共查询到18条相似文献,搜索用时 187 毫秒
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采用固相法制备了LSCM(La0.75Sr0.25Cr0.5Mn0.5O3)粉体。按不同质量比将其与3%-mol氧化钇稳定氧化锆粉体(3YSZ)混合,制备得到系列混合导体。根据热膨张系数、微观形貌等物理特性,选取合适比例的混合导体。采用Pt浆粘合法将其与8YSZ固体电解质叠层制作成致密扩散障型极限电流氧传感器。经测试,使用LSCM质量比分别为60%和70%的混合导体作为致密扩散障时,对应的氧传感器在973 K氧浓度分别为6 000×10-6~2.28%和1.22%~8.01%范围内具有良好的测氧特性,并且极限电流与氧浓度之间存在良好的线性关系;其在不同氧浓度下的响应时间曲线显示传感器重复性好,响应时间约数十秒。 相似文献
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本文采用一种新的制备工艺-共压共烧法,以8mol%Y2O3稳定的ZrO2(YSZ)为固体电解质,混合导体材料La0.8Sr0.2MnO3和YSZ的混合物作复合障碍扩散层,成功制备出了限流型氧传感器.借助动态电位扫描分别研究了电流与施加电压的关系,极限电流与氧浓度的关系.结果表明,在T=998K,氧浓度为0~3.375 ppm时该传感器给出了较好的电流平台,极限电流与氧浓度存在很好的线性关系,相关系数达到0.99以上.该传感器对微量的氧有很好的敏感性,与以往的极限电流氧传感器相比具有结构简单,成本低廉等优点. 相似文献
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采用流延技术制备了YSZ电解质膜,并在其两面丝网印刷了电极和扩散障,将它们叠层共烧获得了氧气传感器,再将它与在氧化铝基片上丝网印刷铂浆制备的加热器组装获得了传感器器件,并测试了相关性能。加热器温度随输入电压增大而迅速上升。在13V时可达690 ℃。通过对传感器在空气中线性电压扫描测试,典型的极限电流平台在输入电压为9V、11V和13V时均被发现,表明它在此工作温度范围内具有监测21%下氧气浓度的能力。扫描电压固定在0.7V又在这三种工作温度下测试了它对1%-21%范围内不同浓度氧气的响应电流信号。发现传感器可在10s内快速响应。信号值与氧气浓度间存在较好的线性关系,且重复性好,表明它具有快速监测宽域氧气浓度的稳定性能。 相似文献
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实验中采用的三种粉体,对其化学成分、物相组成、颗粒形貌、比表面积、和流延配方的匹配性、烧结性能、制备的片式传感器的性能进行了综合评估。结果表明POWDER A粉体适合流延成型,但是烧结温度较高(1 500℃),且烧结陶瓷中会有较多的小尺寸的气孔存在,这是由于粉体中存在两种物相的氧化锆,可以制备出有很好响应的片式氧传感器。POWDER C粉体流延时制备的基片性能较软,导致后续工艺较难完成,且制备的片式传感器样品没有测得信号;POWDER B粉体制备的基片较脆,且其中的杂质含量较高,制备的片式传感器样品没有测得信号。得出对流延成型制备片式氧传感器用YSZ粉体的要求:Si及Fe的含量尽可能少;颗粒具有粒径小、粒度分布单分散;比表面积控制在12~15 m2/g左右。 相似文献
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《Sensors and actuators. B, Chemical》2001,72(1):35-40
A new type of amperometric oxygen sensor has been developed in which a dense Pt-YSZ composite layer, a mixed ionic–electronic conductor (MIEC) membrane, is used as the diffusion barrier. Accelerated materials stability tests in the exhaust of a gas-fired engine indicate that yttria-stabilized zirconia (YSZ) with fluorite structure has excellent stability while the stability of La0.9Sr0.1Ga0.2Mg0.8O3 (LSGM) is questionable. A dense Pt-YSZ composite layer has been prepared on a YSZ electrolyte using nanoparticles of platinum, derived from a sol–gel process. The fabricated sensors based on a bi-layer structure, Pt-YSZ/YSZ, exhibit well-defined diffusion-limited currents for oxygen concentrations up to 6% and the current responses depend linearly on oxygen concentration. The developed sensor is anticipated to have excellent chemical, microstructural, and thermal stability because of the remarkable stability of a dense composite layer consisting of YSZ and Pt. 相似文献
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研究了CO气体对极限电流型氧传感器特性的影响,将小孔型极限电流型氧传感器放置在不同CO体积分数的环境中进行了电学性能测试。实验结果表明:在CO-O2-N2环境中,O2体积分数分别为7.5%,10%,CO体积分数在0.75%~4.25%变化时,传感器的电压—电流特性曲线均有良好的极限电流平台,且极限电流IL随着CO体积分数的增大而减小。理论分析在CO-O2-N2环境中IL与-ln(1-(XO-47XCO))有良好的线性关系,且该传感器对CO的上升响应时间与下降响应时间分别在10 s和15 s以内。 相似文献
