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双选择电极传感硫离子监测仪的电分析性能 被引量:1
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作者 郭鼎力 纪昌林 +5 位作者 周激 马波 林承基 辛万生 文江 卢万新 《化学传感器》 CAS 1992年第3期50-55,共6页
双选择电极传感硫离子监测仪的设计,是基于硫离子在溶液中的酸碱平衡理论,仪器采用三电极系统。仪器的特点是:试液 pH 在一定范围内波动,而测值不受影响。仪器采用加法电路测量电平、使用比例放大器、增益与定位电路、高输入阻抗低输入... 双选择电极传感硫离子监测仪的设计,是基于硫离子在溶液中的酸碱平衡理论,仪器采用三电极系统。仪器的特点是:试液 pH 在一定范围内波动,而测值不受影响。仪器采用加法电路测量电平、使用比例放大器、增益与定位电路、高输入阻抗低输入电流的运放跟随器等,对测量按键示作了新安排。 监测仪的直流电压测量误差为士0.lmv,pH测量误差为士O.O01pH、测定方法误差为士5%水平,对pHI^5.5试液,测值波动士1.3mV,对pH9~12试液其实际测值波动士1.OmV。用于流通系统中硫子的监侧,对3.OO×10^(-3)、3.00×10(-4)、3.00×10(-x),mol/L溶液,其标差分别为0.14×l0(-3)、0.15×10(-4)、0.17×10(-5)mol/L均能满足环境监测要求,本仪器具有一定实用价值. 展开更多
关键词 双选择电极 硫离子监测仪 电分析
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双阻离子选择性微电极测定活体不结球小白菜叶片细胞中硝酸根离子的活度 被引量:18
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作者 贾莉君 范晓荣 +2 位作者 尹晓明 曹云 沈其荣 《土壤学报》 CAS CSCD 北大核心 2005年第3期447-452,共6页
详细介绍了用双阻离子选择性微电极活体测定小白菜叶片活体细胞中硝酸根离子的活度的方法原理及注意事项。微电极与溶液中硝酸根离子的浓度呈对数曲线的关系,斜率为48~58mV,对硝酸根离子浓度有较低的检出限,是一种选择性高、灵敏、经... 详细介绍了用双阻离子选择性微电极活体测定小白菜叶片活体细胞中硝酸根离子的活度的方法原理及注意事项。微电极与溶液中硝酸根离子的浓度呈对数曲线的关系,斜率为48~58mV,对硝酸根离子浓度有较低的检出限,是一种选择性高、灵敏、经济的测定植物活体细胞中离子活度的方法。小白菜生长至六叶期时,用含有5molm-3NO3-的营养液诱导48h。测定结果表明,叶片细胞中硝酸根离子活度分布在活度高低明显不同的两个区间内,在细胞质中是0.24~10molm-3,液泡中20~110molm-3,且两个区间在细胞跨膜电位上也有差异。液泡占整个细胞体积的90%,所以,植物所吸收的硝酸根离子都集中在液泡中。 展开更多
关键词 阻离子选择性微电极 叶片细胞 硝酸根离子 不结球小白菜 活度测定 活体
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双阻NH_4^+选择性微电极测定水稻叶片细胞中NH_4^+的活度
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作者 尹晓明 范晓荣 沈其荣 《植物营养与肥料学报》 CAS CSCD 北大核心 2009年第3期701-706,共6页
本文介绍了双阻NH_4^+选择性微电极的制作方法、工作原理及操作方法。微电极电位响应值与溶液中NH_4^+的活度呈对数曲线的关系,NH_4^+选择性微电极与其他类型的电极(如H^+、NO_3^-)最大区别是K^+的干扰,在含有72 mmol/L K^+的标定溶液中... 本文介绍了双阻NH_4^+选择性微电极的制作方法、工作原理及操作方法。微电极电位响应值与溶液中NH_4^+的活度呈对数曲线的关系,NH_4^+选择性微电极与其他类型的电极(如H^+、NO_3^-)最大区别是K^+的干扰,在含有72 mmol/L K^+的标定溶液中,电极标定曲线的斜率为48~58 mV,对NH_4^+的检出限小于10^(-4)mol/L,说明电极对NH_4^+有较高的选择性,受K^+的影响较小,可以用来测定。用以测定2.5 mmol/L NH_4^+培养2周的水稻叶片,结果表明,叶片细胞中NH_4^+活度分布在高低不同的两个区间内,分别代表了细胞质和液泡中的测定,水稻叶片细胞质和液泡NH_4^+的活度分别为2.58~9.30 mmol/L和11.36~25.20 mmol/L。水稻叶片组织中的NH_4^+主要来自液泡,流动分析仪测定的水稻叶片组织的NH_4^+浓度为11.12 mmol/L。NH_4^+选择性微电极为研究水稻对NH_4^+的吸收利用提供了技术支撑。 展开更多
关键词 阻NH4^+选择性微电极 水稻叶片 细胞 NH4^+
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双选择性电极三电极系统中氟离子选择性电极响应特性研究
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作者 马晨 刘兴利 《西南民族学院学报(自然科学版)》 2000年第3期291-295,共5页
用双选择性电极三电极系统研究了在非最佳酸度条件下直接测试F-的可能性 .从理论上推导出F-选择性电极其响应特性满足ΔE池F| PH2PH1dE池F=- 2 .30 3RTF lg(Ka′+ [H+]) | [H+ ] tn + 1[H+ ] tn并通过实验可知ΔE池F的实验值与理论值... 用双选择性电极三电极系统研究了在非最佳酸度条件下直接测试F-的可能性 .从理论上推导出F-选择性电极其响应特性满足ΔE池F| PH2PH1dE池F=- 2 .30 3RTF lg(Ka′+ [H+]) | [H+ ] tn + 1[H+ ] tn并通过实验可知ΔE池F的实验值与理论值基本吻合 . 展开更多
关键词 选择电极 电极系统 氟离子选择电极 F^-选择电极 响应特性 PH值 电位分析
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Kinetic Characteristics of Nitrate Uptake by Wheat and Rape and Their Determination 被引量:2
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作者 ZHANGLI-GAN XUANJIA-XIANG 《Pedosphere》 SCIE CAS CSCD 1993年第2期127-132,共6页
