木质纤维素乙醇专利分析研究

对世界范围内的木质素乙醇相关专利技术进行了深入分析,包括技术发展趋势分析、技术生命周期分析、申请人分析、国家技术实力分析、关键技术分类分析、同族分析,旨在通过专利分析洞悉木质素乙醇技术的整体发展态势,为本领域的技术创新和决策提供参考。     

Genetic parameters of growth and wood quality traits in Picea abies

Genetic parameters were estimated for wood and growth traits in two 19-yr-old clonal trials and a 40-yr-old full-sib progeny trial of Norway spruce [Picea abies (L.) Karst.]. In the clonal trials high (>0.4) broad-sense heritabilities were found for wood density traits, lignin content, number of internal cracks, growth traits, spiral grain and number of resin canals. Moderate (0.2–0.4) heritabilities were found for tracheid lumen diameter and cell wall thickness, microfibril angle and tracheid length, while low heritabilities (<0.2) were found for pulp yield, fibre strength, wood stiffness and wood colour. Lignin content and pulp yield showed low genetic variation, whereas the genotypic coefficient of variation for most other traits ranged between 5 and 15%. Most traits showed low levels of genotype by environment interaction. Among the wood properties, latewood proportion, earlywood density and ring density showed significant, adverse correlations with volume in both clonal trials.     

FDA‐active fungal mycelium and lignin concentrations in some needle and leaf litter types

The concentration of live fungal biomass (FDA mycelium) was investigated in seven chemically very different litter types, i.e. grey alder leaves, green and brown leaves of white birch, green and brown needles of both Scots pine and lodgepole pine. Concentration of FDA mycelium in the litters changed with the season, being low during the dry late summer and relatively higher during the more rainy, wet autumn. During autumns, when moisture was not limiting, lignin concentration and live fungal biomass were negatively related. It was concluded that the concentration of live fungal biomass in litter decreased linearly as the lignin concentration increased and thus also decreased linearly to decomposition level of the litter.     

Chemical composition of wood and its connection with wood anatomy in Betula pubescens

ABSTRACT

The connection between chemical composition and anatomy of wood is poorly studied. Abiotic and biotic growth conditions affect the synthesis of structural compounds and the anatomy of wood at the same time as they affect growth. In this study, the wood chemical composition, and connections between wood chemistry and anatomy were studied in downy birch (Betula pubescens Ehrh.) grown on four growth sites possessing mineral and peat soils. Lignin, holocellulose, extractive and ash contents, and effective heating value were analysed and compared with libriform fibre double wall thickness and lumen diameter, vessel size and number, and ray and axial parenchyma numbers. Measured lignin and extractive contents were exceptionally high and holocellulose content low. Correlations between wood anatomy and effective heating value were partly different on different soils. Correlations between holocellulose and anatomy were the opposite of the correlations between other chemical compounds and anatomy. The significant correlations between chemical composition and anatomy were commonly opposite in trees grown on peat than in trees grown on mineral soil. Particularly, vessel characteristics and fibre wall thickness correlated significantly with wood chemistry in trees grown on mineral soil. The connections between wood anatomy and chemistry proved to be soil-dependent.     

Decomposition of tree root litter in a climatic transect of coniferous forests in northern Europe: A synthesis

The purpose of this study was to understand the variation in root litter mass‐loss rates in a climatic transect across a large region ranging from the Arctic Circle (66°N) in Scandinavia to Berlin (52°N) in north‐east Germany, dominated by coniferous monocultural forests. To investigate the combined influence of litter quality and climate, data were used from 37 sites and plots at which root litters of three coniferous species (Pinus sylvestris, Pinus contorta and Picea abies) had been incubated. In spite of the considerable climatic differences among sites, there were no strong relationships between any climatic variable and the lst‐yr mass loss (range 17.0–40.9%). For the lst‐yr mass loss, the average annual temperature was the most rate‐regulating factor for all litter combined, with a value for R ² _adj of 0.186. Substrate quality also had an influence. Thus, for the whole region lignin concentration was significant, with a value for R ² _adj of 0.142. For the separated groups of pine and spruce stands the value for r ² increased but the factor average temperature still dominated and for pine the R ² _adj reached a value of 0.346. Over the region N concentration in the fresh pine root litter was significant (R² _adj = 0.232). For the root litter of P. abies the average temperature in July was the strongest rate‐regulating climatic factor, with a value for R ² _adj of 0.381. A combination of temperature in July and the initial P concentration in the litter gave an R ² _adj value of 0.713 for P. abies litter, thus explaining about 71% of the variation.     

