Proteins in Norway spruce thermomechanical pulp

Two methods of cytochemical staining using Coomassie dye and Cu⁺-bicinchoninic acid, respectively, showed that there are proteins in thermomechanical pulp (TMP) of Norway spruce. Protein isolated from TMP was analyzed for amino acid composition. There was about twice the amount of acidic amino acid material compared with basic amino acids, and the presence of glucosamine indicated that the isolated polypeptides also contained glycoproteins. The presence of proteins in ray cells and fiber tracheids in TMP adds to the chemical heterogeneity of the structurally complex high-yield pulp.     

杉木间伐材低浓纸浆流变特性

对不同浓度、温度、打浆度、剪切速率对低浓杉木间伐材机械浆流变特性的影响进行了实验研究,并对不同因素引起浆料表观粘度变化的机理进行了分析。结果表明:浆料浓度、打浆度、温度及剪切速率都会对浆料的表观粘度产生影响。随着浆料浓度的增加,浆料表观粘度呈指数式增加;随温度的升高,浆料表观粘度则缓慢下降;打浆度影响浆料的微观结构,随着打浆度的升高,纸浆的表观粘度呈下降趋势;低浓纸浆的表观粘度则随剪切速率提高而递减。在实验测量范围内,杉木间伐材低浓纸浆为满足幂律关系的非牛顿流体,拟合的本构方程的流变特性指数n<1,因此其在测量范围内为假塑性流体。低浓纸浆流变特性的研究纸浆模塑生产线流送系统设计提供了依据。图12表2参16。     

Micromorphology and topochemistry of extractives in Scots pine and Norway spruce thermomechanical pulps: a cytochemical approach

Due to the increasing demand for Norway spruce as prime raw material for high-yield pulping, recent interest has focused on Scots pine as an alternative. However, the intrinsic properties of Scots pine, particularly the high amounts of extractives and the fiber properties, have been considered a disadvantage for thermomechanical pulping. A study was therefore conducted on the variations in the spatial distribution and redistribution of lipophilic extractives in spruce and pine wood and thermomechanical pulp (TMP) using cytochemical staining methods and chemical analysis. Chemical analyses showed chips from pine thinnings and sawmill slabs to contain three to five and two to three times, respectively, more extractives than found in spruce; in particular, the amount of triglycerides differed significantly. Results from staining techniques on the abundance and distribution of extractives (i.e., fats) between pine and spruce correlated with amounts detected by Fourier transform infrared spectroscopy and gel permeation chromatography. Cytochemical observations revealed information pertaining to species-specific distribution and redistribution of extractives among TMP fines and fibers and indicated the presence of a molecular film of extractives. Results indicate that the high concentrations of extractives in pine ray parenchyma are released during TMP processing and are redistributed onto the surfaces of the pulps, negatively affecting energy usage during primary refining.     

Structural changes of residual lignin in softwood kraft pulp treated with manganese peroxidase

Structural changes of residual lignin in unbleached softwood kraft pulp (SWKP) during manganese peroxidase (MnP) treatment were investigated to obtain some understanding of the biobleaching action of SWKP with MnP treatment. Alkaline-extracted lignin from darkened SWKP by MnP showed more intense color and contained moreo-quinone than that from control SWKP. However, no difference in the conjugated-carbonyl was observed between the lignins from MnP-treated and control SWKP. The nitrobenzene oxidation analysis revealed that oxidative condensation of non-condensed lignin in SWKP occurs during an early stage of MnP treatment. These observations were supported by the model experiment in which the lignin prepared from control SWKP was subjected to MnP treatments three times, and the changes of color and functional groups in the lignin were determined after each treatment. These results suggested that an increase ino-quinone and the condensation reaction of non-condensed lignin in SWKP are responsible for the characteristic darkening of SWKP during MnP treatment. It was also ascertained that darkened lignin was degraded and brightened by repeated MnP treatments.     

