基于速率累加算法的地磁谐波振幅比异常分析

随着观测数据的积累和地磁谐波振幅比方法的推广,近些年积累了丰富的地磁谐波振幅比异常震例,但地磁谐波振幅比异常的识别困难,而"形变速率累加方法"对异常数据进行积分计算,更加易于异常的判定和异常指标的提取。基于此,使用2013年1月至2017年12月临汾台、湟源台和成都台地磁分钟值数据,计算得到各台地磁谐波振幅比南北向和东西向6个周期共计12条时间序列变化曲线,再运用速率累加方法对地磁谐波振幅比南北向和东西向各周期的计算结果进行二次计算,得到6条各周期的速率累加时序变化曲线。研究结果表明:①临汾台、湟源台和成都台三个台站地磁谐波振幅比速率累加方法计算结果分别在2016年山西运城4.4级地震、2016年青海门源6.4级地震和2017年四川九寨沟7.0级地震前出现异常,其异常表现为:6条速率累加曲线(6个周期)至少有2条出现超过1年以上的持续下降或水平波动变化(持续上升变化为正常);②速率累加方法使得地磁谐波振幅比异常更易识别、异常特征的统计更加准确,且与原有的地磁谐波振幅比异常判别结果基本一致。     

Anaerobic biodegradation of trimethoprim with sulfate as an electron acceptor

Anaerobic biodegradation of trimethoprim (TMP) coupled with sulfate reduction. Demethylation of TMP is the first step in the acclimated microbial consortia. The potential degraders and fermenters were enriched in the acclimated consortia. Activated sludge and river sediment had similar core microbiomes. Trimethoprim (TMP) is an antibiotic frequently detected in various environments. Microorganisms are the main drivers of emerging antibiotic contaminant degradation in the environment. However, the feasibility and stability of the anaerobic biodegradation of TMP with sulfate as an electron acceptor remain poorly understood. Here, TMP-degrading microbial consortia were successfully enriched from municipal activated sludge (AS) and river sediment (RS) as the initial inoculums. The acclimated consortia were capable of transforming TMP through demethylation, and the hydroxyl-substituted demethylated product (4-desmethyl-TMP) was further degraded. The biodegradation of TMP followed a 3-parameter sigmoid kinetic model. The potential degraders (Acetobacterium, Desulfovibrio, Desulfobulbus, and unidentified Peptococcaceae) and fermenters (Lentimicrobium and Petrimonas) were significantly enriched in the acclimated consortia. The AS- and RS-acclimated TMP-degrading consortia had similar core microbiomes. The anaerobic biodegradation of TMP could be coupled with sulfate respiration, which gives new insights into the antibiotic fate in real environments and provides a new route for the bioremediation of antibiotic-contaminated environments.     

微电脑烟尘采样器的使用

根据作者在仪器使用和维修过程中的一些经验,介绍TH880Ⅳ型智能烟尘平行采样仪在实际应用中遇到的问题,并提出相应的解决方法及建议。     

Long-Term Impacts of Land-Use Change on Non-Point Source Pollutant Loads for the St. Louis Metropolitan Area, USA

A land-use-change simulation model (LEAM) and a non-point-source (NPS) water quality model (L-THIA) were closely coupled as LEAMwq in order to determine the long-term implications of various degree of urbanization on NPS total nitrogen (TN), total suspended particles (TSP), and total phosphorus (TP) loads. A future land-use projection in the St. Louis metropolitan area from 2005 to 2030 using three economic growth scenarios (base, low, and high) and a long-term precipitation dataset were used to predict the mean annual surface runoff and mean annual NPS pollutant loads in the region. Results show mean annual TN increases of 0.21%, 0.13%, and 0.14% by 2030 compared to 2000 under the base, high, and low scenarios, respectively. TSP and TP showed similar trends with different magnitudes. Corresponding changes in annual mean surface runoff were shown to be lower than expected, which might be attributed to the small-scale conversion pattern of land uses. In the most dramatic change (high growth) scenario, the runoff would increase across time but at varying rates, and temporal pollutant loads would result in a more complicated pattern than in the other scenarios. This is attributed to the complex interactions between event mean concentrations of pollutants and the magnitude of changes in land-use acreages. By integrating L-THIA with LEAM, LEAMwq was found to be a useful planning tool to illustrate in a quick and simple manner how future water quality is connected to decision-making on future land-use change.     

