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1.
1976及1979年在杉木全分布区内分别收集杉木代表性种源21个及58个,在杉木造林不同生态区的2及5个试点上进行田间试验。根据6-9年生的试验观测得出杉木存在广泛的地理变异,种源间生长差异非常显著。优、劣种源类群间生长差异达2倍以上。为云南各杉木造林区选出了2-3个较佳种源,选择增益达14%-55%。  相似文献   

2.
《江西林业科技》1994,(3):83-91,127
1976及1979年在杉木全分布区内分别收集杉木代表性种源21个及58个,在杉木造林不同生态区的2及5个试点上进行田间试验,根据6-9年生的试验观测得出杉木存在广泛的地理变异,种源间生长差异非常显著,优,劣种源类群间生长差异达2倍以上,为云南各杉木造林区选出了2-3个较佳种源,选择增益达14-55%。  相似文献   

3.
该研究在区划工作的基础上,进一步对马尾松种源进行了亚染色体结构水平上的分析鉴别。结果表明,马尾松种源具有丰富的着丝粒C-带和中间C-带。抽样研究的5个种源的C-带,在同一种源内带型基本相同,不同的种源间带型各不相同,呈现出种源差异。聚类分析表明,种源的C-带带型与区划基本上相符合,证明马尾松种源的表型地理变异与染色体亚结构的变异是紧密相关的。  相似文献   

4.
《江西林业科技》1994,(3):40-46
对5、9、12年生的三次种源试验林进行生长、林质、抗性观测分析表明,种源间的生长量、木材密度、结实量、保存率、冻害等方面都存在明显的遗传变异,以速生优质为主评选出10个优良种源,其材积遗传增益比当地种源大32.5-47.2%,本省参试的9个源(除丽水外),材积只有总体平均值的72.7%-83.5%。邻近杉木中心产区的优良种源更适合推广应用,木材密度最大的种源比最小的大11.8%,各种源的变异系数幅  相似文献   

5.
在吴县太湖孤山丘陵进行的55个产地杉木种源造林试验表明,种源间生长性状,抗性,适应性状有显著的差异,纬度和经度是生长性状地理变异的主要因子,种源选择增产效果显著,11年生时,广西融水,贵州锦屏,福建南平,四川洪雅,荥经,广东乐昌,广西那坡,浦北,广东信宜等种源丰产性好,适应性,抗性较强,小径材材积比本省对照增的41.16-96.90m^3/hm^2,表型产益,遗传增益分别达43.5%-109.6%  相似文献   

6.
海南岛东部地区桉树树种/种源试验*   总被引:4,自引:7,他引:4       下载免费PDF全文
在海南岛东部进行的桉树11个树种79个种源试验,5年的结果表明,不同树种种源间生长差异极显著,来自印度尼西亚Mt.mandiri的尾叶桉12895种源是所有参试树种/种源中表现最好的,树高、胸径和每公顷材积分别为13.82m、12.54cm和128.34m3。同一树种种源间生长差异也极显著,最佳种源的每公顷材积与最差种源相比,尾叶桉为8.46:1,细叶桉5.86:1,赤桉5.32:1和巨桉3.04:1。细叶桉、赤桉和巨桉种源树高、胸径和材积生长与原产地纬度显著负相关,尾叶桉种源与原产地海拔高极显著负相关。本文提出了适合海南岛东部地区生长的树种和种源。  相似文献   

7.
马尾松种源幼林生长节律研究   总被引:2,自引:2,他引:0  
对4、5、6年生马尾松高、胸径、枝长、枝粗生长节律及其与环境因子的关系进行了探讨。结果表明,各月间生长量差异显著,4、5月份树高、枝长生长量分别占全年生长总量的57.7%、69.5%,胸径、枝粗生长盛期为4-9月;不同地理带种源在其适应性上有明显差异;生长与降水量、土壤湿度、日照时数呈显著正相关,与蒸发量、相对湿度、20cm深处土壤温度呈显著负相关。  相似文献   

