工艺流程中氨泄漏事故后果分类研究

氨是重要的化工原料和产品,工艺流程中氨主要以氨气、液氨、氨溶液三种状态存在。氨气、液氨、氨溶液理化特性及危险特性不同,可能造成的事故后果类型不同,分别进行三种相态下氨泄漏的事故情景分析。氨气泄漏主要考虑蒸气云爆炸、中毒,液氨泄漏主要考虑沸腾液体扩展蒸气爆炸、蒸气云爆炸、中毒,氨溶液泄漏主要考虑中毒和腐蚀。运用半球模型和高斯模型计算某尿素企业液氨球罐泄漏的危害范围。半球泄漏模型计算方法较简单,但没有考虑氨本身性质及气象条件等因素;高斯模型计算过程较复杂,其计算结果与风速、大气稳定度等条件相关。该两种方法计算结果对预防氨泄漏事故发生和氨泄漏事故预警均具有一定参考意义,如何提高模拟分析的准确度是今后研究工作的重点。     

基于故障树与灰色模糊理论的城市CNG加气站安全评价

城市CNG加气站安全状况好坏,直接影响到整个城市天然气汽车的安全运行,为此提出运用故障树分析法与灰色模糊理论对城市CNG加气站进行安全状况分析。通过对站内危险因素的分析,建立了加气站主要系统的故障树,得到引起加气站主要系统失效的70个基本事件,建立加气站安全评价指标体系,利用专家评分法对指标进行评分,利用层次分析法计算各指标层次相对权重。运用灰色关联分析法,计算参评数据序列与标准数据序列的关联系数矩阵,即得出模糊评判矩阵。再由模糊理论得出加气站安全等级,并给出相应的日常安全工作重点。用该方法对常州市CNG加气站进行安全评价,得出安全等级为Ⅱ级,这与加气站实际运行状况相符,说明用该方法对加气站进行安全评价是有效的、可靠的,能够为城市CNG加气站安全管理提供依据。     

大学生宿舍潜在火灾危险性调查研究

随着学校学生数量不断增加,大学生宿舍楼越来越多。由于生活条件的提高,学习用品不断增多,发生火灾事故的隐患也就逐渐增多,一旦发生火灾事故,后果严重。本文根据对大学生寝室极易发生火灾的安全隐患进行深入调查研究,分析导致寝室火灾的5个主要原因：安全意识薄弱,可燃物多,建筑存在安全隐患,人员集中,不易疏散人群及安全管理滞后。然后应用安全检查表对某校大学生寝室火灾进行分析,得出安全评价结果,经过研究、分析发现,该寝室存在着火灾危险性,应采取防范措施进行预防。之后运用事故树分析的方法对宿舍火灾进行结构重要度分析研究,找出容易发生火灾的原因。最后从预防人的不安全行为及物的不安全状态出发,提出了有针对性的安全措施。     

重要基础设施脆弱性计算理论

为了给重要基础设施的保护提供决策理论支持,基于重要基础设施保护中出现的安全问题,在综述脆弱性概念的发展基础上,提出脆弱性的一种可操作性概念,并将重要基础设施保护中的脆弱性分为2类:一类为保护方面的脆弱性,一类为响应方面的脆弱性。在此基础上研究了综合脆弱性的数学表达式,提出了重要基础设施综合脆弱性的评价程序,该评价程序可以应用于重要基础设施的防灾减灾研究中。     

Development of machine learning multi-city model for municipal solid waste generation prediction

● A database of municipal solid waste (MSW) generation in China was established. ● An accurate MSW generation prediction model (WGMod) was constructed. ● Key factors affecting MSW generation were identified. ● MSW trends generation in Beijing and Shenzhen in the near future are projected. Integrated management of municipal solid waste (MSW) is a major environmental challenge encountered by many countries. To support waste treatment/management and national macroeconomic policy development, it is essential to develop a prediction model. With this motivation, a database of MSW generation and feature variables covering 130 cities across China is constructed. Based on the database, advanced machine learning (gradient boost regression tree) algorithm is adopted to build the waste generation prediction model, i.e., WGMod. In the model development process, the main influencing factors on MSW generation are identified by weight analysis. The selected key influencing factors are annual precipitation, population density and annual mean temperature with the weights of 13%, 11% and 10%, respectively. The WGMod shows good performance with R² = 0.939. Model prediction on MSW generation in Beijing and Shenzhen indicates that waste generation in Beijing would increase gradually in the next 3–5 years, while that in Shenzhen would grow rapidly in the next 3 years. The difference between the two is predominately driven by the different trends of population growth.     

