共查询到20条相似文献,搜索用时 142 毫秒
1.
2.
3.
木棉(Gossampinus malabarica)又名攀枝花、红棉、英雄树、烽火树,属木棉科木棉属落叶高大乔木.木棉广泛分布在我国四川、云南、贵州、广西、广东,生长在江河沿岸、山地阳坡及村边道路旁,喜光、耐高温,对土壤要求不苛刻.在四川攀枝花地区木棉树于1月-2月份开花,先花后叶,花色艳丽,有红色、金黄、淡黄色等颜色,树形高大伟岸,是优良的园林绿化树种.木棉树现是攀枝花市市花和广州市市树,在园林绿化中常作行道树、庭荫树、景园树、盆景树等.木棉经嫁接后2 a-3 a开花,嫁接苗可作盆景矮化栽培,观赏价值高.本文介绍了木棉的嫁接育苗技术. 相似文献
4.
One compound approach combining factor-analytic model with AMMI and GGE biplot to improve multi-environment trials analysis 总被引:1,自引:0,他引:1
To improve multi-environmental trial(MET)analysis,a compound method—which combines factor analytic(FA)model with additive main effect and multiplicative interaction(AMMI)and genotype main effect plus genotype-by-environment interaction(GGE)biplot—was conducted in this study.The diameter at breast height of 36 open-pollinated(OP)families of Pinus taeda at six sites in South China was used as a raw dataset.The best linear unbiased prediction(BLUP)data of all individual trees in each site was obtained by fitting the spatial effects with the FA method from raw data.The raw data and BLUP data were analyzed and compared by using the AMMI and GGE biplot.BLUP results showed that the six sites were heterogeneous and spatial variation could be effectively fitted by spatial analysis with the FA method.AMMI analysis identified that two datasets had highly significant effects on the site,family,and their interactions,while BLUP data had a smaller residual error,but higher variation explaining ability and more credible stability than raw data.GGE biplot results revealed that raw data and BLUP data had different results in mega-environment delineation,test-environment evaluation,and genotype evaluation.In addition,BLUP data results were more reasonable due to the stronger analytical ability of the first two principal components.Our study suggests that the compound method combing the FA method with the AMMI and GGE biplot could improve the analysis result of MET data in Pinus teada as it was more reliable than direct AMMI and GGE biplot analysis on raw data. 相似文献
5.
Natural spruce-fir mixed stand is one of the main forest types in the world,and also has huge ecological,economic and social benefits.According to the structural characteristics and succession laws of natural spruce-fir forest,it is urgent and significant to develop scientific management measures for natural spruce-fir mixed stand in line with local conditions.The article outlined the characteristics of the distribution and structure, regeneration and succession laws of natural spruce-fir forest,and analyzed the current situation and existing problems of natural spruce-fir forest management.The following recommendations were eventually made:1) In no cutting area,all logging activities should be banned.In a restricted cutting area,the cutting intensity should be generally controlled within 15%of the stock volume before cutting.On the commodity forest management area, the appropriate cutting intensity should be determined according to the volume per hectare,determine and classification management should be implemented in accordance with the characteristics of forest,to ensure the scientific selective cutting.2) Closure for afforestation,planting and repair planting should be adopted on vegetation-intensive land,sparse shrubs covered land and harvesting slash,in order to accelerate natural regeneration.3) The in situ conservation should be conducted in nature reserves and scientific experiment stations of rare and endangered species,such as Abies chensiensis,Picea neoveitchii,Abies vuanbaoshanensis,to reduce human destruction.4) It is supposed to collect seeds in time,establish nursery,actively establish forest, expand artificial population and promote natural regeneration. 相似文献
6.
7.
8.
《技术与市场》2007,(1):23
当前现代化的航天、航空、汽车、机械、电子、民用建筑、化工等行业迫切要求具备很高的力学性能及耐热、耐磨、耐化学性能的材料.因此高分子材料发展的一个重要方向就是通过对现有聚合物进行物理和化学改性,使其进一步高性能化、结构化、工程化.北京化工大学研制的聚氯乙烯合金是通过挤出机的力学、化学作用及接枝、复合技术使聚氯乙烯塑料工程化,成为物理性能可与ABS相比拟的新材料.聚氯乙烯合金具有高流动性、高韧性,完全可以代替ABS注塑计算机、电视机、冰箱、照相机、仪表等外壳.聚氯乙烯合金还具有良好的耐寒性,可制作各种规格的异型材,包括门窗、上水管道等.产品市场前景好,具有很强的竞争力,有很好的经济效益和社会效益. 相似文献
9.
According to the unification principle of system structure and system function of the Water Resource Conservation Forests,seven factors were selected from stand spatial structure,trees structure and healthy of woods,the multifunction management optimization model target was confirmed by using nonlinearity multi-objective programming approach, and the target function-stand spatial structure homogeneity index was defined to establish spatial optimization models with restraining conditions set up in diversity of stand structure and spatial structure.The spatial structure of available typical stand in the wet land area in southern Donting Lake was optimized by means of selective cutting and reinforcement planting.The results showed that the spatial structure was improved obviously and trees diversity and stand health were not weakened.It’s suggested that the established optimization model can effectively guide multifunction management,stand structure optimization and the steadiness of ecological ecosystem and it is convenient and operable in practice,and it’s very important to protect and recover ecosystem of Water Resource Conservation Forests. 相似文献
10.
