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1.
间伐小径木指接技术研究 总被引：7，自引：0，他引：7
间伐材指接胶合加工，变短材为长材，弯材为直材，为合理，有效利用间伐材开辟了新路。对间伐材木材含水率，指接端压的大小和时间，指接后养护时间，涂胶量，指榫规格等对指接材抗弯强度的影响进行了研究，并测定了苯酚，间苯二酚，甲醛树脂胶胶合的指接材快速老化性能。 相似文献
2.
测定研究了不同直径兰考泡桐的根材和枝桠材的各种解剖因子及其基本密度，结果表明：兰考泡桐根材和枝桠材构造区别明显，不同直径的根材和枝桠材木材解剖性和基本密度均有变异，仅少数指标差异显著，根材和枝桠材相比，基本密度和木纤维含量为枝材＜根材，其余因匀为根材＞枝材。进一步分析论证表明，根材和枝桠材是刨花板的好原料；而枝材适宜于生产纤维板，但根材不合适。 相似文献
3.
对南洋楹枝桠材和间伐小径材分别进行了制浆造纸的试验，结果表明，枝桠材和间伐小径材的制浆造纸性能接近规格材。为充分利用南洋楹资源提供了依据。 相似文献
4.
利用黑荆树干材、枝桠材、树皮为原料制造粉状活性炭，与其他原料制造的粉状活性炭的质量对比，说明利用黑荆树干材，枝桠材、树皮废渣制活性炭是可行的，为活性炭的制造提供了原料来源。 相似文献
5.
白桦枝桠材制造刨花板的优化工艺 总被引：1，自引：0，他引：1
以白桦枝桠材为原料，在测定材质的基础上对制板工艺进行研究，提出了制板的优化工艺参数，利用白桦枝桠材制造优质刨花板，将为枝桠材的有效利用开辟新途径。 相似文献
6.
以森林经营模式理论为指导，提出了湿地松纸浆材原料林模式林分的最适经营密度模型，编制了湿地松纸浆材原料林模式林分的生长过程表，以期为现实湿地松纸装材原料林的经营提供科学的参考依据。 相似文献
7.
运用６００－ＥＸ型锥形除砂器，对落叶松硫酸盐浆中早、晚材纤维进行了分离。通过正交试验运用极差分析方法，得出了影响分离效果折因素大小次序为纸浆浓度、除砂器下出口径和进浆压力；最佳操作工艺条件为纸浆浓度０．２５％￣０．２２％，进浆压力０．５ＭＰａ、出渣口径为Φ１０．７４ｍｍ。分级前原浆中早材纤维含量为４３．２％；分级后早材浆中早材纤维为７８．７％，晚材浆中早材纤维为７．６６％。 相似文献
8.
以提高刺槐矿柱材出材率为目标。根据矿柱材小头直径≥８ｃｍ出材标准要求，直接量测了立木柱材高度。通过对立木柱材高度的变异分析，以及与生长性状、干形性状、冠枝性状间的相关分析，表明：立木柱材高度是一个能综合反映生长和树干干形的性状。 相似文献
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10.
秦洪清 《云南林业调查规划》2000,25(2):28-31
云南省森林采伐限额中，烧材的比重，“八五”为５１．２％，“九五”为５５．６％，造成烧材消耗量过大的原因，除了自然地理的原因之外，还有计算方法和调查方法上的原因，并论证了烧材的合理消耗量，以及解决途径。 相似文献
11.
HU Yanjie LIN Fengming SHI Kunshan Research Institute of Forestry Policy Information Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2007,6(2):62-73
The historical transition of timber distribution pattern in China was presented firstly with main parts of timber flows in China, which included timber markets, timber transport system and regulations of timber transport. Based on the overview on tropical timber flows in China, the trade flows of tropical timber from production and imports of tropical timber to export of tropical timber products were analyzed by vivid illustrations. At the same time, problems in timber trade flows in China were analysed in the end. 相似文献
12.
预测2010年东北、内蒙古地区木材的供需状况。到2010年区域木材供给量为4808.50万m^3,其中区域木材产量占58%,从俄罗斯进口的木材占42%。木材的需求量为6475.81万m^3,供需缺口达1 667万m^3。不考虑区域外的需求及国外的需求,东北、内蒙古地区的木材供给还是能够满足本地区经济建设需求的。木材供需的缺口对本地区木材需求不会造成太大的影响,但却对其他地区对木材的需求将产生重要影响。对于东北、内蒙古地区而言,俄罗斯远东地区是理想的木材供应基地,应规范企业的对俄木材贸易,将这一地区开发成可持续的木材供应市场。 相似文献
13.
Okumu Gordon Wanyama Kei Sawata Takuro Hirai Akio Koizumi Yoshihisa Sasaki 《Journal of Wood Science》2012,58(4):315-321
In this study, an experimental study was conducted on the nailed timber–plywood–timber joints extended from the standard wall–floor joints of wooden light frame constructions, where the bottom plates of shear walls are nailed to the floors consisting of joists and floor sheathings nailed to them. The principal conclusions are as follows: The allowable lateral resistance of the nailed timber–plywood–timber joints can roundly be estimated by neglecting the plywood panels if their densities are higher than those of the timber main-members and they are fastened effectively onto the timber main-members. The stiffness of the timber–plywood–timber joints is less than that of the control timber–timber joints, which is improved by increasing the number of nails used to fasten the plywood panels onto the timber main-members. The stiffness of the joints whose floor sheathings are glued onto the joists is equivalent to the control timber–timber joints. The timber–plywood–timber joints with appropriate specifications have greater energy capacity until the failure than that of the control timber–timber joints. This ensures their energy capacity, which is important in dynamic resistance, to be equivalent to the control timber–timber joints. 相似文献
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15.
