乌鲁木齐市民用住宅室内氡浓度水平调查研究

对乌鲁木齐市具有代表性的民用住宅室内氡浓度进行了连续一年的监测调查,调查结果显示室内氡浓度平均值55.4 Bq／m3,低于国标的“200 Bq／m3”,并据此估算出其所致居民的年均有效剂量为1.400 mSv,以及所致居民支气管上皮组织、肺、性腺、骨髓及骨表面细胞等关键组织的年吸收剂量分别为1886．49,378.96,2.80,3.20,3.20μGy／a,大于UNSCEAR2000年报告的世界平均值1.008 mSv,结合室内氡的主要来源,提出了对建筑材料进行放射性监测、控制装修、工程竣工后开展室内环境监测、加强室内通风以及开展室内氡污染治理等措施控制室内氡浓度水平。     

江汉平原土地资源诅咒效应研究

将资源诅咒的研究领域由传统的矿产资源转向土地资源研究问题域,以近10a江汉平原18个县(市)的统计数据为依据,运用诅咒系数对其进行资源诅咒的实证分析。结果显示,近年来发展滞后的荆州市所辖的监利县、江陵县以及其他7个县市的土地资源诅咒系数大于1,确实存在资源诅咒现象,且江陵县与监利县还属于严重诅咒区。通过对选取指标作进一步的计算分析,得出导致其产生资源诅咒的原因主要为:以土地资源为依托的农业没有得到高效发展,而受到发展观念与投入等束缚,其二、三产业发展同样滞后。根据影响资源诅咒地区产业发展的具体因素,有针对性地给出化解土地资源诅咒的对策建议,为今后资源诅咒地区打破诅咒束缚,持续快速发展指明方向。     

Impact of leakage location and downwind storage tank on the gas dispersion in a typical chemical tank storage area

Toxic gas leakage in a tank area can have catastrophic consequences. Storage tank leakage location (particularly for high leakage) and downwind storage tanks potentially influence gas diffusion in tank areas. In this study, we developed a numerical and experimental method to investigate the impact of a high leakage location and downwind storage tank on gas diffusion based on three (1.05H, 0.90H, and 0.77H, H was the tank height, 22m) leakage field experiments on the leeward side of storage tank, which have been not conducted before. The experiments revealed an unexpected phenomenon: the maximum ground concentration first decreased and then increased with increasing leakage height. The simulations illustrated that the differences in micrometeorological conditions caused the maximum ground concentration of gas emitted from the roof to be higher than that emitted from the tank wall near the storage tank height. The downwind storage tank 1) had little influence on the entire diffusion direction but altered the local diffusion pattern; 2) reduced the maximum ground concentration (∼18.7%) and the distance from the emission source (approximately a storage tank diameter); and 3) had strong influences on the concentration, velocity, turbulence, and pressure on the leeward side. The concentration negatively correlated with the velocity, pressure, and turbulence in the middle of the two storage tanks on wind centerline. Our results can improve understanding of gas dispersion in tank areas and provide references for mitigating loss and protecting lives during emergency response processes.     

Air assimilative capacity-based environment friendly siting of new industries--a case study of Kochi region, India

Air pollution has become a matter of grave concern, particularly in mega-cities and urban areas, where the situation is alarming and becoming more and more severe day-by-day and warrants, therefore, careful planning to facilitate future industrial development. Site selection, with the objective of minimizing adverse environmental impacts based on environmental criteria is a vital prerequisite, particularly for air polluting industries. In order to locate any air polluting industry, the assimilative capacity of the region needs to be assessed carefully and planned accordingly, so that the receiving environment is not adversely affected. Assimilative capacity of a region/airshed, widely represented through the ventilation coefficient by many researchers in the past, does not give a clear picture about the amount of emission load that can be assimilated in a given region. The ventilation coefficient, at best, can only present a broad picture about the air pollution dispersion potential (low, medium or high) of the region. A modified approach, which utilizes air quality modelling as a tool to estimate the maximum allowable emission load that a region can assimilate without violating the stipulated standards, has been used for estimating the assimilative capacity of the air environment. Details of this approach have been presented in this paper through a case study carried out for the Kochi region, located in the Kerala State of India. A variety of emission and meteorological scenarios have been considered and critical emission loads have been estimated. This approach shall provide necessary technical guidance to the environmental regulatory authorities as well as to the industries in planning environment friendly industrial development.     

焊接工艺多源散发的高温颗粒污染物扩散特性数值模拟

为探究热工艺过程产生的热气流作用下颗粒的迁移规律,基于气固两相离散粒子模型(DPM)对多源浮射流伴生的高温颗粒的扩散特性进行了数值研究,讨论了两相流运动过程中热气流与颗粒群的温度和速度的瞬时变化情况.结果表明,对于473K£T₀£673K的高温颗粒群,温度衰减趋势类似,颗粒群温度分布呈中心对称;当5μm£d_p£20μm时,颗粒与气流之间的跟随性随着粒径的增大而降低;热羽流随时间经历了独立发展和相互合并的过程,羽流之间涡旋结构的消失导致中心位污染源散发的d_p=10μm的颗粒更容易发生沉降.     

