运材汽车后桥的使用与修理

介绍了运材汽车后桥的使用和修理方法,对提高运材汽车的使用寿命具有一定的参考价值。     

运材汽车的选择

从众多类型中选择适合本企业需要的运材汽车,是新建企业汽车运材规划和老企业运材汽车更新要解决的重要问题。也是从国外引进运材汽车的关键环节。选择运材汽车的目的是为林业企业内部木材运输提供优良的技术装备。同时,运材汽车选择得是否恰当,还将直接影响运材生产率和运材成本。所以,选择运材汽车的原则应该是技术上先进,经济上合理,生产上适用。也就是说,要从技术和经济上综合起来加以选择。选择运材汽车的依据在于对运材汽车进行正确的评价。     

汽车运材工艺设备的新结构及应用

在汽车运材作业中,运材工艺设备的结构及其性能直接影响汽车运材的效率。随着汽车运材的发展,国内外先后出现了一些工艺设备的新结构。本文对其进行分类,指出其特点、新颖性和应用条件,有利于我国今后汽车运材工艺设备的研制和使用。     

林区运材汽车的选型

运材汽车的选型,对采用汽车运材的森工企业是十分重要的问题,同时又是一个比较复杂的问题,一定要慎重从事。运材汽车是森工企业的主要生产设备之一,选型正确与否,将直接关系到企业     

汽车运材经济效益的评价

本文阐明了汽车运材经济效益的含义,从汽车运材经济活动过程入手,抓住评价汽车运材经济效益的三个关键性指标,即车吨产量、单位运材成本和运输质量,并提出三个指标的计算公式,作为汽车运材经济效益评价的主要指标。     

对黑龙江林区木材运输方式的探讨

本文用数理统计方法,对森林铁路(以下称森铁)运材、汽车运材的经济指标进行了相关分析,得出了单位成本随年运量、平均运材距离而变化的经验公式。通过对单位成本的比较,提出了森铁运材和汽车运材各自的适宜范围。同时,对汽车与森铁接运运材方式予以评价。对森铁改为汽车运材的可行性进行了探讨,以便取得好的经济效果。     

国产斯太尔汽车用于运材的试验研究

介绍了采用国产斯太尔1491.280/043.6×4型汽车用于运材试验的研究过程。通过对8辆该型汽车,经过两个冬运期的木材运输试验,总结出了17项试验对比数据。并对该型汽车的可靠性、经济性、维修性、适用性及主要技术经济指标等项目进行了全面、科学分析和考核。采用的试验方法科学合理,试验数据准确、可靠。对木材运输企业在重型运材汽车选型及使用经验方面,具有重要的理论和使用参考价值。     

运材汽车经济寿命计算方法的探讨

汽车使用期限的长短,直接关系到运材费用的高低,能使汽车在使用期内平均费用最少的使用期限叫做汽车的经济寿命,它是确定汽车最佳更新期的依据。目前,我国林区不少运材汽车使用期超过了经济寿命。因此,认真地探讨运材汽车的经济寿命,及时更新老龄车辆,进一步提高林业企业管理水平和提高企业经济效益,是具有现实意义的。林区运材,特别是北方林区,季节性很强,冬忙夏闲。每年5—8月,运材汽车多     

运材汽车承载梁上载荷分配问题的浅析

运材汽车列车承载梁上载荷的正确分配，是关系到运材汽车列车各轴轴荷的大小，牵引汽车动力性，制动性和操纵稳定性，以及牵引汽车和长材挂车的使用寿命和运材汽车的行驶稳定性，运材生产率和运材成本等一系列技术经济问题。     

汽车运材板式轨道的研究

作者根据运材岔线和装车场的装车线具有临时性的特点,研制了可拆卸的汽车运材钢筋混凝土板式轨道。其设计是把水泥混凝土板块作为纯受弯构件,在荷载作用下,根据破坏的不同阶段,并考虑到平截面、弹性体和受拉区不参加工作等假设条件,用许用应力法和极限状态法分别进行设计和比较,确定出适用于不同车型和运材方式的板块。     

Improved harvesting systems for wet sites

Environmentally acceptable and economical forest operations are needed for sustainable management of forest resources. Improved methods for harvesting and transporting timber are especially needed for wet sites. As the demand for hardwood lumber continues to increase, improved and alternative methods are needed to ensure acceptance of timber harvesting for the wet site conditions that are typical of bottomland hardwoods. Some alternative technological developments include grapple saw feller-bunchers, wide tires, larger forwarders, clambunk skidders, two-stage hauling, mats, cable systems, helicopters and towed vehicles and air-cushioned vehicles. These developments have the potential to improve the performance of the harvesting system and to reduce the negative effects of conventional operations on conventional sites and on difficult sites such as wet areas. Although many of these new alternatives are now operational, others are just concepts or evolving prototypes. More research is still needed to optimize these alternative technologies and to reduce costs associated with their implementation.     

