农村环境监测的布点原则与指标优化研究

通过对农村环境污染特征分析,结合试点村庄的现场调研,确定了农村环境质量监测的点位布设原则,并以267个村庄环境质量监测结果为基础,结合城市现有监测指标,对农村环境质量的监测指标进行了优化,为构建农村环境质量监测技术体系奠定了良好基础。     

钢铁企业固定式煤气报警器规范安装的详细探讨

煤气安全作为钢铁企业防范重特大事故的重要工作,规范性设置固定式煤气检测报警器,是防范事故发生的主要措施.结合国家现行安全标准和行业现状,就固定式检测报警器的安装位置、安装高度、与释放源水平距离以及报警器检测覆盖范围进行详细探讨.     

自然灾害防治综合立法研究:定位、理念与制度

近年来,国家高度重视防灾减灾救灾,发布了防灾减灾救灾系列重要文件,实施了应急管理体制机制重大改革举措。落实防灾减灾救灾新思想新理念新要求,契合国家发展改革的现实需要,应加紧推进自然灾害防治综合立法。自然灾害防治综合立法的定位是自然灾害防治的基本法、应急管理的特别法、公共安全的支撑法。自然灾害防治综合立法应在坚持以人民为中心理念、风险防范理念、综合防治理念、权利保护理念的基础上,确立自然灾害风险隐患排查、危险区避让及搬迁转移、自然灾害科普、自然灾害防治社会参与、自然灾害保险等制度,为推进我国自然灾害防治体系和防治能力现代化提供法制保障。     

Locating the gas leakage source in the atmosphere using the dispersion wave method

A new and simple method for locating emission source was proposed in this work based on gas dynamic dispersion information. The simulation of the unsteady state dispersion of leakage gas emission from the geosequestration project showed that the transportation process of emission gases in the atmosphere is similar to wave propagation, and the time parameter of the dispersion wave is linearly related to the downwind distance. Therefore, monitoring the dispersion wave at different downwind positions can be used to estimate the leakage source position. An estimation formula for locating emission sources was derived. First, an estimation formula for locating emission sources was derived under some initial assumptions. Then, the deviation of the location formula was investigated using a computational fluid dynamics (CFD) model and analytic solution to get the offset distance under different conditions. The results showed that the average distance is stable for a certain atmosphere and terrestrial conditions. This method needs no more than 3 sensors’ dynamic information to locate the emission source, and hence it is highly useful for conditions with limited sensors. A numerical test demonstrated that the absolute error of the source estimation is within the range of 1–30 m. Finally, experimental tests were conducted to verify the feasibility of the source location with dispersion waves. Therefore, the dispersion wave monitor is a potentially simple and feasible way to estimate the source location for gas emission event management with limited sensors in the process industries.     

多目标应急服务设施选址与资源配置问题研究

为合理解决应急系统管理中的应急资源选址和配置问题,实现应急资源优化管理,构建基于应急系统综合可靠性的多目标应急服务设施选址和资源配置模型。根据突发事件特征,考虑到应急资源布局是不确定的、动态的,有时间约束等问题,提出同时考虑应急需求点的危险权重、应急救援最迅速及应急救援服务点之间可以进行资源调运等因素,以确保危险权重越大的应急需求点被越多的应急服务点覆盖。在保证应急物资供应时效的前提下,降低应急管理成本,最大化应急系统的综合可靠性,实现对应急资源科学选址和合理配置,并进行算例分析。     

基于声发射技术的立柱试验过程安全性研究

液压立柱在接受型式检验时,存在因质量不过关而引发的爆缸、液压喷射等现象,给国家财产和现场检验人员人身安全带来极大威胁。为提高安全性,需对立柱试验过程进行监控,及早发现爆缸或液压喷射等迹象,特引入声发射技术对被试的立柱进行监测。声发射技术对立柱在受压过程中产生的裂纹弹性波进行捕捉、分析、处理和显示,并用时差定位方法和小波包技术对声发射信号进行处理以进一步提高定位精度。研究结果表明:该技术可以实时展现立柱缸体内部声发射源信息,帮助检验人员及时发现裂纹的产生,从而避免立柱钢筒爆裂现象发生、提高试验安全。     

江西赣南数字地震台网JOPENS系统常用地震定位方法比较

利用JOPENS系统提供单纯型法、Hypo2000、HypoSAT等地震定位方法,对赣南台网记录的赣南境内、赣粤闽交界区、中国台湾地震分别进行定位、比较,并分别提出适合赣南台网的地震定位方法.     

不同隧道坡度与车厢火灾位置情况下烟气蔓延特性研究*

为研究含坡度隧道不同火源位置情况下车厢火灾烟气蔓延特性,采用CFD数值模拟方法,建立全尺寸地铁隧道与列车数值模型,研究车厢不同火源位置情况下火灾烟气纵向温度分布规律,探讨倾斜隧道车厢火源位置对烟气蔓延的影响。研究结果表明:当火灾烟气蔓延处于纵向通风惯性力与热浮力竞争作用控制阶段时,火源位于车厢上游方向时火灾烟气向车厢方向蔓延距离小于火源位于车厢下游方向情况,且随坡度增大,火源位于车厢上游方向烟气逆流长度不断减小,位于下游方向烟气逆流长度不断增大;当纵向通风风速达到2 m/s时,火源位于车厢上下游方向2种情况下,列车车厢方向均无烟气蔓延（逆流长度为0）,此时火灾烟气蔓延将主要由纵向通风控制,隧道坡度无显著影响。     

多路况指标下的高速公路应急物资选址方案评价

为了筛选合理的应急资源布局位置,阐述了以实际路况评价应急物资选址的合理性,提出了以实际路况指标为基础构建的选址方案评价模型。考虑到城市道路和高速公路的阻因不同,将主要影响应急物资选址的路况属性量化。通过对应急车辆驾驶员的调查获得路况指标权重,引入模糊评价用以区分路况指标值接近的最优选址方案,经实例分析证明了该选址方案评价方法的可行性。研究表明,良好的选址方案应具备动态交通因素影响小、通行路径道路等级高、行驶里程短、平面交叉口和转弯次数少的特点。     

Leak location of pipelines based on transient model and PSO-SVM

An improved and integrated approach of support vector machine and particle swarm optimization theory (PSO-SVM) is first used to detect the leak location of pipelines and overcome the problem of multiple leaks. The calibration and predictive ability of improved PSO-SVM is investigated and compared with that of other common method, back-propagation neural network (BPNN). Two conditions are evaluated. One with a leak involves a set of 20 samples, while another with two leaks has 127 samples. Both internal and external validations are performed to validate the performance of the resulting models. The results show that, for the two conditions, the values calculated by improved PSO-SVM are in good agreement with those simulated by transient model, and the performances of improved PSO-SVM models are superior to those of BPNN. This paper provides a new and effective method to inspect the multiple leak locations, and also reveals that improved PSO-SVM can be used as a powerful tool for studying the leak of pipeline.