共查询到20条相似文献，搜索用时 46 毫秒
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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
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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
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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
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《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
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浙江省重点公益林松类生物量模型研究 总被引：2，自引：0，他引：2
根据浙江省森林群落和树种分布特点,在浙江省200万hm^2重点公益林范围内,按气候区、林分类型、林龄组成、立地条件、林分组成等设置松类树种（包括马尾松、黄山松、湿地松、华南松和火炬松）典型样地122个,实测标准木255株。通过相关分析表明,树干干重、木材干重、皮干重、枝干重、冠干重、根干重与胸径和树高的相关系数较大,其冠干重、枝干重、叶干重则与胸径和树高以及枝下高有较大的相关系数,从变量得到的简洁性和准确性考虑,经不同模型的拟合和检验,确定了松类生物量各器官的独立模型,总量、木材、树皮、树根、树干的模型结构为W=c1D^c2H^c3,树叶、树枝、树冠的模型结构为W=c1D^c2L^c3;拟合了浙江省重点公益林松类生物量各器官及总量的独立模型和相容性模型,经检验,各模型均具有较好的拟合精度和预估水平,样本总体预估精度指旨标（P％）在多数分量中以相容性模型最高,而且相对误差绝对值指标（E2％）最小,总量、木材,树干、树皮的预估精度超过了独立模型,其他分量仍保持了独立模型的水平;而且相对误差绝对值均略高于或等于独立模型。 相似文献
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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
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农夫 《绿色中国(A版)》2014,(18):72-74
九月全国气温转凉,开始进入初秋天气。在乍起的秋风中出游,的确可以使脚步更加轻快。秋天,天空越来越高,云越来越淡,人的心情也随着天空变得晴朗起来。此时若能在名山大川中领略风景之妙,可以说是最佳选择。我国四川自古被称为“天府之国”,是一块富饶而美丽的土地。四川境内的旅游景区很多,峨眉山风景区、乐山风景区、青城山风景区、四姑娘山风景区、海螺沟风景区、九寨沟风景区等等,都是全国闻名的风景游览区。这里我们为大家推荐一条最普通的,也是最好的游览线路,那就是成都——黄龙、九寨沟风景区——峨眉山、乐山风景区观光线路。 相似文献
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徐凤翔 《绿色中国(综合版)》2009,(8):38-41
1978年后，我的主要工作范围转向了举世瞩目的西藏高原，开始了此后近四分之一个世纪的西藏森林生态和高原生态的探索。连我自己都没有想到，此生会与西藏结下不解之缘。我援藏的单位西藏农牧学院位于藏东南的林芝，若从陆路走，需经漫长而险要的川藏公路进入，这一行，沿途经过川西林区、横断山脉“三江”峡谷区而进入藏东南林区。我完整地走过川藏线达7次，单程就是“八千里路云和月”，几乎每次都有险象环生的经历，其中最令人难忘的，还是第一次从川藏线进藏的情景。 相似文献
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农夫 《绿色中国(A版)》2014,(9)
九月全国气温转凉，开始进入初秋天气。在乍起的秋风中出游，的确可以使脚步更加轻快。秋天，天空越来越高，云越来越淡，人的心情也随着天空变得晴朗起来。此时若能在名山大川中领略风景之妙，可以说是最佳选择。我国四川自古被称为“天府之国”，是一块富饶而美丽的土地。四川境内的旅游景区很多，峨眉山风景区、乐山风景区、青城山风景区、四姑娘山风景区、海螺沟风景区、九寨沟风景区等等，都是全国闻名的风景游览区。这里我们为大家推荐一条最普通的，也是最好的游览线路，那就是成都--黄龙、九寨沟风景区--峨眉山、乐山风景区观光线路。 相似文献
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2005-2006年综合应用地理信息系统、全球定位系统、遥感技术对四川白河自然保护区内川金丝猴的栖息地进行监测评价.结果表明:在不考虑人为干扰的情况下,保护区内川金丝猴的最适宜栖息地面积为20.079 4 km2,占保护区总面积的12.39%;适宜栖息地面积为18.152 2 km2,占保护区总面积的11.20%;勉强适宜栖息地面积为64.439 3 km2,占保护区总面积的39.77%;不适宜栖息地面积为59.509 1 km2,占保护区总面积的36.72%.由于放牧、采药的影响,川金丝猴的适宜栖息地大面积丧失.在川金丝猴的实际栖息地内,最适宜栖息地面积为5.811 9 km2,仅占保护区总面积的3.59%;适宜栖息地面积为8.072 1 km2,占保护区总面积的4.98%;勉强适宜栖息地面积为46.920 4 km2,占保护区总面积的28.96%;而不适宜栖息地面积为101.235 6 km2,占保护区总面积的62.48%. 相似文献
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四川桑寄生科Loranthaceae植物研究 总被引：2，自引：0，他引：2
四川桑寄生科Ｌｏｒａｎｔｈａｃｅａｅ植物研究刘军（四川农业大学林学园艺学院）龚固堂（四川省林业科学研究院）本文对分布于四川的桑寄生科植物进行了系统的分类学研究。结果表明：四川共有７属、１９种及９变种。文中给出了分属、分种及变种检索表,对部分种（变种）... 相似文献
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阐述了四川省广元市森林生态旅游现状和特点,对森林生态旅游开发中存在的主要问题进行了分析,在此基础上提出广元森林生态旅游资源开发和生态旅游经营的建议。 相似文献
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川金丝猴生态生物学研究进展 总被引：1，自引：0，他引：1
川金丝猴（Rhinopithecus roxellanae）是我国特有物种,主要分布在陕西、四川、湖北的一些地区。本文依据近年来川金丝猴有关文献,对川金丝猴的习性、食性、社群结构、种群现状做了综述并提出了相应保护对策。 相似文献
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介绍川西云杉生态、生物学特性.根据保存的人工川西云杉林成活及生长情况,认为迪庆州寒温带地区是川西云杉适生区,川西云杉是高寒山区天然林采伐后理想的迹地更新树种.藉此,对其种子采集、圃地选择、播种育苗、苗期管理、造林地选择、整地、造林方法、抚育管理、病虫害防治等一系列苗木培育及造林技术进行了阐述. 相似文献