15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNO3 for a definite period of time. The changes in NO3- concentration of the solutions were determined by the... 15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNO3 for a definite period of time. The changes in NO3- concentration of the solutions were determined by the double ion-selective electrode method, and then the amount of NO3- taken up by the plants was estimated and values of Km and Imax of the Michealis-Menten equation were calculated. Results show that both the method and conditions of determination affected the values of Km and Imax. For example, the Km value was appreciably reduced when the volume of culture solution was increased or when the duration of nutrient uptake was shortened; the Km value obtained with short-term depletion method was higher than that obtained with long-term one. Similar Variations were found for the values of Imax. There was a considerable difference in the characteristics of uptake kinetics between wheat and rape when determined under the same conditions of determination. The isotherm of NO3- uptake by wheat could be separated into saturated and unsaturated parts, and when the concentration of NO3- exceeded 180 uuuuuuuuuuuuM, the relationship between the rate of NO3- uptake and NO3- concentration tended to be linear. However, the isotherm of NO3- uptake by rape was found to fit the Michealis-Menten equation and no linear relationship could be found. 展开更多
关键词 double ion-selective electrode method kinetic parameter NITRATE
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Adsorption Kinetics of Pb^(2+) and Cu^(2+) on Variable Charge Soils and Minerals: Ⅲ. Adsorption Kinetics of Pb^(2+) Within 30 Minutes 被引量:2
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作者 HUGUO-SONG YUMING-FENG 《Pedosphere》 SCIE CAS CSCD 1993年第4期349-359,共11页
The adsorption kinetics of Pb^2+ on different soils and minerals with variable charges was studied by the two ion-selective electrode technique at different pH and concentrations.The results showed that more than 95% ... The adsorption kinetics of Pb^2+ on different soils and minerals with variable charges was studied by the two ion-selective electrode technique at different pH and concentrations.The results showed that more than 95% of adsorption on all the samples occurred during the first 5 minutes.All adsorption time-dependent data could fit the surface second-order equation very well.The values of Xm were goethite>kaolinite,and latosol>red soil at the same initial reaction concentration.The values of k were kaolinite>>goethite,and latosol>red soil at the same reaction pH and initial concentration.The higher the suspension pH,the faster the adsorption occurred.The meaning of Xm got by the two ion-selective electrode technique(one kind of batch technique) was different from that by the miscible displacement technique in that the former was only the equilibrium adsorption amount at a definite concentration and pH,but the latter was almost equal to the adsorption capacity at a definite pH with much less influence of concentration.One Pb^2+ was supposed to occupy two adsorption sites as the adsorption mechanism is concerned. 展开更多
关键词 ADSORPTION KINETICS PB2+ two ion-selective electrode technique variable charge surfaces
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