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71.
作者根据哈尔滨实际情况,论述了底部框架砖房防震设计中应注意的问题。对指导哈尔滨城市建设,具有一定的实用性。 相似文献
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Ground-layer vegetation was sampled along selected trail corridors to determine whether corridors provide habitat for certain species and act as conduits for species movement. Patterns of plant species composition were analyzed in relation to distance from trail edge, level of trail use, and distance from trailheads, junctions, and campgrounds. Species composition was significantly affected by distance from trail edge and level of trail use, as species were favored or inhibited by the corridor, depending upon their growth habits. Species composition was also affected by distance from trailheads. These findings, along with the presence of exotic species, indicate that trail corridors in Rocky Mountain National Park function as habitat and conduits for movement of plant species. 相似文献
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Jaime Villacís Cristina Armas Susana Hang Fernando Casanoves 《Land Degradation \u0026amp; Development》2016,27(7):1771-1780
One of the requirements for the forest restoration of soils disturbed by the oil‐exploitation industry is that saplings be able to endure soil‐adverse conditions. In this study, saplings of 20 species susceptible to be used in reforestation programs were evaluated for their ability to grow on substrates derived from soils disturbed by petroleum extractions in the Ecuadorian Amazon. Seeds of each species were planted in germination trays. Once seedlings reached 5 cm in height they were transplanted to plastic bags with three treatment substrates: two derived from petroleum‐exploitation activity (soils from mud and drill cutting cells and from areas surrounding oil wells) and a control soil. Plant survival rate, stem height, and diameter were measured on a weekly basis until 14 weeks after transplantation, when we harvested the plants and also measured plant biomass and calculated the Dickson quality index for each species. Oil‐exploitation by‐product substrates impaired the performance of many saplings, with the substrate from mud and drill cutting cells being the one that most affected plant performance. Only saplings of five native species in the Amazon basin—Apeiba membranaceae, Cedrelinga cateniformis, Inga densiflora, Myroxylon balsamum, and Pouroma cecropiifolia—exhibited high or similar Dickson quality index values in all soil treatments and performed better than the rest. The use of these five species in remediation of soils disturbed by petroleum extraction in the Amazon basin could prove important because of their high potential to adapt to these disturbed sites. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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不同人为干扰尺度对米槠群落外貌特征影响研究 总被引:2,自引:0,他引:2
从群落外貌探讨不同人为干扰尺度对福建武平米槠林的影响。结果表明:随着人为干扰尺度(CK对照、A级择伐更新、B级天然更新、C级人工促进天然更新和D级杉木林)的加大藤本植物、地面芽植物、地上芽植物、中型叶、草质叶、复叶和落叶的种类逐渐上升或呈“S”型上升,而高芽位植物、小型叶、革质叶、全缘叶、单叶和常绿的种类逐渐下降或呈“S”下降;CK、A级、B级和C级的外貌是由革质、单叶、小型叶为主的常绿高位芽植物所决定的,而D级由草质、单叶、中型叶为主的常绿高位芽植物所决定的。 相似文献
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用综合加权评分法优化钻井泥浆配方的研究 总被引:1,自引:8,他引:1
通过对影响泥浆质量因素的分析,进行了泥浆配方试验,并运用多指标试验的综合加权评分法,结合直观分析、极差分析,寻找出了一个最优泥浆配方,在实践中产生了良好的经济效益 相似文献
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厩肥对粉煤灰微量元素释放规律影响的研究 总被引:2,自引:0,他引:2
该文对粉煤灰在降雨淋洗条件下微量元素的释放规律进行了室内模拟试验。试验处理分别为粉煤灰、粉煤灰+石灰、粉煤灰+石灰+厩肥及其混合物的堆肥腐熟4种情况。实验结果显示淋出液中B、Sr、Ba和Li的最大浓度大于1 mg/L,而其它元素均小于此值。石灰的应用增大了淋出液中B和Ba的浓度而降低了Li、Mo和Cr的浓度;厩肥的应用及其堆肥腐熟处理增大了B、Mo、Zn、V以及Cu、Ni、Cd、As、Mn、Ti、Co、Sn和Se的浓度,而降低了Sr、Ba、Li和Cr的浓度。除V外,淋出液中所有微量元素的浓度随淋出液体积的增加而减小。Cr、Zn以及Cd、Cu和As可能是粉煤灰对环境产生潜在危害的主要元素。 相似文献
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Avifaunal responses to understorey fire disturbance and subsequent changes in habitat structure were examined within 20 burnt and unburnt forest plots of 0.25 ha (10×250 m), 10-15 months after an unprecedented understorey fire swept through the Tapajós-Arapiuns Extractive Reserve of central Brazilian Amazonia following the severe 1997-1998 El-Niño dry season. Although these surface fires in the previously undisturbed primary forest were relatively mild, they resulted in dramatic changes in forest structure consistent with those found elsewhere in Amazonia. Bird species negatively affected by these changes tended to be the least common, the most disturbance-sensitive, and habitat specialists. Considering different guilds, ant followers, dead-leaf gleaners, terrestrial gleaners, and arboreal sallying insectivores were the most negatively affected, whereas nectivores and arboreal granivores became more abundant in the burnt forest. The results highlight the severe consequences of even relatively mild surface fires in neotropical forests, and the importance of controlling haphazard frontier expansion for the conservation of susceptible species that are endemic to fire-prone regions. 相似文献