线性扫描溶出伏安法同时测定水样中铅镉铜锌

通过多壁碳纳米管-Nafion复合膜修饰电极,建立水样中痕量铅、镉、铜、锌同时测定的线性扫描溶出伏安分析法,优化支持电解质及pH值、修饰剂用量、富集电位及时间等测定条件。实验结果表明,在pH 4.0的NaAc-HAc缓冲液中,-1.20V富集5min后,在电位-1.04V、-0.72V、-0.45V及-0.16V附近分别产生锌、镉、铅、铜的灵敏溶出峰,测定各元素的线性关系良好,相对标准偏差均小于5.4%。该法已成功应用于实际水样中痕量铅、镉、铜、锌的同时测定,加标回收率在93.3%~106.7%之间,结果满意。     

Pure and Mg-doped self-assembled ZnO nano-particles for the enhanced photocatalytic degradation of 4-chlorophenol

A novel self-assembled pure and Mg doped ZnO nano-particles （NPs） were successfully synthesized by a simple low temperature co-precipitation method. The prepared photocatalysts were characterized by X-ray diffraction, high resolution scanning electron mi- croscopy, high resolution transmission electron microscopy, diffuse reflectance spectroscopy and photoluminescence （PL） spectroscopy. The results indicated that the prepared photocatalysts showed high crystallinity with a uniform size distribution of the NPs. The degradation of cholorphenols is highly mandatory in today＇s scenario as they are affecting the environment adversely. Thus, the photocatalytic degradation of 4-chlorophenol （4-CP）, a potent endocrine disrupting chemical in aqueous medium was investigated by both pure and Mg-doped ZnO NPs under UV-light irradiation in the present study. The influence of the Mg content on the structure, morphology, PL character and photocatalytic activity of ZnO NPs were investigated systematically. Furthermore,the effect of different parameters such as 4-CP concentration, photocatalyst amount, pH and UV-light wavelength on the resulting photocatalytic activity was investigated.     

国外节水扫描

<正>水是地球生命的源泉。由于世界人口飞速膨胀,地球上的淡水资源日益紧缺。在环境污染严重和淡水资源紧缺的今天,让我们来看看世界其他国家在环保和节水方法上有哪些值得我们学习的好经验。     

基于事故管道断后碰撞痕迹的轴向载荷研究

针对典型油气管道焊缝事故案例,基于管道断口特征和现场痕迹,推断管道轴向承载和环焊缝开裂失效过程,是揭示管道环焊缝失效机理的途径之一。本文以某X70管道环焊缝开裂事故为例,根据管道断口碰撞痕迹,采用有限元仿真分析方法,通过反演推算方式研究了管道开裂后的运动碰撞过程,确定了管道开裂前的轴向承载情况。结果表明：管道环焊缝位置断裂前的轴向应力范围约为590～640 MPa,此时环焊缝的轴向应力已超过管道自身的屈服强度。该研究为事故管道轴向承载评估提供了一种估算方法。     

山东临沂矿务局电磁信息观测震例初析

本文初步总结了临沂矿务局电磁信息观测震例资料,并介绍我站利用点频接收天线进行方位扫描的方法,确定异常最大幅度的方向,用来预测震中方位,以及在对莒县3.8级和射阳4.7级地震预报中取得的结果。     

Photoelectrocatalytic degradation of Rose Bengal

An innovative photoelectrode, TiO2/T1 mesh electrode, was prepared by galvanostaticanodisation. The morphology and the crystalline texture of the TiO2 film on mesh electrode were examined by scanning electronic microscopy and Raman spectroscopy respectively. The examination results indicated that the structure and properties of the film depended on anodisation rate, and the anatase was the dominant component under the controlled experimental conditions. Degradation of Rose Bengal (RB) in photocatalytic (PC) and photoelectrocatalytic (PEC) reaction was investigated, the results demonstrated that electric biasing could improve the efficiency of photecatalytic reaction. The measurement results of TOC in photoelectrocatalytic degradation showed that the mineralisation of RB was complete relatively. The comparison between the degradation efficiency of RB in PEC process and that in aqueous TiO2 dispersion was conducted. The results showed that the apparent first-order rate constant of RB degradation in PEC process was larger than that in aqueous dispersion with 0.1%--0.3% TiO2 powder, but was smaller than that in aaueaus disverslon with 1.0% TiO2.     

环球扫描

环保总局局长呼吁给予江河湖海人文关怀，今年中秋香港的垃圾山终于减少了，人类逼近环境恶化“引爆点”，绿色生态消费是否真的有助于环保，中国2006环境公报：2567亿元治污历史最高，     

环球扫描

全球变暖,为何这个冬天这么冷;污染竟让雄鸟歌声更动听;日本提出一揽子减排方案。     

环球扫描

查尔斯王子：富国应每年为阻止热带雨林砍伐而付费;富国应助穷国应对气候变化;中国供应商受限;绿色工作机会究竟有几多？吸收碳——温室气体。     

环球扫描两极秋千效应

在末次冰期（第四季最后一次冰期）时代，格陵兰岛和南极洲之间千年温度尺度变化的异步关系已经导致了“两极秋千效应”，而这种“两极秋千效应”使大西洋的经向环流发生了逆转变化。过去数千年，南极洲与北大西洋之间的温度变化幅度大约在1至3度之间。这两个不同的冰芯被欧洲南极冰芯研究项目的科学家描述成是“两极秋千”，