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31.
珠江上游少数民族县域经济活动的累积环境效应研究--以贵州三都水族自治县为例 总被引:1,自引:0,他引:1
为了探索珠江上游少数民族区域经济活动的累积环境效应与生态安全,我们选择三都水族自治县作为定位研究基地.对建国以来区域内经济活动变迁进行历史、现状研究和综合评估,揭示历史时期发展政策、发展模式、重大经济活动等人为扰动因素在区域生态环境系统退化过程中的作用.评估少数民族经济活动的累积环境效应与生态安全。 相似文献
32.
Most previous studies have focused on the direct impact of green supplier integration on environmental performance, and treated this relationship as a “black box.” To address this research gap, this study explores how green supplier integration affects environmental performance via supply chain resilience, and the moderating role of knowledge combination on the link between green supplier integration and supply chain resilience. Drawing on natural resource‐based view and knowledge‐based view, we develop four hypotheses and examine these hypotheses using two‐waved data from 206 Chinese manufacturing firms. We find that green supplier integration has positive effects on both proactive dimension and reactive dimension of supply chain resilience. Proactive dimension and reactive dimension of supply chain resilience partially mediate the link between green supplier integration and environmental performance. In addition, knowledge combination strengthens the positive impact of green supplier integration on reactive dimension of supply chain resilience. These findings suggest that supply chain resilience and knowledge combination cannot be overlooked when firms expect to gain environmental profits by conducting green supplier integration. 相似文献
33.
针对城市热岛效应引起城区浅层土地温场升高这一观测结果,采用室内快速模拟试验方法,对城区酸性土壤腐蚀混凝土材料的温度效应开展了试验研究.试验研究了在温度为5℃、20℃和40℃条件下,混凝土试样在酸浓度分别为0%、5%和10%的沙土介质中放置30 d、90 d后的抗压强度变化规律,并对混凝土试样在腐蚀过程中的腐蚀系数变化规... 相似文献
34.
大气作用下膨胀土地基的水分迁移与胀缩变形分析 总被引:1,自引:0,他引:1
运用土体渗流和蒸发理论,建立了大气-非饱和土相互作用模型;以现场观测的气象数据作为边界条件,进行了地基土中水分迁移的数值模拟,得到了大气作用下地基土体含水量的动态分布规律.计算结果表明,地基土中含水量变化幅度随深度增加而递减,3.5m深度以下土体的体积含水量基本不变,从而确定了南宁地区膨胀土地基的大气影响层深度为3.5... 相似文献
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针对不同结构多层商住楼的具体特征,运用结构易损性分析方法对各类房屋未来的震害情况进行了分析,给出了震害损失与投资效果的综合评价方法,为进行这类房屋的结构选型、设计及工程投资的优化提供一定的理论依据。 相似文献
38.
Chung-Ming Liu 《Chemistry and Ecology》1996,12(1):147-161
In this paper, three sensitivity studies are designed to analyze the effect of the NMHC (Non-Methane HydroCarbon) composition, the aerosol back-scattering and the high chimney NOx emission to the photochemical prodution of ozone by using a one-dimensional photochemistry-diffusion model under a favourable meteorological condition. Measurements of the NMHC composition in Taipei indicated that the percentage of iso-butene, cis-2-butene, trans-2-butene and benzene in a unit volume was much higher than of those observed in other major cities. the high ratio of benzene was directly linked to its high percentage in gasoline. As to the unusually high amount of iso-butene, cis-2-butene and trans-2-butene, more researches are needed to identify their source. Concerns are raised as to how productive is NMHC composition is to the photochemical production of the surface ozone. A rough estimate shows that the total reactivity of the Taipei NMHC composition is about 1.21 × 10-9 cm3 s-1 which is 1.6 times that of the Los Angeles (LA) NMHC composition, while the simulated noon peak will be different by 28 ppbv, i.e. 18% more than that simulated with a LA composition.
Meanwhile, high aerosol loading is a serious problem in Taipei. the attenuation of the UV radiation by aerosols cannot be ignored. A numerical simulation shows that the noon ozone level will decrease from 178 to 141ppbv, i. e. about 21% reduction, with deterioration of the visual range from 85 to 5 km.
In the southern Taiwan, industry parks are mixed with the populated Kaohsiung city, hence the large emission of NOx from high chimneys cannot be ignored. in this study, NOx is assumed to be emitted in the layer between 235-460 m high with an emission rate of 0.05 or 0.145 ppbv/sec. the results show that the NOx emitted from the elevated stack lead to a considerable reduction of surface ozone. Such conclusion is obtained due to the fact that a one-dimensional model is used in this paper. Whereas, if a three-dimensional regional model was used, then a higher productivity of ozone downstream would be simulated. 相似文献
Meanwhile, high aerosol loading is a serious problem in Taipei. the attenuation of the UV radiation by aerosols cannot be ignored. A numerical simulation shows that the noon ozone level will decrease from 178 to 141ppbv, i. e. about 21% reduction, with deterioration of the visual range from 85 to 5 km.
In the southern Taiwan, industry parks are mixed with the populated Kaohsiung city, hence the large emission of NOx from high chimneys cannot be ignored. in this study, NOx is assumed to be emitted in the layer between 235-460 m high with an emission rate of 0.05 or 0.145 ppbv/sec. the results show that the NOx emitted from the elevated stack lead to a considerable reduction of surface ozone. Such conclusion is obtained due to the fact that a one-dimensional model is used in this paper. Whereas, if a three-dimensional regional model was used, then a higher productivity of ozone downstream would be simulated. 相似文献
39.
在不同工况下,通过采取不同的岩土体物理力学参数来计算沙坝沟滑坡的稳定系数并分析影响因素,得到影响该滑坡稳定性的主要因素为降雨、地下水作用及人类工程活动,在一定条件下可能成为滑坡失稳破坏的诱导因素。最后为滑坡防治提出一些建议,对滑坡的预测和防护提供依据。 相似文献
40.
关于雾灾几个相关问题的探讨 总被引:20,自引:0,他引:20
首先,基于灾害系统的理论,构建了雾灾灾害系统模式和灾害链模式,提出了以机场和高速公路为承灾体的雾灾灾害链.其次,构建了雾灾承灾体脆弱性评价体系和模型,并对中国雾灾脆弱性分省区进行了评价,结果表明雾灾脆弱性高值区是上海、北京、天津3市;次高值区是江苏、山东、海南、广东等省.最后,以2002年12月的一次大雾天气为例,运用灰色关联度方法,着重对机场客运的雾灾灾情进行了评估,以期为雾灾损失厘定和防灾减灾提供科学的依据. 相似文献