北京城区夏季O3化学生成过程

选取2007年7月1日—8月31日中的21个晴空日,利用观测资料和光化学箱模式计算了北京城区测点的O₃生成速率G(O₃)和O₃生成效率OPE.结果表明,21个晴空日中G(O₃)日最高小时值分布在(18~82)×10^-9h^-1之间;在O₃污染和非污染日G(O₃)最高值的平均水平无显著差异,且与O_x浓度之间不存在一致的对应关系,表明O₃化学生成过程不能全面解释地面O₃浓度的累积,物理传输过程对测点O₃实测浓度有显著作用;各个化学过程对G(O₃)的贡献率对比结果显示,HO₂ 在 NO向NO₂的转化中贡献最大;OPE值分布在2.8~5.8之间,总体水平为4.1±0.1;OPE值与NO_x浓度之间为非线性关系,OPE值随NO_x浓度的增加而减少,表明消减测点附近VOCs排放能有效降低O₃浓度.     

Optimization of C/N ratio for preparation of protein-rich and multi-enzymes feed thallus through synergic fermentation of mixed distillers'grains

A new procedure of determining optimal C/N (the rate of carbon source to nitrogen source) of mixed distillers' grains for combined bacteria synergic fermentation is established. At the same time an improved method evaluating bacteria growth, called method of dry cell weighing by filtering is developed. For each combination of C and N , their initial and residual contents before and after fermentation respectively are determined. Then followed the calculation of utilization of C and N sources by the compound bacteria. The optimal C/N is finally located from among the utilization of C and N of several combinations and the weight of produced mass of oven-dried thallus The conditions of fermentation are: inoculum size 10%, temperature 30.0℃, rotational speed 170 r/min, shake culture time 48h. The best results obtained from orthogonal experiments are: maximum mass of oven dried thallus is 14.693g in a liter liquid medium, maximum utilization rate of carbon source is 98.13% and maximum utilization rate of nitrogen is 78.14%. Optimal C/N is 5.1.     

微量Fe3+对过氧化氢异丙苯热稳定性影响研究

为研究微量铁离子（Fe³⁺）对过氧化氢异丙苯（CHP）热稳定性的影响,采用绝热加速量热仪（ARC）对CHP及含4种不同浓度Fe3+的CHP进行了绝热分解测试,测试分析了5个样品在绝热条件下的起始分解温度（To,s）、绝热温升（ΔTad,s）、最大温升速率（mm,s）和最大温升速率到达时间（θm,s）等参数,并利用热惰性因子Φ对实验数据进行了修正。研究结果表明:在绝热条件下,微量Fe3+的存在对CHP分解的To,s,ΔTad,s,mm,s和θm,s均有较大影响,且浓度不同对各参数的影响不一样;Fe³⁺的存在增加了CHP分解的剧烈程度,且浓度越大,CHP分解越剧烈,其热分解失控可能性越大,危险性越高;储存运输CHP时要避免与高浓度的Fe³⁺接触。研究结果可为CHP的热稳定性安全提供一定参考。     

美国某给水厂处理工艺及净水效果

介绍了美国某给水厂的臭氧-生物活性炭深度处理工艺、主要构筑物、设计参数和运行效果。实验结果表明:原水中TSS、BOD5、COD、UV254和浊度平均值分别为18.25 mg/L、5 mg/L、7.34 mg/L、0.08和17.38 NTU,经过系统处理后的出水指标分别为1.33 mg/L、2 mg/L、0 mg/L、0.01和0.86 NTU,相应的平均去除率分别为88%、60%、100%、88%和81%。净水效果明显,五项常规指标均满足我国《生活饮用水卫生标准》(GB5749-2006)使用要求,这种深度处理技术及设计思路值得国内给水处理行业参考借鉴。     