This paper proposes an automatic method of pore combination recognition,which is an important feature to hardwood recognition.After extracting edge from wood microscopic cross-section, based on area histogram of the similar circle regions,the method classifies all regions into two classes with maximum between-class variance,so as to distinguish the pore from other textures,which are similar in shapes but different in sizes.Meanwhile, second objective function about average area of closed regions is used to improve the pore segmentation performance.At last,the method uses adjacency degree of pore set to judge pore combination.The experiments demonstrate that the task of pore segmentation can be completed successfully for all kinds of pore distribution and combination,and also the correct combinations of pores are given. 相似文献
11.
用TA-XT2i质构仪测定不同酸碱条件下的扁桃凝胶,研究扁桃凝胶胶体在不同酸碱条件下的质构特性的变化规律.结果表明,不同酸碱条件下各水平之间质构特性曲线总体分布存在极显著差异.不同酸碱条件下的扁桃凝胶质构特性各表现指标:硬度、脆性、黏附性、黏合性、咀嚼性、回复性等各参数特性的F值分别为12.989 09、6.036 852、37.317 64、17.234 81、16.070 2、12.538 75,差异达到极显著水平,而弹性和黏结性的F值分别为0.058 577和1.113 238,差异不显著.各特性对不同酸碱环境的反应规律呈现多样性. 相似文献
12.
对相同条件下相同种源相同苗龄东北红豆杉实生苗和扦插苗生长状况进行了对比研究。结果表明:相同条件下相同种源同龄实生苗树高、冠幅生长要远大于扦插苗;实生苗和扦插苗不同年份生长量存在一定的差异,总体来看,初期实生苗要大于扦插苗,后期两者相差不多;实生苗和扦插苗生长指标存在一定程度的变异,但规律不甚明显。 相似文献
13.
通过比较喷雾干燥、冷冻干燥和喷雾冷冻干燥各自的特点,介绍了一种新型的干燥方法即喷雾冷冻干燥的机理,归纳和总结国外喷雾冷冻干燥在植物提取和医药中的应用研究进展,分析了通过喷雾冷冻干燥获得的干燥产品的特性,并提出了其可能的应用领域和范围,为进一步研究喷雾冷冻干燥技术提供相应的理论和实践基础。 相似文献
14.
对打鼓坪林场常绿阔叶林的物种及植物群落进行调查,结果表明:该地区共有木本植物85科、240属、559种,植物区系属于热带、亚热带性质,并有较强的过渡性质;对群落植物生活型的统计分析说明该地群落植物生活型是相当丰富的;对植物群落类型统计得出该地拥有9个群系,并分别对每个群丛进行了群落类型、特征和分布的简要描述. 相似文献
15.
研究了深圳福田红树林无瓣海桑 +海桑人工林群落的Ca、Mg、Na元素的吸收、分布、累积和循环。结果表明 ,该群落植物现存量中 ,库存Ca、Mg、Na总量分别为 2 5 975 4 6、10 332 4 6、115 832 16mg·m-2 ,其中地下部分分别为 86 38 93、6 342、894 99 0 1mg·m-2 。该群落Ca、Mg、Na元素生物循环为 :年吸收量分别为 9337 6 2 6、36 73 318、5 0 2 0 3 5 4 7mg·m-2 ,年归还量分别为 4 32 6 96、16 79 2 97、11792 3474 8mg·m-2 ,年存留量分别为 5 0 10 6 6 6、1976 0 2 8、384 11 2 0mg·m-2 ,周转期分别为 :7a、7a、10a。其中Ca、Mg的循环比Na要快 相似文献
16.
应用通用引物ITS1和ITS4从4个姬松茸(Agaricus blazei Murill.)菌株子实体中扩增出rDNA ITS序列(登录号分别为EF195648,EF471305,EF471306,EF471307),4菌株ITS序列长度分别为734bp、700bp、724bp和735bp。通过GenBank中BLAST,四个姬松茸菌株与A.brasiliensis(AJ884651)和A.blazei(AF161013)相似率最高,分别为:94%、99%、97%和98%。四个姬松茸菌株同源性较高,达93%以上,其中,ABM-B与ABM-D相似率最高,为97%;ABM-B与ABM-C相似率为96%,ABM-A与ABM-C、ABM-C与ABM-D相似率为94%,ABM-A与ABM-D相似率为93%。 相似文献
17.
18.
19.
20.
建立了液液萃取-高效液相色谱法测定水体中DEP、DBP、DCHP和DEHP4种内分泌干扰素的方法。以二氯甲烷为萃取剂,氮吹蒸发浓缩后进样分析。HPLC分析条件为:100%甲醇作流动相、流速1.2mL/min、柱温35℃、紫外检测器(224nm)。方法的线性相关系数大于0.999,相对标准偏差小于6.2%,仪器检测限分别为0.011mg/L、0.009mg/L、0.016mg/L、0.020mg/L,加标回收率为84.1%~99.5%。实际水样检测结果为河流中4种PAEs总浓度在35.6~184.2μg/L,表明该河流水体受到不同程度的PAEs污染。 相似文献