气球施放安全与风险评估方法初探

根据有关法律、法规,阐述了气球施放安全与风险评估的必要性,并结合工作实际,介绍气球施放安全与风险评估应包括的主要内容和具体的操作流程。研究结果认为,适当而足够的风险评估方法应包括6个方面的内容：一是识别所有的危险源;二是评估事故出现的机会和几率;三是对事故可能引发的后果进行分析、分级;四是判断风险是否可以被容忍,辨别事关重大的风险;五是如果风险或潜在后果不可以被容忍的话,辨别出必须做些什么,如何落实防范风险措施;六是为制定在一段相当的时期内保持有效的控制方法提供依据,对不能通过控制活动降低事故发生几率的,依法对气球施放申请作出不批准的决定。     

Analysis of the institutional and social responses to the eruption and the lahars of Mount Pinatubo volcano from 1991 to 1998 (Central Luzon, Philippines)

Mount Pinatubo volcano erupted in June 1991 in the main island of Luzon belonging to the Philippines archipelago. Huge economic losses and population exodus have followed. This major crisis has been relayed with other crises due to rain-fed lahars which have been supplied with eruption deposits. These lahars have occurred every year since 1991 during the rainy season. They will probably last until 2005. After a brief presentation of the Philippine official response system to disasters, this paper draws up a critical analysis of the different kinds of institutional and social responses deployed to manage the different crisis and post-crisis phases of this event. Based on three viewpoints: from population, media and other actors, this analysis attempts to point out the strengths and weaknesses of the official management system, especially by studying the efficiency and the range of the solutions taken. So, it appears that the management of the June 1991 main crisis (eruption) was a success. On the other hand, difficulties have occurred with lahars risk management. Indeed, these lahars have obliged the authorities to protect and relocate thousands of people. In spite of persistent problems, the management system (monitoring/warning/evacuation) of lahar crises improves year after year. Failures appear especially within the rehabilitation program (protection/rehousing). Many direct (lack of means, preparedness, coordination, dialog, etc.) and indirect (politico-administrative, socio-economic, cultural contexts) factors come together to lock the wheels of the institutional response system. They defer the socio-economic start of this vital northern Philippines area. This revised version was published online in July 2006 with corrections to the Cover Date.     

Investigation of drag crisis phenomenon using CFD methods

When fluid flow passes a cylinder, the drag crisis phenomenon occurs between the sub-critical and the super-critical Reynolds numbers. The focus of the present studies was on the numerical prediction of the drag crisis based on CFD methods. In this work, block structured meshes with refined grids near the cylinder surface and in the downstream were employed. Both 2D and 3D simulations were performed using various turbulence models, including the SST k − ω model, the k − ϵ model, the SST with LCTM, the DES model, and the LES model. In the convergence studies, the effects of the grid size, the time step, the first grid size and the aspect ratio (for 3D simulations) on the solutions were examined. The errors due to spatial and time discretizations were quantified according to a V&V procedure. Validation studies were carried out for various Reynolds numbers between Re = 6.31 × 10⁴ and 7.57 × 10⁵. The averaged drag force, the RMS of lift force and the Strouhal number were compared with experimental data. The studies indicated that standard 2D and 3D RANS methods were inadequate to capture the drag crisis phenomenon. The LES method however has the potential to address the problem.     

Numerical benchmark studies on drag and lift coefficients of a marine riser at high Reynolds numbers

Numerical benchmark studies on drag and lift coefficients of a marine riser have been organized by the 27th ITTC Ocean Engineering Committee. The purpose of the studies was to benchmark the capabilities of CFD methods through quantitative comparisons and validation studies against the model test results of a circular cylinder by MARIN. Studies were focused on the drag crisis phenomenon for the stationary smooth cylinder in the critical Reynolds number regime. Eight organizations have participated in the studies by using RANS, DES and LES methods. An overview of the model test results, test cases, submissions and comparison results are presented in this paper. Conclusions and recommendations are made for future studies.     