金华旱涝趋势统计分析

根据对旱涝自身变化及其与太阳黑子活动，厄尔尼诺事件关系的分析，，得出了金华旱涝趋势的几点认识：（1）在未来的十几年之内，金华站将从涝年占优势的阶段转入旱年占优势的阶段；（2）在太阳黑子活动22年的磁周期转变年前后，金华站3年平均年降水量明显偏多；（3）在春季型厄尔尼诺事件的当年和夏季型厄尔尼诺事件的次年，金华站年降水量偏多；（4）厄尔尼诺事件的结束时间若超过5月1日，那么次年金华站年降水量偏多；（5）厄尔尼诺事件的强度越大，对金华站年降水量的影响也越大；（6）在太阳黑子活动22年磁周期转变年前后的厄尔尼诺事件的次年，金华站年降水量明显偏多。这些认识对长期及超长期的旱涝趋势预测具有重要的现实意义。     

CONFLICT AND COOPERATION OVER INTERNATIONAL FRESHWATER RESOURCES: INDICATORS OF BASINS AT RISR1

ABSTRACT: In this paper we seek to identify historical indicators of international freshwater conflict and cooperation and to create a framework to identify and evaluate international river basins at potential risk for future conflict. We derived biophysical, socioeco‐nomic, and geopolitical variables at multiple spatial and temporal scales from GIS datasets of international basins and associated countries, and we tested these variables against a database of historical incidents of international water related cooperation and conflict from 1948 to 1999. International relations over freshwater resources were overwhelmingly cooperative and covered a wide range of issues, including water quantity, water quality, joint management, and hydropower. Conflictive relations tended to center on quantity and infrastructure. No single indicator—including climate, water stress, government type, and dependence on water for agriculture or energy—explained conflict/cooperation over water. Even indicators showing a significant correlation with water conflict, such as high population density, low per capita GDP, and overall unfriendly international relations, explained only a small percentage of data variability. The most promising sets of indicators for water conflict were those associated with rapid or extreme physical or institutional change within a basin (e.g., large dams or internationalization of a basin) and the key role of institutional mechanisms, such as freshwater treaties, in mitigating such conflict.     

Technical Procedures for CDM Project Design

The success of CDM depends on active participation of public and private entities. In particular, participation of wide range of private companies is an important factor for the success. In order to promote the participation of private companies in the CDM project activities as project participants, the authors clarify the steps and technical issues involved in the CDM project design procedures in a step-by-step approach. The steps consist of outlining the project plans, identifying project impacts, defining a project boundary, estimating GHG emissions reduction/enhancement of removals, documenting the results of estimation, and designing of monitoring plans. The authors also propose guidance for project participants, especially for those not familiar with the CDM, which provides plain explanation of major technical issues. In order to further develop a complete guideline, it is necessary to integrate the outputs of the ongoing international initiatives concerning technical issues of CDM into the stepwise approach proposed in this paper. This revised version was published online in August 2006 with corrections to the Cover Date.     

核电站重要敏感性设备分析

核电站重要敏感性设备管理是国内首次采用归纳法和演绎法对核电站重要敏感系统和设备进行识别和设备分级的一种新方法。目标是为了找到导致反应堆紧急停堆、强迫停机和非计划跳机跳堆风险的主要部件 ,并采用 80 - 2 0的原理进行有效的管理 ,建立有效的风险管理 (预防、探测、改正行动 PDC ,Prevention/Detec tion/Correction)大纲和PDC管理数据库 ,并对大部分的重要敏感设备的子部件进行的FMEA(FailureModeandEffectAnalysis)分析 ,识别其失效机理 ,从而确定重要敏感设备清单和预防跳机跳堆的改正行动 ,减少未来由于设备失效导致的跳堆次数 ,达到提高核电站的设备可靠性、安全性和经济性的目的。