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131.
During the citified course at present for construction of old mountain cities is very important. This paper has analyzed the following problems: the contradiction for construction of cities, style of mountain cities, reconstruction of city construction and reflecting the features of our age from cities.  相似文献   
132.
Interspecific F1 hybrids were produced after artificial intercrossing of six Sideritis species indigenous to Greece, namely: S. athoa, S. euboea, S. syriaca, S. raeseri, S. scardica, S. clandestina and a cultivated clone of S. raeseri. It was found that all species cross with each other, but the level of crossability varied with the cross-combination. In the yield evaluation experiments, the interspecific hybrids with a common female parent were considered as a group. It was observed that yield during the year of establishment was relatively low, but the interspecific hybrids out-yielded the control in both fresh and dry weight. All hybrids produced higher yields in the following years and their productivity started to decline after the fifth year. All hybrids produced higher yields than the control in all six years of the experiment. The highest yield over the years, in fresh and dry weight, was produced by the group Sideritis raeseri cultivated clone (cc) ×Sideritis spp. This yield, however, was not always significantly different from the yield produced by the second in the rank group (S. clandestina×Sideritis spp.). A high correlation (r > 0.99) between fresh and dry weight was observed. The two groups with the highest yield also had the highest essential oil content. In addition, all the interspecific hybrids had a higher essential oil content than the control species. Furthermore, the essential oil content of the selected individual hybrid plants ranged between the midparental value to a value higher than the high-parental species, indicating an additive and dominance gene action. It was also found that the content of the essential oil in the seven most important components (pinene, lemonene, cynene, menthone, copaene, caryophyllene and valerianic ester) varied from hybrid to hybrid. Given that Sideritis reproduces mainly asexually, the direct use of individual interspecific hybrids with higher yield and content in essential oil than the control species is possible in cultivation.  相似文献   
133.
典型岩溶峰丛山区土地利用与水土流失   总被引:4,自引:0,他引:4       下载免费PDF全文
以广西马山县加方—古寨地区为例,在分析自然地理及地质条件的基础上,分析了土地开发利用现状、土地利用空间的合理调配与岩溶石山区水土流失的治理,提出了水土流失的治理方法。  相似文献   
134.
为避免山地果园单轨运输机运行时碰到前方穿越的移动物体或轨道上的静止障碍物,提高运输机工作的安全性和稳定性,研制了山地果园单轨运输机超声波避障系统。该系统由核心微处理器、超声波探头及收发电路、电源模块、无线通信模块和按键等组成。以规则物块、不规则小石块等作为轨道上的障碍物,以树枝、侧枝较多的盆栽柑橘树作为轨道旁的非障碍物,将超声波探头安装在3个不同位置,使运输机工作在慢、中、快3个不同的速度,测试了避障系统的工作性能。试验结果表明,在一定条件下,避障系统能识别轨道上的障碍物和轨道旁的非障碍物。该研究提升了单轨运输机在轨道上无人驾驶运行的安全性和可靠性。  相似文献   
135.
商洛山区主要药用植物土地利用配置初步研究   总被引:1,自引:2,他引:1       下载免费PDF全文
张晓虎  何军 《水土保持通报》2007,27(5):151-154,158
根据区域土地资源合理利用及生态治理的要求,在调查分析商洛山区基本地貌类型、土地资源现状、特点及水土流失情况和水土保持状况的基础上,对商洛山区重点发展的12种中药材的生境特性、药用部位、土壤要求及其土地利用配置作了初步研究。  相似文献   
136.
Considerable differences observed in the home-range size of individual three-toed woodpeckers (Picoides tridactylus) may be linked to variation in resource availability. We used radio-telemetry to test this hypothesis in an alpine mountain forest in southeastern Germany between 1994 and 2000. Stepwise backward multiple-regression showed that adaptive kernel home-range size using 95% use distribution (n=24 woodpeckers) was positively related to forest extent and tree-species diversity. Conversely, we found smaller home ranges with increasing density of potential cavity trees, and with increasing dbh-range of trees at breast height. The habitat variables shown to effect home range selection were attributes of mature boreal forests. This implied that maintaining a boreal-like habitat (i.e. spruce-dominated autochthonous forests including their natural disturbance regime) would be the best option for successful conservation of the alpine subspecies of the three-toed woodpecker.  相似文献   
137.
以美登等4个蓝莓品种为试验材料,在吉林省东部山区进行冬季棚式防寒新技术与覆土防寒效果的比较研究,结果表明:棚式防寒较覆土防寒可节约成本4 485元·hm-2,果实产量增加收益12 942元·hm-2,总体收益提高了17 427元·hm-2,经济效益十分显著。  相似文献   
138.
Surface area processing in GIS for different mountain regions   总被引:1,自引:0,他引:1  
Surface area is a fundamental parameter derived from terrain analysis in geographical information systems (GIS) for modeling the real world. Therefore, an evaluation of the techniques implemented by GIS models is important in order to obtain reliable area measurements. The study compares two raster-based methods with a TIN-based (triangulated irregular network) method for surface area approximation using a digital elevation model (DEM) with 25 m × 25 m resolution in six mountain regions of Shandong Province, China. Raster-based method Ⅰ calculates surface-area grids from DEMs directly. Eight 3-dimensional triangles connecting the center point of each cell with the center points of the eight surrounding cells are generated and then the areas of the portions of each triangle that lay within the cell boundary are calculated and summed. Raster-based method Ⅱ produces the surface area of each cell directly from the pixel size and the slope value for the pixel. The results demonstrate that the surface areas calculated by raster-based method Ⅰ are equal to those of the TIN-based method. The results of raster-based method Ⅱ are the lowest but the difference in areas between the two raster-based methods decreases with the decrease in terrain complexity. Compared to the method with TINs, raster-based method Ⅱ can do better because it has some advantages, such as neighborhood analysis, more consistent output and faster processing speed. The results also demonstrate that the difference between surface and horizontal areas should be considered if more than 30% of the area of a region has slopes steeper than 18.2 degrees.  相似文献   
139.
沉香山位于粤西沿海地区,地处重要的南药产地,区内植物资源丰富.经初步调查发现,药用植物种类达406种(其中苏铁蕨、土沉香、金毛狗等属珍稀濒危物种),分属106科;植物的药用范围十分广泛,遍及19大类.  相似文献   
140.
中国西部山地旅游资源的基本特征及其开发的限制因素   总被引:3,自引:0,他引:3  
山地旅游资源是中国西部地区极为重要的一种自然旅游资源 ,从地理学角度对中国西部地区山地旅游资源的基本特征进行了分析 ,认为西部山地旅游资源具有 6个显著的特点 ,并对西部山地旅游资源开发的限制因素及需注意问题进行了初步探讨  相似文献   
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