Change in genotoxicity of wastewater during chlorine dioxide and chlorine disinfections and the influence of ammonia nitrogen

The effects of chlorine dioxide and chlorine disinfections on the genotoxicity of different biologically treated sewage wastewater samples were studied by umu-test. The experiment results showed that when chlorine dioxide dosage was increased from 0 to 30 mg/L, the genotoxicity of wastewater first decreased rapidly and then tended to be stable, while when the chlorine dosage was increased from 0 to 30 mg/L, the genotoxicity of wastewater changed diversely for different samples. It was then found that ammonia nitrogen did not affect the change of genotoxicity during chlorine dioxide disinfection of wastewater, while it greatly affected the change of genotoxicity during chlorine disinfection of wastewater. When the concentration of ammonia nitrogen was low (< 10–20 mg/L), the genotoxicity of wastewater decreased after chlorine disinfection, and when the concentration of ammonia nitrogen was high (> 10–20 mg/L), the genotoxicity of wastewater increased after chlorine disinfection.     

气田开发对生态环境的影响初探

西北干旱、半干旱地区气田开发可能对沙漠、荒漠等生态脆弱地区的生态环境造成一定的影响和破坏。本文通过采用点线结合,文件资料调研、现场调查并与3s技术相结合的方法。对地处干旱区的气田开发进行了生态环境影响初探。尤其对工程占地、土壤、植被、土地利用等因子做了进一步的分析,并提出了一些环境影响减缓措施与建议,这对做好气田环境保护工作具有一定的借鉴意义。     

Carrier-mediated uptake of pyrrolizidine alkaloids in larvae of the aposematic and alkaloid-exploiting moth Creatonotos

We appreciate the technical assistance by E. Roth, U. Sachade, H. Söchting-Mayr, M. Weyerer. We thank for support the Fonds der chemischen Industrie and the Deutsche Forschungsgemainschaft (M.W.) and the Max-PlanckGesellschaft (D.S.).     

On the relationship between PM2.5 concentrations and regional-scale primary PM emissions for the United Kingdom: an issue of subsidiarity

A site-specific particulate matter PM source apportionment model has been used to estimate the contributions from local primary PM emissions, regional primary PM emissions and the regional background to PM_2.5 concentrations at 102 monitoring site locations and to the centres of 1 km × 1 km grid squares across the United Kingdom. The local primary PM contributions have then been compared with Europe-wide urban PM_2.5 increments estimated at 50 km × 50 km in European-scale integrated assessment models. It is concluded that Europe-wide PM increments used in policy analyses grossly underestimate urban PM concentrations obtained from the site-specific PM source apportionment model for the United Kingdom. Europe-wide urban PM_2.5 increments estimated at 5 km × 5 km scale are significantly improved, particularly for London, but underestimate those for smaller towns and cities by factors of 2–3. These underestimations have important air quality policy ramifications. Although environmental policies may well be best formulated at the European scale, the underpinning air quality modelling may be best carried out at the local scale.     

牟氏角毛藻在海水养殖废水中的生长及其对废水的净化作用

用f／2培养基作对照,利用不同浓度的海水养殖废水,对牟氏角毛藻进行了培养。结果表明：在不同浓度养殖废水处理下牟氏角毛藻的生长均有明显差异,具体生长情况如下：100％〉90％〉75％〉50％〉25％〉10％〉海水,而稍低于f／2;不同浓度养殖废水处理下牟氏角毛藻叶绿素的积累情况大致一致,f／2最高,100％、90％、75％相差不大,而50％〉25％〉10％,均高于纯海水;不同浓度海水养殖废水培养牟氏角毛藻后N、P养分均有一定的去除,NH3-N、NO3-N、NO2-N、PO4-P均大大降低。     

幼教活动过程中实践环保教育

在幼教活动中实施环保教育具有重要的意义,须从引导幼儿关注环境入手,通过教学计划和活动、幼儿园环境创设和一日生活的引导培养幼儿初步的环保意识。     

利用微生物消除故黄河藻类的初步研究

采用徐州迈克尔·派克微生物工程有限公司提供的 Micro-Bac发酵液 ,对藻类有明显的沉降和消除效果 ,研究结果表明水体中 BOD5、CODMn、CODCr和总磷 ( TP)的平均去除率分别为 66%、73 %、78%和94 % ,处理后 ,可使故黄河水质基本达到功能区划规定的 类水标准。     

