共查询到20条相似文献,搜索用时 180 毫秒
1.
采用水泥粉喷柱、砂砾垫层与覆膜土工布三者结合的综合加固法处理滨海相淤泥沉积,水泥粉喷桩的施工及成桩检测;土工布的施工;软基处理应注意的问题。 相似文献
3.
土工布的出现,使在不良地段筑路有了新的前景,土工布应用的建筑布料分为织造布和非织造布。本文着重讲了在道路工程上,主要应用的非织造布,道路工程对土工布的物理力学及化学指标的要求,土工布夹层在湿软地段筑路时的应用效能,林区公路沼泽湿软地段土工布夹层铺设的施工工艺,土工布在湿软地段筑路的经济效果分析。 相似文献
4.
5.
分析旧路补强的原理及补强方法,就土工布应用特性作一介绍,使用专用土工布能有效减缓沥青混凝土面层反射开裂。 相似文献
6.
7.
8.
近年来,随着土工布的广泛使用,已经成功地证明了可以减少反缝的发生,从而延长了沥青混凝睡面的使用寿命,土工布置于沥青混面层与其下层之间,主要起防水、排水和增加路面柔韧性作用,从而增加了沥青混凝土路面的抗疲劳破坏能力。 相似文献
9.
10.
11.
12.
Nyam-Osor Batkhuu Don Koo Lee Jamsran Tsogtbaatar 《Journal of Sustainable Forestry》2013,32(6):600-617
Since 1990, after the dramatic change in Mongolia's political and economic system, human impact on forest resources highly increased and became continuously degraded due to improper exploitation, forest fire, mining, pest and disease, uncontrolled grazing, and inadequate management which negatively affect its environmental conditions causing severe deforestation, desertification, and ecological stress in some regions of the country. Forestry research and education became fragmented in Mongolia. Several institutions and universities conducted vague and in some cases duplicating research topics. Hence, this article aims to understand the current status and issues as well as to formulate possible solutions in strengthening and developing forest and forestry research and education in the country. 相似文献
13.
14.
德国奥地利森林资源监测与经营管理的特点及启示 总被引:6,自引:1,他引:5
深入分析了德国在同一抽样体系下,实施森林资源及其生态状况监测的技术特点、永续利用的经营理念与近自然的经营管理方法,以及奥地利信息技术在森林资源监测中的应用特点与科技创新的发展措施,对比我国森林资源监测状况,提出了完善森林资源监测内容和指标体系,建立森林资源及生态状况综合监测体系,加强新技术的创新研究和应用,积极争取国家基础数据共享应用的建议。 相似文献
15.
Kindu Mekonnen Roland J. Buresh Richard Coe Kering Maru Kipleting 《Agroforestry Systems》1998,42(3):265-282
Measurements of root and nutrient distributions in agroforestry systems have often been obtained from unreplicated plots.
We, therefore, measured the vertical and horizontal distribution of root length and soil nitrate in replicated plots of sesbania
[Sesbania sesban (L.) Merr.] to assess plot-to-plot variation and identify appropriate sampling schemes. Sampling was on profile
walls exposed from pits at two on-farm sites (Ochinga and Muange) in Kenya. At Ochinga, soil was sampled at 27 0.15-m depth
intervals and eight 0.15-m-wide locations perpendicular to 2.25-m-wide rows of 19-month-old sesbania. At Muange, sampling
was 18 months after establishment of sesbania from seedlings with a 1 m by 1 m spacing. Soil was sampled at 17 0.15-m depth
intervals and nine 0.15-m-wide sampling locations – one exactly below the tree and four each on opposite sides of the tree.
Root length density generally decreased with distance from sesbania and with soil depth. Soil nitrate, however, followed different
trends in the four replications at Ochinga and the three replications at Muange. At Ochinga, nitrate above 2.5-m depth clearly
increased with distance from the tree in two replications but followed no distinct trend in another replication. At Muange,
nitrate above 1.2-m depth decreased with distance from the tree in one replication, increased with distance from the tree
in another replication and followed no clear trend in another replication. The suitability of various sampling schemes for
measuring root length and nitrate was accessed from percent bias between measured values at sampling locations in the scheme
and actual values for an entire transect of sampling locations. Bias associated with selection of sampling locations tended
to be higher within the 2.25-m-wide sesbania rows than the 1 m by 1 m sesbania spacing. Soil sampling in systems with rows
of young trees should be at several locations along a transect perpendicular to tree rows in order to minimize bias.
This revised version was published online in June 2006 with corrections to the Cover Date.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
木竹经营加工是湖南祁阳县一个传统优势产业.近年来,祁阳县木竹产业在快速发展的同时也暴露出一些实际困难和问题,制约了产业的进一步发展壮大.新时期木竹经营加工发展思路就是要坚持科学布局.加强引导服务,加大政府扶持,加强领导监管. 相似文献
17.
18.
19.
城市森林与城市绿化可持续发展 总被引:14,自引:0,他引:14
针对目前城市绿化中存在的生态环境效能低下 ;绿化维护成本高 ;绿化的社会价值未能充分体现等主要问题 ,提出将城市森林建设作为城市绿化可持续发展的立足点。在阐明城市森林概念和范围的基础上 ,论述了城市森林的主要生态作用。并提出了城市森林建设的思路。 相似文献
20.
天水市古树名木资源和古树名木保护历史及现状综述 总被引:1,自引:0,他引:1
天水是中国历史文化名城之一.它的重要标志之一是留存有众多的古树名木,数量居甘肃省各市之首,在全国也是留存古树较多的城市之一.在现有天水古树资源及其保护资料和工作的基础上,对天水古树名木资源、历史及其现状、研究成果、保护工作等方面进行梳理总结,以期对今后进一步开展这些古树的研究工作提供参考. 相似文献