BIM技术在钢结构建筑抗震减灾管理中的应用

为提高钢结构建筑抗震减灾性能,降低建筑坍塌风险,研究BIM技术在钢结构建筑抗震减灾管理中的应用方法是非常必要的。利用BIM技术在钢结构建筑整体建造中的动态建模、可视化、信息共享管理以及抗震减灾性能检测等优势,在建筑抗震减灾管理决策阶段,选出最优方案,针对方案中影响建筑抗震减灾性能风险制定管理策略;在设计阶段,创建三维建筑模型,调整存在风险建筑模型数据信息,并通过振荡模拟分析降低风险;在施工阶段,管理钢结构建筑材料,提升建筑构件的刚度,并依据建筑施工阶段的抗震减灾管理原则制定相应的管理方法,实现对钢结构建筑的抗震减灾管理。结果表明,BIM技术可实现抗震减灾管理中的地震波检测,检测结果精准可靠;可提升建筑构件的刚度与承载力及建筑的抗震减灾性能,降低建筑坍塌等风险,实现钢结构建筑抗震减灾管理。     

餐饮业建筑功能规划及设施建设的环保问题思考

在酒店厨房工程设计和施工的实践工作基础上,对目前城市餐饮建设项目现状与居民生活环境之间存在的矛盾加以归纳、分析,根据问题现状,分别从城市餐饮业建筑功能规划、餐饮业厨房建筑设施建设相关的环保问题及全民参与环境保护等方面提出具体的解决对策。     

浅析沈阳市高层建筑周边PM_(10)与PM_(2.5)质量浓度对应性

以空气中可吸入颗粒物(PM2.5和PM10)为研究对象,分析了采暖期和非采暖期不同监测点位PM10与PM2.5的相关性。结果表明,采暖期和非采暖期不同高度PM10与PM2.5的相关性均相当明显,可吸入颗粒物中PM2.5占绝大比重;采暖期不同高度PM10与PM2.5的相关系数大于非采暖期,季节变化规律明显。     

Policy implementation of the Republic Act (RA) No. 9003 in the Philippines: A case study of Cebu city

Municipal Solid Waste Management (MSWM) is considered to be one of the most serious environmental issues in the Philippines. The annual waste generation was estimated at 10.6 million tonnes in 2012 and this is expected to double in 2025. The Republic Act (RA) No. 9003, widely known as the Ecological Solid Waste Management Act of 2000, provides the required policy framework, institutional mechanisms and mandate to the Local Government Units (LGUs) to achieve 25% waste reduction target through establishing an integrated solid waste management plan based on the 3Rs (reduce, reuse and recycling). Although the initial impact of the LGUs is still very limited in implementing the national mandate, this article highlights the successful experiences of Cebu, the second largest city in the Philippines, in reducing its MSW generation by more than 30% in the past three years. This study also explores the implementation process, innovative actions taken by the Cebu City Government in implementing the national mandate at local level and identifies the factors that influence the policy implementation. The findings suggest that the impacts of the national mandate can be achieved if the LGUs have the high degree of political commitment, planning and development of effective local strategies in a collaborative manner to meet with local conditions, partnership building with other stakeholders, capacity development, adequate financing and incentives, and in the close monitoring and evaluation of performance.     

Defining Historical Baselines for Conservation: Ecological Changes Since European Settlement on Vancouver Island,Canada

Abstract: Conservation and restoration goals are often defined by historical baseline conditions that occurred prior to a particular period of human disturbance, such as European settlement in North America. Nevertheless, if ecosystems were heavily influenced by native peoples prior to European settlement, conservation efforts may require active management rather than simple removal of or reductions in recent forms of disturbance. We used pre‐European settlement land survey records (1859–1874) and contemporary vegetation surveys to assess changes over the past 150 years in tree species and habitat composition, forest density, and tree size structure on southern Vancouver Island and Saltspring Island, British Columbia, Canada. Several lines of evidence support the hypothesis that frequent historical burning by native peoples, and subsequent fire suppression, have played dominant roles in shaping this landscape. First, the relative frequency of fire‐sensitive species (e.g., cedar [Thuja plicata]) has increased, whereas fire‐tolerant species (e.g., Douglas‐fir [Pseudotsuga menziesii]) have decreased. Tree density has increased 2‐fold, and the proportion of the landscape in forest has greatly increased at the expense of open habitats (plains, savannas), which today contain most of the region's threatened species. Finally, the frequency distribution of tree size has shifted from unimodal to monotonically decreasing, which suggests removal of an important barrier to tree recruitment. In addition, although most of the open habitats are associated with Garry oak (Quercus garryana) at present, most of the open habitats prior to European settlement were associated with Douglas‐fir, which suggests that the current focus on Garry oak as a flagship for the many rare species in savannas may be misguided. Overall, our results indicate that the maintenance and restoration of open habitats will require active management and that historical records can provide critical guidance to such efforts.     

The problem of estimating recent genetic connectivity in a changing world

Accurate understanding of population connectivity is important to conservation because dispersal can play an important role in population dynamics, microevolution, and assessments of extirpation risk and population rescue. Genetic methods are increasingly used to infer population connectivity because advances in technology have made them more advantageous (e.g., cost effective) relative to ecological methods. Given the reductions in wildlife population connectivity since the Industrial Revolution and more recent drastic reductions from habitat loss, it is important to know the accuracy of and biases in genetic connectivity estimators when connectivity has declined recently. Using simulated data, we investigated the accuracy and bias of 2 common estimators of migration (movement of individuals among populations) rate. We focused on the timing of the connectivity change and the magnitude of that change on the estimates of migration by using a coalescent‐based method (Migrate‐n) and a disequilibrium‐based method (BayesAss). Contrary to expectations, when historically high connectivity had declined recently: (i) both methods over‐estimated recent migration rates; (ii) the coalescent‐based method (Migrate‐n) provided better estimates of recent migration rate than the disequilibrium‐based method (BayesAss); (iii) the coalescent‐based method did not accurately reflect long‐term genetic connectivity. Overall, our results highlight the problems with comparing coalescent and disequilibrium estimates to make inferences about the effects of recent landscape change on genetic connectivity among populations. We found that contrasting these 2 estimates to make inferences about genetic‐connectivity changes over time could lead to inaccurate conclusions.     