某锅炉包墙过热器开孔区域的强度计算

文章基于热力耦合有限元理论,对某锅炉包墙过热器进行了稳态热力耦合分析。从分析结果可以看出,该包墙过热器强度是满足规范要求的。     

几种禾本科纸浆纤维在造纸法再造烟叶中的应用研究

对几种禾本科纸浆纤维微观结构、质量及其对再造烟叶理化性质的影响进行研究。结果表明:随着片基中纤维比例增加,片基的抗张强度和涂布率提高;在相同的添加比例下,添加稻麦草浆、大麻秆芯NaOH-AQ浆的再造烟叶表面致密、匀整,而添加蔗渣浆、大麻秆芯APMP浆和针叶浆的再造烟叶表面粗糙、孔隙较大;在相同的添加比例下,添加大麻秆芯机械浆、APMP浆、NaOH-AQ浆、稻麦草氧碱浆、蔗渣浆、针叶浆的再造烟叶,总糖、还原糖、钾离子、氯离子、总植物碱和总氮总体均呈下降趋势。     

我国纸浆材需求现状

随着中国人均生活水平的提高,对纸和纸制品的消费量也日渐增多起来。由于人为的不断破坏和乱砍滥伐使得全球森林资源逐年在下降,作为制浆造纸工业的主要原料的木材也在逐年减少,解决纸浆材供应与利用问题,是当今世界林业及造纸工业发展的重要研究课题。文章从对我国森林资源进行分析,简要说明现今我国对纸浆材的需求现状,并举例说明了林纸一体化的对策。     

黑龙江省纸浆用材林发展前景

木材造纸质量好、得浆率高,适于大企业生产的原料供应.尽管黑龙江省是林业大省,但造纸原料也严重不足.目前的纸和纸板年生产能力约75万t,纸浆和木材的自给率仅为30%,即每年进口283万m3;到2010年,纸和纸板年生产能力将达200万t,木材消耗将达1 132万m3,木材缺口将达800万m3.黑龙江省5年内将增加有林地面积222万hm2,在有林地中约有500万hm2森林需要改造,土地资源丰富,具有广阔的纸浆林发展空间.有杂种落叶松、中美山杨、中黑防杨树、1344杨树等适合于寒地栽培的速生丰产优良新品种,具有良好的科技支撑.总之,黑龙江省纸浆林具有非常广阔的发展空间.     

模糊控制在纸浆模塑包装容器生产环节中的实现

纸浆模塑生产过程是一个典型的多变量、强耦舍、多干扰、时变复杂的系统。根据其控制过程中被控对象复杂而难以控制的特点。采用模糊控制策略构建了纸浆模塑包装容器生产环节中的软、硬件系统。     

发展竹浆造纸 节约木材资源

随着社会经济水平的发展,中国纸及纸板的现有产品结构已不适应纸张消费市场的变化与发展,加剧了国内市场对进口纸及纸板的依赖性。竹材纤维细长,是制浆造纸的优质原料。竹浆纸的开发有利于节约木材资源,有利于环境保护。中国竹资源丰富,发展竹浆造纸的市场前景非常广阔。因此,在造纸工业中实现以竹代木,建立林纸一体化的竹浆生产基地,将成为节约木材资源,减少纸及纸浆的进口,使制浆造纸工业得以持续发展的有利途径。     

北亚热带高山区欧洲云杉不同栽植密度比较试验研究

为探讨不同栽植密度对欧洲云杉林生长量的影响,在国有大老岭林场对4～10年（苗龄3年）生欧洲云杉林,在6种密度下的生长状况进行了调查研究,结果表明：虽然不同密度间欧洲云杉林生长优势还未出现显著差异,但从各生长量指标来看,密度1（1 m×1 m）下欧洲云杉生长优势最明显;10年生林木树高、地径、抽梢、冠幅年生长量分别增长了近15.7％,25.1％,35.3％和26.8％。     

福建省北部山区优良纸浆竹种引种试验

介绍了邵武市引种撑绿竹、硬头黄竹、坭竹、单竹、青皮竹及大眼竹的成活率、出笋率等生长情况,并就福建省北部山区纸浆竹林苗圃基地建设有关问题进行了探讨。     

黑龙江省主要杨树纤维用材品种纸浆性能综合评价

选择黑龙江省7个主要杨树纤维用材品种为研究对象,测定了木材纤维形态、化学成分和成浆性能,分析了林龄与主要纸浆性能间的相关关系,对7个品种纸浆性能进行了综合评价。试验结果表明:7个品种的纤维长度为0.88～1.17mm,纤维素含量为49.28%～59.77%,粗浆得率为50.41%～54.97%,上述指标均达到或超过优质纸浆标准;林龄与纤维长度、纤维素含量和粗浆得率间无显著相关关系;纸浆性能综合评价由高至低的顺序为黑青杨>小青黑>银中杨>大青杨>青山杨>小黑杨>迎春5号。     

