自动电位滴定法测定烟气氨法脱硫模拟浆液中氯离子的研究

氯离子含量是氨法脱硫工艺中的一个重要监控指标,用自动电位滴定法测定氨法脱硫浆液中的氯离子。结果表明,实验加入乙醇有利于增大电位突跃幅度;pH值为3~5时实验结果准确;加标回收率为90%~110%;与莫尔法相比,测定结果准确度、精密度更高,且不受灰分颜色干扰;与离子色谱法测定结果准确度、精密度相近,但测定高浓度氯离子电位滴定法更有优势。     

类固醇雌激素分析方法研究进展

类固醇雌激素因其对野生动物、人类健康及生态环境安全造成危害而受到全世界的普遍关注,并成为环境科学和生态毒理学研究的重点和热点之一.针对4种典型的类固醇雌激素(雌激素酮、17-β-雌二醇、雌三醇和17-α-乙炔基雌二醇),对其羟基和酮基衍生化技术、水和固体样品的前处理技术及仪器检测方法进行了综述,总结了类固醇雌激素分析方法的研究动态和进展.     

A dual-sensor-based method to recognize pipeline leakage and interference signals

During the detection of pipeline leakages, false alarms of leak detection could be markedly reduced if the interference signals resulting from pressure regulating, pump regulating or valve movements could be accurately distinguished. A digital recognition method for interference signals and leakage signals based on a dual-sensor system is proposed in this paper. It is demonstrated that the direction of the signal can be recognized by a cross-correlation calculation between two signals from the dual-sensor, one of which undergoes forward linear interpolation and backward linear interpolation. Based on this theory, the interference signal and the leak signal can be discriminated exactly, and the distance between the two sensors in the dual-sensor system can be considerably reduced without needing to increase the sampling frequency. The monotonicity of the cross-correlation function is demonstrated, and a fast discrimination algorithm based on a binary extreme search method, which decreases the computational load and maintains global optimization, is also proposed. A pre-processing method of the actual signal is proposed to decrease the identity requirement for the two sensors in a dual-sensor system. In the experiment based on artificial signals, the proposed discrimination algorithm could achieve accurate recognition of the abnormal signal, and as such, the theory and application of pipeline leak detection based on dual-sensor systems are extended.     

寒区典型湿地浮游植物功能群季节变化及其与环境因子关系

安邦河湿地是一个典型的寒区湿地,本文运用功能群的方法对其浮游植物季节变化进行研究,并运用多元分析方法分析其与环境因子的关系.安邦河湿地共有浮游植物种8门104种,划分为14个功能群,分别是C、D、E、F、H1、J、Lo、M、MP、N、P、SN、X1和Y.其中重要功能群是C、D、E、J、Lo、N、P和Y.浮游植物的功能群组成季节变化明显,春季以功能群E和Lo生物量所占比例最大,分别为27.45%和20.49%;夏季以功能群D、J、P占优,为28.59%、18.53%和19.47%;秋季以功能群J、P为主,占39.65%和13.34%.可见,安邦河湿地浮游植物功能群的季节变化呈现为E+Lo→D+J+P→J+P的特点,反映了水环境特征:春季低水温低营养盐、夏季高水温高营养盐且水体混浊、秋季水温和营养盐均较高.运用冗余分析(RDA)分析浮游植物功能群与环境因子之间的关系,结果显示水温(WT)、无机氮(DIN)和溶解性磷酸盐(SRP)是安邦河湿地浮游植物功能群季节变化的主要环境因子.     

