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1.
方正林业造纸厂是我国林业系统最大的造纸厂,产品品种为挂面牛皮箱板纸,设计规模为3.4万t/年。造纸车间原料为:以制浆车间来的阔叶材半化学浆为底浆,以针叶材化学浆为面浆。1打浆工段1.1主要设备①ZNW21型圆网浓缩机面积5m2;转鼓规格1500mm×1065mm;生产能力3~3.5t/m2·d;进浆浓度1%~2%,出浆浓度4%。②ZNW23型圆网浓缩机面积15m2;转鼓规格1500mm×3330mm;生产能力3~3.5t/m2·d;进浆浓度1%~2%;出浆浓度4%。③450双盘磨ZDP-11型,…  相似文献   

2.
火炬松纸浆林材性变异和优质原料培育期的确定*   总被引:6,自引:2,他引:6       下载免费PDF全文
16年生火炬松纸浆材性状研究表明:管胞长度径向呈递增稳定的模式,纵向呈递减变化;其长宽比变异类似于管胞长度的变化;管胞长度变化范围为1.403~4.456mm,长宽比为46.7~70.1,腔径比为0.711~0.786,壁腔比为0.381~0.496。基本密度径向由0.324g/cm3递增到0.428g/cm3;纵向递减,其均值变动于0.314~0.401g/cm2;株间木材密度均值与管胞长度两性状不相关。纤维素含量由髓心附近37.04%递增到树皮附近43.91%,木素、多缩戊糖含量分别由28.78%、14.59%递减到25.74%、12.05%,其苯醇抽出物含量变化在2.12%~8.38%之间。火炬松木材幼龄期约为10~13a。基于火炬松木材各树龄材性的变化,结合生长量指标,确定其短周期纸浆林适宜采伐树龄约为12~13a。  相似文献   

3.
对美洲黑杨×小叶杨新无性系木材性状遗传相关分析结果表明,年轮宽度与早材宽度、晚材宽度遗传相关比较密切;与晚材率之间相关很弱;而年轮密度与早材密度、晚材密度、最小密度及最大密度之间遗传相关密切(ry=0.84-0.95),与早晚材密度比及木材密度相关很弱;年轮密度与年轮宽度之间呈负弱相关。  相似文献   

4.
研究了兰考泡桐(Paulowniaelongata)木片用4种酶液(纤维素酶液ES28、半纤维素酶EAn76、木质素酶E025及E014)预处理制生物机械浆。测定了预处理对木片主要化学组成、磨浆能耗、纸浆强度的影响。结果表明:(1)E014、E025、ES28、EAn76预处理后,木片失重3.18%~3.72%,其中3.9%~18.6%为木质素损失,纤维素损失则高达38.2%~46.2%;(2)磨浆度为55SR时,4种酶液可节省能耗2.0%~7.0%,裂断长变化为-18.1%~7.9%,耐破度变化为-13%~7.3%,撕裂度为-12.9%~8.4%,光学性质(如白度、光散射系数)变化不大,不透明度几乎不变。综合能耗节省与强度性质的提高,E014及EAn76效果较好,ES28则由于纤维素酶对纤维的损伤效果不佳,E025效果则一般。  相似文献   

5.
黑荆木材硫酸盐法制浆试验研究   总被引:1,自引:1,他引:0  
试验对6年生黑荆木材硫酸盐法制浆工艺进行正交试验,得出最佳制浆工艺为:用碱量15%,硫化度20%,最高温度165℃,保温时间120min,细浆得率51.61%,硬度12.08K值,黑液残碱4.70g/L,纸浆纤维平均长度0.845μm,平均纤维宽度15.84μm,长宽比为53.33,接近黑荆木材的纤维形态;利用该纸浆手工抄纸,定量为5.86g/m2,纸张拉力为3.34kg,裂断长度为3842m,表明黑荆木材适宜作为造纸的原料。  相似文献   