焙烧炉筒体结构强度有限元分析

对焙烧炉筒体结构进行有限元建模仿真,考虑热应力、压力和重力对筒体结构受力的影响,计算了焙烧炉关键部位的蠕变疲劳寿命,同时探究进气温度、保温层及对流系数等参数的影响。结果表明:热应力是影响结构强度的关键因素;焙烧炉筒体在许用蠕变变形量为5%的情况下,其使用寿命超过设计寿命;在筒体加热过渡段铺设保温层,降低与外界空气对流和提高进气温度,有利于降低筒体应力。     

车用高分子材料不同地区户外曝晒试验相关性研究

目的将3种高分子材料以及3种车用外饰材料分别投放在中国海南琼海和美国佛罗里达州2种典型湿热环境中进行户外曝晒试验,研究气候相似的2种地区的试验相关性。方法通过测试相同时间间隔下不同材料在2处试验场曝晒过程中的黄变程度,表征材料的老化现象。采用斯皮尔曼等级相关系数的统计方法,研究材料在2个地区相同时间节点的试验结果的相关性,并利用时间同轴的作图方法比较2个地区严酷度的差异。结果琼海与佛罗里达州2个地区在各个时间节点的相关系数接近于1,且在材料黄变方面呈现一定比例关系。结论琼海和佛罗里达州2个地区的试验结果呈现出较好的相关性,且严酷度比值约为琼海︰佛罗里达=1︰1.19。     

洞庭湖钉螺扩散与水情变化规律

洞庭湖区是目前我国钉螺分布范围最广且血吸虫病疫情最难防治的疫区。为揭示近年来洞庭湖区钉螺扩散与疫区水情变化的关系，从洪水对钉螺扩散及其孳生地环境淹没时间影响考虑，提出了表征疫区钉螺扩散及孳生地变化的水情指标，选用最能综合反映洪水年水情变化的汛期平均水位作为疫区水情变化的表征指标，并以洞庭湖为例定量分析了洞庭湖区钉螺扩散与以城陵矶站汛期平均水位为指示性指标的疫区水情的相关关系。其结果显示洞庭湖区钉螺面积与湖区汛期平均水位线性相关性显著，其相关关系式为y＝0.107 2x+14382(r=0822,p<005)，其中y为洞庭湖区钉螺分布面积，x为城陵矶站汛期平均水位。     

土壤中磺胺二甲嘧啶赋存对水稻生长的影响

为探究土壤中残留抗生素对植物生长的影响,选取土壤中检出率较高的磺胺类抗生素磺胺二甲嘧啶作为外源污染物,分析水稻苗期和成熟期生长指标、根系和叶片生理生化指标、水稻各器官中抗生素残留量和富集转运因子的变化特性,并评价水稻籽粒中残留磺胺二甲嘧啶的健康风险.结果表明,磺胺二甲嘧啶对水稻株高和生物量的抑制作用存在于整个生长周期中,且苗期的影响大于生长成熟期,根部受到的影响大于苗部.苗期秧苗根系活力、硝酸还原酶活性和叶片叶绿素含量受到随抗生素含量增加而增大的抑制作用,而抗氧化酶活性的变化趋势表现出不同特征,具体为超氧化物歧化酶活性增强、过氧化氢酶和过氧化物酶先被激活后被抑制.磺胺二甲嘧啶在水稻各器官中的积累量表现为：根>叶>茎>籽粒,且水稻籽粒的抗生素风险评估结果显示EDI/ADI<0.1,不构成健康风险.生长成熟期土壤中磺胺二甲嘧啶对水稻富集因子和转运系数的影响大于苗期.综合磺胺二甲嘧啶对水稻的不利影响,在水稻种植中施加畜禽粪便作为有机肥和使用养殖水进行农田灌溉时,需要关注磺胺二甲嘧啶的生态效应,保障水稻等作物的安全生产.     

柳枝稷苗期对钾营养胁迫耐受性的综合评价

为明确能源作物柳枝稷在缺钾条件下的耐受能力,筛选出耐贫瘠性强的优质种质资源,以13个柳枝稷品种为供试材料,在人工气候室中开展水培试验,通过相关农艺性状和生理指标等评价指标的测定,采用标准差系数赋予权重法对柳枝稷在缺钾胁迫下的表现做出综合评价。结果表明：在缺钾胁迫下,13个柳枝稷品种地上及地下部的生长均受到显著抑制,具体表现为：生长速度下降,叶绿素含量减少,光合面积减少,光合速率降低,进而导致其总生物量积累下降。由标准差系数赋予权重法得出的13个品种耐胁迫性由高到低依次为：Cave—In—Rock、Trailblazer、BJ-5、Forestburg、BJ-4、Pathfinder、BJ～3、BJ一2、Blackwell、Alamo、BJ-1、BJ-6、Kanlowo