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1.
为提高高烈度地震区隧道抗震性能,以某铁路隧道为研究背景,分析3种抗减震措施下隧道不同监测点隧道拱顶沉降、边墙收敛、衬砌结构PGA及最小安全系数,通过对比分析得到最优抗减震措施。结果表明:相比于工况1,工况2隧道拱顶沉降减小10.54%~81.10%,边墙收敛减小13.92%~78.77%,衬砌结构PGA减小31.42%~72.02%,最小安全系数增加18.04%~66.13%;相比于工况1,工况3结构拱顶沉降减小3.04%~18.02%,边墙收敛减小4.70%~32.00%,PGA增加13.95%~27.48%,最小安全系数增加7.49%~30.99%;工况4即“减震层+SFRC衬砌”刚柔并济法,相比于工况1,隧道拱顶沉降减小18.46%~83.98%,结构边墙收敛减小17.54%~85.47%,PGA减小30.00%~69.98%,最小安全系数增加47.95%~83.56%;4种工况抗减震性能由高到低依次为:工况4>工况2>工况3>工况1。研究结果可为隧道软硬围岩交接段抗震设防提供理论参考。  相似文献   
2.
Brazil hosts the largest expanse of tropical ecosystems within protected areas (PAs), which shelter biodiversity and support traditional human populations. We assessed the vulnerability to climate change of 993 terrestrial and coastal-marine Brazilian PAs by combining indicators of climatic-change hazard with indicators of PA resilience (size, native vegetation cover, and probability of climate-driven vegetation transition). This combination of indicators allows the identification of broad climate-change adaptation pathways. Seventeen PAs (20,611 km2) were highly vulnerable and located mainly in the Atlantic Forest (7 PAs), Cerrado (6), and the Amazon (4). Two hundred fifty-eight PAs (756,569 km2), located primarily in Amazonia, had a medium vulnerability. In the Amazon and western Cerrado, the projected severe climatic change and probability of climate-driven vegetation transition drove vulnerability up, despite the generally good conservation status of PAs. Over 80% of PAs of high or moderate vulnerability are managed by indigenous populations. Hence, besides the potential risks to biodiversity, the traditional knowledge and livelihoods of the people inhabiting these PAs may be threatened. In at least 870 PAs, primarily in the Atlantic Forest and Amazon, adaptation could happen with little or no intervention due to low climate-change hazard, high resilience status, or both. At least 20 PAs in the Atlantic Forest, Cerrado, and Amazonia should be targeted for stronger interventions (e.g., improvement of ecological connectivity), given their low resilience status. Despite being a first attempt to link vulnerability and adaptation in Brazilian PAs, we suggest that some of the PAs identified as highly or moderately vulnerable should be prioritized for testing potential adaptation strategies in the near future.  相似文献   
3.
Wildlife provides food, medicine, clothing, and other necessities for humans, but overexploitation can disrupt the sustainability of wildlife resources and severely threaten global biodiversity. Understanding the characteristics of consumer behavior is helpful for wildlife managers and policy makers, but the traditional survey methods are laborious and time-consuming. In contrast, culturomics may more efficiently identify the features of wildlife consumption. As a case study of the culturomics approach, we examined tiger bone wine consumption in China based on social media and Baidu search engine data. Tiger bone wine is one of the most purchased tiger products; its consumption is closely related to tiger poaching, which greatly threatens wild tiger survival. We searched a popular social media website for the term “tiger bone wine” and focused on posts that were originally created from 1 January 2012 to 31 December 2018. We filtered and classified posts related to the purchase, sale, or consumption of tiger bone wine and extracted information on providers, consumption motivations, year of production, and place of origin of the tiger bone wines based on the texts and photos of these posts. We found 756 posts related to tiger bone wine consumption, 113 of which mentioned providers of tiger bone wine, including friends (53%), elder relatives (37%), peer relatives (7%), and others (3%). Out of the 756 posts, 266 indicated the motivations of tiger bone wine consumption. Tiger bone wines were consumed as a tonic (34%), medicine (23%), game product (30%), and a symbol of wealth (28%). Some posts indicated ≥2 consumption motivations. These findings were consistent with the search queries from Baidu index. Such information could help develop targeted strategies for tiger conservation. The culturomics approach illustrated by our study is a rapid and cost-efficient way to characterize wildlife consumption.  相似文献   
4.
During the artificial reproduction of salmonides, the fecundity can be increased either by improving the viability of spermatozoa, or by extending the time period during which a roe micropile remains open, thus allowing its fecundation. Practically, this can be achieved by the use of some fertilising techniques suitable for fish species. Here, we show that the reproduction of rainbow trout in a 1:1 solution of deuterium-depleted water and distilled water led to a significant increase in survival of roes during their embryonic development. Moreover, the addition of glucose and fructose into the deuterium-depleted fertilising solutions led to a further increase in roe survival during embryonic development. The increase in survival is mainly explained by an increase in the motility of spermatozoa.  相似文献   
5.
