新型木材削片机的结构特点

从传统削片机存在的缺点和不足的角度入手，概述了当今国外削片机为提高削片质量、减少冲击和振动、提高削片效率所采取的措施和方法，并分析了新型削片机的结构特点。     

小型削片机的推广应用

介绍了小型削片机的组成及几种主要型号小型削片机的技术参数,给出了削片生产注意事项.     

沙柳试验削片机切削机构的设计

沙柳材在人造板制造中存在嫩梢切断困难,功率不匹配、削片质量不佳等问题。结合沙柳的特性,设计并生产了沙柳试验削片机切削机构,寻找适合沙柳削片的最佳切削参数。通过计算沙柳切削阻力矩,设计驱动电动机功率为22 k W,降低了功耗;采用鼓式削片机铣削方式削片,对刀辊进行飞轮设计,使生产能力达到5 m3/h,提高了生产效率;采用单因子试验方法计算6种切削角度下的削片合格率,确定了当切削角度为45°时削片合格率较高,合格率可达72.45%,提升了削片质量。不仅验证了机器设计的性能,也为后期切削速度、进料速度的测定试验和新型沙柳削片机的设计提供了理论依据。     

纤维板生产过程中削片机噪音及废水的处理

湿法纤维板生产过程中有二大污染源,一是噪音,二是废水。我们通过对削片机设备的改造,对废水处理采用建造污水池等措施,解决了二大污染问题。 1 降低SO_3型削片机噪音 1.1 削片机组的噪音分析 削片机组的噪音主要是削片机主机产生的,其次是风送机。根据环保局来厂实测,削片机正常工作时噪音为105dB,有时高达110dB,即使空载运转也达到97dB。而国家标准规定,每天工作8h噪音不得超过90dB。可见削片机的噪音值已大幅度超过国家标准。     

伐区剩余物削片简易压缩包装装置

为了充分利用伐区剩余物，根河林业局前几年推广使用了伐区移动式削片机，该机由Ｊ—５０集材拖拉机和固定式削片机改装而成。首先将Ｊ—５０上的搭载板和绞集装置卸去，然后将削片机安装在Ｊ—５０的车架上。削片机的动力来源是在Ｊ—５０原绞集动力输出轴上安装一皮带轮，驱动削片机的工作。移动式削片机的优点是直接进入伐区内的副道上工作，将直径３～１２ｃｍ，长度２ｍ以下的枝桠、树头进行削片，充分利用了伐区剩余物，为国家节约了大量木材。进行伐区剩余物削片可为根河林业局刨花板厂生产刨花板提供丰富的木材原料。 对伐区剩余物…     

几种新型伐区削片生产设备

本文介绍了近年研制成功的适于伐区应用的削片机、木片运输车、移动式木片筛选机、森铁削片筛选车等七种新型伐区削片生产设备,以及它们的适用范围、技术性能及其优缺点。     

刀具前角与切削量对柠条材切削力影响的研究

内蒙古地区灌木资源十分丰富,柠条、沙柳等灌木是防风固沙的优良树种,同时又是生产人造板的优质原料,但在削片加工过程中存在木片质量不稳定、树皮切不断等问题。从刀具前角和切削量对柠条材切削力的影响进行深入研究,寻求柠条材最佳切削参数,以改进削片机性能,提高柠条材削片质量,为新型沙生灌木削片机的设计与研制提供理论依据。     

林机大事记

▲由林业部哈尔滨林机所研制的800系列三种型号:BX638、BX138、BX618削片机技术鉴定会于1991年5月21～22日在内蒙古伊图里河林机厂通过技术鉴定。BX638自走式削片机是由林场使用的J-50集材拖拉机改装而成,可进行集材和削片生产的换季作业,能深入伐区削片。既可节省投资,又可达到一机多用的目的;BX618是自带4105或4115柴油机的双轴拖挂式设备,适于缺乏电源的山上楞场或集材道旁削片作业;BX138爬犁底式电动削片机主要用于有电源的单位。鉴定会后,由伊图里河林机厂等单位批量生产。     

浅析鼓式削片机的几个设计问题

本文就鼓式削片机削片过程中的运动分析，受力分析等设计计算问题进行了讨论。     

用PC中的CNTR指令监控机械传动速度

在纤维板、刨花板的生产自动线上,备料工段中的削片部分是由木片料仓、刮板运输机、削片机、2号进料皮带运输机、1号进料皮带运输机等五台设备组成。其中木片料仓中的液压泵站、出料螺旋等是由备料工段的下一部分所控制,削片部分只受料仓的高料位计控制。削片机由刀轮及上、下喂料辊三部分组成。它的工艺布置见图1。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.