通过RNAi技术抑制杨树c3h基因表达提高糖转化效率

利用克隆得到的毛白杨c3h1基因构建其RNAi抑制表达载体,通过根癌农杆菌介导的叶盘法转化银腺杨无性系84 K,Realtime PCR检测表明其转基因株系323、325和322中c3h1基因表达量较野生型植株分别下调89.04%、82.22%和68.38%;茎横切片组化染色和显微结构观察表明转基因植株木质部发育和木质素沉积方式发生了改变;木质素、纤维素含量测定及苯酚—硫酸法总糖含量与HPLC法可溶性总糖和单糖含量检测结果表明:转基因植株木质素含量平均降低23.00%,最高可达39.71%;酸前处理效率最高提高了41.39%;未经酸处理直接酶解的糖化效率是对照植株的2.34～2.72倍,322株系和323株系比对照植株经酸前处理后再酶解的糖化效率高出81.18%和375.53%。     

氧等离子体改性酶解木质素/杨木纤维复合材料热压工艺研究

采用响应面法优化了氧等离子体改性酶解木质素/杨木纤维复合材料的热压工艺参数。结果表明,纤维含水率和热压温度对复合材料的物理力学性能有显著影响。优化后的热压工艺参数范围为:热压温度205～210℃,纤维含水率17%～20%,热压时间63～68 s/mm。     

超声波法活化麦草碱木素及用于PF胶黏剂的研究

麦草碱木素是我国造纸工业重要的剩余物,但是麦草碱木素的结构决定了其反应活性较低,从而使其应用受到较大的限制。笔者根据麦草碱木素的特点分别对比超声破碎仪不同的超声条件(时间:10、20、30、40min;振幅:60、80、100)和不同的溶液质量比(100:0,60:1,20:1)对麦草碱木素的活化效果,并探索用活化后的木素代替部分苯酚(10%、20%、30%、40%)制备酚醛树脂胶黏剂的可行性。研究结果表明:超声波作用可显著提高酚羟基的含量。超声波作用时间在20min、振幅80、溶液质量比20:1时效果相对较好。经过超声波活化的木素按20%的量替代苯酚制备LPF,压制的胶合板的胶合强度都达到国家Ⅰ类胶合板的要求,并能与未改性的酚醛树脂(PF)胶黏剂相媲美。     

蒸汽爆破过程麦秆木质纤维素的转化

采用低压蒸汽爆破技术处理小麦秸秆木质素。通过单因素试验,考察蒸汽爆破过程汽爆压力、液固比、物料粒度、维压时间对木质纤维素降解的影响,木质素的降解率达到22.67%。设计L9(34)正交试验,上述因素影响主次顺序为汽爆压力>液固比>维压时间>物料粒度,优化条件为汽爆压力0.6 MPa,液固比为20︰1,维压时间为30 min,物料粒度为20～60目,且对优化结果进一步验证。红外光谱分析表明,经汽爆后麦秆木质素结构受到了一定程度的破坏;扫描电镜观察,麦秆的纤维束受到了破坏,发生了断裂,且出现了多孔的结构。     

Accumulation and composition of total organic carbon in reclaimed coal mine lands

Reclaimed coal mine lands have the potential to sequester atmospheric carbon (C); however, limited information exists for the western USA coalfields. This study was carried out on two chronosequences (BA‐C₃ grasses and DJ‐shrubs) of reclaimed sites at two surface coal mines to determine the effects of vegetation, soil texture, and lignin content on soil total organic carbon (TOC) accumulations. In the BA chronosequence, TOC increased over 26 years at an average rate of 0·52 Mg C ha⁻¹ yr⁻¹ in the 0–30 cm depth and was significantly correlated with clay content. Comparison between < 1 and 16‐year‐old stockpile soils indicated TOC content did not differ significantly. In the DJ chronosequence, TOC content in the 0–30 cm depth declined from 31·3 Mg ha⁻¹ in 5‐year‐old soils to 23·4 Mg ha⁻¹ in 16‐year‐old soils. The C:N ratios suggested that some (up to 2·0 per cent) of the TOC was potentially derived from coal particles in these reclaimed soils. Soil total N (TN) contents followed a similar trend as TOC with TOC and TN concentrations strongly correlated. Lignin contents in TOC of all reclaimed soils and topsoil stockpiles (TSs) were higher than that of nearby undisturbed soils, indicating the recalcitrant nature of TOC in reclaimed soils and/or possibly the slow recovery of lignin degrading organism. Results indicated that TOC accumulations in DJ were largely controlled by its composition, particular lignin content. In BA sites TOC accumulation was strongly influenced by both clay and lignin contents. Copyright © 2008 John Wiley & Sons, Ltd.