Kiln-dried and air-dried Sitka spruce battens were exposed to outdoor weathering within stickered, close packed and wrapped
packs and at the upper surface of these packs. A four-week exposure period was used in James Jones and Sons Ltd. sawmill yard
near Aboyne, NE Scotland. The wettability of batten samples removed from the packs of timber was determined by a drop contact
angle method using a video tape technique. Timber exposed to air drying before weathering in the experimental packs generally
had a greater wettability than kiln-dried timber at the end of the exposure period. However, kiln-dried timber stored in stickered
packs developed a greater wettability than similarly stored air-dried timber, suggesting that the kiln drying process increased
the susceptibility of timber to developing increased wettability. Close-packed timber protected from sunlight and rain water,
by covering the upper surface of the pack with microporous plastic sheeting, maintained a lower wettability than unprotected
close-packed or stickered timber. Fungal spoilage was unlikely to develop on timber stored in pack types which developed high
timber wettability, the storage conditions leading to an increase in wettability were adverse to fungal development. Kiln-dried
timber stored in stickered packs in the sawmill yard may become particularly vulnerable to fungal attack if subsequently exposed
to damp conditions in service.
Received 15 October 1998 相似文献
16.
基于效用函数的木材物流网络中的运输木材量控制研究 总被引：1，自引：0，他引：1
在木材物流网络中,降低木材物流成本,提高木材物流效率成为亟待解决的突出问题,而木材量的控制对于木材物流网络中的成本控制是一个极具挑战性的问题。针对上述问题,在研究木材运输成本控制的基础上,提出一种新的木材物流网络中的运输木材量控制方案来解决木材运输过程中的成本过高问题。此方案基于效用函数理论,来最小化木材物流网络中的运输成本。文章中围绕运输木材量控制模型展开讨论,构建基于效用函数的运输木材量控制模型,并研究模型的有效性,通过数字化仿真进行模型及结果验证。仿真表明通过所构建的模型可以得到木材物流网络中的最优化的运输木材量控制,从而有效的降低木材运输过程中的运输成本。 相似文献
17.
通过小径木的力学性能分析，确定小径木可以作为新式木结构房屋的主要建筑用材，从而拓展了小径材在建筑行业的应用领域，使低价值的小径木原材料变成高附加值的建筑产品。 相似文献
18.
Klaus Zimmermann Tobias Schuetz Holger Weimar 《European Journal of Forest Research》2018,137(4):463-475
In this study, we explore the determinants of forest enterprises’ timber storage accumulation after severe storm events. The explanatory power of variables reflecting economic, institutional and tree species-related factors is tested via econometric analyses. Timber storage accumulation is assessed conducting a weighted multiple linear regression analysis. In addition, the moderating effect of timber price alterations on timber storage accumulation is tested employing timber price alterations as a moderator variable in a hierarchical regression analysis. The results show a linear positive relation between forest enterprises’ damaged and stored timber quantities. It was found that coniferous timber was stored to a greater extent than non-coniferous timber which can be explained by higher storm damage as well as better suitability for multiyear storage. State forestry stored the highest shares of damaged timber, followed by municipal and private forest enterprises, which can be explained as a countervailing measure. A further central finding of our study is that the timber price drops after storm events act as a moderator variable on the relation between damaged and stored timber quantities. Hence, empirical timber price reactions help to improve estimation accuracy regarding the shares of damaged timber which are stored. Derived from our results, we find timber storage accumulation to be a common practice by forest companies to mitigate revenue losses caused by extreme storm events. As coefficients vary strongly among the analyzed variables’ categories, we consider case-specific storage accumulation estimations to be crucial for improving the accuracy of national wood and timber accounting, but also for a full view on storm-related economic damage in the forest sector. In addition, it is likely that capturing the proportions of timber storage in forests will gain relevance in the future, since forest damage from natural disturbances is expected to increase as a consequence of climate change. 相似文献
19.
Static bending tests and compressive test parallel to the grain of sugi (Japanese cedar, Cryptomeria japonica) green round timber were conducted to confirm whether its strength would satisfy the referenced strength determined by the Construction Ministry. The strength of green round timber and air-dried round timber were compared for bending and compression parallel to the grain. The strength change ratio in response to a 1 % change in the moisture content of round timber was compared with that of small clear specimens and timber. The results revealed that a 5 % parametric tolerance limit of bending and compressive strength parallel to the grain satisfied the referenced strength, even when using green round timber. The average strength of air-dried round timber was higher than that of green round timber, in both bending and compression parallel to the grain, with significant differences indicated at a 5 % significance level. The relation between the cross-section area that includes round timber, timber and the small clear specimens, and the strength change ratio in response to a 1 % change in moisture content change was fitted to a logarithm curve. Thus, the size of the specimen was considered to affect the strength change ratio. 相似文献
20.
基于2018—2020年浙江省龙泉市900宗活立木交易数据,采用半对数多元线性回归模型研究木材市场价格、单位面积蓄积、林分质量等因素对活立木交易价格的影响。结果表明,龙泉市活立木交易平均价格为3 976元/hm2,木材市场价格、单位面积蓄积、单位面积株数、平均胸径对活立木交易价格有显著的正向影响;流入方性质和流出方性质对活立木交易价格有显著影响,且影响存在差异性。提出规范木材市场交易,加强森林资源评估工作,提升交易的公平性,全面推进林权抵押贷款等建议。 相似文献