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991.
生物防火工程阶段调查报告 总被引:2,自引:0,他引:2
在森林防火线的生土带上营造以木荷为主体的生物防火工程,经6~8年的管护后,可初步达到生物防火要求,调查表明,在海拔800~1000m的南坡山地,可营造木荷防火工程,海拔800m以下山地则不受坡向的影响,木荷较为耐瘠薄,可在脊地带营造生物防火工程。 相似文献
992.
Ming Hung Wong Yuk Sing Gilbert Chan Chaosheng Zhang Charles Wang‐Wai Ng 《Land Degradation \u0026amp; Development》2016,27(3):500-510
This study dealt with a restoration project conducted at South‐East New Territories Landfill in Hong Kong, in order to screen suitable tree and shrub species (both native and pioneer species) for revegetation. For engineered landfills, landfill gas migration and leachate contamination to the topsoil are rarely problematic, but the lack of nutrients and moisture and poor physical soil conditions may jeopardize potential woodland establishment. The growth performance of 25 woody plant species subjected to 12 different soil amelioration and seedlings planting methods was compared. The results showed that the general performance (mortality rate, apical height, crown diameter and basal diameter) of pioneer species (notably Acacia species) was much better than that of native species in all blocks of woodland mix and scrub mix. The notch planting method was effective in helping seedling roots to have better contact with soil for water uptake, which subsequently increased the survival rates of seedlings, leading to a better tree coverage. Soil ameliorations (horticultural soil with fertilizer and horse and pig manure) generally increased the seedling survival rate and improved plant growth. Tree coverage on all the plant trial blocks was mainly established by the three Acacia species. A planting distance of 1 m was recommended for woodland establishment, and such dense seedlings planting would achieve a better tree coverage under a shorter period of time (than the distance of 3 m). Difficulties in woodland establishment were discussed, and the strategies for achieving a better tree growth were recommended. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
993.
Based According to the on the careful investigation in site of highway tunnel, the classification of tunnel disease is obtained. , design and construction of tunnel, in relation to the distribution of stress and loading of tunnel by numerical analysis and back analysis, the existing condition and reasons of tunnel diseases are carefully analyzed. At the same time, the disease management methods are provided, which are important to guide similar tur/nel to search diseases reasons and manage diseases. 相似文献
994.
Jigong Mountain Tunnel is a controlled project in the reconstruction of Xinyang-Chenjiahe section.Based on hydrogeological investigation,tunnel's hydrogeology character such as geological structure,development of surface water and underground water,recharge of surface water and groundwater is evaluated,and normal and maximum water yield are predicted in the way of groundwater runoff modulus.It has been shown that normal and maximum water yield are equal to 860 m3/d and 1 283 m3/d,so the whole tunnel is a poor water section,while the speculated are ebbing water ones. 相似文献
995.
The Dacromet technology,which is a potential surface treatment method,has achieved extensive application in automobile industry.The Dacromet coating is prepared through dipping & curing process,and the microstructure and anticorrosion performance of zinc,aluminum galvanized specimens are comparatively investigated.The results shows that the zinc,aluminum,chromium distributed evenly and Zn/Al flakes overlapped and embedded in amorphous chromium binder in Dacromet coating which anticorrosion is superior to hot dip galvanized but slightly inferior to hot dip aluminum coating with lowered adhesion,its adhesive ability to matrix is weaker than that of aluminum coating. 相似文献
996.
LIN Xian ming 《保鲜与加工》2001,(5):6-15
In this paper, the water resources development and water environment protection in Chongqing is analyzed systematically by investigating and monitoring for water, especially, the water ecology protection in Three-gorges reservoir region is discussed. It is proposed that there should be five protection systems for water formed in Chongqing and it is of great value to the authorities concerned. 相似文献
997.
天门山国家森林公园野生花卉资源调查及其园林应用 总被引:1,自引:1,他引:0
依据野外调查和有关资料,评价和分析了天门山国家森林公园野生花卉种类的多样性、观赏特性和园林应用的多样性,经统计发现,天门山有较高观赏价值的野生花卉资源共108科253属375种。其中宿根花卉75种,球根花卉45种,一二年生花卉19种,草质藤本花卉17种,木质藤本花卉50种,木本花卉154种,蕨类花卉15种;根据观赏特性划分,有观花类249种、观果类89种、观叶类133种等3大类;根据园林用途划分,有盆花类182种、花坛花境类115种、地被类148种、垂直绿化类71种、湿生类25种、盆景类45种、绿篱类57种、园景树115种等8类。并对合理保护、开发利用野生花卉资源提出建议。 相似文献
998.
为了解鸭圆环病毒(Duck circovirus,DuCV)在我国鸭群中的感染状态,从我国养鸭业比较集中的山东、江苏、四川、福建、广东5个省份36个鸭群采集临床有发病表现的343只病、死鸭的病理组织样品,以提取的组织DNA为模板通过特异性斑点杂交和PCR方法检测DuCV的感染情况.结果显示上述5个省份的鸭均检出了DuCV,病、死鸭中DuCV的个体阳性率为81.63%(280/343),群体阳性率为94.44%(34/36).结果表明我国鸭群中已普遍存在DuCV的感染. 相似文献
999.
陕西省关中地区奶牛结核病调查 总被引:1,自引:0,他引:1
2006-2008年对陕西关中部分地区(西安、宝鸡、咸阳和渭南)奶牛结核病依据我国国家标准《GB/T118645-2002》"结核菌素试验"进行调查,调查数据显示2006年-2008年检测奶牛分别为6090头、5328头、4286头,阳性率分别为0.77%、1.05%、1.42%,陕西关中地区奶牛结核病阳性率有明显上升趋势。西安、宝鸡、咸阳和渭南地区的检测头数分别为4129头、4680头、3797头、3058头,阳性率分别为0.90%、0.80%、1.18%、1.43%,其中渭南地区的阳性率最高。从养殖规模上来看,10头以下养殖户奶牛结核阳性率最高为1.48%。 相似文献
1000.
按经纬度坐标整数交叉点为中心布设广西森林资源遥感样地,每个方形样地面积为10×10 km2,以遥感样地为研究对象,以Landsat TM为数据源,运用3S技术,监测1990、2000和2005年3期变化,结果表明:TM数据是一种高效可行的森林覆盖动态监测数据源;TM数据需要辅助资料才能满足广西林业一级地类区分要求;1990~2005年广西遥感样地的森林覆盖率不断提高,从34.35%上升到53.41%。 相似文献