oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 91 )

2018 ( 1888 )

2017 ( 1983 )

2016 ( 2111 )

Custom range...

Search Results: 1 - 10 of 93843 matches for " 罗建举 "
All listed articles are free for downloading (OA Articles)
Page 1 /93843
Display every page Item
21世纪木材改性技术展望
曹琳
世界林业研究 , 1998,
Abstract: 本文提出了木材材性遗传改良的设想,并运用唯物辩证思想、以遗传变异的对立统一矛盾促进生物进化的观点,对木材遗传改良的基本原理进行了哲学考证。在此基础上,根据生物技术的现状与未来,论述了木材遗传改良的发展方向。通过讨论和分析,确信木材遗传改良将取代传统的木材工艺改良方法而成为21世纪木材改性的主要方式。
20种红木类木材颜色和光泽度研究
何拓,
- , 2016, DOI: 10.13360/j.issn.2096-1359.2016.02.008
Abstract: 为了探索红木类木材表面的视觉特性的分布特征,测量了20种红木类木材颜色L*a*b*色空间物理量、平行于木材纹理方向的光泽度(GZL)和垂直于木材纹理方向的光泽度(GZT),建立了L*a*b*三维空间坐标系,并对20种红木类木材进行聚类分析,深入剖析了20种红木类木材视觉物理量的分布特征和相关关系。结果表明,20种红木类木材的明度值普遍较低,基本属于偏暗红色和红褐色的色调范围,根据聚类分析,乌木类、条纹乌木、黑酸枝类木材归为第一大类,花梨木类、香枝木类和红酸枝类木材归为第二大类; 平行于木材纹理方向的光泽度值比垂直于纹理方向的光泽度值大,红木类木材的表面光泽度比普通木材高; 明度L*、色调H都与红绿色品指数a*之间呈显著的负相关,与黄蓝色品指数b*呈正相关,色饱和度C与黄蓝色品指数b*呈显著的正相关。试验结果为红木类木材制品的综合评价提供了理论基础。
In order to explore the visual characteristics of rosewood, the wood color parameters of lightness(L*), redness(a*)and yellowness(b*)and the wood luster parameters parallel and perpendicular to the grain direction of twenty species of rosewood were examined quantitatively. The data collected were the L*a*b* color space, and a clustering analysis was carried out. The distribution characteristics and the correlations of the visual parameters were analyzed profoundly. The results showed that the lightness of the twenty species of rosewood is generally low, ranging from the dim red to reddish brown. According to the cluster analysis, the Diospyros spp. wood, Diaspyros spp. wood and Dalbergia spp. wood were classified as the first category. The Pterocarpus spp. wood, Dalbergia spp. wood and Dalbergia spp. wood were classified as the second category. The wood luster parameters parallel to the grain were greater than that perpendicular to the grain. The luster parameters of the rosewood were greater than those of the other species wood. The lightness(L*)and the hue(H)exhibited a significantly negative correlation with a* and positive correlation with b*. The color saturation(C)displayed a significantly positive correlation with b*
交趾黄檀及其相似树种木材构造的比较分析
何拓,
- , 2016, DOI: 10.13360/j.issn.2096-1359.2016.04.009
Abstract: 交趾黄檀属于红木树种,木材材质优异,市场价值高,在市场上常有其他木材冒充交趾黄檀,损害了消费者的利益。为了识别交趾黄檀及其相似树种,通过木材解剖和显微摄影技术,对交趾黄檀及其相似树种木材宏观构造和木材显微构造进行综合分析和比较。结果表明:交趾黄檀的木材底色比其他相似树种深,木材新切面呈紫红色或暗红褐,久置后为深红色或暗红色; 交趾黄檀木材常具黑色条纹,且黑色条纹比其他树种粗; 交趾黄檀木材具有酸辛味,而其他树种木材气味微弱或无。交趾黄檀轴向薄壁组织为带状和翼状,与射线局部交叉为网格状; 交趾黄檀单列木射线较多,多列木射线宽2~3个细胞,高6~14个细胞,与其他树种有明显差异。交趾黄檀及其相似树种木材可通过木材颜色、纹理、气味等宏观特征以及轴向薄壁组织、木射线等显微构造特征来进行识别。
Dalbergia cochinchinensis Pierre belongs to the family of Mahogany, which is an extremely high-value wood material. Some other low-cost wood species are often posed as D. cochinchinensis Pierre in the market and hurts consumers' benefits. In order to distinguish the identification of D. cochinchinensis Pierre from its posing species, the macroscopic structure and microscopic structure of the wood were analyzed and compared comprehensively by means of wood anatomy and microphotography. The results of the research showed that the wood color of D. cochinchinensis Pierre is much darker than that of other wood species and