横向风对油池火烧试验的影响

以模拟包装容器的油池火烧试验为例,利用FLUENT计算流体动力学模拟软件,对不同风速条件下直径为3 m的煤油池火灾进行三维定常模拟,获得了风速大小与火焰倾角和火焰锋面的变化关系,并拟合出了火焰倾角随风速变化的简化公式;分析了横向风对包装容器周围火焰热辐射通量分布产生的影响,验证了风速低于2 m/s对包装容器火烧试验不会产生较大影响的结论,对包装容器耐火特性试验的开展具有实际指导意义。     

BVR多芯铜导线过电流故障下燃烧及火焰传播研究*

为深入研究BVR多芯铜导线过电流故障下燃烧及火焰传播特征,采用堆栈技术分析导线受热形变,并利用高速摄像机记录故障导线发热、熔断及绝缘燃烧现象,研究导线发热形变、熔断时间及燃烧时火焰传播速度与电流值变化关系。结果表明:当I=136 A时,导线不发生熔断,只有当高温线芯直接接触周围可燃物才可引发火灾;当I=153 A时,导线会发生熔断现象,且熔断时间随过电流值升高而缩短;当I=204 A时,导线发生熔断,断路电弧引燃周围热解气体,火焰前沿迅速蔓延至导线两端,平均火焰前沿传播速度达2.2 m/s,平均明火持续时间达8.2 s,整根导线无需外界可燃物即可发生明火燃烧。研究结果可为起火原因认定提供技术指导。     

南京实施跨江发展战略的环境保护对策

阐述了跨江发展是南京市"十一·五"期间发展的战略重点之一,分析了江北地区自然、社会、经济与环境的现状,找出其主要的环境问题与面临的压力,提出合理的环保对策措施,以实现江北地区社会经济发展与环境保护的双赢.     

A GENETIC ALGORITHM TO REDUCE STREAM CHANNEL CROSS SECTION DATA1

A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near‐optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.     

近年几次大地震震害的若干启示

本文通过分析近年发生的几次著名大地震的震害资料和震时现象，讨论了与其相关的工程地震问题，并对西安市工程地震问题进行了研究。     

不同布置方式220 kV变电所对周围环境的电磁辐射分布

通过对不同布置方式220 kV电压等级变电所在运行中对周围环境产生的工频电场、磁感应强度和无线电干扰的监测分析,了解了不同布置方式220 kV电压等级变电所对周围环境电磁辐射的分布规律.指出在建设220 kV电压等级变电所的同时,只要做好建筑屏蔽和电缆入地等工作,就可以降低对周围环境的电磁辐射影响.     

山区的一种特殊灾害生态现象研究

山区泥石流发生后的泥石流滩地呈现复杂多样的生态过程,是山区所特有的一种灾害生态现象,在人烟稀少的较高海拔,泥石流滩地植物生长表现为一种自然恢复过程。通过贡嘎山东坡高海拔黄崩溜沟泥石流滩地上发生的灾害生态现象和过程的实地研究、发现泥石流滩地植物的生态过程和群落特征,可以揭示近代泥石流的形成时间和自然植被生态系统的演替规律。研究表明,加强泥石灾害生态现象的研究,可以促进灾害学与生态学科的渗透,具有重要     

Characterization of surface runoff from a subtropics urban catchment

Characteristics of surface runoff from a 0.14-km^2 urban catchment with separated sewer in Macau was investigated. Water quality measurements of surface runoff were carried out on five rainfall events during the period of August to November, 2005. Water quality parameters such as pH, turbidity, TSS, COD, TN, Zn, Pb, and Cu were analyzed. The results show that TN and COD are the major pollutants from surface runoff with mean concentration of 8.5 and 201.4 mg/L, both over 4-fold higher compared to the Class V surface water quality standard developed by China SEPA. Event mean concentration （EMC） for major pollutants showed considerable variations between rainfall events. The largest rainfall event with the longest length of antecedent dry weather period （ADWP） produced the highest EMC of TN, TSS and COD. From the pollutographs analysis, the peak concentration of TN precedes the peak runoff flow rate for all three rainfall events. The tendency of the concentration of TSS, turbidity and COD changing with runoff flow varies between rainfall events. The relationship between TSS and other parameters were analyzed to evaluate the efficiency of the physical treatment process to control the surface runoff in the urban catchment. Based on the correlation of parameters with TSS, high treatment efficiency of TSS, TN and COD was expected. The most significant event in term of first flush is the one with the strongest rainfall intensity and longest length of ADWP. TN always showed first flush phenomenon in all three rainfall events, which suggested that the surface runoff in the early stage of surface runoff should be dealt with for controlling TN losses during rainfall events.     

PREDICTION OF MEAN ANNUAL FLOWS IN THE FRASER RIVER CATCHMENT,BRITISH COLUMBIA1

ABSTRACT: A method of predicting annual flows is presented and is applied to the Fraser River catchment. Statistical tests show the annual flow records to be stationary and aerially independent and can be adequately approximated by Gaussian distributions. Estimates are made of the Gaussian parameters for each subbasin. The spatial variations of these parameters are described by third order trend surfaces. The fitted surfaces can then be used to predict parameters of ungaged basins using the latitude and longitude of the basin centroids. The predicted parametric values are substituted into the Gaussian distribution to generate flows of various return periods.     

应用多孔玻璃膜分离水中纳米有机胶体质的研究

应用新型的硼硅酸多孔玻璃膜（porous glass)于错流超滤（cross-flow ultrafiltration）系统中，分离出30－300nm有机质胶体。分别试验孔径为30nm、50nm和100nm等多孔玻璃膜对一些标准有机大分子的截留率。实验结果显示过滤溶液的酸度、温度、盐度对该分离膜的分离性能影响甚微。