饰面工艺对家具板件翘曲度的影响

对硬枫薄木和杨木多层板为材料的薄木饰面家具翘曲变形的影响因素:涂胶量、热压压力、热压温度、热压时间,进行4因素3水平的L9(34)正交试验;用方差分析法对翘曲度变化量进行分析,得出最佳的贴面工艺.研究表明:涂胶量的影响显著,热压温度、热压时间和热压压力的影响不显著.     

淤地坝系试点示范建设浅见

通过回顾水土保持淤地坝建设的发展历程，阐述了做好淤地坝建设试点示范的重要意义，揭示了试点示范工作对淤地坝建设的推动作用。围绕淤地坝可研、设计、建设管理和运行管护4个阶段，分析了当前淤地坝试点工程建设应注意的问题，以及开展以支流为单位淤地坝系建设对淤地坝长远发展和水土保持治黄事业的优越性，指出了实施好支流坝系试点示范工程应抓住的关键环节，旨在为广大从事淤地坝建设的同仁们提供参考。     

Ⅰ-69杨旋切单板性能指标的研究

以生长在长江滩地、不同倾斜角度的Ⅰ-69杨为实验材料,分析了杨木旋切单板的性质。结果表明：在所选的杨树中,在旋切单板中,从髓心向外方向的起毛率和变形率明显严重。     

Ⅰ-69杨旋切单板性能指标的研究

以生长在长江滩地、不同倾斜角度的Ⅰ-69杨为实验材料,分析了杨木旋切单板的性质。结果表明：在所选的杨树中,在旋切单板中,从髓心向外方向的起毛率和变形率明显严重。     

Study on Drying Characteristic of Chinese Fir and Poplar Plantation Wood

The drying characteristic was studied for plantation wood of Chinese fir and poplar, which are typical plantation wood of southern and northern part of China, respectively. Through 100-degree-method the drying characteristic and basic drying condition were gotten, then drying schedule was developed for practical drying, the results showed that the drying schedule is suitable for Chinese fir and poplar plantation lumber, but shrinkage is large. The recommendation was made that enough dead weight is needed to decrease shrinkage in drying process. The drying quality of the two species of lumber is good in conventional drying method.     

用偏差活化能方法分析研究木材的干燥特性

偏差活化能可以表示被干燥物料的传质传热特性.通过理论分析和实验,该文研究了木材的不同几何尺寸与其偏差活化能的关系.基于木材的湿基试样之上,首先得到不同几何尺寸的木材的干燥率实验数据,然后建立模型计算扩散系数和偏差活化能.研究结果表明,不同几何尺寸木材试样的偏差活化能值随着环境温度和湿度而变化,并且影响着木材的传质传热动态特性;被干燥物料的偏差活化能在其几何尺寸较小时变化微小,并且随着尺寸的变小偏差活化能也下降;当干燥温度上升时,相对偏差活化能很快接近1,反之亦然.这些研究结果为进一步研究木材的动态干燥特性奠定了基础.     

运动功能相关的中华鲟和西伯利亚鲟幼鱼侧视形态比较研究

通过选取11个侧视形态特征度量进行主成分分析(principal component analysis,PCA),同时设置26个标记点进行相对扭曲分析(relative warp analysis,RWA),比较了中华鲟(Acipenser sinensis)和西伯利亚鲟(A.baerii)幼鱼在侧视形态上的差异以及相对扭曲分析和传统多元分析在鲟鱼形态研究中的优劣。结合前期对它们的有氧游泳能力比较结果(西伯利亚鲟比中华鲟强25%),分析了鲟鱼形态的水动力功能。主成分分析比较表明,中华鲟头长、头高、背鳍前基点之后的躯干高度、尾柄长、背鳍前缘长度均显著大于西伯利亚鲟(P<0.05),而尾鳍上叶显著短于西伯利亚鲟(P<0.05)。相对扭曲分析计算样本的几何信息并可视化统计结果,表明中华鲟的吻厚、吻长、头高、头长、躯干后半段高、背鳍前缘长显著大于西伯利亚鲟,而尾柄长和尾鳍上下叶长显著小于西伯利亚鲟(P<0.001)。上述形态特征直接影响着两种鲟鱼的游泳能力。     

河淤土区玉米3种肥料配比的应用效果比较

通过田间试验方法,研究并比较3种不同N、P、K配比施肥与当地常规施肥在玉米上的应用效果。试验结果表明,当河淤土区玉米生产的N、P、K适宜配比为N∶P2O5∶K2O=1.0∶0.5∶（0.4～0.5）时,既可增加作物产量,又具有显著的经济效益。     

Rotational position of curved saw logs and warp of the sawn timber

With the development of scanning technology in sawmills, it is possible to optimise log rotational position when sawing. However, choosing a different rotational position than horns down might be detrimental for the board shape after drying, especially for curved logs. Thus, there is a need to investigate at what level of log curve it is possible to freely rotate logs without causing board warp. This study was carried out through a test sawing that was conducted at a sawmill situated in the middle of Sweden. The tests were made on 177 Norway spruce logs, with varying amount of curve. Half of the logs were sawn in the horns-down position, half were sawn rotated perpendicular to horns down. Log shape and warp of the dried boards were measured. The results indicated a relationship between board spring, log curve and choice of rotational position. Furthermore, board bow was related to log curve but not rotational position. It can be concluded that for straight logs, with a bow height of less than 15 mm, an unconventional rotational position does not cause excess spring in the boards. Bow and twist are not affected by the rotational position at all.