有风条件下剧院火灾自然排烟效果分析

为研究某剧院休息厅的自然排烟效果的问题,根据建筑特征设计6个火灾场景。运用理论计算和数值模拟的方法,分别研究不同开窗位置、开窗面积以及环境风速对火灾时的热流场和烟气蔓延的影响。结果表明：不同开窗位置达到临界值的时间为顶窗〉东西立面侧窗〉北立面侧窗;有风条件下3.5%的开窗面积的排烟效果和无风时6%的开窗面积的排烟效果相当。结论是考虑当地环境风速,选择顶部5%和东西侧3.5%开窗方式,增强该剧院的自然排烟效果。     

玻璃钢管线在英买力潜山原油集输中的应用

埋地管道的腐蚀是影响油气田地面工程安全运行的重要因素之一,玻璃钢管道的非金属特性根除了腐蚀环境的形成,杜绝了管道腐蚀穿孔事件的发生,降低了污染土壤等环境问题发生的机率,塔里木油田管道服役现状、史密斯公司30a的研究结果对此做了充分的诠释。英—红外输油管道和哈森-威廉姆斯公式分别从实践和理论上展示了玻璃钢管卓越的水力特性,英买力潜山玻璃钢管线具有良好的经济和社会效益。     

黄山市珍稀濒危药用植物资源及保护策略

归纳<国家珍稀濒危保护植物名录>、<国家重点保护野生植物名录(第一批)>和<国家重点保护野生药材物种名录>,黄山市拥有珍稀濒危药用植物42种,通过对其种类、分布,药用部位、功能主治的介绍,以期为制定黄山市珍稀濒危药用植物的保护措施和合理开发利用提供参考.     

中国混合遗产的管理机制研究——以泰山为例

世界遗产是人类的共同财富,它具有脆弱性、不可替代性等特点,但是在我国世界遗产保护方面仍没有一部专门保护世界遗产的法律,以致于在管理方面产生了混乱.以泰山为例,与国内外的混合遗产进行对比分析,以借鉴可取之处,并提出了改变管理观念、统一管理、动态管理、完善法律法规等措施来加强世界遗产的管理.     

水合物法的天然气提氦技术研究

氦气是发展国防军工和高科技产业不可或缺的战略性物资之一.由于氦气在自然界中的富集度很低,目前工业规模化提氦来源主要是含氦天然气.常用的提氦方法有吸附法、吸收法、低温冷凝法、膜分离法等,但它们都不能很好地解决提氦难度大、成本高、规模化工业应用水平较低等缺点.因此,引入水合分离技术,利用含氦天然气各组分生成水合物的条件差异在水合反应过程中对氦气提浓,同时辅以催化脱氢工艺,实现粗氦的精制.     

秦皇岛市城镇水土保持工作主要做法及成效分析

随着城镇建设的迅猛发展,项目开发建设占用大量具有生态功能的地表,人为造成的水土流失日趋严重,因此做好城镇水土保持工作至关重要。秦皇岛市从2004年起通过制定规划、建立工作体系、强化预防监督、加强宣传等措施,水土保持工作取得了显著成效:提高了全民水保法制观念,规范了城镇建设项目管理工作,城郊水土流失治理度达90%以上,城区碧水工程已基本完成,实施了城市雨水资源利用试点工程,城市区人均绿地面积达到12 m2,森林覆盖率达40%以上。     

Residential Demand for Water in the Chicago Metropolitan Area1

Mieno, Taro and John B. Braden, 2011. Residential Demand for Water in the Chicago Metropolitan Area. Journal of the American Water Resources Association (JAWRA) 47(4):713‐723. DOI: 10.1111/j.1752‐1688.2011.00536.x Abstract: This paper provides the first contemporary analysis of residential water demand in humid Northeastern Illinois, in the vicinity of Chicago, and explores seasonal and income‐based differentials in the responsiveness of water use to water prices. Using a panel of system‐level data for eight water systems and controlling for seasons, weather, incomes, and community characteristics, the analysis yields low estimates of price elasticity of demand for water in line with other studies. Furthermore, price response is greater in summer and less in higher income communities. We suggest that use of seasonal pricing can help mitigate equity issues arising from differential income elasticities while taking advantage of the greater price responsiveness of summertime water use.     

Forecasting population trend from the scaling pattern of occupancy

Forecasting the temporal trend of a focal species, its range expansion or retraction, provides crucial information regarding population viability. To this end, we require the accumulation of temporal records which is evidently time consuming. Progress in spatial data capturing has enabled rapid and accurate assessment of species distribution across large scales. Therefore, it would be appealing to infer the temporal trends of populations from the spatial structure of their distributions. Based on a combination of models from the fields of range dynamics, occupancy scaling and spatial autocorrelation, here I present a model for forecasting the population trend solely from its spatial distribution. Numerical tests using cellular automata confirm a positive correlation, as inferred from the model, between the temporal change in species range sizes and the exponent of the power-law scaling pattern of occupancy. The model is thus recommended for rapid estimation of species range dynamics from a single snapshot of its current distribution. Further applications in biodiversity conservation could provide a swift risk assessment, especially, for endangered and invasive species.     

Dispersal connectivity and reserve selection for marine conservation

Although larval dispersal is crucial for the persistence of most marine populations, dispersal connectivity between sites is rarely considered in designing marine protected area networks. In particular the role of structural characteristics (known as topology) for the network of larval dispersal routes in the conservation of metapopulations has not been addressed. To determine reserve site configurations that provide highest persistence values with respect to their connectivity characteristics, we model nine connectivity topological models derived from graph theory in a demographic metapopulation model. We identify reserve site configurations that provide the highest persistence values for each of the metapopulation connectivity models. Except for the minimally connected and fully connected populations, we observed two general ‘rules of thumb’ for optimising the mean life time for all topological models: firstly place the majority of reserves, so that they are neighbours of each other, on the sites where the number of connections between the populations is highest (hub), secondly when the reserves have occupied the majority of the vertices in the hub, then select another area of high connectivity and repeat. If there are no suitable hubs remaining then distribute the remaining reserves to isolated locations optimising contact with non-reserved sites.     

Scientists' opinions on the global status and management of biological diversity

The large investments needed if loss of biological diversity is to be stemmed will likely lead to increased public and political scrutiny of conservation strategies and the science underlying them. It is therefore crucial to understand the degree of consensus or divergence among scientists on core scientific perceptions and strategies most likely to achieve given objectives. I developed an internet survey designed to elucidate the opinions of conservation scientists. Conservation scientists (n =583) were unanimous (99.5%) in their view that a serious loss of biological diversity is likely, very likely, or virtually certain. Scientists' agreement that serious loss is very likely or virtually certain ranged from 72.8% for Western Europe to 90.9% for Southeast Asia. Tropical coral ecosystems were perceived as the most seriously affected by loss of biological diversity; 88.0% of respondents familiar with that ecosystem type agreed that a serious loss is very likely or virtually certain. With regard to conservation strategies, scientists most often viewed understanding how people and nature interact in certain contexts and the role of biological diversity in maintaining ecosystem function as their priorities. Protection of biological diversity for its cultural and spiritual values and because of its usefulness to humans were low priorities, which suggests that many scientists do not fully support the utilitarian concept of ecosystem services. Many scientists expressed a willingness to consider conservation triage, engage in active conservation interventions, and consider reframing conservation goals and measures of success for conservation of biological diversity in an era of climate change. Although some heterogeneity of opinion is evident, results of the survey show a clear consensus within the scientific community on core issues of the extent and geographic scope of loss of biological diversity and on elements that may contribute to successful conservation strategies in the future.