毛竹纸浆林砍伐技术研究

在垦复，施肥等集约培育的纸浆毛竹林中，实施砍伐４，５年生竹，竹材产量砍伐６，７年生竹的一般材用竹林相若，差异不显著。在竹林生长季节的３，６，９月伐竹，与一般材用林的大年１２月伐竹相比，竹材产量差异也不显著，但小年１２月伐竹产量降低较多，生产上应避这个     

贵州省赤水市纸浆竹林培育技术

根据纸浆竹林的林学特性及其培育技术研究成果,提出了赤水市纸浆竹林培育的技术路线和主要技术措施。     

草木半纤维素的研究进展

结合前人的研究成果综述了各种草木原料中半纤维素的类型、结构形式及制备方法,特别指出在造纸原料和纸浆中存在部分半纤维素与木质素发生化学键连接形成了木质素-碳水化合物复合体(LCC),还对纸浆中的半纤维素对浆性能所产生的影响加以阐述,针对半纤维素在造纸工业中所引起的"假木质素"问题总结出相应的应对策略.此外,还概述了从草木原料中制备粗半纤维素的分离方法以及对其进一步纯化的技术,对半纤维素的检测手段也做了介绍.     

Control of tracheid cross-sectional dimensions in Norway spruce and Scots pine wood raw material

Abstract

Wood properties, including tracheid cross-sectional dimensions, show a large degree of variation. To improve the properties of products made from wood, different methods to control variation have been developed. This study aims to determine the theoretical efficiency of three control strategies: the fractionation of pulped tracheids into earlywood and latewood, the separation of juvenile and mature wood, and sorting of logs according to tree size. The efficiency of each method was studied by first constructing virtual trees from measured tracheid cross-sectional dimensions, then simulating the efficiency of above-mentioned methods. The tracheid dimension data include Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). The simulations show that separation into earlywood and latewood classes has the highest theoretical efficiency and yields the lowest variances in raw material. Classification into juvenile and mature wood groups is the second most efficient method, and the sorting of logs according to the size class of the tree is the least efficient method. It was also concluded that the variation in cell-wall thickness and radial diameter mainly originates from differences between earlywood and latewood, whereas the variation in tangential diameter mainly originates from differences between mature and juvenile wood.     

Comparative growth,dry matter accumulation and photosynthetic rate of seven species of Eucalypt in response to phosphorus supply

Plantations of eucalypts as short-rotation tree crops are rapidly expanding in tropical and sub-tropical regions, including southern China, where the soils are acidic and available phosphorus(P) is limited. We investigated seedling growth, dry matter accumulation, and the dynamics of photosynthetic rate and chlorophyll content of seven Eucalyptus species/hybrids(E. dunnii, E. grandis, E. grandis × E. camaldulensis, E. urophylla × E. camaldulensis, E. urophylla × E. tereticornis, E. grandis × E. tereticornis, E. urophylla × E. grandis) in response to different levels of P supply(0, 6, 12 and 18 mg?kg-1 KH2PO4). The photosynthetic rate and the chlorophyll content significantly declined as the P supply declined in almost a linear fashion for all species as the P stress period extended. In the absence of P supply, height growth of seedlings of all species was significantly impaired, while root collar diameter growth and whole plant dry matter accumulation was not affected by the level of P supply in most of the species. Significant inter-species variations in growth, dry matter accumulation and photosynthetic rate in response to P supply were detected. Eucalyptus dunnii had the lowest growth performance across all levels of P supply while E. urophylla × E. tereticornis showed superior growth performance. From a practical point of view, E. urophylla × E. tereticornis is suggested as a candidate hybrid for planting on slightly P-deficient sites in southern China while E. dunnii, being a slow-growing species, is not suitable for short-rotation plantation. On plantation sites where severe P deficiency exists, P fertilization needs to be considered to boost rapid growth of seedlings so as to meet the management objectives of short-rotation plantation.     

贵州赤水纸浆竹林经营中几个问题的探讨

赤天化纸浆厂建设以来,赤水市及周边县市营造了大规模的纸浆竹林。根据现有竹林经营状况,分析了纸浆竹林生产中的采伐、施肥、垦复、健康及道路运输等较为突出的问题,为纸浆竹林的合理经营管理提供参考。