突发事件现场警戒区域的研究

阐述了事故危险区域、现场警戒区域的基本概念、设置目的和原则，提出将突发事故现场警戒区域分为三层，分别对应现场封锁线、警戒封锁线和交通封锁线，并就吸入毒性危害物质泄漏、燃气泄漏、建筑物火灾等事故，制定了具体的设置方法。现场警戒区域的设定，可在较小成本投入的前提下，通过采取积极的防范和应对措施，有效减少人员伤亡和财产损失，提高救援效率和效果。     

Effects of Exurban Development and Temperature on Bird Species in the Southern Appalachians

Land‐use dynamics and climatic gradients have large effects on many terrestrial systems. Exurban development, one of the fastest growing forms of land use in the United States, may affect wildlife through habitat fragmentation and building presence may alter habitat quality. We studied the effects of residential development and temperature gradients on bird species occurrence at 140 study sites in the southern Appalachian Mountains (North Carolina, U.S.A.) that varied with respect to building density and elevation. We used occupancy models to determine 36 bird species’ associations with building density, forest canopy cover, average daily mean temperature, and an interaction between building density and mean temperature. Responses varied with habitat requirement, breeding range, and migration distance. Building density and mean temperature were both included in the top occupancy models for 19 of 36 species and a building density by temperature interaction was included in models for 8 bird species. As exurban development expands in the southern Appalachians, interior forest species and Neotropical migrants are likely to decline, but shrubland or edge species are not likely to benefit. Overall, effects of building density were greater than those of forest canopy cover. Exurban development had a greater effect on birds at high elevations due to a greater abundance of sensitive forest‐interior species and Neotropical migrants. A warming climate may exacerbate these negative effects. Efectos del Desarrollo Exurbano y de la Temperatura sobre Especies de Aves en las Apalaches del Sur     

Integrating Paleobiology,Archeology, and History to Inform Biological Conservation

The search for novel approaches to establishing ecological baselines (reference conditions) is constrained by the fact that most ecological studies span the past few decades, at most, and investigate ecosystems that have been substantially altered by human activities for decades, centuries, or more. Paleobiology, archeology, and history provide historical ecological context for biological conservation, remediation, and restoration. We argue that linking historical ecology explicitly with conservation can help unify related disciplines of conservation paleobiology, conservation archeobiology, and environmental history. Differences in the spatial and temporal resolution and extent (scale) of prehistoric, historic, and modern ecological data remain obstacles to integrating historical ecology and conservation biology, but the prolonged temporal extents of historical ecological data can help establish more complete baselines for restoration, document a historical range of ecological variability, and assist in determining desired future conditions. We used the eastern oyster (Crassostrea virginica) fishery of the Chesapeake Bay (U.S.A.) to demonstrate the utility of historical ecological data for elucidating oyster conservation and the need for an approach to conservation that transcends disciplinary boundaries. Historical ecological studies from the Chesapeake have documented dramatic declines (as much as 99%) in oyster abundance since the early to mid‐1800s, changes in oyster size in response to different nutrient levels from the sixteenth to nineteenth centuries, and substantial reductions in oyster accretion rates (from 10 mm/year to effectively 0 mm/year) from the Late Holocene to modern times. Better integration of different historical ecological data sets and increased collaboration between paleobiologists, geologists, archeologists, environmental historians, and ecologists to create standardized research designs and methodologies will help unify prehistoric, historic, and modern time perspectives on biological conservation. Integración de Paleobiología, Arqueología e Historia para Informar a la Biología de la Conservación     

Impacts of Upstream Building Width and Upwind Building Arrangements on Airflow and Pollutant Dispersion in a Street Canyon

A two-dimensional numerical model for evaluating the wind flow and pollutant dispersion within a street canyon was first developed using the FLUENT code, which was then validated against a wind tunnel experiment. Then, the effects of the upstream building width and upwind building arrangement on the airflow and pollutant dispersion inside an isolated street canyon were investigated numerically. The numerical results revealed that: (1) the in-canyon vortex center shifts downwards as the upstream building width increases; (2) the recirculation zone covers the entire upstream building roof for the cases when W/H = 0.5, 1.0, 1.5, and 2.0 (W is the upstream building width and H is the building height), whereas the flow reattaches the upstream building roof for the cases when W/H = 2.5 and 3.0; (3) when the upstream building width is shorter than the critical width W_C (= 2H), an increase in the upstream building width leads to an increase in the pollution level on the leeward wall of the canyon and a decrease in the roof-level concentrations at the upstream building; (4) when the upstream building width is longer than the critical width, the roof-level concentrations at the upstream building are negligibly small and the pollution level on the leeward wall of the canyon is almost unaffected by a further increase in the upstream building width; (5) when the buildings are placed upwind of the canyon, the flow attaches the upstream building roof and, therefore, almost none of the pollutants are distributed on the upstream building roof; and (6) the pollution levels inside the canyon and on the downstream building roof increase significantly with the number of upwind buildings.