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1.
苗圃转让     
今年顺义区苗圃绿化、美化苗木达1120多种、1.12亿株。其中油松、白皮松、华山松、雪松、桧柏、侧柏等常绿树13157亩,1650万株,占育苗总面积的23%;连翘、碧桃、榆叶梅、紫叶李、紫蔽、紫荆、月季、玫瑰、黄刺梅、黄杨、女贞等花灌木5468亩,1455万株,占育苗总面积的10%;白腊、元宝枫、栾树、国槐、银杏、合欢、龙爪槐、杜仲、千头椿、金丝柳、各种品种杨等落叶乔木37375亩,8095万株,占育苗总面积的67%。  相似文献   

2.
大丽花块根繁育和栽培技术   总被引:2,自引:0,他引:2  
大丽花(Dahlia pinnata Cav)菊科,大丽花属,多年生草本,原产墨西哥,又名大丽菊、大理花、天竺牡丹、西番莲、地瓜花,具有植株粗壮、花期长、花朵硕大,品种繁多、花色鲜艳、适应性强等特点。是美化公园,布置庭院、花坛、花境以及切花陈设的较好花卉材料。大丽花为世界名花之一,目前世界约有3万多个品种,我国有500余品种。  相似文献   

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.
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.
蚊子、苍蝇、螳螂、臭虫、蜘蛛、蚂蚁之类害虫,在家庭、工厂、办公室、医院、学校、酒店等地,随处可见,无处不入.这些昆虫不但给人们的生活带来很多烦恼,更重要的是,他们导致疾病传播,从而严重危害人们的身体健康.所以,根除害虫,改变居住环境,早已成为人们关注的问题.  相似文献   

7.
肥胖是一种常见的慢性疾病,它是由于生理化机能的改变而引起的体内脂肪沉积量过多,造成体重增加,导致机体发生一系列病理、生理变化的病症.肥胖症是一种全身性代谢疾病,除引起身体外形的改变外,过多的脂肪可带来物理性的负荷,还是各种疾病的"培养箱".肥胖人群平均寿命明显低于正常体重的人群,同时肥胖症还是心血管疾病、糖尿病、脂肪肝、肿瘤的温床,它是一种营养代谢性疾病.减肥首先必须从能量的摄入入手,减少热能的吸收.  相似文献   

8.
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.
丽江市低效林改造初探   总被引:1,自引:1,他引:0  
丽江市森林资源丰富,但由于受人为或自然因素的影响,仍然存在森林树种结构不合理、林分质量差、效益低等问题.分析丽江市低效林改造的有利条件和不利因素.结合丽江市林业发展的实际,提出了低效林改造的改造方式选择以及树种选择原则,以及促进低效林改造的措施.  相似文献   

12.
低取代度季铵型半纤维素合成及其结构的研究   总被引:4,自引:0,他引:4  
以蔗渣提取的半纤维素为原料,通过醚化反应制备出低取代度季铵型半纤维素.主要讨论了醚化剂3-氯-2-羟丙基三甲基氯化铵(CHMAC)、催化剂NaOH用量对改性产品取代度的影响.当CHMAC与半纤维素的物质的量之比值为1.0、NaOH与CHMAC物质的量之比值为1.2时,得到取代度为0.02的季铵型半纤维素.通过红外、核磁共振光谱表征了改性前后半纤维素的结构.  相似文献   

13.
汽轮机降低真空运行,提高循环水温做为冬季供暖是一项社会效益和经济效益都十分显著的节能技术,下面把利用汽轮机低真空运行循环冷却水采暖技术及其显著的经济效益简述如下。  相似文献   

14.
分析低碳园林的实现途径,旨在更好地推广低碳理念,同时为低碳园林建设提供理论依据,也为今后低碳理念在园林景观设计中的进一步应用提供参考资料。    相似文献   

15.
袁琼 《绿色大世界》2012,(3):218-220
指出了低碳交通运输是实现节能减排,发展低碳经济的重要组成部分。分析了低碳交通运输的内涵,探讨了通过发展低碳交通运输,以促进经济的可持续发展,并提出了相应对策与建议。  相似文献   

16.
范旭辉 《林业科技情报》2013,45(3):80-81,84
主要探讨低噪音沥青混合料的研究和应用工作。首先,分析低噪音沥青路面的特点,研究交通噪音分类及其产生机理,提出解决噪音的主要措施;其次,对比分析国内外传统的低噪音沥青混合料矿料的级配范围,提出改进的矿料级配范围,并进行相应的低噪音沥青混合料设计。在某公路上铺筑了试验段,探讨低噪音沥青混合料的施工方法,试验段与普通路段的对比检测结果显示本研究的设计具有良好的效果。  相似文献   

17.
低温对木材性质影响研究进展   总被引:1,自引:0,他引:1  
通过总结低温对木材性质影响的研究结果,分析在低温环境中木材强度与比热性能的变化规律,比较木材经低温处理与未处理材性质的变化,论述低温处理后木材性质的变化机理,并对今后开展超低温下木材性质变化研究提出几点建议。  相似文献   

18.
基于小批量生产的统计过程质量控制的研究   总被引:4,自引:0,他引:4  
曹翠珍  苗瑞 《森林工程》2005,21(1):71-72
用概率积分变换理论,给出了控制过程均值、过程方差的标准化控制图,适用于小批量生产环境下对过程均值、过程方差的有效控制。  相似文献   

19.
对从化流溪河林场和连平九连山林场的毛竹低产林进行改造试验,结果表明:毛竹低产林进行带状垦复,并合理施肥等改造措施,林分各项生长指标均得到提高,以九连山林场改造效果较为理想。与对照比,从化试验地的毛竹改造林分高、竹产量达0.10水平显著差异,但胸径差异不显著,树高、胸径和竹产量增益分别为5.1%,1.2%,21.2%;连平试验地的改造林分高、胸径和竹产量三项指标均达0.0l水平显著差异,其增益分别为49.5%,55.0%,192.7%。通过改造,能够改善毛竹的生长环境,提高发笋率,促进竹笋萌发成长为新竹,同时可以提高毛竹质量和产量。  相似文献   

20.
云南省低产林改造面临的问题及对策措施   总被引:1,自引:0,他引:1  
杨韩 《林业调查规划》2006,31(3):148-152
云南省森林面积大,质量不高,立地条件较好的林地多已绿化成林而限制了林业的进一步发展,因此,实施低产林改造,最大限度地发挥林地生产力已成为云南省林业发展中重要而紧迫的任务。文章阐述了低产林的概念及标准,深入分析了云南省低产林改造工作中面临的问题,并针对不同的问题提出了相应的对策措施。  相似文献   

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