归一化差植被指数(NDVI)在林火监测中的应用

本文通过将归一化差植被指数（ＮＤＶＩ）应用于林火监测，弥补了地理信息系统（ＧＩＳ）难以随时更新数据的不足，排除了云体对ＮＯＡＡ／ＡＶＨＲＲ传感器ＣＨ３通道的干扰，提高了森林火灾监测的准确性、及时性和可靠性。     

气象卫星探测林火精度的改进

气象卫星探测林火精度的改进舒立辅，杜永胜（林业部规划院）（林业部防火办）地面上的物体，都有一定的温度，并产生一定的辐射。从卫星上接收到的不同波长的辐射参数，依据一定的数学关系，即可以测算出地面物体的温度。应用ＮＯＡＡ系列卫星的ＡＶＨＲＲ资料进行森林火...     

森林火情卫星遥感监测用户信息服务系统

森林火情卫星遥感监测用户信息服务系统张树誉，赵礼铮，李登科（陕西省气象局遥感中心）邱宇红，窦民生，吴宽让（陕西省林业厅防火办）１９９０年元月，我中心从中国气象局国家卫星气象中心引进“极轨气象卫星ＡＶＨＲＲ／ＨＰＲＴ资料微机处理系统”，开展了森林、草场...     

美国加州将推行新的控制甲醛释放规则

美国：加利福尼亚州环境保护局的空气资源委员会（California Air Resources Board，CARB）接受了新的严格控制甲醛释放的规则（Airborne Toxic Control Measure to Reduce Formaldehyde from Composite Wood Products），将从2009年开始实施，到2012年完全实行。规则涉及刨花板、MDF、纤维板和阔叶材胶合板等用脲醛胶制造的产品，将影响到家具、箱柜等产品的制造。建筑用板材不在控制之列。     

加州实施甲醛释放控制法规的准备情况

美国：加利福尼亚州率先在美国实施严格的甲醛释放控制法规已追在眉睫。该法规涉及家具常用的各种人造板的甲醛释放量。板材生产厂家必须取得第三方的检测证明，因此担心成本将会提高。负责实施该法规的加州空气资源委员会（The California Air Resources Board，CARB）估计，全球人造板厂很多，在中国就至少有1万家阔叶材胶合板厂和数百家刨花板厂。越南一些厂家已通过了认证。第三方认证要求每年进行一次。     

Ikea更新甲醛释放规范

瑞典：Ikea（宜家）公司于今年3月发表了更新过的IoS—MAT-0003规范的AA-10899—6版本,该规范对木质人造板材和产品甲醛释放的限度作了新的规定,将于今年9月实施。此外,从明年1月起,还将依照美国加利福尼亚空气资源委员会（California Air Resources Board’s,CARB）关于控制木质复合材料产品甲醛释放的规定,首先对在美国销售的产品实行进一步的质量保证,     

阻燃杨木胶合板挥发性有机化合物释放研究

选取四种品牌四种厚度阻燃杨木胶合板,待其释放稳定（第28天）,采用小型环境舱采集其挥发性有机化合物（VOCs）,并结合气相色谱-质谱法,分析挥发性有机化合物种类和含量.实验结果表明：不同品牌阻燃杨木胶合板总挥发性有机化合物（TVOC）释放量在50.14μg/m3 ～ 248.92μg/m3之间;各个板材VOCs释放量和检出物不完全相同,单个板材检出物种类最高为36种;芳香类和烃类化合物质量浓度之和占挥发性有机化合物总质量浓度的55.10％～85.72％;同时还捡出醛类、酮类和酯类等其他挥发性有机化合物;经过磷-氮-硼系阻燃剂处理的板材VOCs释放量比磷-氮系阻燃剂处理板材高;同种品牌阻燃杨木胶合板随厚度增加TVOC释放量呈增加趋势.     