农业旱灾形成过程中的承灾体脆弱性分析--以湖南鼎城为例

农业旱灾的形成是降水不足或不均与农业生产系统脆弱性共同作用的结果,承灾体脆弱性的高低会起到“放大“或“缩小“灾情的作用,因此降低承灾体的脆弱性是抗灾减灾的主要和有效途径.选择湖南省鼎城区为研究区,通过分析灾前期-灾中期旱灾的形成过程及其与承灾体脆弱性的关系,分别针对轻度干旱和中重度干旱建立了评价指标体系,采用加权求和法对水田-水稻农业生产系统的脆弱性进行了评价.结果表明,该区的承灾体脆弱性分布存在一定的区域差异,脆弱度由高至低排序为西北岗地区、南部低山/丘陵区、中部平原/岗地区、东北湖/平原区,这一分析结果与实际灾情的分布规律基本一致.通过分析脆弱性分布规律和变化原因,发现地形和灌溉分别是影响灾前期和灾中期承灾体脆弱性的最重要因素,进而提出了具体的减灾防灾建议.     

Effects of Duststorms on the Air Pollution in Beijing

The objective of this study was to investigate the air pollutionin Beijing before, during, and after duststorms occur. There aretwo different phenomena of air pollution in Beijing during a duststorm; one being related to the concentration of particulatematter and the second related to gaseous chemical pollutant concentrations. In this study, the concentrations of the chemicalpollutants, such as SO₂, NO_x and CO, were high prior to the occurrence of the duststorms. At the beginning of the two duststorms studied, the air quality related to these chemicalconstituents was improved due to a strong wind blowing away the chemical pollutants, which caused a decrease in the concentrations of SO₂, CO and NO_x. During the duststorm, the concentration of particulate matter, quantified by PM₁₀, wasobserved to increase and the atmospheric visibility decreased.     

生物吸附法处理含铀废水研究进展

生物吸附法处理含铀废水是新兴的研究领域。本文介绍了吸附铀的生物材料的来源以及影响吸附过程的各种因素，总结了生物吸附的机理、生物材料的改性和固定化、生物吸附的数学模型等方面的研究进展。     

重庆市城市污泥的质量现状及利用对策

重庆市城市污泥产生量大，污泥的集中处理能力小，污泥中重金属的质量状况较好，N、P、K、有机质的含量高，综合利用潜力大，开发潜力巨大。     

重庆市大足县生态环境质量建设成效

大足生态农业县经过13年的建设，生态环境质量改善明显，通过对大足县大气、水质、农田土壤和农作物（水稻，小麦）的监测分析可知，污染程度都有比较明显的改善，特别是重金属在土壤和农作物中的含量有着显著的降低。     

废旧车用载钯催化剂中钯的浸出研究

针对汽车尾气的污染,汽车排气系统都安装有含铂族金属的汽车催化剂.废旧汽车催化剂已成为铂族金属重要的二次资源.本文采用湿法浸出整体式蜂窝陶瓷汽车催化剂中的铂族金属钯.氧化焙烧废汽车催化剂除去积炭和其他有机物,再磨细过筛100目后烘干.预处理过的废催化剂用还原剂HCOOH溶液将催化剂中氧化态钯转化为单质钯,在70℃恒温下,用盐酸和氧化剂NaClO3选择性浸出钯.本文比较了几种浸出方法的结果,考察了HCl-NaClO3浸出体系的几个因素对钯浸出的影响,确定了最佳浸出条件.实验结果表明,HCl-NaClO3浸出体系在优化条件下能完全浸出催化剂中的钯,该方法可以用于钯的回收和对催化剂中的钯进行定量分析.