8.
枫杨种源苗期生长节律及生物量预测   总被引:2,自引:0,他引:2  
于枫杨全分布区内收集的55个种源为试材进行苗期试验。在北亚热带地区,枫杨的高生长季节约为8个月,即3月至8月底。7月为其生长高峰,净生长量占整个生长季生长量的37.72%,6月与8月、5月与9月的净高生长量相差无几,分别占22%-25%以及8%-10%,民苗高净生长节律主要受气温因子的影响,而与雨量关系不大。枫杨高生长种源间差异表现在7-9月,5个生长最快与5个生长最慢种源组间的月均相差在15cm以上。7月可以作为速生种源苗期初步选择的时期,以各月苗高净生长量、年度苗高与地径生长量分别构建2 生物量预测模型,2组模型均具有较好的预测潜力,其中以各月苗高净生长量为自变量的模型具有更高的预测精度,且能提前3个月左右建模。  相似文献   

9.
30个墨荆树国内外种源,在我国南方四省(区)5个点造了13mh^2种源试验林,5年生时的调查材料分析结果表明:不同种源生长、发育、通直度、树皮厚度、单宁含量、抗性等性状差异显著。各试点个入选种源的平均单株材积,比总体平均值大21%-95%,单宁含量比总体均值高2%-7%。种源与地点的互作不显著,说明种源表现具有较高的稳定性。根据生长量、产皮数量与质量、抗逆性及种源稳定等指标,综合评定出6个适合在我  相似文献   

10.
不中种源马尾松造林效果及经济效益对比分析   总被引:9,自引:1,他引:8  
丁贵杰  严仁发 《林业科学》1994,30(6):506-512
分不同地位指数,对比分析了广西容县种源和贵州龙里种源马尾松人工林的林分结构和生长效果的差异。以现实林分蓄积量为基础,结合材种出材量(率)预测模型和研究区的技术经济指标,用动态分析方法进行了经济效果评价。结果表明,在贵州引种广西容县种源是可行的,在相同立地条件,容县种源林分生产力高于贵州龙里种源,树高,胸径,蓄积量分别高15.0-21.7%、5.4-19.1%和28-40%。经济效益、净现值高38.  相似文献   

11.
12.
Dissolving pulps are the raw materials for the production of many different end-products. Jute is a very good source of cellulose. In this investigation, jute fiber was subjected to pulping in soda process in order to produce dissolving pulp under different prehydrolysis conditions and compared with prehydrolysed kraft pulp from jute. An increase of the prehydrolysis temperature or H2SO4 in prehydrolysis liquor increased the α-cellulose content and decreased the viscosity of pulp. The effect of ethylenediamine in soda liquor was also investigated when producing dissolving pulp. Jute fiber produced pulp having 90–97% α-cellulose. Ethylenediamine in soda liquor produced pulp of higher yield, viscosity and higher α-cellulose content than that of prehydrolysis soda or kraft pulp. The α-cellulose content and viscosity were increased with the increase of amine in soda liquor. The kappa number of dissolving pulp from jute was very low (9–5), which indicated that less bleaching chemicals are required for bleaching. The bleachability of soda-ethylenediamine pulp was lower than prehydrolysed soda and kraft pulp in ECF bleaching sequences. The bleachability of soda-ethylenediamine pulp was improved at the sacrifice of pulp yield when prehydrolysis was done prior to pulping. The alkali solubility S 10 and S 18 were 4–9 and 2–4%, respectively.  相似文献   

13.
世界木材制浆技术新进展   总被引:1,自引:0,他引:1  
文章论述了木材制浆技术的新进展,在硫酸盐法制浆技术的革新方面,推荐了间歇蒸煮的快速置换加热(RDH)技术与连续蒸煮的改良连续蒸煮(MCC)和深度脱木素改良连续蒸煮(EMCC)技术。还介绍了超高得率制浆方法,特别是碱性过氧化氢机械制浆(APMP)法和爆破制浆(EP)法,用这两种方法生产的纸浆得率高、白度高、强度高、能耗较低。  相似文献   

