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重金属离子-二乙基二硫代氨基甲酸钠螯合体系的HPLC分析方法研究 总被引:5,自引:0,他引:5
采用二乙基二硫代氨基甲酸钠(NaDDC)为螯合剂,对Cu(Ⅱ)、Hg(Ⅱ)、Pb(Ⅱ)、Zn(Ⅱ)、Cd(Ⅱ)、Cr(Ⅵ)六种重金属离子进行了螯合萃取分离体系的方法研究,用HPLC方法建立了上述金属离子的最佳分离条件及定性定量分析方法.结果表明,用C18反相柱(5μm,150×4.6mmi.d.)和流动相(V(乙腈):V(甲醇):V(水)=55:15:30)能有效分离上述重金属离子,最低检测限在0.1~1.6ng范围内,线性范围及线性关系满足定量分析要求. 相似文献
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我国东亚飞蝗发生的气候背景及长期预测 总被引:5,自引:0,他引:5
我国东亚飞蝗的发生发展与大气环流的变化密切相关。对1952—1999年我国东亚飞蝗的发生面积与大气环流的74项特征指标值进行了相关研究。结果表明,上一年9月到当年4月大西洋副高面积、强度、脊线位置、北界,上一年9月、10月西藏高原指数,当年1月、2月、5月亚洲区极涡面积。北半球1月极涡面积,亚洲3月纬向环流指数以及亚洲5月经向环流指数与我国蝗虫发生面积相关明显。其中大西洋副热带高压对我国东亚飞蝗发生的影响主要是通过影响秋冬季节蝗卵的孵化和越冬期间的地面温度,从而影响蝗卵基数和孵化为成虫的数量,进而影响着我国东亚飞蝗发生、发展和危害情况的变化。通过上述对蝗虫发生有明显影响的大气环流特征值进行回归分析,结果表明。上年9月和当年4月大西洋副高脊线、3月大西洋副高北界、上年9月西藏高原指数、5月亚洲区极涡面积和3月亚洲纬向环流指数与发生面积拟合较好,说明这些大气环流特征值的强弱是决定东亚飞蝗发生的关键因素。 相似文献
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我国健身器材质量和检验现状分析及其对策 总被引:1,自引:0,他引:1
笔者从产品质量、检测体系和质检监管等方面系统地阐述了我国健身器材产业的现状 ;通过对国内外健身器材产业的比较和分析 ,指出了我国健身器材产业普遍存在技术含量低 ,质量不稳定 ,检测标准和设备欠缺 ,服务不完善等突出问题 ;同时还具体探讨了国内外健身器材的安全要求和使用性能在生化和环保两方面的不足 ;就上述种种问题提出了相应的发展对策 ,即遵循“以人为本 ,保障安全”的原则 ,积极发展现代化生产企业 ,前瞻性地开发高技术含量的安全型产品 ,健全符合国情实际的检测体系 ,从而全面提升我国健身器材的安全性能、服务水平和市场竞争力 相似文献
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介绍了江苏省重污染天气监测预报预警系统以及大气重污染预警会商流程,将2015年13个地级市的模式预报、人工预报结果分别与实际观测值进行比较。结果表明:人工预报更准确,PM_(2.5)日均值、臭氧日最大8 h平均值、AQI 3个指标人工预报和实况的相关性分别比模式预报高出12.8%、0.3%、11.4%,平均标准误差(MNE)分别低20.7%、3.1%、23.1%。依据国家空气质量预报技术指南评分办法,对各市2015年全年空气质量级别为"良"时进行评分。通过开展07∶00预报更新,使2015年上半年空气质量预报级别得分平均提高了0.9分,全年级别得分平均提高了2.6分;通过改进模式预报参数,使PM_(2.5)日均预报值、臭氧日最大8 h平均预报值、AQI预报值和实际观测值的相关性比上年同期分别提高26.0%、5.0%、33.9%,MNE分别降低3.6%、31.3%、7.6%。 相似文献
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Anders Kullgren Helena Stigson Anders Ydenius Amanda Axelsson Emma Engström Matteo Rizzi 《Traffic injury prevention》2019,20(4):S7-S12
AbstractObjective: The objective of this article is to describe the characteristics of fatal crashes with bicyclists on Swedish roads in rural and urban areas and to investigate the potential of bicycle helmets and different vehicle and road infrastructure interventions to prevent them. The study has a comprehensive approach to provide road authorities and vehicle manufacturers with recommendations for future priorities.Methods: The Swedish Transport Administration’s (STA) in-depth database of fatal crashes was used for case-by-case analysis of fatal cycling accidents (2006–2016) on rural (n?=?82) and urban (n?=?102) roads. The database consists of information from the police, medical journals, autopsy reports, accident analyses performed by STA, and witness statements. The potential of helmet use and various vehicle and road infrastructure safety interventions was determined retrospectively for each case by analyzing the chain of events leading to the fatality. The potential of vehicle safety countermeasures was analyzed based on prognoses on their implementation rates in the Swedish vehicle fleet.Results: The most common accident scenario on rural roads was that the bicyclist was struck while cycling along the side of the road. On urban roads, the majority of accidents occurred in intersections. Most accidents involved a passenger car, but heavy trucks were also common, especially in urban areas. Most accidents occurred in daylight conditions (73%). Almost half (46%) of nonhelmeted bicyclists would have