输电线路试验检测预警系统的开发和应用

针对输电线路试验检测项目人工管理,在周期内存在漏检、重检等不规范现状,对计划预警措施进行分析,利用 ASP 技术和 SQL SERVER 2000 数据库开发了输电线路试验预警系统,实现了线路例行、诊断性试验的到期提醒、查询、打印、备份等功能。系统界面操作简单、查询数据准确、维护便捷。应用结果表明:该系统提高了设备的管理水平,为架空输电线路科学管理提供了可参依据。     

土壤溶液性质对Zn的形态变化及其微生物毒性的影响

采集了我国具有代表性的12种不同性质土壤,利用基础诱导硝化(SIN)方法测定了不同土壤中锌的微生物毒性阈值,同时利用850离子色谱仪与WHAM6.0模型,测定了溶液不同阴离子组成及自由Zn2+含量,建立了基于不同土壤性质与溶液离子的土壤中Zn毒性预测模型.结果表明,基于SIN测定的不同土壤Zn微生物毒性阈值在不同土壤间有显著差异,其中EC50从196mg/kg至1310mg/kg;EC10值从48mg/kg增加至682mg/kg,不同土壤EC50与EC10的最大值与最小值的比例分别达到了6.68及14.3倍,表明土壤性质对Zn的微生物毒性有非常显著的影响;基于SIN的Zn的毒性阈值ECx(x=10,50)与溶液自由Zn2+浓度的负对数p(Zn2+)间呈正相关关系,表明随着土壤溶液中自由Zn2+值的升高,Zn的毒性逐渐增加.土壤pH值、OC、CEC、F-、Cl-、Ca2+及Mg2+与Zn的毒性阈值ECx(x=10,50)及p(Zn2+)呈正相关关系,其中土壤pH值为最重要的影响因子,偏相关系数均达到极显著水平(P<0.01),其次为OC、CEC及F-,ECx与溶液中NO3-, SO42-呈负相关关系.基于不同主控因子的土壤中Zn毒性阈值(ECx)及P(Zn2+)的预测模型表明,pH值、OC、CEC、F- 四个变量因子分别解释了log(EC50)、log(EC10)及p(Zn2+)预测模型变异的89.9%、81.2%和92.3%.     

畜禽养殖排放的雌激素对周边水体环境的影响

环境雌激素是一大类化学物质,它们能够干扰生物体内激素的合成、分泌、转运、活性等,或与生物体内激素结构相似而发挥激素作用,对生物体的生长、繁殖及行为产生不利影响。环境雌激素包括天然雌激素及人工合成类雌激素。随着国内畜禽养殖的规模与数量的不断扩大,养殖场成为了一个很大的环境雌激素的产生源,其环境风险应得到相应的重视。目前对畜禽养殖过程中环境雌激素的产生量以及雌激素进入环境后的迁移转化行为已有很多的研究,包括野外的调查与实验室内机理研究。畜禽养殖过程产生的大量雌激素进入环境后能够被土壤吸附及微生物降解。室内的静态平衡吸附实验、土柱迁移试验及降解研究均表明雌激素进入环境后绝大部分迅速被吸附到土壤颗粒或悬浮胶体、沉积物颗粒上,同时发生转化与生物降解,由此推断其对周边环境中的雌激素贡献很小。然而,野外调查结果却表明实际情况下雌激素的迁移性高于理论期望值。因此,畜禽养殖对周边环境中雌激素的贡献量的大小尚未明确。本论文综述了畜禽养殖过程中环境雌激素的排放情况,结合国内外的调查研究,阐述了畜禽养殖产生的环境雌激素在土壤及水体中的迁移与降解行为,探讨了影响准确评估畜禽养殖排泄物对周边水体中雌激素贡献大小的因子,并提出了今后应开展原位吸附与迁移的实验,重点考虑天然有机质及抗生素等共存物质对雌激素环境行为的影响,建立综合模型来估算不同时期养殖场对周围水环境雌激素的贡献量的建议。     

Effects of three years’ increase in density of the geometrid Epirrita autumnata on the change in metabolome of mountain birch trees (Betula pubescens ssp. czerepanovii)

The principal objective of the study was to characterize effects of increasing density of the autumnal moth, Epirrita autumnata (Lepidoptera, Geometridae), for 3 successive years on the change in metabolome of mountain birch trees (Betula pubescens ssp. czerepanovii). During the three study years (2000–2002), the larval density varied from low to very high (outbreak) density. Samples of leaves were collected from the same 12 trees at the same phenological stage of the trees each year. The leaves were collected from undamaged trees in the first year, from trees slightly damaged by larvae in the second year, and from trees heavily damaged by larvae in the third year. Metabolome analysis showed that the increase in density of E. autumnata larvae and degree of damage of birch trees caused multiple biochemical changes in the leaves, including increased concentrations of phenolic compounds (proanthocyanidins and hydrolysable tannins) and reduced concentrations of nutritive metabolites (monosaccharides, amino acids and some organic acids). These changes reduced the quality of leaves as food for larvae and, probably, were associated with induced chemical resistance of the birches to herbivorous insects. Additionally, the concentration of α-tocopherol was significantly higher in both slightly and heavily damaged trees. Mechanisms of changes in the metabolism of phenolic compounds and carbohydrates, and the role of α-tocopherol in their regulation are discussed.     

