具对称电极结构的中温固体氧化物电解池电解水制氢技术

该文基于传统阳极-电解质-阴极结构的固体氧化物电解池,设计并研究了一种新型的具有对称电极结构的固体氧化物电解池。采用化学沉淀法制备了电解质材料Ce_(0.8)Sm_(0.2)O_(1.9)-Na_2CO_3(NSDC)以及选择与之兼容性良好的电极材料Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2-δ)(NCAL)。该文利用X射线衍射法与环境扫描电子显微镜对制备的材料进行了性能表征和分析,分析结果表明合成的NSDC粉体材料也为萤石型结构,其粒子大小范围约为30~80 nm。基于制备的电解质材料和电极材料,进一步制备了具有对称电极结构的固体氧化物电解池的单电池。电化学试验结果表明:在电解池模式,单电池具有良好的制氢性能。互换电极后,仍表现出良好的电化学性能。理论分析和试验结果充分说明,该电解池具有良好的结构对称性。为中温固体氧化物电解制氢技术与太阳能光热、光电技术耦合研究提供参考。     

用铜离子选择性电极电位滴定法测人发和尿液中的铜

本文以铜离子选择性电极作指示电极,用Trien作滴定剂,就电位滴定法对人发和尿中铜(Ⅱ)的测定条件、发样处理以及干扰实验进行了探讨.本法简便快速,结果与原子吸收法基本一致,其相对偏差小于5%,人发中铜的测定回收率在96.2-106.8%之间.     

豆浆连续通电加热中电源频率对极板黏附的影响

为解决豆浆通电加热过程中的极板污染问题,该文研究了在豆浆的连续通电加热过程中,电源频率对于电源极板污染的影响。试验表明,相比于100Hz的低频交流电,频率超过1000Hz的高频交流电能有效抑制电源极板污染。研究结果对于通电加热在豆浆加工的应用提供了依据,并对富含蛋白质液体食品连续通电加热中极板污染的研究提供参考。     

Superfloc127用于电极法测定土壤硝态氮含量的可行性分析

样本前处理是影响离子选择电极测土时效性的关键环节。以缩短静置时间为目的,该文探讨了高分子絮凝剂Superfloc127用于土壤硝态氮浸提前处理操作的可行性。首先,基于相界电位模型对Superfloc127加入土样硝态氮浸提液后电极反应动力学过程进行建模分析,理论可行性验证后,开展测土试验,分析其对自制全固态电极（PPy-NSISE）及商用电极（PVC-NISE）电化学性能的影响。结果表明：使用Superfloc127后,样本制备时间由1.5 h缩短至10 s;PPy-NSISE及PVC-NISE响应斜率分别为-51.4和-52.1 mV/Decade,检测灵敏度无明显改变,测土结果与标准结果之间的决定系数分别为0.69和0.31;连续测定12 h后,PPy-NSISE和PVC-NISE的响应斜率分别降低至-35.1和-25.4 mV/Decade,性能不可恢复。通过理论解析及大量分析试验证明,絮凝剂Superfloc127无法应用在基于离子选择电极法的土壤硝态氮快速分析,提高土壤前处理效率的研究工作仍需深入开展。     

Validation of the bovine blood calcium checker as a rapid and simple measuring tool for the ionized calcium concentration in cattle

Point-of-care (POC) devices that veterinary practitioners can use to easily and rapidly measure blood ionized calcium (iCa) levels in cows immediately after withdrawing a blood sample on the dairy farm are needed. Aims of present studies was to compare the commercially available ion-selective electrode handheld iCa meter (bovine blood iCa checker) with the benchtop blood gas analyzer GEM premier 3500 and handheld analyzer i-STAT 1. Sixty-two paired-point whole blood samples were obtained from three cows with hypocalcemia experimentally induced by Na₂-EDTA infusion. Whole blood samples were also obtained from the 36 cows kept on a farm in field conditions. The results using the bovine blood iCa checker correlated with those using the GEM premier 3500 and i-STAT 1. Bovine blood iCa checker was “compatible” with the GEM premier 3500 and i-STAT 1 because the frequency of differences between the measurements within ± 20% of the mean were 100% (65/65, >75%) and 90.8% (59/65, >75%), respectively. In the field trial, the blood iCa concentration measured by the bovine blood Ca checker was significantly positively correlated with that measured by the i-STAT 1 portable analyzer. Bovine blood iCa checker was “compatible” with the i-STAT 1 because the frequency of differences between the measurements within ± 20% of the mean was 100% (36/36, >75%). Results from these findings, the bovine blood iCa checker may be applied as a simplified system to measure the iCa concentration in bovine whole blood.     