Assessing the uptake of small-scale photovoltaic electricity production in Argentina: the PERMER project

Supplying electricity to remote rural communities in lesser developed countries (LDCs) is key to improving livelihoods and reducing poverty. Decentralised renewable energy systems such as solar photovoltaic (PV) electricity have the potential to provide a viable and sustainable alternative to overcome the physical and economic barriers facing the expansion of low and medium tension grids. This paper critically assesses the impact of small-scale PV systems installed in homes, schools and public buildings over the last six years under the PERMER project—Renewable Energy Project for the Rural Electricity Market—co-funded by a range of public and private sources. The structure of financial subsidies has enabled these remote rural communities to receive an electricity supply that, in many cases, would otherwise not have been possible. Replacing traditional energy sources such as candles and kerosene lamps, the PV electricity systems are providing better quality light, reducing indoor air pollution levels, as well as a means to power communications technologies and extend hours for cultural and productive activities. There are, however, certain technical, organisational and intellectual barriers that remain to be overcome before the project can be considered to be operating optimally.     

水资源水质水量联合评价综述

根据国内外近30a来对水资源的评价研究,综述讨论了水资源评价的4种理论和方法,认为水质与水量联合评价并考虑生态环境需水的水资源评价才能客观地表现水资源现状,而且对湖泊水体的相应研究也应受到广泛关注。     

The prognostic factors in the prenatal diagnosis of the echogenic fetal lung

The prenatal diagnosis of an echogenic fetal lung (EFL) is now often made in the early second trimester using high-resolution ultrasound. This ultrasound appearance is usually caused by a congenital cystic adenomatoid lung malformation (CCAM), an intrapulmonary lung sequestration or obstruction of a major airway. In order to provide prognostic guidelines to parents who may be considering termination of a fetus with these findings, we have analysed a series of 11 cases diagnosed in our centre over the past 2 years in conjunction with 60 cases from major published series. The data suggest that in the absence of non-immune hydrops fetalis (NIHF) or other anomalies, the outcome for the fetuses is excellent, with over 90 per cent survival. Neither early diagnosis (24 weeks) nor the presence of mediastinal shift is a poor prognostic indicator. In addition, it appears that if NIHF is absent at diagnosis, the chance that it will develop as the pregnancy continues is small (6 per cent). Furthermore, there is a significant (up to 30 per cent) chance that this ultrasound finding will resolve in utero. The development of in utero fetal surgical techniques may be the only hope for those hydropic fetuses who appear to have a dismal prognosis.     

巴布亚新几内亚新生代埃达克岩的地球化学证据

本文根据对新几内亚火山岩的10个化学分析数据与典型埃达克岩进行对比,讨论了巴布亚新几内亚埃达克岩的地球化学特征.结果表明:巴布亚新几内亚埃达克岩微量元素特征为高锶(一般大于400×10-6),Sr/Y比值平均＞41.7;在微量元素蛛网图上有Sr、Ba正异常峰和明显的Nb、Th负异常.Y和重稀土元素Yb含量很低(分别为≤20×10-6和1.9×10-6).稀土元素表现为LREE富集模式,La/Yb比值平均为9.3～27.8.巴布亚新几内亚埃达克岩的Mg#值＞0.45;87Sr/86Sr一般小于0.7045.巴布亚新几内亚埃达克岩分别位于弧-陆碰撞带大地构造环境中的大洋岛弧和大陆边缘造山带中.埃达克岩的分布区域与世界级斑岩铜-金矿和浅成热泉金矿成矿带的分布相一致.     

Variation in the heritability and evolvability of human lifespan

 The heritability and evolvability of lifespan in two socioeconomically different groups of humans, including birth cohorts for 1600–1800s, were investigated. Among the aristocratic Europeans, the heritability estimates based on offspring–mother regressions ranged from 0.46 to 0.89, while the estimates based on offspring–father regressions varied from 0.23 to 0.59. However, the rural Finns possessed either no inheritable component or a clearly lower level of heritability than did the aristocrats, the estimates ranging from 0 to 0.40, depending on the method used. The additive genetic coefficients of variation and standardized evolvabilities were high in the aristocrats, especially in the data set including all data instead of limiting the data to the older age group. Among rural Finns, the values were considerably lower. Received: 1 September 2000 / Accepted in revised form: 6 November 2000