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971.
汽车车厢底板用竹木复合板的研制 总被引:6,自引:1,他引:6
采用马尾松作芯板、竹片作表板、酚醛树脂作胶粘剂,制造汽车车厢底板用竹木复合板。在确定的涂胶量、热压温度、热压时间条件下,研究了不同的热压压力与竹木复合板性能的关系,得出了适宜的热压工艺条件。研究结果表明,竹木复合板的物理力学性能达到林业行业标准LY1055—91规定的指标值,为充分、合理、经济、有效地利用竹木资源提供了依据 相似文献
972.
蓝桉幼林施肥效应研究 总被引:1,自引:0,他引:1
在云南省保山市石灰岩红壤地区进行了历时4年的蓝桉幼林N、P、K不同配比的10种处理施肥试验。结果表明,施肥能明显促进蓝桉(Eucalyptusglobulus)幼林的生长;其中处理6、9、10增产效果极显著,树高增加16.31%~20.40%,胸径分别增加18.78%~19.21%,材积增加65.04%~70.19%。有机肥对蓝桉生长有促进作用,施过有机肥的处理10生长始终保持优势;磷肥是蓝桉增产的主要因素,每株施430g钙镁磷肥做底肥能使树高、胸径分别增加14.67%、15.87%,每株施215g钙镁磷肥则树高、胸径分别增加11.44%、7.83%;氮肥各水平间无差异,增产效果不明显;钾肥1、2水平间无差异,3水平可能过量,阻碍了肥效发挥。施肥能提高蓝桉生产的经济效益,较好的几个处理依次为6、9、2、10、3产出投入比值均大于对照。综合以上几个因素,N2P3K2为蓝桉幼林的最佳施肥方案。 相似文献
973.
The subject of risk management is attracting more and more attention around the world. The risk of forest fire disasters should
be faced and dealt with for forest fires cannot be avoided. Treating forest fire disasters as a risk management issue promotes
important measures and methods for fire fighters to prevent, reduce and control the risks of forest fires. In this paper,
the risk concept and risk connotation as well as the management risks for forest fire suppression are discussed clearly. Issues
such as risk judgments, risk analysis, risk control and the assessment of risk, including their contents and corresponding
methods are clarified.
Translated from Forest Resources Management, 2006, 2: 24–27 [译自: 林业资源맜理] 相似文献
974.
针对哈尔滨市南岗区果戈里大街的路面设计、施工状况的调查,分析了沥青路面裂缝原因与几个因素的关系,并结合有关资料提出一些防治措施。 相似文献
975.
落叶松木材的高强度微波辐照法改性 总被引:1,自引:0,他引:1
LIU Hong-Hai WANG Qing-Wen YANG Lin JIANG Tao CAI Ying-Chun 《林业研究》2005,16(3):237-240
The larch wood was treated by microwave irradiation under different radiant intensity and treating duration. The microwave-treated wood specimens together with the un-treated for comparison were impregnated by water in pressure vessel and then tested for permeability, mechanical properties and microstructure change by SEM to study the modification performance of microwave treatment on larch wood. The results showed that under suitable conditions of microwave treatment the permeability of larch wood was improved without noticeable decreasing of the modulus of rupture (MOR) and the modulus of elasticity (MOE). The radial parenchyma and some pit membrane were ruptured, and tiny cracks were formed in the cell walls. The formation of tiny cracks in the cell walls serves as man-made channels of gas and liquid and this contribute to improve the permeability of the wood. 相似文献
976.
Gao Zhongxin Gao Erhu ZouHongfci JinKun SuJinbaoNortheast Foresty UniversityJiang ZhigongAlbeta University Canada 《林业研究》1993,4(1):64-68
Heilongjing(China)and Alberta(Canada)provinces are situated at the same lati-tude,with similar nature conditions.Mammals in Alberta account for 87 species and in Heilongj-ing,97 spesics,among which a number of orders,families and species are in common.Continentsof Eurisia and North America histoi cally were connected and separated for several times,sothere are a number of animal forms in common,among them the similarity of herbivores is rath-er high.The similarity index of cervidae is 0.54.Other orders with comparatively similarcompiosition are Insevtivora,Chiroptera and Lagomorpha.In two orders,there are no commonspecies.In these two regions,duc to historical reasons,a number of specific genera and specieswere formed. 相似文献
977.
Growth and yield models were developed for individual tress and stands based on336 temporary plots with 405 stem analysis trees of dahurian larch(Larix gmelinii(Rupr.)Rupr.)plantations throughout Daxing’anling mountains.Several equations were selected using nonlinearregression analysis.Results showed that the Richards equation was the best model for estimatingtree height,stand mean helght and stand dominant height from age; The Power equation was thebest model for prediction tree volume from DBH and tree height; The logarithmic stand volumeequation was good for predicting stand volume from age,mean height,basal area and other standvariables.These models can be used to construct the volume table, the site index table and other for-estry tables for dahurian larch plantations. 相似文献
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