3种黑杨无性系耐氮瘠薄能力的差异

通过扫描离子选择电极技术及15N同位素示踪技术研究3种黑杨无性系02-34-334、03-04-97和108号对于硝铵的吸收及累积规律,揭示02-34-334号较03-04-97和108号更能适应低氮环境的原因。离子电极试验设置0 mmol/L NH4NO3(CK)、0.25 mmol/L NH4NO3和0.5 mmol/L NH4NO33种氮素水平1。5N同位素示踪试验设置2 g15NH4NO3和2 g NH415NO3(中氮)两种氮素处理。结果表明:①在0.25 mmol/LNH4NO3水平下,02-34-334号苗木根部硝铵的吸收比值为1.3,而其他两个无性系苗木根系在所有处理下的硝铵吸收比值均较低。说明02-34-334号在0 mmol/L NH4NO3(CK)到中氮范围内对于硝态氮的吸收较另两个无性系具有明显的潜在优势。②02-34-334号无性系与另两个供试无性系相比,根部15NO3-的氮素分配率低,而地上部分15NO3-的氮素分配率高。说明02-34-334号在中氮水平对于硝态氮有较强的转运能力。对硝态氮较强的吸收潜力及较强的转运能力可能是02-34-334号黑杨无性系更能适应低氮环境的原因之一。结果为进一步研究黑杨无性系的氮高效机制及生产应用提供了科学依据。     

基于极限学习机的土壤硝态氮预测模型研究

利用极限学习机模型解译高氯离子干扰下盐碱土中硝酸根离子选择电极响应信号,系统分析了漂移校正算法、能斯特及极限学习机模型对电极法硝态氮(NO~-_3-N)预测结果准确性的影响差异。结果表明,漂移校正算法可明显提高传感器标定方程的重复性和一致性,响应斜率及截距电位的波动范围分别缩小了3.67%和7.25%;极限学习机模型的最优隐含层节点数为14;基于极限学习机的电极法NO~-_3-N质量浓度预测模型可较好抑制盐碱土中氯离子干扰,与标准检测结果之间的最大绝对误差和均方根误差分别为6.36 mg/L和4.02 mg/L。相关研究结论可为电极法测土过程中的信号校正、数据处理模型和模型参数选取提供参考。     

pH-dependent modulation of intracellular free magnesium ions with ion-selective electrodes in papillary muscle of guinea pig

A change in pH can alter the intracellular concentration of electrolytes such as intracellular Ca²⁺ and Na⁺ ([Na⁺]_i) that are important for the cardiac function. For the determination of the role of pH in the cardiac magnesium homeostasis, the intracellular Mg²⁺ concentration ([Mg²⁺]_i), membrane potential and contraction in the papillary muscle of guinea pigs using ion-selective electrodes changing extracellular pH ([pH]_o) or intracellular pH ([pH]_i) were measured in this study. A high CO₂-induced low [pH]_o causes a significant increase in the [Mg²⁺]_i and [Na⁺]_i, which was accompanied by a decrease in the membrane potential and twitch force. The high [pH]_o had the opposite effect. These effects were reversible in both the beating and quiescent muscles. The low [pH]_o-induced increase in [Mg²⁺]_i occurred in the absence of [Mg²⁺]_o. The [Mg²⁺]_i was increased by the low [pH]_i induced by propionate. The [Mg²⁺]_i was increased by the low [pH]_i induced by NH₄Cl-prepulse and decreased by the recovery of [pH]_i induced by the removal of NH₄Cl. These results suggest that the pH can modulate [Mg²⁺]_i with a reverse relationship in heart, probably by affecting the intracellular Mg²⁺ homeostasis, but not by Mg²⁺ transport across the sarcolemma.     

rGO/Ag复合修饰电极的微生物燃料电池对五氟磺草胺的降解效果

为研究微生物电池在浓药降解方面的应用,以纳米银(rGO/Ag)复合修饰/石墨毡(graphite felt,GF)电极作为阳极,研究双室微生物燃料电池(microbial fuel cell,MFC)的产电性能及其对五氟磺草胺降解的影响。结果表明:以Desulfovibriode sulfuricans为产电菌,初始五氟磺草胺质量浓度为10mg/L时,经rGO/Ag复合修饰MFC的GF阳极后,MFC的产电性能及对五氟磺草胺的降解作用皆有所提高,其中,分别以GF电极和rGO/Ag/GF复合电极为阳极时,MFC的双电层电容量分别为1.46×10^-3和3.85×10^-3 mF,电子转移阻抗分别为114和61Ω,五氟磺草胺降解率分别为53.6%和67.3%。改变初始五氟磺草胺浓度和酸碱度可以影响MFC产电性能和五氟磺草胺降解作用,初始五氟磺草胺浓度为5 mg/L时,MFC的最大功率密度和五氟磺草胺的降解率分别为136.8 mW/m²和70.5%,但随着初始五氟磺草胺浓度增加,其产电性能和降解作用会受到一定程度的抑制。初始酸碱度为...     

电化学氧化法降解高浓度氧乐果农药废水的研究

采用三维屯极电化学法对模拟氧乐果农药废水进行降解研究,考察了在各种实验条件各参数对氧乐果去除率的影响,确定了操作最佳条件为电压:20V,pH值:3,进水浓度:450mg/L,反应时间30min.此法适用于对高浓度氧乐果农药废水的预处理过程.