人工林主伐生产工艺研究

研究表明，采用“山猫”轻型油锯和“ＳＪ２—０．４／２”轻型遥控索道等小型、轻型化机械系统的伐倒木集材工艺是比较适宜的人工林主伐生产工艺。     

基本型动力链锯锯木参数的研究

本文在试验的基础上,考查链锯锯木参数中的切削速度,同名齿进给量,锯口长度和进锯角变化对锯切指标的影响,得出了上述参数影响锯切指标(切削力、锯木功率。锯木生产率、单位锯切功)的方差分析结果,进一步采用逐步回归分析方法,得到含有主要影响因素的各锯切指标的回归公式,对链锯设计与计算有着重要意义。     

链锯模拟试验台微机检测部分的程序设计

本文介绍了T—2B型链锯模拟试验台中微机检测部分的硬件结构和程序设计。给出了微机检测部分的结构图,A/D转换器和微机的连接图,主程序框图和中断服务程序框图。重点介绍了链锯切削参数的采样程序,各切削参数工程值转换程序,数据处理以及“间竭”打印程序的设计方法和技巧。同时还给出一些主要的实用程序。     

War on foot and mouth disease in the UK, 2001: Towards a cultural understanding of agriculture

This article applies some ofthe insights from framing studies in policyresearch, metaphor analysis, and the history ofmedicine to a cultural understanding ofagriculture, using the 2001 outbreak of footand mouth disease in the UK as a case study.The article will show how metaphors of war wereused as a rhetorical frame by the media andas an implicit action frame by policy makers.It will be argued that although the war framemight initially have been useful in rallyingsupport for the slaughter policy, the metaphorlater backfired, when a metaphorical war turnedinto a literal holocaust. This might haveencouraged the public to perceive the policy asmedieval, brutal, and misguided, thuspotentially undermining the willingness ofsections of the public to support the slaughterpolicy in future outbreaks. If, on the otherhand, a vaccination policy were adopted in thefuture, care would need to be taken to avoidmetaphorical linkages with other controversiesover vaccination in other domains.     

锯叶棕体细胞胚胎发生及植株再生体系的建立

从锯叶棕成熟种子中成功实现体细胞胚胎发生和植株再生。成熟种子放在MS培养基上培养，加入0.15%活性炭，452 μmol/L 2,4-D和14.7 μmol/L N6-2iP，所有成熟合子胚培养5周后长出体胚簇，12周后，外植体转移到2,4-D浓度减到90.4 μmol/L的MS培养基中进行体胚增殖，之后体胚转移到含有0.9, 9 μmol/L TDZ或没有生长调节剂的基本培养基中转化成小植株。9 μmol/L TDZ对植株再生是无效的，然而，在0.9 μmol/L TDZ中作次培养有12%胚胎能长成完整植株，没有生长调节剂中35%胚胎长出嫩枝，这些嫩枝转移到含有22.2 μmol/L NAA的培养基中全部都会生根。picloram和2,4-D对锯叶棕幼苗愈伤的诱导效果最佳，6-BA次之，对子叶来说，picloram和2,4-D对愈伤的诱导起不到任何作用，而对茎尖的诱导效果最好。     

基于单片机的推台锯控制系统的研究

研究了精密推台锯的控制系统,在确保并进一步提高控制精度和性能的前提下,采用成本相对较低,但性能优良的单片机作为控制核心,驱动步进电机控制推台锯的各项参数,通过步进电机的细分驱动技术,可以非常方便的提高参数的控制精度。本系统由液晶显示器实时显示推台锯的运行状态,并以菜单形式显示各项操作,操作界面非常简洁,比较直观且操作方便。     

承载75t框架车车架的有限元分析

在UG环境下,建立了承载75 t框架车车架各零件的三维实体模型,装配成车架总成后,以Parasolid格式输入到ANSYS软件中,以得到该车架的有限元模型。并利用ANSYS软件分析了该车架在5种不同工况下的静态特性。分析结果表明该车架的设计方案是可行的。     

Measuring the outer shape of Pinus sylvestris saw logs with an X‐ray LogScanner

The accuracy of measuring the outer shape of Scots pine (Pinus sylvestris L.) saw logs with an X‐ray LogScanner has been compared with the accuracy of using a 2‐axis optical scanner, a 3‐axis optical scanner and an ideal 3‐D optical scanner. The different scanners were simulated using computed tomography (CT) data from the Swedish Stem Bank. The outer shape of 60 saw logs was measured every third centimeter. The error attributable to bark when using optical scanners was simulated separately. The results from the simulations showed that when measuring the outer shape on bark, the X‐ray LogScanner facilitated measurement of the minimum shadow diameter with the same accuracy as with a 3‐D optical scanner. The results also showed that the potential of combining the X‐ray LogScanner with a 3‐D optical scanner should be investigated.     

室外木结构用胶粘剂胶合制品分层试验对比

以红松、落叶松、杉木和桦木为试验材料，使用苯酚-间苯二酚-甲醛树脂胶粘剂（RPF）和酚醛树脂胶粘剂（PF），将试材顺纹胶合成抗分层试件，经过3个真空-加压-真空-加压-干燥循环，研究2种胶粘剂的抗分层能力。试验表明，RPF树脂与PF树脂的抗分层能力相近，桦木试件的抗分层能力低于其他木材试件。     

基于圆木带锯切速度控制的优化设计

根据切割效率最大化的基本要求,推导出去除率与进给速度、时间的方程式,解决了切割机设计中长期存在的效率问题;并建立了当去除率为恒定时,剪切速度与时间的关系曲线。运用该方法进行圆木切割机设计,可以提高设计的科学性和准确性,具有较高的应用价值。