SO_(2)、CS_(2)和H_(2)S作为绝缘气体SF_(6)的重要分解气体,它们的种类和含量对SF_(6)气体绝缘设备的诊断具有重要意义。文中提出了一种紫外吸收光谱法和最小二乘拟合联用的方法用于SF_(6)分解气体的3组分混合气体定量检测。在实验过程...SO_(2)、CS_(2)和H_(2)S作为绝缘气体SF_(6)的重要分解气体,它们的种类和含量对SF_(6)气体绝缘设备的诊断具有重要意义。文中提出了一种紫外吸收光谱法和最小二乘拟合联用的方法用于SF_(6)分解气体的3组分混合气体定量检测。在实验过程中,发现较高体积分数的SO_(2)和CS_(2)对较低体积分数H_(2)S的体积分数计算存在干扰并且干扰的程度大小与两种气体的体积分数呈正相关。因此,文中获得了干扰气体体积分数较高时H_(2)S体积分数计算的修正公式,可以实现3种气体的准确定量检测,SO_(2)和H_(2)S检测范围为1~10μL/L(part permillion),CS_(2)为30~300μg/m L(part per billion)。文中提供了一种简便高效的检测方法,方便集成于检测设备中,为SF_(6)绝缘设备在线监测提供了技术支撑。展开更多
A rapid and sensitive on-line preconcentration method for spectrophotometric determination of chromium (VI) in nature water is described. Preconcentration and determination are based on (i) the quantitative and fast a...A rapid and sensitive on-line preconcentration method for spectrophotometric determination of chromium (VI) in nature water is described. Preconcentration and determination are based on (i) the quantitative and fast adsorption of chromium (VI) on the high surface area nanometer-size TiO2 (anatase) powders, which prepared by a sol-gel method from hydrolysis of TiCI4 and (ii) the quantitative and reproducible elution of Cr (VI) by 2. 0 mol. L-1 HCI. A mini-column system for preconcentration is developed, Cr(VI)on the mini-column is eluted and merged with a stream water and DPCB (1, 5-diphenylcarbazide ) as the chromogenic reagent. The Proposed system permits throughputs of 6 sample h--l (0. 001 μg mL-1 Cr(VI) ) or 20 sample h-1 (0. 1 μg mL-1Cr (VI) . The preconcentration factor is 55. The detection limit is 0. 8 ng·mL-1 Cr(VI). The reproducibility is satisfactory with a relative standard deviation of less than 3. 35% (0. Of μg'mL-1Cr (VI), n = 5).展开更多
In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment.The as-prepared sample was characterized by X-ray diffractio...In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment.The as-prepared sample was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).A series of morphological and structural characteristics confirm that the SnSe/SnO_(2) NPs composite shows a core-shell structure with a SnO_(2) shell with thickness of 6 nm.The prepared SnO_(2) NPs and SnSe/SnO_(2) NPs composite were applied as gas-sensing materials,and their gas-sensing properties were investigated at room temperature systematically.Experimental results show that the response value of the SnSe/SnO_(2) composite sensor toward 100×10^(-6) SO_(2) is 15.15%,which is 1.32 times higher than that of pristine SnSe(11.43%).And the SnSe/SnO_(2) composite sensor also has a detection limit as low as 74×10^(-9) and an ultra-fast response speed.The enhanced gas-sensing performance is attributed to the formation of p-n heterojunction between SnSe and SnO_(2) and the appropriate SnO_(2) shell thickness.展开更多
文摘SO_(2)、CS_(2)和H_(2)S作为绝缘气体SF_(6)的重要分解气体,它们的种类和含量对SF_(6)气体绝缘设备的诊断具有重要意义。文中提出了一种紫外吸收光谱法和最小二乘拟合联用的方法用于SF_(6)分解气体的3组分混合气体定量检测。在实验过程中,发现较高体积分数的SO_(2)和CS_(2)对较低体积分数H_(2)S的体积分数计算存在干扰并且干扰的程度大小与两种气体的体积分数呈正相关。因此,文中获得了干扰气体体积分数较高时H_(2)S体积分数计算的修正公式,可以实现3种气体的准确定量检测,SO_(2)和H_(2)S检测范围为1~10μL/L(part permillion),CS_(2)为30~300μg/m L(part per billion)。文中提供了一种简便高效的检测方法,方便集成于检测设备中,为SF_(6)绝缘设备在线监测提供了技术支撑。
文摘A rapid and sensitive on-line preconcentration method for spectrophotometric determination of chromium (VI) in nature water is described. Preconcentration and determination are based on (i) the quantitative and fast adsorption of chromium (VI) on the high surface area nanometer-size TiO2 (anatase) powders, which prepared by a sol-gel method from hydrolysis of TiCI4 and (ii) the quantitative and reproducible elution of Cr (VI) by 2. 0 mol. L-1 HCI. A mini-column system for preconcentration is developed, Cr(VI)on the mini-column is eluted and merged with a stream water and DPCB (1, 5-diphenylcarbazide ) as the chromogenic reagent. The Proposed system permits throughputs of 6 sample h--l (0. 001 μg mL-1 Cr(VI) ) or 20 sample h-1 (0. 1 μg mL-1Cr (VI) . The preconcentration factor is 55. The detection limit is 0. 8 ng·mL-1 Cr(VI). The reproducibility is satisfactory with a relative standard deviation of less than 3. 35% (0. Of μg'mL-1Cr (VI), n = 5).
基金financially supported by the National Natural Science Foundation of China (No.51777215)the Key Laboratory of Engineering Dielectrics and Its Application (Harbin University of Science and Technology),Ministry of Education (No.KFZ1801)。
文摘In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment.The as-prepared sample was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).A series of morphological and structural characteristics confirm that the SnSe/SnO_(2) NPs composite shows a core-shell structure with a SnO_(2) shell with thickness of 6 nm.The prepared SnO_(2) NPs and SnSe/SnO_(2) NPs composite were applied as gas-sensing materials,and their gas-sensing properties were investigated at room temperature systematically.Experimental results show that the response value of the SnSe/SnO_(2) composite sensor toward 100×10^(-6) SO_(2) is 15.15%,which is 1.32 times higher than that of pristine SnSe(11.43%).And the SnSe/SnO_(2) composite sensor also has a detection limit as low as 74×10^(-9) and an ultra-fast response speed.The enhanced gas-sensing performance is attributed to the formation of p-n heterojunction between SnSe and SnO_(2) and the appropriate SnO_(2) shell thickness.