the wood color of the new-cut surface presents purple or dark reddish brown. D. cochinchinensis Pierre often has black stripes, and the black stipes are thicker than other wood species. In addition, D. cochinchinensis Pierre has a smell of sour-acid, while the other species have a weak smell or smell-less. The axial parenchyma of D. cochinchinensis Pierre looks like ribbon and poly, and crossed with ray locally for grid, relatively more uniseriate wood rays. The multiseriate wood ray has a width of 2-3 cells and a height of 6-14 cells, which have obvious difference with other wood species. Furthermore, D. cochinchinensis Pierre can be identified from its similar wood species by the macrostructure features such as wood color, wood texture and wood smell, as well as the microstructure features such as the axial parenchyma type and the wood rays
悬铃木树皮美学图案分析及应用研究
孟陶陶,吴义强,
- , 2018, DOI: 10.13360/j.issn.2096-1359.2018.01.023
Abstract: 悬铃木生长快、树形优美,多用作行道和园林绿化树种。开展悬铃木树皮美学属性的研究,以进一步发掘其美学利用价值。该研究从美学角度分析了不同树龄时期悬铃木树皮的美学特征,采用不同的构图方式创作出多种形式的美学图案,并将这些美学图案应用于服装、皮包、家具等产品的研发设计,获得3种悬铃木树皮美学应用的设计作品。研究结果表明,不同时期的悬铃木树皮外观特征存在较大差异:幼龄期树皮表面平滑,均匀分布着由皮孔与树皮射线形成的灰白色斑点; 老龄期树皮多为黄褐色,呈碎裂状条片层叠堆积。这两个时期的树皮图形单调,美学利用价值较低。成熟期的树皮多为绿褐色,凹凸不平的不规则形斑块构成丰富多变的图形,色彩丰富、层次分明、肌理粗犷朴实、构型奇异多样、线条流畅自然,是点、线、面的完美组合,具有很好的审美价值,可以作为美学素材应用于日用产品的美学设计。
With fast-growing and beautifully-shaped features, Platanus acerifolia is often used as a tree species for landscaping. This study investigated the aesthetic attributes of the bark of P. acerifolia, as well as its aesthetic value. Firstly, the aesthetic characteristics of the bark for different ages were analyzed from the aesthetic point of view. Then aesthetic patterns of various forms were created through different composition methods, which included the natural aesthetic pattern, the quartet continuous aesthetics pattern, the fractal geometrical aesthetic pattern and the fractal geometrical and quartet continuous aesthetic pattern. The created aesthetic patterns were used in the development and design of daily-use products, such as hand bags, clothes, furniture. The results showed that there were significant differences in the bark of P. oriental at different growth periods. The appearance of young P. acerifolia bark was smooth and evenly covered with gray-white spots formed by lenticels and bark rays evenly distributed. The appearance of old P. acerifolia bark was yellow-brown and covered with broken pieces. The patterns in these two periods were monotonous and the aesthetic value was low. The appearance of mature P. acerifolia bark was greenish-brown, with irregular patches on the surface, meandering lines between adjacent patches, and gray-white spots of lenticels and bark rays. The mature bark was rich in color, distinct in hierarchy, rugged and simple in texture, varied in configuration, smooth and natural in line, which was perfect combination of points, lines, and faces. The mature bark of P. acerifolia provided numerous elemental sources for the aesthetic patterns with great aesthetic value, which could be used as special materials in aesthetic design of daily-use products
水浸时效对红锥木材蠕变特性的影响
The Influence of Water Immersion Aging on Creep Characteristics of Castanopsis hystrix Wood