14.
The pulping wood quality of Acacia melanoxylon was evaluated in relation to the presence of heartwood. The sapwood and heartwood from 20 trees from four sites in Portugal were evaluated separately at 5% stem height level in terms of chemical composition and kraft pulping aptitude. Heartwood had more extractives than sapwood ranging from 7.4% to 9.5% and from 4.0% to 4.2%, respectively, and with a heartwood-to-sapwood ratio for extractives ranging from 1.9 to 2.3. The major component of heartwood extractives was made up of ethanol-soluble compounds (70% of total extractives). Lignin content was similar in sapwood and heartwood (21.5% and 20.7%, respectively) as well as the sugar composition. Site did not influence the chemical composition. Pulping heartwood differed from sapwood in chemical and optical terms: lower values of pulp yield (53% vs 56% respectively), higher kappa number (11 vs. 7), and lower brightness (28% vs 49%). Acacia melanoxylon wood showed an overall good pulping aptitude, but the presence of heartwood should be taken into account because it decreases the raw-material quality for pulping. Heartwood content should therefore be considered as a quality variable when using A. melanoxylon wood in pulp industries  相似文献   

15.
Wood density and pulp yield are key parameters in the evaluation of tree productivity and quality for pulping and their relationships are of high practical importance. The influence of wood density on pulp yield and other pulp quality parameters was investigated using Acacia melanoxylon and its natural variability as a case study. Twenty trees were harvested (five trees in each of four sites in Portugal), and wood discs taken at different height levels, from the base to the top of the tree, providing 100 wood samples, covering the natural variability of wood density ranging from 449?kg?m?3 to 649?kg?m?3. Under the same experimental conditions of kraft pulping, screened pulp yield ranged 47.0?C58.2?%, Kappa number 10.9?C18.4, ISO brightness 14.9?C45.6, fibre length 0.660?C0.940?mm and fibre width 16.2?C22.9???m. The pulp yield and Kappa number were not correlated with wood density. Higher pulp yields were associated with lower Kappa numbers and alkali consumption, suggesting the important role of chemical composition of wood on kraft cooking. The results confirm the high pulping potential of Acacia melanoxylon trees grown in Portugal and suggest the possibility of tree selection using both wood density and pulp yield.  相似文献   

16.
17.
本文介绍了用杨木生产漂白化学浆,包括硫酸盐法,硫酸盐-蒽醌法,烧碱-蒽醌法和碱性亚硫酸钠-蒽醌法制浆;用杨木生产漂白化学热磨机械浆;用杨木生产碱性过氧化氢机械浆;特别是杨木碱性过氧化氢机械浆是90年代发展研制成功的高得率、高白度和强度性好的新化学机械浆种,它适用于配抄低定量胶印新闻纸、低定量涂布纸等。  相似文献   

18.
Lignin Characterization of Triploid Clones of Populus tomentosa Carr.   总被引:2,自引:0,他引:2  
In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin (MWL), lignin carbohydrate complex (LCC) and the residual lignin from kraft pulp (KP) and sulfite pulp (SP) were isolated and analyzed by Fourier transform infrared (FTIR) spectrum and ^13C nuclear magnetic resonance (NMR). The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.  相似文献   

19.
To develop a new nonchlorine bleaching technology, hardwood and softwood kraft pulps, before and after oxygen-alkali predelignification, were treated with dilute sulfuric acid solutions (pH 1.0-1.8) at 100°C for 1 h and then extracted with aqueous sodium hydroxide at 70°C for l h. Hardwood kraft pulp was successfully bleached. The delignification selectivity was similar to that seen with oxygen-alkali bleaching; and it was greatly enhanced by the addition of sodium nitrate and sodium nitrite. The sulfuric acid bleaching can replace the presently adopted oxygen and chlorine stages if the additives are allowed. This bleaching process was also effective for oxygen-bleached hardwood kraft pulp, but it was less effective for softwood kraft pulp and oxygen-bleached softwood kraft pulp. The effectiveness of the addition of sodium nitrate and sodium nitrite was more apparent for softwood kraft pulp than for hardwood kraft pulp.Part of this report was presented at the 7th International Symposium on Wood and Pulping Chemistry, Beijing, July 1993  相似文献   

20.
竹子作为造纸原料的性能和潜力   总被引:22,自引:0,他引:22  
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。  相似文献   

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