survived with a helmet. It was assessed that nearly 60% of the fatal accidents could be addressed by advanced vehicle safety technologies, especially autonomous emergency braking with the ability to detect bicyclists. With regard to interventions in the road infrastructure, separated paths for bicyclists and bicycle crossings with speed calming measures were found to have the greatest safety potential. Results indicated that 91% of fatally injured bicyclists could potentially be saved with known techniques. However, it will take a long time for such technologies to be widespread.Conclusions: The majority of fatally injured bicyclists studied could potentially be saved with known techniques. A speedy implementation of important vehicle safety systems is recommended. A fast introduction of effective interventions in the road infrastructure is also necessary, preferably with a plan for prioritization. 相似文献
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Thomas Zobel 《Journal of Environmental Planning and Management》2016,59(4):587-606
The debate concerning the environmental effectiveness of environmental management systems (EMS) based on ISO 14001 is still open and scholars have called for further studies that can explain the contrasting evidence in previous research. As a response, this study aims to contribute knowledge about the effects of ISO 14001-based EMS by presenting fact-based environmental data. The study focuses on changes in performance over a period of 12 years and includes both firms with an EMS (66 firms) and firms without one (50 firms). Consideration is given to the improvement efforts in the firms before EMS adoption making it possible to neutralize any selection effects where better environmental performance precedes ISO 14001 adoption. Analysis has been carried out using statistical methods for six different environmental areas. No statistically significant differences between certified and non-certified firms concerning the change in the rate of improvement could be found in any of the six areas. However, it can be suspected that EMS adoption has positive effects on energy use and waste production whereas the non-adopting firms seem to perform better concerning air emissions. These mixed results mirrors previous research, which is rather worrying considering the worldwide popularity of EMS based on ISO 14001 in industry. 相似文献
40.
Yonglan Tian 《International Journal of Green Energy》2016,13(15):1556-1563
In the past decades, a novel strategy has arisen, as required by time, to get a rational production of biogas from contaminated biomass, which may be, on purpose, harvested from contaminated soil phytoremediation process. The present review focuses on the possibility and potential of utilizing the agricultural residues generated during phytoremediation for production of biogas. As a general result of the studies compiled in this review, the harvested biomass can subsequently be utilized for the winning of biogas, and it provides a solution of waste disposal for phytoremediation technology. According to the analysis of previous results, not more than 1 mg/L of cadmium in fermenters shows promoting or at least no inhibitory effect on cumulative biogas yields. This strategy is promising for dealing with both environmental and energy problems in spite of many challenges in the coming future. 相似文献