6.
三种速生建筑材料树种制造中纤板的制浆工艺和磨片选型   总被引:3,自引:3,他引:0  
曹忠荣  黄洛华 《木材工业》1999,13(3):3-6,13
研究了供制造中密度纤维板用的三种速生建筑材的制浆工艺和磨片齿形。试材树种杉木,火炬松及湿地松;磨片齿形有中细齿、粗齿及中齿三种;木片蒸煮汽压固定为0.4-0.65MPa蒸煮时间分别为3,6,9及12min,磨盘间隙为0.1mm。结果表明;三种齿形制浆所得中长纤维(留于32-115目)占总张的50-70%,尤以中齿形磨片制浆,效果更好,在3-12min的蒸煮时间内,纤维分离效果及制板后板的平面抗拉强  相似文献   

7.
日本落叶松纸浆材造纸性能及工艺成熟期的研究   总被引:1,自引:1,他引:0  
通过日本落叶松8、15、20、25年生4种年龄木材物理性能和形态,化学分析及纸浆造纸性能的研究,并与美国,加拿大进口的纸浆比较,认为该树种木材纤维素含量高,纤维长、粗浆得率高达47.3%,而且制浆容易,成本低,纸浆造纸性能较好,是良好的造纸用材树种。分析确定,日本落叶松纸浆材工艺成熟期为15 ̄20年生。  相似文献   

8.
刚果12号桉的木材性质及制浆试验   总被引:4,自引:0,他引:4  
蔡则谟 《林业科学》1996,32(4):361-365
进行了5龄刚果12号桉的木材性质和制浆试验。以胸高圆盘加权平均数为单元,平均导管直径90μm,管孔数16N/mm2;射线数15N/mm;纤维长度0.868mm,壁厚2.9μm;组织比量(%):导管14.0,薄壁组织29.8,纤维56.2;基本比重0.577。研究了这些性质的径向变异性。木材强度中等。综纤维素含量77.62%,木素含量25.09%。烧碱-蒽醌法制浆试验表明,容易成浆,粗浆得率46.92%,漂浆白度73.8%,纸片成型性良好,耐破指数4.58kPa·m2/g,撕裂指数7.53mN·m2/g。  相似文献   

9.
研究表明黑荆木材1—3年生密度为0.59—0.65g/cm3,5—10年生为0.72g/cm3;1—7年生木材成分变化不大,纤维素在45%以上,半纤维素在25%以下,木素在21%以下。比较6年生黑荆木材及其KP、CTMP的纤维形态,纤维长度在0.76mm以上的,木材为72.04%、Kp为72.22%、CTMP为82.58%;平均纤维长度木材为0.856mm、KP为0.845mm、CTMP为1.165mm;纤维宽度在12一24μm,木材为92.62%、KP为92.86%、CTMP为34.63%;平均纤维宽度木材为15.6μm、KP为15.8μm、CTMP为30.7μm;长宽比木材为54.9、KP为53.3、CTMP为37.9。  相似文献   

10.
楸树造林密度及其效应的研究   总被引:1,自引:0,他引:1  
楸树造林密度7年试验总结。在7种造林密度中,树高最高(平均5.13m)的密度为21m×1m、3m宽窄行,最低(平均4.40m)的密度为2m×2m,相差16.6%;最大胸径(平均7.4cm)和最大单株立木材积(平均0.00866m ̄3)的密度为3m×4m,最小胸径(平均5.7cm)和最小单株立木材积(平均0.00471m ̄3)的密度为2m×2m,胸径相差29.8%,材积相差84.9%;密度居中的2m×1m、6m宽窄行及3m×3m,对光照的利用较佳,冠下平均光照强度0.80—0.95万勒克司,冠下、株间、行间光照平均透过率分别为12.4—14.4%、16.0—21.2%、50.8—59.1%;2m×1m、6m宽窄行的光台强度较2m×2m增加20.1%;密度愈小,郁闭愈晚,径阶偏向大径阶分布,密度愈大,郁闭愈早,径阶偏向小径阶分布,并需较早的间伐。  相似文献   

11.

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.  相似文献   

12.

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.  相似文献   

13.

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.  相似文献   

14.

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.  相似文献   

15.
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。  相似文献   

16.

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.  相似文献   

17.
18.

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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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