欧洲板材联合会2012研讨会

木质人造板的防火性能、轻质板材和木材的热改性将成为欧洲板材联合会（EuropeanPanelFederation，EPF）2012年研讨会的议题。该研讨会将于今年10月l0-12日在德国汉诺威举行，     

阻燃无胶高密度蔗渣碎料板的研究

不施加任何胶黏剂,通过添加阻燃剂聚磷酸铵(APP)制造阻燃无胶高密度蔗渣碎料板。探讨APP含量对板材物理力学性能的影响,并利用热重分析和锥形量热分析对阻燃板材进行燃烧性能的表征。结果表明:APP的加入使板材强度有所下降,但板材强度仍能满足室内结构用板的标准要求;APP有效地抑制了蔗渣的受热分解,促进成炭;APP有效抑制了阻燃板燃烧时的热释放和烟释放。     

中密度纤维板真空热处理

中密度纤维板真空热处理旨在降低中密度纤维板甲醛释放量，并改进中密度纤维板性能。研究结果表明，在温度为６０℃、真空度为６６６６１Ｐａ（５００ｍｍＨｇ）的真空和加热条件下，中密度纤维板的甲醛释放主要集中在最初的２￣４ｈ内；甲醛释放量显著降低，同时板材的力学性能提高约１０％。     

Modeling lumber yield of white spruce in Alberta,Canada: a comparative approach

Estimation of lumber yield from a forest inventory is important in determining the optimal utilization of available regional wood supply. In this study, we review existing approaches of lumber yield estimation, including knowledge-based empirical board-foot log rules used in the United States and some regions of Canada, survey-based wood conversion factors, and optimization technology-based computer simulations. Lumber yields estimated from different approaches are then compared using six datasets from a white spruce commercial thinning experiment in Alberta, Canada. Our results indicated that (1) estimated lumber yield can be significantly different when different methods are employed; (2) board-foot log rules often underestimate lumber yield; (3) wood conversion factors represent regional average of lumber yield as a constant and thus are unsuitable for forest inventory-based lumber yield estimation; and (4) optimization technology-based computer simulations can provide the best estimate of lumber yield for a given forest inventory as long as the mill conditions and lumber dimensions from market demand are specified. Forestry investment in applying computer simulation methods should be encouraged in sawmill operations to improve lumber yield and enhance environmental protection, because, for a given amount of lumber, improving lumber yield means reduced demand for harvest operations.     

杉木生材含水率分布及其对气干的影响

以人工林杉木为研究对象,研究生材状态下不同厚度锯材含水率的差异,比较含髓心、钝棱与其他类型等3类锯材的含水率差异,建立生长轮宽度与锯材含水率的关系,分析生材状态含水率对锯材气干周期的影响。研究结果显示,25mm和40 mm的锯材含水率差异极显著;含髓心锯材含水率最低,其次是其他类的,最大是含钝棱锯材;随着生长轮宽度减少,锯材含水率增大;生长轮宽度为4 mm时,是生材含水率分界线,即当生长轮平均宽度小于和不小于4.0 mm时,锯材含水率差异极显著;25 mm和40 mm厚不同含水率锯材各2组气干至含水率25%,低含水率锯材较高含水率的气干周期分别缩短57%和66%。     

Impact of precommercial thinning on tree growth,lumber recovery and lumber quality in Abies balsamea

Abstract

Precommercial thinning (PCT) is often used to improve stand growth and value. While PCT may accelerate tree growth and reduce mortality, it may also have a negative effect on product quality. This study examined the effect of moderate and heavy thinning on tree growth, lumber recovery and quality in a natural balsam fir [Abies balsamea (L.) Mill.] PCT trial 35 years after thinning. Compared with the control, the heavy thinning increased merchantable tree diameter, stem volume per tree and lumber volume recovery per tree by 41.1%, 100.9% and 92.7%, respectively, reduced the Select Structural grade (the best grade) recovery by 33.7%. Thinning did not affect the no. 2 and better grade yield. There was a 12.2% and 15.0% difference, respectively, in the lumber bending modulus of elasticity (MOE) and modulus of rupture (MOR) between the control and heavy thinning. Moderate thinning had little impact on the visual grade recovery, lumber bending MOE and MOR. Heavy thinning is recommended if the goal is to get sizeable sawlogs in the shortest time, whereas moderate thinning is preferable if the intention is to minimize the negative effects on lumber quality while retaining modest tree growth and lumber recovery. Overall, PCT of very dense young balsam fir stands appears to be an effective and viable silvicultural treatment.     

