四川省境内核工业放射性废物污染的潜在危险及防治对策

本文通过对四川省境内核工业放射性废物污染的潜在危险分析，提出了污染的对策。     

混凝过程中流场结构的PIV测量与表征

采用粒子成像速度场仪(PIV)在不投加专用示踪粒子的条件下,以混凝絮体为示踪粒子,对Taylor-Couette反应器内的絮凝反应流场进行测量与表征.结果表明,内筒旋转雷诺数Re在900~2900时,流场中产生的涡具有相似的特殊波状涡结构,相邻涡旋形态大小发生周期性变化,涡间存在主流液体的移动,这种涡结构有利于絮体结合生长成较大的絮体颗粒,便于沉降而导致较高的絮凝沉淀去除率.这也证实PIV技术能够在进行混凝反应的同时,用混凝过程中的微絮体为示踪粒子对混凝过程进行流场测量,不必再额外添加示踪粒子,就能较好地反映混凝过程中涡旋的形态变化特征,从而实现对絮凝过程的同步测量与表征.     

环球

福岛第一核电站将再产生大量放射性废弃物 4月7日,东京电力公司宣布,由于福岛第一核电站要进行反应堆报废作业,在2027年前,将新产生包括高放射性瓦砾在内的约56万立方米废弃物,其中16万立方米需要新设保管设施。福岛第一核电站院内现在已经保存了30多万立方米的瓦砾和砍伐的树木等,这些废弃物都是福岛第一核电站发生事故时产生的。由于东京电力公司预定在2020年开始取出反应堆内熔毁的燃料,所以需要清除反应堆所在建筑上部残留的高放射性瓦砾,导致废弃物继续增加。     

微波碳化减容放射性废物尾气取样研究

在微波碳化减容核电放射性废物过程中,将释放出HCl、H2、CO、CO2、二恶英等可燃或有毒气体,利用自行设计的负压状况下取样装置实现尾气样品的采集。通过对废物尾气取样分析,获得如下结论:尾气中氢气、甲烷和总烃等可燃气体的浓度小于4%的燃爆限值;在较高温度(200℃)以上,释放出CO和CO2气体,说明PVC裂解产生的残炭在高温段发生氧化反应,使得减容率和减重率进一步提高;通过控制升温程序可大大降低二恶英的产生,使尾气中二恶英的浓度低于排放标准一个数量级。     

放射性废物桶内干燥接收输送装置的研制

放射性废物桶内干燥处理前需要对其进行暂存、预处理和输送,通过试验开发了主要由接收缓冲单元、输送单元和树脂沥水单元组成的接收输送装置。试验验证表明该装置能够基本满足放射性废物桶内干燥要求。     

Evaluating the emission status of light-duty gasoline vehicles and motorcycles in Macao with real-world remote sensing measurement

Roadside remote sensing measurement was used to explore the real-world emission status of light duty gasoline vehicles （LDGVs） and motorcycles in Macao. Both fuel-based and distance-based emission factors were derived using the mass balance method. The emission concentration profile of LDGVs illustrated the benefits of tightening emission standards at the source country or region of import. The distance-based emission factors for CO, HC and NOx of LDGVs registered before 2000 were 8.00, 1.04 and 1.36 g/km, respectively. The distance-based emission factors for CO, HC and NOx of LDGVs registered in or after 2000 were 1.16, 0.15 and 0.18 g/km, respectively. The fuel-based CO emission factors of light duty motorcycles （LDMCs） and heavy duty motorcycles （HDMCs） registered before 2000 were about 10 times higher than those of LDGVs of the same age group. As the emissions of LDGVs decreased more quickly after 2000, the gap widens for newer vehicles. The distance-based HC emission factors of LDMCs and HDMCs registered before 2000 were 4.81 and 2.91 g/km, respectively. The distance-based HC emission factors of LDMCs and HDMCs registered in or after 2000 were 3.52 and 0.93 g/km, respectively. The poor emission performance of motorcycles and their larger share in the traffic flow will cause them to be the major contributor to traffic CO and HC emissions. LDMCs, especially two-stroke models, should be the priority for vehicle emission control efforts in Macao.     

On-board measurement of emissions from liquefied petroleum gas, gasoline and diesel powered passenger cars in Algeria

On-board measurements of unit emissions of CO,HC,NOx and CO2 were conducted on 17 private cars powered by different types of fuels including gasoline,dual gasoline–liquefied petroleum gas(LPG),gasoline,and diesel. The tests performed revealed the effect of LPG injection technology on unit emissions and made it possible to compare the measured emissions to the European Artemis emission model. A sequential multipoint injection LPG kit with no catalyst installed was found to be the most efficient pollutant reduction device for all of the pollutants,with the exception of the NOx. Specific test results for a sub-group of LPG vehicles revealed that LPG-fueled engines with no catalyst cannot compete with catalyzed gasoline and diesel engines. Vehicle age does not appear to be a determining parameter with regard to vehicle pollutant emissions. A fuel switch to LPG offers many advantages as far as pollutant emissions are concerned,due to LPG's intrinsic characteristics.However,these advantages are being rapidly offset by the strong development of both gasoline and diesel engine technologies and catalyst converters. The LPG's performance on a chassis dynamometer under real driving conditions was better than expected. The enforcement of pollutant emission standards in developing countries is an important step towards introducing clean technology and reducing vehicle emissions.     

巷道通风气流对氡浓度测量的影响

为了提高花岗岩山体水平巷道内的氡浓度测量数据的可靠性,对氡浓度测量方法进行了研究。通过对不同通风状态下,测氡仪在不同放置位置的测量数据进行分析,研究巷道形状对测量数据的影响程度。测量结果表明:(1)自然通风状态下,坑道内氡浓度基本均匀一致。在测量区域无其他因素影响的情况下,测量仪器可以放置在任意位置。(2)机械通风状态下,空气流通断面内氡浓度存在差异;而涡流区氡浓度与空气流通断面内氡浓度差异更为明显,浓度分布情况比较复杂。在进行巷道内氡浓度测量时,应将仪器放置在流通断面的中心位置,尽可能避开涡流区。     

无组织排放中二氧化硫测量不确定度的评价

本文的目的是对无组织排放中二氧化硫测量的不确定度进行分析和评价。方法:对二氧化硫的测定选择甲醛缓冲液吸收盐酸副玫瑰苯胺分光光度法,抽取样品后按照GBZ/T160.33-2004对其进行十次重复测量,对测量结果进行不确定度评定。实验结果表明,无组织排放中二氧化硫测量结构分析,其含量为(0.808±0.213)μg/ml,k为2,p为95%,相对标准扩展不确定度为2×1.50%=3.0%。在实验中得出以下结论,在无组织排放二氧化硫测量不确定分析中,发现采样体积、标准物质不确定度、实验总体误差等均是主要的因素。     

关于不同类型教室声环境特点实验的研究

依据《室内混响时间测量规范》,对高校不同类型教室的空场和满场混响时间进行测量,分析测得数据,研究不同类型教室的混响时间的规律,从而为教学楼的声学设计提供科学依据。