao, Yulei;Wu, Yiqiang;Li, Xianjun
期刊：
Drying Technology ,2017年35(15):1909-1918 ISSN：0737-3937
通讯作者：
Lu, Jianxiong
作者机构：
[Gao, Yulei; Lu, Jianxiong; Xu, Kang] Chinese Acad Forestry, Res Inst Wood Ind, State Key Lab Tree Genet & Breeding, Beijing, Peoples R China.;[Wu, Yiqiang; Lu, Jianxiong; Li, Xianjun] Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, Changsha 410004, Hunan, Peoples R China.;[Wu, Yiqiang; Li, Xianjun] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha, Hunan, Peoples R China.
通讯机构：
[Lu, Jianxiong] C;Chinese Acad Forestry, Res Inst Wood Ind, State Key Lab Tree Genet & Breeding, Beijing, Peoples R China.;Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, Changsha 410004, Hunan, Peoples R China.
关键词：
Bound water;CPMG sequence;free water;NMR;relaxation time;SE-SPI sequence;wood drying
摘要：
In this article, the low-field nuclear magnetic resonance was used to measure the moisture content (MC) and MC profiles in poplar wood during real-time drying. The T2 distribution curve at each drying stage measured using the Carr–Purcell–Meiboom–Gill pulse sequence provided detailed information in the dynamic change of free water as well as bound water of the whole wood sample. In addition, a new developed SE-SPI pulse sequence was first used to evaluate the spatially resolved T2 distribution of the successive nondestructive sliced layer of wood. Combined with the area integration method, the moisture content in each layer was calculated, and the change of MC profiles within wood at the MC above and below fiber saturation point was well reflected. © 2017 Taylor & Francis.
语种：
英文
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Effect of thermal treatment on functional groups and degree of cellulose crystallinity of eucalyptus wood (eucalyptus grandis × eucalyptus urophylla)
作者：
Cheng, Xi Yi;Li, Xian Jun* ;Xu, Kang;Huang, Qiong Tao;Sun, Hong Nan;...
期刊：
FOREST PRODUCTS JOURNAL ,2017年67(1-2):135-140 ISSN：0015-7473
通讯作者：
Li, Xian Jun
作者机构：
[Li, Xian Jun; Cheng, Xi Yi; Xu, Kang; Wu, Yi Qiang] Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha, Hunan, Peoples R China.;[Huang, Qiong Tao; Sun, Hong Nan] Yihua Enterprise Grp Co Ltd, Yihua Timber Ind, Shantou, Guangdong, Peoples R China.
通讯机构：
[Li, Xian Jun] C;Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha, Hunan, Peoples R China.
摘要：
In this study, eucalyptus wood was subjected to thermal treatment with super-heated steam under various conditions. The effects of temperature and exposure time on the functional groups and degree of cellulose crystallinity of the eucalyptus wood (Eucalyptus grandis3Eucalyptus urophylla) were analyzed. The results showed that the thermal treatment caused significant changes in the chemical composition and structure of wood. The Fourier transform infrared spectroscopy (FTIR) absorption peaks of the hydroxyl group decreased from 3,425 to 3,250 cm1 for all thermally treated samples. Higher treatment temperature and extended exposure led to the lower methyl levels, with almost no methyl present at 2208C. The aromatic ring first increased and then decreased with increasing temperature and exposure time. The carbonyl group maintained the same intensity, with small fluctuations, across the different thermal treatment conditions. Compared with the untreated wood sample, the X-ray diffraction peak position of thermally treated samples shifted slightly left from 22.028 to 21.068, and the distance between crystal planes increased. The degree of cellulose crystallinity of eucalyptus wood was affected significantly by treatment temperature with a confidence level of 99 percent. © Forest Products Society 2017.
语种：
英文
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过热蒸汽处理对马尾松木材干燥质量的影响
作者：
韦妍蔷;姜帅成;李昀彦;程曦依;谢杰;...
期刊：
木材科学与技术 ,2017年31(6):50-53 ISSN：2096-9694
作者机构：
中南林业科技大学材料科学与工程学院,湖南长沙,410004;[李贤军; 李昀彦; 姜帅成; 韦妍蔷; 程曦依; 谢杰] 中南林业科技大学
关键词：
马尾松;过热蒸汽;颜色;脱脂;微观构造
摘要：
采用过热蒸汽对马尾松锯材进行干燥处理,研究干燥条件对木材颜色、厚度含水率偏差和脱脂效果的影响.结果表明:过热蒸汽干燥对木材颜色影响不显著;试材厚度含水率偏差小于1％;木材内部的松脂排出至木材表面或固着在其内部,可以达到干燥和脱脂的双重目的.
语种：
中文
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速生杨木常规-过热蒸汽干燥特性研究
作者：
李昀彦;韦妍蔷;程曦依;全鹏;李贤军
期刊：
林产工业 ,2017年44(10):27-30 ISSN：1001-5299
作者机构：
中南林业科技大学材料科学与工程学院;[李贤军; 李昀彦; 韦妍蔷; 全鹏; 程曦依] 中南林业科技大学
关键词：
杨木干燥;过热蒸汽;常规干燥;联合干燥;干燥质量
摘要：
以20 mm厚速生杨木锯材为研究对象,采用连续常压过热蒸汽干燥和常规-过热蒸汽联合干燥两种方法对其进行干燥处理,系统研究了干燥方法和条件对杨木锯材干燥特性的影响规律.结果表明,过热蒸汽干燥的温度及含水率变化可分为三个阶段,联合干燥时间较常规干燥缩短2.5～3倍,能显著提高干燥速率;联合干燥质量均可达到锯材干燥一级标准,采用常规-过热蒸汽联合干燥方法可以实现杨木锯材的快速高效干燥处理.
语种：
中文
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泛木材科学与工程专业学生DIY式培养模式探讨
作者：
胡进波;苌姗姗;李贤军;刘元
期刊：
家具与室内装饰 ,2017年(09):126-128 ISSN：1006-8260
作者机构：
中南林业科技大学材料科学与工程学院,湖南长沙,410004;[李贤军; 苌姗姗; 刘元; 胡进波] 中南林业科技大学
关键词：
木工;个性化;成才;创新
摘要：
随着时代的发展和科技的进步,木材科学与工程专业范畴已经延展,一些新兴的、符合当前人们需求的专业方向被发现.对于专业学生的培养,应该迎合当下青年追求个性、要求发展的心里.通过对中南林业科技大学木材科学与工程专业在校大学生培养状况调查,进行深度研究分析,探究当前培养过程中的问题,从专业方向设置、课程设置与教学方法、职业规划等培养要素出发,阐述了泛木材科学与工程专业学生DIY式培养模式的建议与对策,以期望在高校双一流建设中为深化大学生个性化人才培养模式改革提供参考.
语种：
中文
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