地理科学的价值与地理学者的情怀

本文强调了前辈地理学家提出的关于地理学是介于自然科学和社会科学之间的交叉学科的观点。从中国国家需求及当代国际地理学的发展趋势,从理论与实践的结合上论述了地理科学的学科对象、学科性质及区域性、综合性、知识结构等方面的特点,特别突出地阐述了地理科学与纯自然科学或纯社会科学的诸多不同点。提倡地理学家要十分关注中国的环境变化及带来的严重的可持续发展问题,并发挥综合和交叉研究的优势。此外还指出中国地理学面临着重要的发展机遇,也出现了深刻的危机。     

金融危机下国家大规模投资政策模拟

构建了一个中国多区域可计算一般均衡模型(MReCGE-C),利用该模型分析了我国应对国际金融危机的大规模投资政策。MReCGE-C根据城乡属性和年龄结构对居民进行了分组,放松了要素流动的限制,使劳动力和资本可以同时跨区域跨部门流动,并设计了一种基于居民终生效用的区域均衡机制,通过区域差距变量可以调控和测度区域差距。最后利用MReCGE-C模型针对国家大规模投资计划下的3种典型投资方案进行了模拟。结果发现在等量新增投资下,针对中部地区投资方案的GDP增长率高于针对中西部和全国投资方案的GDP增长率,同时针对中部地区投资方案对于城乡就业的拉动也要优于其余两种投资方案,而且可以实现缩小区域差距的目标。综合比较,目前国家大规模投资的优势应该指向中部地区。     

金融危机下股市网络的结构特性研究

利用复杂网络的方法,以各国股市为节点,以各股市问的关联性为边,建立起各国股市间的关联网络。通过Matlab编程计算研究了该网络的结构特性,分析出国际股市网络具有典型的小世界性和明显的社区结构,不具有无标度性。进而从网络结构上分析了金融危机的蔓延发生。并通过影响强度分析研究了中国股市在国际股市网络中的位置。     

Climate threats,water supply vulnerability and the risk of a water crisis in the Monterrey Metropolitan Area (Northeastern Mexico)

This paper evaluates the risk of a water crisis – a substantial, sudden reduction in water supply – in the Monterrey Metropolitan Area (MMA), posed by climate threats and the vulnerability of its water supply system. Our analysis of long-term precipitation, water supply and water availability data reveals that the MMA is highly vulnerable to recurring periods of exceptionally low precipitation and scarce surface water availability. We identify two episodes in the recent past (1998 and 2013) when the MMA water supply system almost collapsed as reservoirs neared depletion in the face of abnormally dry weather. Furthermore our climate projections point to warmer and drier future conditions for the region and consequently, heightened climate threats. We conclude that the risk of a water crisis in the MMA is substantial and probably will increase due to climate change. This establishes a clear and pressing need for a comprehensive package of adaptation measures to mitigate the consequences of a water crisis should one occur as well as to reduce the likelihood of such an event.     

Further comments concerning “geographic” and “economic” economic geography

This article considers whether the growing theoretical and methodological diversity or pluralistic nature of economic geography contributes to its lack of engagement outside the discipline and academy. Although we are enthusiastic about the vibrancy this pluralism brings, we also speculate that it contributes to the discipline's tendency to fall short of significantly impacting key debates in the social sciences. In particular, we consider the disciplinary challenges to influencing mainstream debates over financialization and the recent financial crisis and the recurring lament that economic geography “misses the boat” by failing to significantly impact key scholarly and policy issues. Specifically, we suggest that methodological and theoretical diversity, local contextualization, and relational analysis, all of which we support as vital to the discipline, make it difficult to isolate a disciplinary core. We conclude that pluralism produces a vibrant discipline with unique explanatory power but that it also has important impacts on the design, execution, and influence of geographers’ research outside the discipline.