防治"空巢综合症"

“空巢家庭”是指无子女共处,只剩下老年人独自生活的家庭。据了,解,在发达国家,“空巢家庭”出现较早,现在十分普遍,老年人与子女同住的只占10％-30％,除了日本,大多数老年人均与子女分居。美国第二次世界大战前,52％的老年人与子女同住,到了20世纪80年代,与子女同住的只有百分之十几,在比利时、丹麦、法国和英国,65岁以上独居者家庭占全部家庭户11％;     

大气颗粒物吸附的空气微生物毒性效应的研究进展

大气污染与人群健康关系的研究表明,灰霾天气中的大气颗粒物上附着有多种可吸入微生物,包括病毒、细菌和真菌.大气颗粒物中的部分有机物质能够与这些微生物相互作用,进而改变颗粒物上附着微生物的致病性和持久性.大气颗粒物及其所吸附的病原微生物来源广泛,种类繁多,并由于大气污染加重而越发显得重要.本文结合以往文献资料和新型冠状病毒...     

降解苯酚优势菌的筛选分离和培养条件研究

从膨润土中筛选出可在含2 g/L苯酚的PDA培养基上生长的菌种,经过逐级驯化,得到1株可以在1 g/L苯酚的无机盐固体培养基上生长并降解苯酚的优势菌种HJ01,其对苯酚600 g/L降解率可达94%.该菌生长的适宜碳源和氮源分别为蔗糖和NH4Cl,温度为25 ℃,pH值范围为6-7.     

Assessment of population exposure to particulate matter pollution in Chongqing, China

To determine the population exposure to PM(10) in Chongqing, China, we developed an indirect model by combining information on the time activity patterns of various demographic subgroups with estimates of the PM(10) concentrations in different microenvironments (MEs). The spatial and temporal variations of the exposure to PM(10) were illustrated in a geographical information system (GIS). The population weighted exposure (PWE) for the entire population was 229, 155 and 211 microg/m(3), respectively, in winter, summer and as the annual average. Indoor PM(10) level at home was the largest contributor to the PWE, especially for the rural areas where high pollution levels were found due to solid fuels burning. Elder people had higher PM(10) exposure than adults and youth, due to more time spent in indoor MEs. The highest health risk due to particulate was found in the city zone and northeast regions, suggesting that pollution abatement should be prioritized in these areas.     

A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test.     

Fate of anilide and aniline herbicides in plant-materials-amended soils

The fate of herbicides trifluralin, pendimethalin, alachlor and metolachlor in paddy field soils amended with plant materials was investigated. The plant materials were purple sesbania, vegetable soybean and rice straw. The investigation was performed at two temperatures (25 and 40 degrees C) and two soil water moistures (60 and 90% water-holding capacity). The results showed linear and Freudlich equations described the adsorption of amide compound to soil. Adsorption coefficient (K(d)) fit to linear equation were in general greater in plant material-amended soils than in non-amended soil, especially in soil amending with rice straw. Increasing temperature and soil water moisture content shortened the half-lives of compounds in various treated soils. The movement of compounds in the soil columns showed the maximum distribution of aniline type compound, trifluralin and pendimethalin, appeared at the upper top of 0 to 5 and 0 to 10 cm of soil column, respectively, and of anilide type, alachlor and metolachlor, were distributed at 0 to 25 cm of the soil column. The mobility of chemicals in the different treated soils was simulated by the behavior assessment model (BAM). There was no significant difference among different plant material incubated soils on dissipation and mobility of compounds in soils.     

动态膜-生物反应器处理城市污水的运行特性研究

考察了孔径108μm左右的不锈钢丝网动态膜组件处理城市生活污水的特性,并研究了出水水头和曝气强度对动态膜泥饼层形成的影响.结果表明,稳定运行情况下出水平均浊度1.2NTU,COD平均去除率90%,NH<,3>-N平均去除率97%,与传统膜-生物反应器处理效果接近.同时发现,在20、40mm的出水水头下,动态膜运行初期膜通量衰减规律均符合泥饼阻力模型.     

计算机模拟研究UO2+2在人体细胞液的形态分布

建立了由多种金属离子和小分子配体组成的多相细胞液热力学平衡模型.模拟研究了UO2 2在组织液和细胞液的形态分布及CO2-3、氨三乙酸（NTA）和乙二胺四乙酸（EDTA）浓度对细胞液中UO2 2形态分布的影响.在组织液中,正常生理pH下,当各形态UO2 2总摩尔浓度 [U]= 1.0×10-6 mol/L 或[U]=1.0×10-3 mol/L时,UO2 2均主要以[UO2(CO3)3]4-和[UO2(CO3)2]2-形态存在.在细胞液中,当[U]=1.0×10-6 mol/L时,UO2 2主要以[UO2(CO3)3]4-和[UO2(CO3)2]2-存在;当[U]=1.0×10-3 mol/L,pH为6.0～6.8时,细胞液中存在大量的固相(UO2)3(PO4)2·4H2O,当pH为6.8～7.4时,UO2 2主要以[UO2(CO3)3]4-、[UO2(CO3)2]2-和[(UO2)2CO3(OH)3]-存在.细胞液中(UO2)3(PO4)2·4H2O含量随[U]升高而增加.通过调节细胞液pH和增加细胞液CO2-3浓度均能降低其固相UO2 2配合物含量.在细胞液中增加NTA会增加(UO2)3(PO4)2·4H2O含量,当添加EDTA时会显著降低(UO2)3(PO4)2·4H2O含量.     

石灰石／石膏湿法烟气脱硫的水平衡问题探讨

通过对石灰石/石膏湿法烟气脱硫系统的水平衡原理分析,讨论了脱硫系统中的水平衡问题,并针对该脱硫系统如何在低负荷下维持水平衡以保证稳定运行的问题,结合工程实际提出了一些措施.     

四氯乙烯污染对小麦幼苗抗氧化酶系的影响

通过室内模拟试验,采用愈创木酚法、高锰酸钾滴定法、氮蓝四唑法分别测定了四氯乙烯(PCE)污染小麦幼苗的过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物岐化酶(SOD)等抗氧化物酶系,研究了PCE污染对植物生物学指标的影响,以评价土壤PCE污染的生态毒性效应,为土壤性质的变化趋势提供依据.结果表明,PCE浓度较低时,POD、SOD活性被激活,表现出明显的抗氧化能力,但PCE浓度过高时则抑制POD和SOD的活性诱导作用;小麦幼苗中CAT活性只有在PCE为0.10mg/kg时被激活,其他浓度时CAT活性均受到抑制;随着时间的延长,POD、CAT的活性均呈激活态势,而SOD活性在PCE浓度较低时呈降低趋势,在PCE浓度较高时,SOD活性升高.