油桐林生物量和养分循环的研究

对不同生育期的油桐林生物量和大量营养元素(N、P、K、Ca、Mg)的生物循环进行了研究。结果表明,桐林的生物量随树龄的增大逐渐积累,从幼龄期开始到20年生的桐林,其生物量的积累值为79,61t/ha。桐林不同生育期的光合产物在各器官中的分配比例不同。经济产量(果生物量或种仁生物量)随树龄的动态变化服从二次抛物线函数:W_(FR)=-2.11398+0.82471(t-1)-0.03540(t-1)~2W_S=-1.37257+0.38539t-0.01706t~2不同生育期,桐林中大量营养元素的吸收量、存留量、归还量和输出量均不同。     

枫香木材改性利用研究

采取清水浸泡、药物蒸煮、干燥和ＰＣ树脂浸渍处理等措施，对易裂难干、易发生翘曲变形、使用价值较低的枫香木材进行改性处理，可以显著降低其干缩差异，减少翘曲变形，实现均匀干燥．从而大大改善其加工性能和耐腐程度，提高利用价值．实践证明，以浸泡时间为６个月，蒸煮时间为４８ｈ，药量配比为１号药液：２号药液＝０．５％：１．５％进行改性处理的效果最为理想．     

基于遥感的乌鲁木齐市绿地资源信息提取技术研究

城市绿地是城市生态系统中的一个子系统,可以综合调节城市生态环境。本文基于遥感信息,对乌鲁木齐市绿地格局进行研究和探讨,对城市绿地专题信息进行提取。主要通过计算TM影像及各主成分分量和归一化植被指数NDVI的相关系数来进行波段组合,提高遥感影像的目视解译精度和分类精度,然后与其他资料对比研究,可以发现该方法对于城市绿地信息提取能取得较好结果。研究表明乌鲁木齐市城市绿地存在面积较少,分布状况不均匀。     

河南天目山森林种子植物区系研究

经调查,河南天目山有森林种子植物1 824种,隶属于155科,707属。种子植物区系有如下特点:种类组成丰富,优势现象明显;植物区系复杂多样,以温带分布为主,热带成分较为丰富,南北过渡特征明显;在属的层次上,与各大陆的温带、热带保持着较为广泛的联系;在种的水平上,通过华东与东亚植物区系联系密切;天目山植物区系起源古老,有单种属植物40种,中国特有属25个,国家珍稀濒危保护植物20种,均为第三纪植物区系成分。     

竹材热压干燥过程中的水分扩散研究

采用非稳态法测定龙竹竹材热压干燥过程中的水分扩散系数,并探讨了温度对水分扩散系数的影响.结果表明:干燥温度越高,干燥各阶段水分扩散系数及平均水分扩散系数也越大;初始高含水率阶段,随含水率逐渐降低,水分扩散系数呈逐步增加趋势,在纤维饱和点附近时达最大值;随后,随含水率逐渐降低呈逐步减少趋势.     

麦秸/聚氨酯复合人造板的工艺对其吸声系数的影响研究

通过变化麦秸和聚氨酯的比例、麦秸/聚氨酯复合人造板的密度、以及发泡温度,研究了麦秸/聚氨酯复合人造板在不同的声波频率下的吸声系数。试验结果表明:在不同的声波频率下,发泡温度的高低对麦秸/聚氨酯复合人造板的吸声系数有不同的影响;麦秸/聚氨酯复合人造板的密度与其吸声系数的大小关系密切;在声波频率为250～4 000Hz区域内,麦秸和聚氨酯的比例对麦秸/聚氨酯复合人造板的吸声系数影响较大。     

Thermal properties of interior decorating material and the sensation of cold/warm by contact II: the relations among heat flux, temperature change of material, and sensation of cold/warm by contact

The main purpose of this study was to investigate the changes in heat flux and temperature after the subject's palm was in contact with interior decorating materials. The relations among heat flux, temperature, and sensation of cold/warm during contact were studied. Ten men and ten women were selected and introduced to 21 materials for the contact test. They were in contact with the specimens for 30min without seeing them in a climate-controlled room at 25°±1°C and 65% RH. Changes in the heat flux and temperature of the specimens were determined by a heat flux meter. A sensory evaluation test was applied to evaluate the cold-warm contact. Results indicated that the heat flux and temperature increased with increasing time after the subject's palm was in contact with the specimens. The heat flux (Q ₃₀) and temperature (T ₃₀) 30min after the subject's palm contacted the specimens were greater for male subjects than for female subjects. A positive linear regression equation existed between the values for Q₃₀ andT ₃₀, whereas a negative linear regression formula existed the sensation of cold-warm by contact (5) and the values of ln(Q ₁·). Therefore, the sensation of cold/warm by contact could be estimated simply by using the thermal physical properties of the interior decorating materials.Part of this report was presented at the International Conference on Effective Utilization of Plantation Timber, Chi-Tou, Taiwan, ROC, May 1999     

Evaluation of Strength Performance of Finger-jointed Lumbers Using Three Kinds of Nondestructive Techniques

Resonance flexural vibration（Fast Fourier Transform, FFT）, ultrasonic wave（Pundit） and stress wave（Metriguard） techniques were examined as means of evaluating the static modulus of elasticity （MOE） and predicting the modulus of rupture （MOR） of finger-jointed lumber specimens made with four kinds of Eucalyptus （Eucalyptus. citriodora, E. exserta, E. grandis x E. urophylla and E. grandis）. Dynamic MOE was calculated from frequency and time obtained from forced vibrations and sounds induced in the four species of finger-jointed specimens. It was found that correlation coefficients between density and static MOE and dynamic MOE were statistically significant at the 0.01 level. And it was also found that the three nondestructive techniques can provide rapid and accurate means to determine the MOE, and the dynamic MOE was more accurate to predict static MOE than density. But the correlation coefficient between dynamic MOE, static MOE and MOR were lower than results reported by other researchers for solid wood, and were not statistically significant. It can be concluded that the three nondestructive techniques are useful for evaluating the MOE, but not suitable for predicting the MOR of finger-jointed.     

Wood Moisture Content Measurement by X-Ray Exposure Method

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杉木幼龄林叶片营养元素含量与林木生长的相关性

本文重点论述丘陵立地条件下 ,1、2代杉木幼龄林高生长、当年高生长、胸径生长与叶片中营养元素N、P、K、Ca、Mg、Cu、Mn、Zn、Fe含量的相关关系 ,进而从林木营养这个角度 ,为提高林木产量、防治地力衰退提供可靠的科学依据。研究结果表明 :2代杉木幼龄林生长与N、P、Mg、Cu、Mn、Fe含量呈密切的正相关。 1代杉木幼龄林生长虽与P、Mg、Cu、Mn、Fe含量呈正相关 ,但复相关系数数值偏低。也就是说土壤养分含量尚没有明显影响 1代杉木幼龄林正常生长