硝酸铊对浮萍(Lemna gibba L.)的生长抑制及其氧自由基损伤作用

为了探讨硝酸铊(Tl(I)-nitrate)对浮萍(Lemna gibba L.)的生长抑制作用及其可能的氧化损伤机制,设置了Tl(I)-nitrate的8个处理组(0.005、0.01、0.02、0.04、0.08、0.1、0.5和1.0 mg·L-1)和对照组(0.0 mg·L-1),进行96 h急性毒性实验,测定96 h内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性及丙二醛含量。结果表明:96 h暴露时间下,浮萍生长受抑制程度与Tl(I)浓度之间呈正相关,Tl(I)-nitrate对浮萍的96 h EC50为0.076 mg·L-1,NOEC为0.01 mg·L-1。CAT活性随着Tl(I)-nitrate浓度升高逐渐降低,在0.5和1 mg·L-1时,有极显著差异(p0.01)产生,SOD活性在0.1 mg·L-1时显著升高(46%),POD活性和MDA含量在Tl(I)浓度0.5 mg·L-1时明显上升。当Tl(I)-nitrate胁迫超出浮萍抗氧化酶系统清除活性氧的能力时,活性氧积累导致浮萍受到不可逆转的氧化损伤。Tl(I)-nitrate对浮萍生长产生明显的抑制作用     

Genuine saving rate: An integrated indicator to measure urban sustainable development towards an ecocity

The construction of an ecocity is gradually gaining attention as an indicator of sustainable development. Genuine saving rate (GSR), which takes account of various impacts of economic activities including depletion of natural resources, costs of environmental pollution and long-term environmental damage, can be used as an integrated indicator to measure the status quo and potential of sustainability for an ecocity. This paper discusses the concept of an ecocity; and analyses the time-series of GSR in Suzhou between 1991–2001 as a case study used to develop a standard method of measuring sustainability. The status quo and trends in urban sustainability in six case study cities in China are then evaluated and compared. The results show the current status: Suzhou (23.6%), Guangzhou(18.9%), Ningbo (14.7%), Yantai (13.1%), Yangzhou (11.7%) and Sanming (7.9%). The study demonstrates that GSR provides not only a linkage by which local governmental departments for resources management, environmental protection, finance and planning can be connected directly, but also an effective analytical tool for the planning and construction of an ecocity as well as decision-making support for local governments.     

Environmental effects on mineral accumulation in rice grains and identification of ecological specific QTLs

Optimizing the beneficial mineral elements in rice grains is of interest for rice breeders. To study the environmental effects on mineral accumulation in rice grains, we grew a double-haploid (DH) population derived from the cross between cultivars Chunjiang 06 (CJ06, a japonica rice) and TN1 (an indica rice) under two different ecological environments (Lingshui and Hangzhou, China) and determined the content of Ca, Fe, K, Mg, Mn, P, and Zn in brown rice. These contents show transgressive variation among the DH lines. Subsequently, the quantitative trait loci (QTLs) for mineral accumulation in rice grain were mapped on the chromosomes using CJ06/TN1 population. For the 7 mineral elements investigated, 23 and 9 QTLs were identified for Lingshui and Hangzhou, respectively. Of these, 24 QTLs were reported for the first time in this study and 8 QTLs are consistent with previous reports. Only 2 QTLs for Mg accumulation have been detected in both environments, indicating that mineral accumulation QTLs in rice grains are largely environment dependent. Additionally, co-localizations of QTLs for Mn and Zn, Mg and P, and Mg and Mn accumulation have been observed, implying that these loci might be involved in the accumulation of different elements. Furthermore, the QTLs for the accumulation of Fe, K, Mg, Mn, P, and Zn were mapped to a region close to each other on chromosomes 8 and 9, suggesting that clusters of genes exist on chromosomes 8 and 9. Further characterization of these QTLs will provide a better understanding of the molecular mechanism responsible for mineral accumulation in rice grains.     

Arsenic concentration in rice, fish, meat and vegetables in Cambodia: a preliminary risk assessment

To assess arsenic contaminations and its possible adverse health effects, food samples were collected from Kandal, Kratie and Kampong Cham in Cambodia. The highest and the lowest concentrations were observed in fish (mean 2,832 ng g^?1, ww) collected from Kandal province and cattle stomach (1.86 ± 1.10 ng g^?1, ww) collected from Kratie, respectively. The daily intake of arsenic via food consumption was 604, 9.70 and 136 μg day^?1 in Kandal, Kratie and Kampong Cham, respectively. The arsenic dietary intake in Kandal ranked No. 1 among all the 17 compared countries or regions. Fish consumption contributed the greatest proportion of total arsenic daily intake in Kandal (about 63.0 %) and Kampong Cham (about 69.8 %). It is revealed to be a much more important exposure pathway than drinking water for residents in Kampong Cham. The results of risk assessment suggested that the residents in Cambodia, particularly for people in Kandal province, suffer high public health risks due to consuming arsenic-contaminated food.     

