学科分类

已选分类 工学林业工程木材科学与技术
单选题The major forest products include ______. A. full tree、 long log、 short log, chip B. full tree、 round log、 short log, chip C. whole tree、 long log、 short log, sawtimber
进入题库练习
单选题If the timber has been purchased on a lump-sum basis, inattention to bucking decisions can create large financial losses to ______. When timber has been purchased on a (per unit of volume) harvested basis, the losses associated with miss cut logs are borne by the ______. A. timber buyer, landowner B. landowner, timber buyer C. forest manager, logger
进入题库练习
单选题According to the way the machine operated, the felling machine can be classified into ______. A. three-wheel machine vs. four-wheel machine B. drive to tree machine vs. swing to tree machine C. saw-head machine vs. shear-head machine
进入题库练习
单选题椴木树种管孔分布的特征为( )。 A.散孔材 B.半散孔材 C.环孔材 D.半环孔材
进入题库练习
单选题深虫眼是指昆虫蛀蚀圆材的深度自( )以上的虫眼。 A.1mm B.10mm C.3mm D.3cm
进入题库练习
单选题When timber has been purchased on a (per unit of volume) harvested basis, the losses associated with miss cut logs are borne by the ______. If the timber has been purchased on a lump-sum basis, inattention to bucking decisions can create large financial losses to A. landowner, timber buyer B. timber buyer, landowner C. forest manager, logger
进入题库练习
单选题The major forest products include ______. A. full tree. long log. short log, chip B. full tree. round log. short log, chip C. whole tree. long log. short log, sawtimber
进入题库练习
问答题一根锯切用原木,树种为落叶松,材长4.17m,小头短径35.9cm,长径38.4cm。靠小头检尺长终止线上有一活节,尺寸为9.6cm,靠大头有一死节,尺寸为7.8cm。检尺长范围内节子最多1m内有活节三个,死节两个,尺寸分别为5.8cm、3.6cm、2.9cm、6.5cm、2.5cm。没有其他缺陷,求此材检尺尺寸、缺陷百分率和1m内节子个数。
进入题库练习
问答题影响木材力学性质的因素有哪些,它们对木材的力学性质有何影响。
进入题库练习
问答题Please make a detailed companson of CTL vs. Tree-Iength methods.
进入题库练习
问答题木材做为一种室内装修装饰材料具有其特殊的效果,谈谈你对木材这种效果的认识。
进入题库练习
问答题Please make a detailed comparison of cut-to-length vs tree length method.
进入题库练习
问答题Please describe and discuss the timber harvests in depth including the categories and their respective target, purpose, and criteria.
进入题库练习
问答题有一根双桠材,一根干岔的长度为4.18m,短径30.6cm,长径34.1cm;另一根干岔的长度为3.96m,短径27.5cm,长径30cm,求此原木的检尺长和检尺径。
进入题库练习
判断题木材具有一定的导电能力主要是因为在木材中具有一定的自由离子。( )
进入题库练习
判断题红松、落叶松、云杉、臭松,这些树种中都有正常的树脂道。( )
进入题库练习
判断题在树木直径生长过程中,生成的木质部的量要小于韧皮部。( )
进入题库练习
判断题幼龄材不是指幼小的树,而是未成熟的木质部,它属于初生木质部。( )
进入题库练习
判断题有些木材具有很好的声学性质,因此在乐器行业木材应用广泛例如云杉、泡桐等都是很好的共鸣板
进入题库练习
不定项选择题木材中的水分有两种,在针叶树材中自由水的移动途径主要是管胞和( ),阔叶树材中自由水的主要移动途径是( )、穿孔以及环管管胞和导管状管胞等。 A.导管 B.侵填体 C.木纤维 D.纹孔
进入题库练习