丁宗洲 《灾害学》1992,7(2):68-71
本文论述了湖北省农业地质灾害的类型、分布、危害,并提出了防治对策。  相似文献   
6.
面对人口老龄化对经济发展的影响.应以养老和健康保障为先导.逐步加大对社会保障基金的投入.充实基本养老保险和医疗保险基金.建立和完善与生产力发展水平相适应的社会保障制度.继续推进社会保障社会化和产业结构调整的力度.建议政府应大力发展老龄产业。政府必须从实际出发.坚持科学发展观.逐步建立和完善老年社会养老制度和福利制度.根据老年消费市场状况.规范、引导投资.调整、优化产业结构用产业化、市场化、社会化的新运行机制.推进安老、养老产业的发展.根据老年人的不同需求,有计划的发展老龄产业、开发老年用品.增设老年服务项目.满足老年人在物质和文化方面的发展需要.以促使人口老龄化与经济的协调发展。  相似文献   
7.
中国可持续发展综合评价研究   总被引:19,自引:3,他引:16  
可持续发展作为一个动态、开放的复杂巨系统。人口、资源、经济、环境和科技构成了其关键要素。本文基于PREEST系统模型。首先提出了一套中国可持续发展综合评价指标体系:同时。借助于主成分分析法和隶属度分析法。就中国1987~2001年度的综合发展指数与协调发展指数进行了实证分析;最后。基于研究成果。对中国未来的可持续发展提出了若干政策建议。  相似文献   
8.
岷江上游崩塌滑坡分布规律研究   总被引:1,自引:0,他引:1  
岷江为长江—级支流,上游长330km,自1986年以来,发生崩塌滑坡200余处,体积约2.1亿m ̄3。作者研究了岷江上游崩塌滑坡的分布规律。采用统计指标法,将岷江上游分为三种不同的崩塌滑坡分布密度区:①UXS.高密度区;②MXS,中密度区;③LXS_3低密度区。  相似文献   
9.
Study on Assessing Economic Vulnerability of Small Island Regions   总被引:2,自引:0,他引:2  
The main purpose of this study is to assess economic vulnerability of small island development regions as part of their sustainability constraints. By combining economic and environmental time series data, we assessed a composite index of economic vulnerability which is constructed from three exogenous variables, namely economic exposure, economic remoteness, and economic impact of environmental and natural disasters. We used the Amami Islands, Kagoshima Prefecture, Japan as the case studies for this paper.The results indicated that using a gross island products based valuation index, Kikaijima is the most vulnerable island in the Amami Islands with a composite economic vulnerability index (CEVI) value of 0.678, while by using a per capita based index, Okinoerabujima is considered the most vulnerable island with a CEVI value of 0.680. From the results we also revealed that smaller islands have relative higher vulnerability than the bigger one, which also confirms some previous country-level vulnerability studies.However, it is matter of fact that some islands that have relatively high vulnerability also have good economic performance as shown by their per capita income. In this regard, it can be argued that the success of these small islands could have been achieved in spite of and not because of their inherent vulnerability conditions as an indicator of sustainability constraint. Regarding these findings, we also examined a comparison between vulnerability results and the preliminary concept of an island's resilience in order to capture another perspective on sustainability assessment in a small island region.  相似文献   
10.
生态型港口综合评价指标体系初探   总被引:2,自引:0,他引:2  
基于上海市建设生态型城市的长期目标,将港口作为城市生态系统中重要的子系统,对如何建设生态型港口提出了综合评价指标体系。通过筛选得到45项单因素指标,针对不同类型的港区有所分异,整个评价体系分为5个准则层(生态环境、经济效率、污染控制、环境管理、社会评价)和10个因素层(大气/声环境、生物资源、基底质量、经济发展、生产效率、循环经济、污染排放、清洁生产、环保投入、社会参与),并采用AHP(层次分析)法确定了各层次的权重分配。进而根据2005年上海港年均生产状况和2006年上半年的港区环境-资源调查,尝试对上海港7种主要类型(集装箱、件杂货/成品、多用途、干散、粮食港区、液散、客运)的15个港区进行了现状评估。然而,生态港评价系统的指标选取、权重制定、评估级别等实践与完善仍需要多学科和政府职能部门的参与。最后,项目还提出了水生态健康、航道淤积、生态风险、水陆景观等非定量生态港评价因子。  相似文献   
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