利用地径建立林木材积估测模型的探讨

通过实测铁杉、红桦和湖北花楸的地径、胸径、树高和材积，我们建立了根据林木地径估测树木材积的数学模型，具有较高的相关系数，可以应用于森林资源管理和森林生态系统研究。     

Improvements in dimensional stability and lightfastness of wood by butyrylation using microwave heating

Microwave heating was used as the heat source for butyrylation of wood with the aim of reducing the reaction time. The photostability and dimensional stability of butyrylated wood were also investigated in this study. Chemical changes of wood were confirmed by cross polarization/magic angle spin ¹³C-nuclear magnetic resonance and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) after butyrylation by microwave heating. Results from DRIFT with the Si-Carb sampling technique revealed that, using microwave heating, a higher degree of butyrylation of maple wood occurred in the middle of the specimen than on the outer surface. The increase in yellowness index of butyrylated wood treated with microwave heating was much less than that of untreated wood after the lightfastness test, indicating that photoyellowing of wood is effectively inhibited by butyrylation using microwave heating. The dimensional stability of wood was also improved after modification.     

Automatic counting of annual rings on Pinus sylvestris end faces in sawmill industry

One of the essential requirements of current agricultural practice is the need to evolve towards crop techniques that make better use of productive factors behaving in sustainable and environmentally respectful ways. Pest control is one of the most important problems to take into account, due to the significant production losses that pests may cause. The Integrated Production for olive crop defines a set of rules that has to be followed in order to ensure a production of higher quality, and promotes an environmentally respectful model of Olive cultivation. This work presents SAIFA (spanish acronym for Sistema de Alerta e Información Fitosanitaria Andaluz - Andalusian Phitosanitary Information and Alert System) a web-based information system which allows monitoring the Integrated Production for the olive crop in Andalusia, Spain. SAIFA has been built as a tool to assist agricultural technicians to comply with the quality standards of Integrated Production, and to help decision makers to choose the actions to be performed in the crop. Also, it assists coordinators to choose an Integrated Production strategy applicable for the whole region with the main objective of ensuring the safety of crops and reporting the current phitosanitary state to the authorities.     

单板层积梁弯曲蠕变特性

在自制的弯曲蠕变试验台上对桦木和椴木单板层积梁进行弯曲蠕变试验,蠕变测试采用简支梁中部集中加载的方式。选用的加载应力水平分别为层积梁弯曲极限强度的40%、50%和60%,用百分表记录蠕变数值。实验周期为40～60d。试验结果表明,单板层积梁弯曲蠕变特性受树种、加载应力水平的影响较大,与树种的材性有较大关系:桦木单板层积梁的抗蠕变性能要明显好于椴木单板层积梁;同时,相同树种不同应力状态下,蠕变曲线为非线性的,蠕变过程由于加载应力水平不同而呈不同的规律。蠕变变形量和曲线上的跳跃点随着应力水平的增加有增大的趋势。试验测试过程中,60%应力状态下,椴木单板层积梁在连续加载60d时突然断裂。     

改善实木复合地板尺寸稳定性的措施

研究了两种涂料配方的不同配比对木质复合地板尺寸稳定性的影响，结果表明：以醇酸清漆为主的涂料对地板产品进行后期处理，在产品尺寸稳定性和成本方面均优于其它涂料，合理选取涂料组分和配比，不仅能提高产品的尺寸稳定性，而且提高产品外观的美观度。     

表面活性剂与纳米SiO2作用下聚合铝的絮凝特性

在6NTU高岭土原水中,溶入低浓度溶解性有机物-阴离子表面活性剂(十二烷基硫酸钠,SDS),投加聚合铝PAC与新型水处理剂-纳米SiO2稳定分散液进行动态混凝实验与静止沉降实验.借助图像分析技术与分形理论,对SDS与纳米SiO2作用下PAC的絮凝特性与絮体分形结构的形态学特征进行研究.结果表明:存在SDS时,高岭土颗粒表面ζ电位增加.SDS在颗粒表面的吸附等温曲线符合Langmiur方程;PAC对无机颗粒的去除效果明显,但对SDS的表观去除率较低.SDS阻碍絮凝初絮体的形成.纳米SiO2使颗粒表面ζ电位增加,对无机颗粒处理效果较差,但对去除有机物有利.絮凝机理主要是吸附架桥;助凝剂纳米SiO2能促进PAC对无机颗粒与SDS絮凝,处理效果显著.悬浊液中絮体粒径大,有效质量密度增加,沉速加快,分维值下降.     

黄瓜叶片大小解剖结构的对比研究

通过制作石蜡切片对4个黄瓜品种在3个时期的解剖结构进行了观察。其中D9320、D2005为叶面积大品种,D0455、D0401为叶面积小品种。结果表明,D9320、D2005叶面积大的原因是细胞平均面积大,而非数量多;D0401、D0455叶面积小的原因是细胞平均面积小,而非数量少。黄瓜叶为典型异面叶,表皮由一层紧密的形状不规则的表皮细胞组成,维管组织较发达,导管分布较多,上下表皮均分布有表皮毛,但以下表皮为主。     

Application of body size spectra to nematode trait-index analyses

Current trait-based indices of soil fauna for assessing soil quality rely on extensive knowledge of life history traits for hyper-diverse groups. We look at the effects of clear-cut forest harvesting and subsequent wood ash application on the free-living nematode community using trait-based indices and body size spectra. We test the hypothesis that body size is a unifying trait and that the body size spectra can be used to demonstrate changes in soil quality while overcoming taxonomic impediments. Undisturbed boreal forest floor soils were compared with clear-cut sites amended with zero, one-half calcium equivalent wood ash, equivalent calcium reintroduction, and twice calcium reintroduction. Total abundance, trait-based metrics for the Maturity Index, and two metrics of body size spectra were calculated. Nematode abundance was not a good indicator of soil disturbance, while traditional trait-based approaches (the summed Maturity Index) demonstrated predicted changes in community structure. Analysis of two types of body size spectra elucidated how the community had changed under disturbance, and revealed that smaller bodied organisms were lost under ash amended treatments compared to both clear-cut and undisturbed forest. Using the body size spectra for nematodes is a simple addition to current trait-based approaches that can supplement soil assessments for disturbance and quality without requiring taxonomic expertise.     

柳蝙蛾危害对水曲柳木材性质的影响

采集同一立地条件柳蝙蛾危害的幼龄水曲柳,将其木材分4组：健康株、危害1a化学防治后愈合株、柳蝙蛾危害1a未防治株、危害3a以上的水曲柳。对危害部位进行解剖学、物理学实验,结果表明：柳蝙蛾对水曲柳木材的密度、硬度、胞壁率、年轮宽、纤维长度几个指标均有不同程度的影响。化学防治后1a密度这一指标恢复正常水曲柳的密度;年轮宽在被害后第三年才能恢复;对硬度的影响在以后的3a仍十分明显,纤维长度同硬度影响相近。     

木质居室环境综合评价

采用模糊数学理论研究人们对木质居室环境的综合评价,并将其与传统建筑物的室内环境进行了比较。通过调查研究表明,专家们对木质复合墙体结构住宅的室内环境的评价较高,这种结构的住宅在人们的主观意识中能得到认可。