刁海林,,蔡道雄
- , 2015, DOI: doi:10.3969/j.issn.1001-7461.2015.02.38
Abstract: 采用4点加载方式分别对红锥自然气干试材及水浸时效试验材料进行短时间(420 min)弯曲蠕变试验,获取红锥木材在2种不同时效状态下的弯曲蠕变特性常数,分析2种时效状态下红锥的蠕变性能,并对水浸时效对红锥蠕变性能的改善效果作出评价。结果表明,在弯曲应力为σb??40%的荷载下,红锥自然气干材的蠕变特性常数J0为8.408×10-7cm2/N、η0为436.293×10-7min N/cm2、∑Ji为0.784×10-7cm2/N;红锥水浸时效材的蠕变特性常数J0为7.752×10-7cm2/N、η0为502.000×10-7min N/cm2、∑Ji为0.341×10-7cm2/N。红锥木材经水浸时效处理后,其瞬间弹性柔量J0及延迟弹性柔量∑Ji均较气干材有所降低,而粘性系数η0则较气干材有较大幅度的提高。说明红锥木材经水浸时效处理后其抗瞬间弹性变形能力、抗延迟弹性变形能力及抗长期粘性变形的能力得到增强。
By means of the four-point loading, a short time (420 min) bending creep testing on air-dried wood samples and water immersion aging samples of Castanopsis hystrix were respectively carried out to obtain the bending creep characteristic constants of the woods under two different aging states, and to analyze their creep properties under two different aging states, also to evaluate the improvement effect of the creep properties after water immersion aging. Experimental results showed that when the load of bending stress was under 40% of tensile strength, constants J0, η0, and ∑Ji of creep properties of air-dried wood sample were 8.408×10-7cm2/N, 436.293×10-7min N/cm2, and 0.784×10-7cm2/N, respectively. While after the wood had been immersed in water, the constants of J0, η0, and ∑Ji were 7.752×10-7 cm2/N, 502.000×10-7 min N/cm2, and 0.341×10-7 cm2/N, respectively. The conclusions were that comparing with air-dried wood, after the wood had been immersed in water with aging treatment, both of instantaneous elastic compliance J0 and delayed elastic compliance ∑Ji were lower than the constants of the air dried wood, but the resistance of viscous coefficient had been significantly improved comparing with the air-dried wood. It showed that after the immersed treatment in water, the resistance abilities of instantaneous elastic deformation, delayed elastic deformation and long time viscous deformation were improved
21世纪木材改性技术展望
,曹琳?,林?,韦善华?
世界林业研究 , 1998,
Abstract: 本文提出了木材材性遗传改良的设想,并运用唯物辩证思想、以遗传变异的对立统一矛盾促进生物进化的观点,对木材遗传改良的基本原理进行了哲学考证。在此基础上,根据生物技术的现状与未来,论述了木材遗传改良的发展方向。通过讨论和分析,确信木材遗传改良将取代传统的木材工艺改良方法而成为21世纪木材改性的主要方式。
西南桦木包装材料在热处理后的润湿性能研究
高伟,,李荣册,石世亨,郭玺,卢佩
包装工程 , 2013,
Abstract: 通过动态接触角测量、红外光谱分析、表面粗糙度测量、扫描电镜?旌推喙胤治?研究了西南桦木的润湿性能。 结果表明,木材经 180 ℃热处理 4 h 后,润湿性能下降:接触角由 40°增至 121°,羟基和羰基数量减少,粗糙度降低;处理时间与接触角显著相关;西南桦木用作包装材料,若采用热处理,可去除有害生物,还具备疏水功能。
木材胶合界面性能表征技术研究进展
秦理哲?,林兰英?,,傅峰?