木材规格材研究现状与展望

从轻型木结构房屋的角度阐述了规格材的用途, 包括规格材基本概念、规格材分等研究现状、规格材测试研究现状及与规格材有关的标准的研究现状等; 通过对规格材研究的展望, 提出了今后进行规格材研究的主要方向。     

Early prediction of basic density, shrinking, presence of growth stress, and dynamic elastic modulus based on the morphological tree parameters of Tectona grandis

Significant efforts have been made to improve teak; however, evaluation in juvenile step is limited. The objective of this study was to conduct an early assessment of the wood properties of 4-year-old Tectona grandis. Samples of 36 clones were collected to determine their morphological tree parameters [diameter a breast height (DBH), diameter of the second log, tree height, and log quality]. Presence of growth stress, heartwood percentage, shrinkage (radial, tangential, and volumetric), basic density, and ultrasound velocity (USV) were determined for standing trees, logs, green lumber, and dry lumber. The results indicate that DBH and USV in standing trees can be used to predict elastic module (ED), mainly ED of the standing tree and dry lumber, as well as the possible presence of growth stress. Additionally, growth stress can be predicted by UVS in standing tree. Tangential and volumetric shrinkage were not predicted by tree morphology, but radial shrinkage was predicted by diameter and UVS was not affected by any shrinkage. Basic density was predicted by DBH and UVS measured in log.     

蒸汽爆破预处理对柞木地板坯料干燥速率的影响

对柞木地板坯料进行了压力为0.25、0.4和0.55 MPa的蒸汽爆破预处理,并与未处理的对照材进行对比.结果认为:前者干燥速度分别提高了13.6%、27.3%和36.4%.蒸汽爆破预处理的压力越大,干燥速度提高的越多;在设定的试验压力范围内,柞木试材的力学强度未受影响.     

国外结构人造板研究现状与发展趋势

本文介绍了国外新型结构人造板的研发现状，重点介绍了胶合层积木、单板层积材等主要结构人造板的工艺过程、基本性能和相关标准。     

汽蒸法处理山毛榉锯材干燥工艺的研究

通过对比性试验和研究,提出用汽蒸法替代蒸煮法处理俄罗斯产进口山毛榉的新工艺。采用此工艺干燥处理后 的山毛榉,颜色鲜艳,干燥周期短,开裂和变形小,适用于木材加工业的批量生产。     

The potential of young,green finger-jointed Eucalyptus grandis lumber for roof truss manufacturing

South Africa is a timber-scarce country that will most probably experience a shortage of structural softwood lumber in the near future. In this study the concept of using young, green finger-jointed Eucalyptus grandis lumber was evaluated for possible application in roof truss structures while the timber is still in the green, unseasoned state. Drying will occur naturally while the lumber is fixed within the roof truss structure. The objectives of this study were (1) to investigate the strength and stiffness variation of the finger-jointed E. grandis product in both the green and dry state for different age and dimension lumber, (2) to investigate the variation in density, warp and checking in the lumber when dried in a simulated roof-space environment and (3) to evaluate the potential of this finger-jointed product as a component in roof truss structures. Green finger-jointed E. grandis lumber of ages 5, 11 and 18 years and dimensions 48×73?mm and 36×111?mm from Limpopo province were evaluated. The study showed that the young finger-jointed E. grandis timber had very good flexural, tensile parallel to grain, and shear properties in both the green and dry state. The mean and characteristic modulus of elasticity and modulus of rupture values of the finger-jointed E. grandis product were higher and the variation lower in comparison to currently used South African pine sources. The tensile perpendicular to grain and compression perpendicular to grain strength did not conform to SANS requirements for the lowest structural grade (S5). Both tree age and product dimension were sources for variation in the physical and strength properties. Based on the results from this study the concept of producing roof trusses from green, finger-jointed young E. grandis timber has potential.     

NS改性对落叶松材干燥性能的影响

通过NS(一种化学药剂)改性落叶松材和素材在相同干燥基准下干燥速度和干燥质量的对比试验,研究了Ns改性对落叶松材干燥性能的影响。结果表明:NS改性可显著改善落叶松材的干燥性能,40mm厚板材平均干燥速度可提高48％以上,各项干燥质量指标均高于国家二级标准,完全可满足家具等生产的需要。