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In this study, electrical double-layer theory is applied to realize a one-side-electrode-type fluid-based inclinometer combined with complementary metal oxide semiconductor (CMOS) circuitry. Substrate penetration lithography was applied in the fabrication of high-aspect-ratio SU-8 container molds, and molds with heights 1.0 mm were fabricated. Polydimethylsiloxane (PDMS) was used as the container material, and electrodes were fabricated on a ceramic substrate. Considering the electrical double-layer property, low surface tension, the dielectric constant and the problem of volatilization, methanol and propylene carbonate were tested as electrolytes. A charge-balanced capacitance–voltage (C–V) conversion circuit was designed as a detection circuit for this sensor and it was fabricated using 0.35 μm CMOS technology. The sensor part and detection circuit were integrated in one ceramic packaging for realize a miniaturization of inclination sensor system. To overcome the surface tension of the PDMS surface, silicone oil was injected in the container to cover the entire inner surface so that the movement of solution in the container became smooth. The linearity of the analog output of ±60° inclination for container dimensions of Ø 4.0 mm × 1.0 mm (diameter × thickness) was less than 6%/F.S. The minimum moving angle and response time were 0.4° and 0.9 s, respectively, when propylene carbonate was used as the electrolyte. The change in temperature did not affect the output voltage of the sensor between 0 and 50 °C. The effect of vibration was demonstrated in this paper. 相似文献
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Potentiometric oxygen sensor was fabricated and applied to detect several volatile organic compounds (VOCs; acetic acid, methylethylketone (MEK), ethanol, benzene, toluene, o- and p-xylene) at sub-ppm levels in the temperatures range of 400–500 °C. The electromotive force (EMF) linearly changed with the logarithm of VOC concentration. Especially for ethanol and MEK, the sensitivity and EMF at 1 ppm were distinctly lowered for the sensor with the SmFeO3 coated Pt working electrode. It seems that ethanol and MEK were more easily oxidized on the SmFeO3 surface than the other VOCs. A discriminative detection of ethanol and MEK apart from the others could be achieved with the combination of two types of the sensors, Pt|8YSZ|Pt(ref.) and SmFeO3/Pt|8YSZ|Pt(ref.). 相似文献
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金属/YSZ电极对氧传感器性能的影响 总被引:2,自引:0,他引:2
借助交流阻抗谱测试技术和扫描电镜,对Pt,Au,Ag,Ag—Pt,Ag—Pd电极浆料所制金属/YSZ电极的界面电阻、激活能进行了研究,并计算了由其构成的氧传感器达到90%响应量所需时间。研究表明:400-600℃时,02在Ag/YSZ电极上反应速率最快,激活能最低,为91kJ·mol^-1;Pt/YSZ电极激活能最高,为183kJ·mol^-1,电极反应速率控制步骤为吸附氧原子在电极表面的扩散过程;Ag—Pt,Ag—Pd/YSZ电极激活能均较Ag/vsz电极高,Pd含量增大时,Ag—Pd/YSZ电极激活能亦增大;400-450℃时,Ag/YSZ氧传感器响应时间最短,450-600℃时,Ag-1%Pd/YSZ氧传感器响应最快。 相似文献
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沙箱(Sandbox)技术是一种安全保护机制,其目的是通过对程序运行环境的限制来保护系统的安全性.LSM是Linux内核提供的一种轻量级访问控制框架.文中分析了Linux系统中实现沙箱模块的常用技术的不足(实现复杂且资源消耗大),提出一种基于LSM在Linux内核中实现沙箱模块的方法.基于LSM实现沙箱模块,可以减少工作量.且测试结果表明,基于LSM的内核沙箱模块加载后,对系统影响较小,系统性能最大损失约10%. 相似文献