煤气发生站洗冷废水治理研究

研究了以活性炭作为吸附剂处理煤气发生站废水工艺，并摸索出一整套的工艺参数。实验结果表明，采用活性炭吸附工艺使出水水质得到明显改观，硫化物、氰化物和挥发酚的去除效率均达９０％以上，对ＣＯＤｃｒ、氨氮的去除也收到了明显的效果。     

从含银的废催化剂中回收白银

介绍了从含银的废催化剂中回收白银的一种新方法。采用氨浸A还原剂还原,浸出率98.5%,还原率99.9%,直接可获高纯度的银粉,金属银纯度可达99.9%。     

Safe speed limits for a safe system: The relationship between speed limit and fatal crash rate for different crash types

Objective: The objective of this article is to provide empirical evidence for safe speed limits that will meet the objectives of the Safe System by examining the relationship between speed limit and injury severity for different crash types, using police-reported crash data.

Method: Police-reported crashes from 2 Australian jurisdictions were used to calculate a fatal crash rate by speed limit and crash type. Example safe speed limits were defined using threshold risk levels.

Results: A positive exponential relationship between speed limit and fatality rate was found. For an example fatality rate threshold of 1 in 100 crashes it was found that safe speed limits are 40 km/h for pedestrian crashes; 50 km/h for head-on crashes; 60 km/h for hit fixed object crashes; 80 km/h for right angle, right turn, and left road/rollover crashes; and 110 km/h or more for rear-end crashes.

Conclusions: The positive exponential relationship between speed limit and fatal crash rate is consistent with prior research into speed and crash risk. The results indicate that speed zones of 100 km/h or more only meet the objectives of the Safe System, with regard to fatal crashes, where all crash types except rear-end crashes are exceedingly rare, such as on a high standard restricted access highway with a safe roadside design.     

洪水泥石流等自然灾害对旅游景区的破坏作用研究

通过泥石流灾害模拟模型与灾害损失率计算方法了解旅游景区的损失状况,研究自然灾害对旅游景区的破坏作用。旅游景区洪灾模拟模型由分流模型与汇流模型构成,根据泥石流多相流成分中固液两相分离原则构建泥石流分流模型;引用DEM数据得到泥石流流域栅格的汇流方向,根据经验模型计算汇流用时,采用八方向方法获取河道信息,基于这些数据构建泥石流模拟的汇流模型,采用ArcGis软件实时呈现该模型的泥石流灾害模拟效果;结合ArcGis软件显示的灾情数据,采用洪灾损失率计算方法获取旅游景区自然灾害损失率。实验结果表明,该模型计算旅游景区建筑损失率误差均小于5%,在有效模拟泥石流灾害的同时,可准确描述自然灾害对旅游景区的破坏作用。     

臭氧氧化法处理焦化废水生化出水的反应动力学简

对臭氧氧化去除焦化废水生化出水COD的反应动力学及其影响因素进行了实验研究,结果表明,在臭氧投加量为8.50 mg/min,反应温度为20℃和初始pH为10.61条件下,对COD的降解符合表观一级反应动力学模型,其相关系数R²=0.9991,表观反应速率常数k_Abs=1.01×10^-3 s^-1。该条件下,臭氧氧化对COD的降解主要来源于高活性羟基自由基的强氧化作用。在不同的臭氧投加量（4.25~12.75 mg/min）、不同的反应温度（10~40℃）和不同的初始pH（3.76~12.53）下,COD的降解也同样遵循一级反应动力学规律。随着臭氧投加量的增大,COD降解的表观反应速率常数从（0.554×10^-3） s^-1增加到（1.06×10^-3） s^-1;随着反应温度的升高,表观反应速率常数从（0.427×10^-3） s^-1增加到（1.40×10^-3） s^-1,温度越高反应速率提高的幅度却越小;在初始pH3.76~10.61范围内,表观反应速率常数从（0.218×10^-3） s^-1增加到（1.01×10^-3） s^-1,在初始pH为12.53时表观反应速率常数下降到（0.857×10^-3） s^-1。