湖泊生态系统稳态转换理论与驱动因子研究进展

湖泊生态系统会在长期的人为胁迫和短期的强扰动下发生稳态转换,稳态转换前后湖泊生态系统的结构和关键过程会发生明显的变化,探求浅水湖泊稳态转换驱动因子是科学合理确定湖泊管理策略的关键所在。对湖泊生态系统稳态转换的理论内涵、驱动机制进行了总结和探讨。湖泊生态系统稳态转换的概念主要含有发生的突然性和难以预知性、系统的结构与功能发生明显变化以及存在多稳态现象等内涵;具有非线性、多阈值、多稳态,以及修复过程中的迟滞效应等特征。湖泊生态系统稳态转换的驱动因子可分为外部驱动和内部驱动两种类型。外部驱动包括外源性氮磷负荷、气候变化、风浪、湖泊水位等因子;外源性氮磷负荷和气候变化的影响具有长期性和累积性,通过逐步削弱湖泊生态系统恢复力进而引发稳态转换;风浪、湖泊水位等为突发性因子,往往表现为稳态转换的直接诱因。内部驱动包括鱼类、水生植物等因子;鱼类主要通过对水生植物、湖泊底质、浮游动物等生态组分的影响引发湖泊生态系统稳态转换;水生植物对湖泊清水稳态可能不仅存在正反馈作用,也会在一定条件下存在负反馈作用。今后应加强沉水植物生长消亡的主要环境与生物要素综合作用机理、湖泊稳态类型与主控因素等方面的研究。     

A model of 90Sr distribution in the sea near Daya Bay Nuclear Power Plant in China

The impact on the environment ofradionuclide release from nuclear power plants has attracted increased attention, especially after the accident at Fukushima Daiichi Nuclear Power Plant in Japan. Based on the mechanisms of adsorption/desorption at solid/liquid interfaces and a surface micromorphology model of sediments, a theoretical expression of the distribution coefficient Kd is derived. This coefficient has significant effects on the distribution of radionuclide in seawater, suspended sediment and seabed sediment. Kd is then used to simulate ^90Sr transport in the sea near the Daya Bay Nuclear Power Plant. The simulation results are compared with field measurements of tidal level, current velocity, suspended sediment concentration and ^90Sr concentrations in the same period. Overall, the simulated results agree well with the field measured data. Thus, the derived expression for Ka is capable of interpreting realistic adsorption/desorption processes. What＇s more, conclusion is drawn that about 40% ^90Sr released by Daya Bay Nuclear Power Plant will be adsorbed by suspended sediment and 20% by seabed sediment, only about 40% ^90St will remain in the sea near Daya Bay Nuclear Power Plant in South China Sea.     

Investigation on sampling artifacts of particle associated PAHs using ozone denuder systems

Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.     

N2O emission from a sequencing batch reactor for biological N and P removal from wastewater

Nitrous oxide （N2O） is a greenhouse gas that can be released during biological nitrogen removal from wastewater. N2O emission from a sequencing batch reactor （SBR） for biological nitrogen and phosphorus removal from wastewater was investigated, and the aims were to examine which process, nitrification or denitrification, would contribute more to N2Oemission and to study the effects of heterotrophic activities on N2O emission during nitrification. The results showed that N2O emission was mainly attributed to nitrification rather than to denitrification. N2O emission during denitrification mainly occurred with stored organic carbon as the electron donor. During nitrification, NaO emission was increased with increasing initial ammonium or nitrite concentrations. The ratio of N2O emission to the removed ammonium nitrogen （N2O- N/NH4-N） was 2.5% in the SBR system with high heterotrophic activities, while this ratio was in the range from 0.14% to 1.06% in batch nitrification experiments with limited heterotrophic activities.     

城市生命线系统防灾备灾能力极待提高

1 引子 完善的城市生命线系统是城市安全的标志.因为,平时它必须满足城市气、热、水、电、信息、交通的充足供给,灾时它应成为保障城市防灾减灾及恢复的备用系统,所以城市生命线系统建设要以"安全为天".但纵观国内外城市诸多事故与灾害,城市生命线系统现状总是脆弱的.仅2005年5月下旬的时段中事故及酿灾隐患迭出:     

Cu(NO3)2在亚甲蓝湿式氧化处理中的应用

用CWAO技术处理COD为2 000 mg/L的亚甲蓝水溶液.以Cu(NO3)2为催化剂,考察了催化剂投加量、反应温度、压力及进水pH值对亚甲蓝水样COD去除率、脱色率、出水pH值的影响.实验表明,亚甲蓝的氧化效率随催化剂投加量的增加,反应温度及压力的升高而升高.然而,综合考虑亚甲蓝的氧化效率、试剂费用、设备成本及能量消耗,实验确定Cu(NO3)2的投加量以Cu2 计为150 mg/L,反应温度及压力分别为200℃和2.0 MPa.在酸性进水条件下,COD去除率随进水pH值的降低而升高;而在碱性进水条件下,COD去除率随进水pH值的升高而升高.pH值按COD去除率由高到低的排列顺序是:3.87、11.23、5.50、7.25、9.47,实验确定最佳进水pH值是3.87.在以上最佳的操作条件下,反应150 min,水样COD去除率达97.4%,脱色率达99.97%,出水pH值3.63.