An interval dynamic multimedia fugacity (IDMF) model for environmental fate of PAHs and their source apportionment in a typical oilfield,China

An interval dynamic multimedia fugacity (IDMF) model with a new validation criterion of interval average logarithmic residual error (IALRE) was developed in this study. The environmental fate of polycyclic aromatic hydrocarbons (PAHs) and their source apportionment in a typical oilfield of China were simulated from 1985 to 2010. The PAH concentrations predicted by the model were in agreement with the measured concentrations, which were indicated by the IALREs calculated at 0.41, 0.63, 0.52, and 0.58 for air, water, soil, and sediment, respectively. The multimedia concentrations of Σ16 PAHs were 29.55, 39.22, 31.98, and 26.69 times greater in 2010 than those in 1985, and were higher than any other year modelled. Additionally, 87.82% of PAHs remained in the soil in 2010. PAH source emission into the soil was the major modelled source, whereas PAH degradation in the air was the major modelled loss pathway; the dominant transfer process between the adjacent compartments was atmospheric deposition from air to soil. It was demonstrated that high-temperature combustion was the major source of PAHs in the air and soil, whereas biomass and coal combustion were attributed to water and sediment compartments. The IDMF model was effective in the dynamic source apportionment of PAHs.     

Decolorization of azo dyes by a salt-tolerant Staphylococcus cohnii strain isolated from textile wastewater

The salt-tolerant Staphylococcus cohnii strain, isolated from textile wastewater, has been found effective on decolorizing several kinds of azo dyes with different structures. The optimal conditions for azo dye acid red B (ARB) decolorization by S. cohnii were determined to be pH = 7.0 and 30°C. The decolorization efficiency increased with the increase of the salinity concentration, and around 90% of ARB (100 mg·L^?1) could be decolorized in 24 h when the salinity concentration was up to 50 g·L^?1. Moreover, the strain could still decolorize 19% of ARB in 24 h even when the NaCl concentration was increased to 150 g·L^?1. Meanwhile, the dependence of the specific decolorization rate by S. cohnii on the ARB concentration could be described with Michaelis-Menten kinetics (K _m = 585.7mg·L^?1, V _max = 109.8 mg·g cell^?1·h^?1). The addition of quinone redox mediator, named 2-hydroxy-1,4-naphthoquinone and anthraquinone-2,6-disulfonate, significantly accelerated the decolorization performance of S. cohnii. Furtherly, the activities of azoreductase (0.55 ??mol·mg protein^?1·min^?1) and Nicotineamide adenine dinucleotide-dichlorophenol indophenol (NADH-DCIP) reductase (8.9 ??mol·mg protein^?1·min^?1) have been observed in the crude cell extracts of S. cohnii. The decolorization products of ARB were analyzed by HPLC-MS, and the results indicated the reductive pathway was responsible for azo dye decolorization by S. cohnii.     

Uncertainty analysis in the nuclear industry: Analytical unavailability modelling incorporating ageing of safety components

There is a growing interest in analyzing the possibility for current nuclear power plants operation extension. In that sense, life management programs, considering safety components ageing, are being developed and employed. On the other side, the large uncertainties of the ageing parameters as well as the uncertainties associated with most of the reliability data collections are widely acknowledged.This paper deals with uncertainty analysis associated with specific ageing rates database. The analysis is conducted using an analytical unavailability model applied for a selected safety system in a nuclear power plant. The most important problem is the immense uncertainty associated to the component ageing data sets as well as the lack of the very data in general, which would correspond to the more detailed modelling of ageing.New probability distributions, encompassing the ageing rates available in the considered data set, are suggested. The obtained results indicate the extent to which the uncertainty of the considered ageing data set, given the inherently assigned probability distribution, influences the performed unavailability calculations. Additionally, comparative analysis regarding the insights gained out of the application of the suggested probability distributions is conducted.     

高层建筑火灾中的安全疏散

高层火灾事故呈明显上升趋势,群死群伤事故时有发生,给国家和人民生命财产造成了极大的损失。叙述了影响人员安全撤离的因素．提出了火场逃生应注意的事项,对人员的高效、安全逃生有一定的指导意义。     

冶炼厂废水泵的汽蚀

常用离心泵排送冶炼厂废水时,废水泵易发生汽蚀。分析了形成废水泵汽蚀的各种因素,特别分析了废水生成“汽蚀核子”的特点,找出了防治废水泵汽蚀的有效措施。     

印染废水处理工艺工程实例

介绍了改良型水解酸化+生物接触氧化工艺处理印染废水的工程实例,处理后水中的COD、BOD5浓度均低于GB 8978—1996《污水综合排放标准》中的一级标准。该工艺运行费用低、管理简单方便、易于操作、去除色度效果好、无二次污染、投资规模小。