基于效用函数的木材物流网络中的运输木材量控制研究

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。     

南平市建阳区竹山机耕路建设SWOT分析

研究运用SWOT方法系统分析南平市建阳区竹山机耕路建设自身所具有的优势和劣势及外部所面临的机遇和威胁,提出建阳区竹山机耕路建设的战略与对策。结果表明:建阳区竹林资源丰富、交通条件有所改善,竹山机耕路建设优势较为明显,同时政策支持与竹产业股的成立为机耕路建设提供了一定的发展机遇。但基础设施的相对落后与管护模式的不合理及法律法规的不完善与自然灾害的影响成为区域竹山机耕路建设的劣势和威胁。因此,须结合区域自身特点,因地制宜,扬长避短,实现建阳区竹山机耕路的全面开发建设。     

基于GIS和RS技术的木材运输线路优化研究——以吉林省汪清林区为例

林业运输线路优化是林业物流和林业企业木材生产流程中重要部分。以吉林省汪清林区为研究区,基于网络最短路径模型和GIS、RS技术以及伐区、集材和运材等环节约束条件,构建伐区运输线路优化模型,确定伐区木材运输最优线路,并对选取的运输线路进行综合实证分析。     

试谈贮木场改建设计中的几个问题——对山河屯林业局贮木场改变到材方式的思考

磨盘山水库的建设,影响到山河屯贮木场的到材方式,原来的森铁运输有可能改为汽车运输, 贮木场的作业天数、结存量以及生产工艺等发生变化,对贮木场改建设计产生诸多影响。     

Snag density varies with intensity of timber harvest and human access

Many species of vertebrates depend on snags (standing dead trees) for persistence, and limited research suggests that snag density is lower in areas of intensive timber harvest and increased human access. While intensive timber harvest is one source of potential snag loss, ease of human access to forest stands may also facilitate loss via firewood cutting of snags. Accordingly, we hypothesized that density of snags (number of snags/ha) would decline in forest stands with increasing intensity of timber harvest and increasing ease of human access. We tested our hypothesis by sampling stands under varying levels of timber harvest and access on National Forest land in the northwestern United States. Stands with no history of timber harvest had 3 times the density of snags as stands selectively harvested, and 19 times the density as stands having undergone complete harvest. Stands not adjacent to roads had almost 3 times the density of snags as stands adjacent to roads. Unharvested stands adjacent to non-federal lands and closer to towns had lower snag density, as did stands with flat terrain in relation to nearest road. Our findings demonstrate that timber harvest and human access can have substantial effects on snag density. Meeting snag objectives for wildlife will require careful planning and effective mitigations as part of management of timber harvest and human access.     

Softwood sawlog secondary transport travel speed prediction for the South African forestry industry

The objective of this study was to develop a predictive model for travel speed of softwood sawlog timber transport (STT) vehicles over a range of forest and provincial roads of varying condition for the South African forestry industry. Data was accumulated from both the Eastern Cape/KwaZulu-Natal and Mpumalanga forest regions of South Africa. Vehicle location and payload data were collected remotely using a combination of GPS tracking and remotely sensed data. Road condition, including road width, was assessed for each identified road segment in-field according to a visual condition indicator (VCI) index. Two STT contractors were selected from each forest region transporting pine sawlogs directly from compartment roadside landings to either a processing plant or log storage area. Five STT vehicle types, representative of transport operations in the two forest regions, were assessed. Principal component analysis was conducted to determine the degree of communality between the respective predictor variables combining road width and VCI as one factor, and truck maximum power and the percentage of (legal) maximum payload as a second factor. Comparisons of the correlations between average speed and the respective predictor variables showed that road width and percentage of maximum (legal) payload had the highest correlations. Multiple linear regression of these two factor variables were used in the model showing both variables as significant (p < 0.05) with an adjusted r² value of 0.52.     

Investment Potential of Private Forests in Croatia

This paper presents a comprehensive financial analysis of the investment potential of seven private forest categories in the Republic of Croatia (total study area of 268,072 ha). It covers the period from 2018 to 2048 and includes forest purchase costs, management simulation, timber transport to mills, timber processing and veneer production, and finally the selling of sawmill, veneer and forest products. Data from the Croatian National Forest Inventory and forest habitats map were used as a basis for analyses. Spatial data on private forests, roads and timber process plants at the national level were also integrated into the analyses. For the forest management simulation, the MOSES 3.0 simulator was used, and the QGis 3.4 software was used for spatial analyses of forests, roads and mils. Based on data from several world stock exchanges that cover companies of the forestry sector, a real (inflation-free) discount rates were used. The financial analyses showed which forest categories have positive investment potential and under which conditions. Results pointed out that multi-aged European beech forests have the highest internal rate of return (8.45%) and are the only one which would meet the expectations of a financially rational investor using criteria of a risk-adjusted inflation-free discount rate of 8%.     

架空索道转弯结构及其应用问题的探讨

本文在此介绍又一种造价更为低兼，但对目前研究新型架空索道转弯结构很有参考价值的林用无支架绷拉鞍座转弯集运材索道的转弯结构，供共同探讨。     

Heterogeneity of linear forest formations: differing potential for biodiversity conservation. A case study in Italy

Trees outside forests (TOF) are important elements of the landscape and they supply goods and environmental services such as commercial production of timber and fibre, domestic production of food and firewood, carbon sequestration, conservation of habitats and species (plants and animals), erosion control and soil and water quality improvement. TOF include different types of landscape elements: small woodlands, trees along linear features such as property boundaries, roads, railways, rivers and canals, hedgerows or linear forest formations, groups of trees and isolated scattered trees, which have also different ecological functions. The article focuses on the importance and role of linear forest formations (LFF) in the rural context, with special reference to the biodiversity conservation function. It presents the results of research done in the Veneto region, north-eastern Italy. The authors have designed a sampling scheme for LFF based on the Italian National Forest Inventory and tested an indicator system in order to evaluate the quality and biodiversity of the LFF. The indicators used are: LFF type and tree species composition, vertical structure and canopy cover, naturalness, introduced species and deadwood (standing and lying). The main advantages and limitations of the applied method are discussed.