世界林业研究 , 2013,
Abstract: 木材胶合界面是指同时包含木材细胞壁和胶粘剂的区域。在木质胶合产品的加工工艺选择与使用性能评价中,胶合界面发挥着重要作用,其中胶粘剂渗透性能和界面力学性能是重要的评判标准。目前,用于表征胶合界面性能的技术包括光学显微技术、电子显微技术、x射线成像技术、微观力学测试技术等。文中通过对比各表征技术,提出进一步研究界面结合强度的表征、微观力学模型的建立、界面力学特性与木质胶合产品宏观性能的关系等将是未来的探索方向。
动态入流条件下风力机运行控制的数值模拟
袁仁育,,汪建文,冀文,张立茹,王强,
- , 2018, DOI: 10.3785/j.issn.1008-973X.2018.11.011
Abstract: 在动态入流条件下,采用基于致动线模型的大涡模拟方法对一台1.5 MW的商用风力发电机组的转速、转矩以及输出功率的响应特性进行数值模拟.在对数风廓线模型的基础上,通过引入正弦波动获得动态入流边界条件.对风力机引入比例积分变桨距控制和转矩控制,实现对动态入流的追踪.研究结果表明,在当前的变桨距控制和转矩控制条件下,风力机的转速、转矩、输出功率能够很好地响应入流风速的变化.在风加速阶段,三者都在额定风速时达到额定值;当入流风速减到额定风速后,变桨距控制以及转速、转矩、功率的下降都存在10 s的延迟;模拟得到的功率曲线与风力机实际功率曲线整体上吻合良好,不过在风速小于9 m/s的区间段还存在着一定的偏差,有待于进一步优化.
Abstract: The response characteristics of speed, torque and output power of a 1.5 MW commercial wind turbine were simulated based on the large eddy simulation with actuator line method under dynamic inflow condition. On the basis of the logarithmic wind profile model, the sine wave was introduced to develop the dynamic inflow boundary condition. The proportional-integral pitch control and torque control were adopted for the wind turbine to track the dynamic inflow. Results showed that under the effect of pitch control and torque control, the speed, torque and output power of the wind turbine responded well to the change of the inflow wind speed, and all of them reached their rated values at the rated wind speed during the wind acceleration phase. There was a delay of 10 s for the pitch control and the decline of speed, torque and power after the inflow wind speed reduced to the rated value. The simulated wind turbine power curve agreed well with the actual power curve in general, but there was still a certain deviation when the wind speed was less than 9 m/s, which needs further optimization.
Effect of high temperature on the growth, survival and reproduction of a laboratory population of the rice stem borer Chilo suppressalis Walker
高温对二化螟实验种群生长、存活和繁殖的影响

LUO Ju,

生态学报 , 2005,
Abstract: 以2 7℃和30℃恒温为对照,研究了平均温度在2 7~2 9.2℃内的5种变温条件下(每天2 0 h的适温2 7℃和12 :0 0~16 :0 0的高温处理,分别为日最高气温2 7℃、30℃、33℃、36℃、4 0℃)二化螟实验种群的发育历期、存活率和繁殖力的影响,组建了特定年龄生命表和繁殖力生命表。结果表明高温可导致二化螟种群的发育速率延缓、存活率和生殖力下降,主要表现在幼虫历期随日最高温度的升高而延长,36℃时延至12 d以上;在日最高气温高于33℃时,其存活率从2 7℃时的30 .3%降至36℃时的13.1%和4 0℃时的5 .5 % ,繁殖力也从30℃时每雌产卵量14 8.7粒减至36℃时的70 .5粒。因此,夏季异常高温可能是二化螟田间种群数量增长的一个重要抑制因子
Page 1 /93843
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.