竹子作为造纸原料的性能和潜力

竹子的纤维形态及化学组成表现出较好的制浆性能。从制浆性能及纸浆强度来评价，竹子是较好的造纸原料，仅次于针叶木，接近于阔叶木。随着造纸工业的发展，采用连续蒸煮和以氧及过氧化氢等无污染漂白新方法、新技术代替传统的竹子间歇蒸煮及常规含氯漂白的制浆技术是现代竹浆厂的目标。以竹代木，以减轻造纸工业对木材原料需求的压力，适应生态环境保护的要求为竹浆造纸提供了一个广阔的发展良机。     

甜高粱秆酿酒前后化学组成纤维特性及制浆性能的研究

对甜高粱秆及其酿酒后残渣的纤维形态、化学组分进行观察和测定发现,甜高粱秆的发酵酿酒过程并没有对其纤维造成严重损伤,二者均具有较大的纤维平均长度和长宽比,且纤维形态良好。在化学组分上,甜高粱秆及其酿酒后残渣的综纤维素和α-纤维素含量较高,木素含量少,均是较好的造纸原料。制浆性能研究表明,甜高粱秆酿酒后残渣易蒸煮,用碱量低,得率高,成纸具有较好的物理强度,将甜高粱秆酿酒后残渣用于制浆造纸是合理利用酿酒残渣的有效途径。     

甜高粱秆酿酒前后化学组分纤维特性及制浆性能的研究

对甜高粱秆及其酿酒后残渣的纤维形态、化学组分进行观察和测定发现,甜高粱秆的发酵酿酒过程并没有对其纤维造成严重损伤,二者均具有较大的纤维平均长度和长宽比,且纤维形态良好.在化学组分上,甜高粱秆及其酿酒后残渣的综纤维素和α-纤维素含量较高,木素含量少,均是较好的造纸原料.制浆性能研究表明,甜高粱秆酿酒后残渣易蒸煮,用碱量低,得率高,成纸具有较好的物理强度,将甜高粱秆酿酒后残渣用于制浆造纸是合理利用酿酒残渣的有效途径.     

中国林业科学研究院制浆造纸研究开发中心

正研究方向1.纤维资源评估技术研究:制浆原料材性、纤维形态及超微结构、化学组成分析和制桨适应性评估;2.制浆造纸新技术研究:化学法制浆、机械法制浆、化学机械法制浆、各种漂白技术(传统漂白、生物酶处理、ECF/TCF漂白等),纸和纸板抄造技术;3.造纸化学和环保化学品研究:湿部化学和高效水处理剂;4.环境保护技术研究:林业及制浆有机废弃物转化技术;废水污染负荷、污染物特征分析、废水的物理、生物和物理化学处理,高效生物反应器的研制。     

西藏高原云杉、冷杉硫酸盐制浆性能研究

西藏高原云杉、冷杉用硫酸盐法蒸煮、漂白、打浆，结果表明，高原云杉的木素含量较高，蒸煮时用碱量略高于其它地域的云杉原料。两种原料的硫酸盐法化学浆，ＲＥＨ察白程序可以漂到７６度以上的白度；用ＣＥｐＨ漂白程序其白度可漂到８５度以上。两树种均为良好的制浆造纸原料。     

我国几种主要桉树的制浆造纸性能

本文详细论述几种主要桉树的制浆造纸性能。其中包括窿缘桉(E.exserta)、柠檬桉(E.citriodora)、雷林一号桉(E.leizhou No.1)对上述桉树的化学成分、纤维形态、制浆得率、可漂性以及纸页的各项物理强度等进行阐述。占我国桉树种植面积最大的窿缘桉和柠檬桉。以后者制浆造纸性能最好,表现在纤维较长,抽出物及木素含量低,制浆得率高,吨浆耗用木材积少,黑液粘度低等。窿缘桉制浆性能较差。但是窿缘桉浆也有良好的可漂性能,用三段漂白,可将本色浆漂到82%以上的白度。窿缘桉漂白浆加配20%～30%松木浆,可以达到抄制高档文化用纸的指标。雷林一号桉的制浆造纸性能,在已试验的10多种桉树中尚属中等水平。本文最后对每种桉树制浆造纸的可行性程度进行了评价,对充分开发利用我国现有的桉树资源可起到一定的指导作用。     

六种阔叶木CTMP制浆性能的初步研究

对拟赤杨等６种阔叶木进行纤维形态和化学组成的测定、ＣＴＭＰ制浆、打浆强度分析及漂白工艺的研究，结果表明拟赤杨等几种阔叶木具有较好的制浆适应性。     

竹材制浆造纸技术研究与应用现状

随着人们环保意识的日益增强以及对森林资源保护的不断重视,开展低少污染的竹材制浆造纸成为造纸工业发展的必然趋势。该文就竹材的制浆造纸技术研究及应用现状进行总结。在对竹材制浆造纸特性的研究与应用进行概括的基础上,主要从蒸煮和漂白这两方面对低少污染竹材制浆工艺的研究情况及存在问题进行阐述,并分析了竹浆与纸张性能的关系及竹材特种纸的研究情况,以期为大力发展我国竹材产业发展提供参考。     

6种杨树木材的化学分析及纸浆造纸性能的研究

为调整造纸原料结构,优选出理想的造纸林的杨树品种和它们的最佳轮伐期,对6种杨树木材进行了化学全分析和用亚硫酸氢镁为蒸煮药液制取化学浆,进行了制浆性能测定。经试验研究认为,浆的质量优于苇,白度在58.6～66.0%;粗浆得率为51.8～55.9%;裂断长比苇高1～2km;含杂质少、易漂白、强度高。6种杨木都是优良的造纸原料,综合比较,以健杨、鞍杂最为理想。初步认为,同一品种的不同林龄对制浆造纸无大影响,应以林龄最短、出材量最高、经济价值最大为原则,来确定各品种的轮伐期。     

桑木制浆性能的初步研究

研究了桑木的化学组成和纤维形态,并采用硫酸盐法和烧碱法对桑木的制浆性能进行摸索性试验。结果表明:桑木的木素含量为19.31%,综纤维素含量为78.31%,α纤维素含量为47.69%。纤维比量占69.50%,射线比量占16.31%,导管比量占14.19%。纤维平均长度为1 058μm,长宽比为85.98,壁腔比为0.77。从纤维形态上看,桑木是一种较好的阔叶材造纸原料。两种方法比较,硫酸盐法比烧碱法更适合桑木的制浆。     

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.