以Bi(Ⅲ)做内标,结合丝网印刷电极与微型化的电化学检测系统,建立了一种警报型即时检测方法,可以对自来水中铅含量是否超标进行快速准确的判断。采用方波溶出伏安法测定了含10μg/L铅标准溶液的IPb/IBi并计算得出阈值。讨论了3种电极预...以Bi(Ⅲ)做内标,结合丝网印刷电极与微型化的电化学检测系统,建立了一种警报型即时检测方法,可以对自来水中铅含量是否超标进行快速准确的判断。采用方波溶出伏安法测定了含10μg/L铅标准溶液的IPb/IBi并计算得出阈值。讨论了3种电极预处理方法以及不同浓度Cu2+对IPb/IBi测定的干扰与消除。实验结果表明:电极经1.8 V阳极氧化处理2 min后,电子转移电阻大大减小,由4 348Ω减小至715Ω,峰电流增加1.6倍,峰电位之差△Ep由212 m V减小至113 m V。当加入2.0 mmol/L Fe(CN)64-,Cu2+干扰可有效消除。将这种方法用于自来水样的IPb/IBi测定,与阈值对比给出Yes/No判断结果,通过ICP-MS验证方法的有效性,结果令人满意。作为一种简捷、快速和便携的检测平台,该方法无需测出Pb2+的准确浓度,具有巨大的应用潜力。展开更多
Financial crisis is an unfortunate reality that overshadows any financial system regardless its profitability and the level it functions. The appearance of crises across financial markets, especially during the 1990s ...Financial crisis is an unfortunate reality that overshadows any financial system regardless its profitability and the level it functions. The appearance of crises across financial markets, especially during the 1990s that the internationalized markets adopted a rather approachable character, imposed severe costs in financial and social systems. With this paper is proposed the generation of a future interval of time that is vulnerable to enclose the burst of a financial crisis. A time series consisted of approximations of the local Lipschitz constant is examined and in the proposed forecasting approach this constant holds the crisis indicator role. Further the application of two different optimization techniques over the Lipschitz-made time series results to the generation of a future period of time;this interval is likely to envelop the burst of a forthcoming crisis. The usage of a future interval of time empowers the predicting ability of the methodology by providing warning signs priory to the actual crisis burst. To this direction, the obtained results offer strong evidence that the method may be characterized as an Early Warning System (EWS) for financial crisis prediction.展开更多
文摘以Bi(Ⅲ)做内标,结合丝网印刷电极与微型化的电化学检测系统,建立了一种警报型即时检测方法,可以对自来水中铅含量是否超标进行快速准确的判断。采用方波溶出伏安法测定了含10μg/L铅标准溶液的IPb/IBi并计算得出阈值。讨论了3种电极预处理方法以及不同浓度Cu2+对IPb/IBi测定的干扰与消除。实验结果表明:电极经1.8 V阳极氧化处理2 min后,电子转移电阻大大减小,由4 348Ω减小至715Ω,峰电流增加1.6倍,峰电位之差△Ep由212 m V减小至113 m V。当加入2.0 mmol/L Fe(CN)64-,Cu2+干扰可有效消除。将这种方法用于自来水样的IPb/IBi测定,与阈值对比给出Yes/No判断结果,通过ICP-MS验证方法的有效性,结果令人满意。作为一种简捷、快速和便携的检测平台,该方法无需测出Pb2+的准确浓度,具有巨大的应用潜力。
文摘Financial crisis is an unfortunate reality that overshadows any financial system regardless its profitability and the level it functions. The appearance of crises across financial markets, especially during the 1990s that the internationalized markets adopted a rather approachable character, imposed severe costs in financial and social systems. With this paper is proposed the generation of a future interval of time that is vulnerable to enclose the burst of a financial crisis. A time series consisted of approximations of the local Lipschitz constant is examined and in the proposed forecasting approach this constant holds the crisis indicator role. Further the application of two different optimization techniques over the Lipschitz-made time series results to the generation of a future period of time;this interval is likely to envelop the burst of a forthcoming crisis. The usage of a future interval of time empowers the predicting ability of the methodology by providing warning signs priory to the actual crisis burst. To this direction, the obtained results offer strong evidence that the method may be characterized as an Early Warning System (EWS) for financial crisis prediction.