桂林市公共场所空气污染的检测与分析

采用甲醛检测仪、有机气体检测仪等测试分析了桂林市宾馆、商场、候车室、家具城、文化娱乐场等公共场所的甲醛和TVOC浓度。结果显示:候车室和文化娱乐场所的甲醛、TVOC合格率均为100%;宾馆、商场、家具城的TVOC合格率分别为98.7%、98.9%、95.0%,甲醛合格率分别为78.8%、91.1%、85.0%;皮革制品、家具板材等为主要的甲醛和TVOC污染源。     

Structure and Content of the Discourse on Climate Change in the Blogosphere: The Big Picture

Based on the texts of 1.3 million blog posts and the structure of the links between the blogs in which these posts appeared, this study presents an analysis of the discourse on climate change in the English-language blogosphere. Our approach combines community detection with probabilistic topic modeling to show how topics related to climate change are discussed across various parts of the blogosphere. We find that there is one community of predominantly climate skeptical blogs but several accepter communities. The topic analysis reveals a series of issues that are characteristic of the climate change discourse in the blogosphere. Two topics, one related to climate change science and one related to climate change politics, are particularly important for characterizing the discourse. We also find that the distribution of topics over the communities cuts across the divide between skeptics and non-skeptics (accepters) and that there are differences in the patterns of interactions between the skeptics and different groups of accepters.     

中国环境基准研究重点方向探讨

环境基准是环境标准的科学依据,在国家环境质量评价和风险管理体系中处于基础地位。它主要是依据特定对象在环境介质中的暴露数据,以及与环境要素的剂量效应关系数据,通过科学判断得出的,涉及环境化学、毒理学、生态学、流行病学、生物学和风险评估等前沿学科领域。国家环境基准研究是一个长期的系统工程,本文基于环境基准研究的学科特点和国际前沿,结合国家科技需求和相关领域的研究现状,综合分析并提出了未来中国环境基准研究的重点研究方向:1)环境基准的理论与方法学;2)环境基准基础数据库;3)基准目标污染物的筛选甄别和优先排序技术;4)水体营养物基准;5)生物测试与毒性评价技术;6)人体暴露评价理论与相关技术;7)环境基准的审核和校对;8)环境基准与标准转化理论及其对环境管理支撑技术。本文从环境基准学科发展的角度,阐述了与环境基准研究紧密相关的8个重点研究方面的国内外研究进展、关键科学问题以及未来重点研究内容。同时指出,这些重要的研究方向是环境基准研究的根本,未来环境基准的长期战略发展必将是建立在各个重要方向长足发展的基础之上,环境基准研究也必带动这些方向的共同蓬勃发展,为环境地球化学、毒理学、生态学等学科领域发展注入活力。     

Review of the application of quantum dots in the heavy-metal detection

Heavy-metal contamination is a major concern, as excessive heavy metals produce environmental pollution, and the cumulative effects of heavy metals in vivo pose a major threat to human health. There is an urgent need for a rapid, sensitive, and efficient method for detecting heavy metals. Quantum dots (QDs) are in the category of semiconductor nanocrystals whose radii are less than or close to the exciton Bohr radius. QDs possess a potential in the biological and medical fields to function as a new type of fluorescent marker, because of their unique and tunable photophysical properties, which include broad excitation spectrum, narrow emission spectrum, tunable emission wavelengths, and negligible photobleaching. In recent years, QDs made significant progress in quantitative analysis by providing a new approach for determination of chemical content analysis. The aim of this study was to review the research progress of QD detection of heavy metals in water and consider the challenges and future outlook for QD-based sensors for heavy-metal ions.     

Application of cavitational reactors for water disinfection: current status and path forward

Cavitational reactors are a novel and promising form of multiphase reactors, based on the principle of release of large magnitude of energy due to the violent collapse of the cavities. An overview of cavitational reactors in the specific area of water disinfection, in terms of the basic mechanism, different reactor designs including recommendations for optimum operating parameters and applicability of the cavitation phenomena for disinfection of different micro-organisms have been presented. A design of a pilot scale sonochemical reactor has been presented, which forms the basis for development of industrial scale reactors. Economic analysis for comparison of cavitation phenomena with other conventional techniques of disinfection has been discussed. It appears that though cavitation is quite successful in treatment of water at laboratory scale operations, comparatively higher cost of treatment as compared to the conventional chemical methods is a hindrance in its industrial scale application. Intensification of cavitational activity and efficient design of industrial scale hydrodynamic cavitation reactors is required for ensuring successful application of cavitational reactors at industrial scale operation.