固体氧化物燃料电池电解质材料的研究进展

固体氧化物燃料电池(SOFC)是一种能量转换效率高和环境友好的新能源装置.综述了SOFC中固体电解质的研究进展,概述了ZrO2基、CeO2基、Bi2O3基和以掺杂的LaGaO3为代表的钙钛矿结构固体电解质的研究情况.稳定的高离子电导率固体电解质的研制及其薄膜化研究是降低SOFC工作温度的两个主要途径.     

固体氧化物燃料电池中电解质研究进展

从萤石结构型氧化物和钙钛矿结构型氧化物两个方面综述了固体氧化物燃料电池(SOFC)中电解质的研究进展.有关研究表明,掺杂剂的组成和掺杂量以及不同氧化物的结构对固体电解质的电导率和稳定性有着直接的影响.尽管目前已经进行了大量的关于固体电解质电导率促进作用机理的研究工作,但还未形成共识.同时,LaGaO3基钙钛矿型氧化物固体电解质具有广阔的应用前景.     

中温固体氧化物燃料电池材料的研究进展

中温化是固体氧化物燃料电池的发展趋势之一.阳极材料、阴极材料、固体电解质材料和连接材料的性能对整个固体氧化物燃料电池的性能有着十分重要的影响.综述了中温固体氧化物燃料电池各组件对材料的要求及其研究现状,并提出了中温固体氧化物燃料电池在其材料方面的一些有待解决的问题.     

固体氧化物燃料电池电解质材料的研究进展

固体氧化物燃料电池(SOFC)是一种能量转换效率高、环境友好和燃料灵活的全固态发电设备,为能源资源的可持续发展提供选择.氧离子在固体电解质中是通过氧空位传导的,即增大氧空位浓度是提高离子电导率的关键,而高离子电导率的电解质材料促进了SOFC发展.综述了固体电解质的离子传输机制和ZrO2基电解质、CeO2基电解质、Bi2...     

固体氧化物燃料电池阴极材料研究进展

开发性能优良的阴极材料是降低中低温(500～800℃)固体氧化物燃料电池(IT-SOFCs)成本的关键.回顾了IT-SOFCs阴极材料的最新研究进展.阴极材料对高电子电导率的需要,使钙钛矿结构氧化物及类钙钛矿结构氧化物在该领域的研究占据主导地位.除了电子电导率外,阴极材料的研究正在转向具有高离子电导率的组分,这种要求使具有无序自由氧离子迁移通道的双钙钛矿结构氧化物和在间隙位置可引入过量氧的K2NiF4结构及其它间隙氧化物最近受到极大的重视.     

钙钛矿型中低温固体氧化物燃料电池阴极材料研究进展

中低温固体氧化物燃料电池的研制是固体氧化物燃料电池商业化的必然趋势,阴极材料的研制是影响其发展的关键问题之一.本文综述了近年来固体氧化物燃料电池ABO3型钙钛矿阴极材料的研究情况,并提出了其发展方向.     

面向金属-空气电池和中低温固体氧化物燃料电池应用的钴基电催化剂综述

在21世纪的今天,由石油、煤炭等化石资源的过度开发与使用所引发的能源和环境问题日趋严重,开发经济、高效的能源转换与存储装置已成为新时代的研究主题。金属-空气电池和中低温固体氧化物燃料电池,作为高效的能源转换与存储装置,可以实现化学能向电能的高效转换,具有效率高、环境友好、成本低的显著优点,在过去十几年内受到了研究者的广泛关注,取得了惊人的成果。但与此同时,人们在研究中发现阴极(正极)缓慢的氧还原和氧析出反应速率极大地降低了电池转换效率,增加了应用成本,在很大程度上制约了金属-空气电池和中低温固体氧化物燃料电池的商业化发展和应用。钴基催化剂作为一种高效阴极材料,相比贵金属成本较低,且具有混合离子-电子导电性,可以有效降低极化电阻,对阴极氧还原和氧析出反应显示出高催化活性,近年来吸引了国内外学者极大的研究兴趣。对于金属-空气电池,虽然钴基催化剂如钴氧化物、尖晶石型氧化物、钙钛矿型氧化物等材料能够显著地提高金属-空气电池的电容量和循环性能,并且降低充电电压,有效降低极化,但是其催化活性和稳定性有待提高,催化机理和活性位点也需要进一步明确和探究;对于中低温固体氧化物燃料电池,钴基催化剂包括La_(1-x)Sr_xCoO_3-δ、La_(1-x)Sr_xCo_(1-y)FeyO_3-δ、Ba_(1-x)Sr_xCo_yFe_(1-y)O_3-δ和钴基双钙钛矿等材料可以大大降低阴极极化电阻和面积比电阻,提高功率密度,但是相对其他催化剂,热膨胀系数普遍较高,稳定性也较差。为了进一步提高钴基催化剂应用在金属-空气电池和中低温固体氧化物燃料电池中的催化活性,研究者采用了掺杂其他金属元素、与其他物质组成复合阴极材料以及贵金属修饰等方法,在很大程度上提高了这两种电池的性能。本文简要介绍了金属-空气电池和中低温固体氧化物燃料电池的结构、工作原理,并在此基础上着重评述了近年来面向这两种能源转换与存储器件的,包括钴氧化物、钙钛矿型氧化物、尖晶石型氧化物和双钙钛矿氧化物等在内的各种钴基电催化剂的制取、改性和性能研究探索与成果。     

钙钛矿结构固体电解质材料的研究进展

钙钛矿结构固体电解质材料由于其优越的导电性能而被人们发现并广泛研究.综述了SOFC中钙钛矿结构固体电解质材料的研究进展,概述了氧离子导体、质子导体、锂离子导体为代表的钙钛矿结构固体电解质的研究情况以及湿化学法制备中低温下工作的SOFC电解质材料的主要途径.     

固体氧化物燃料电池与陶瓷材料

固体氧化物燃料电池是一种全固态的能量转换装置，该电池通常采用陶瓷作组装材料，于６９０－１０００℃的高温下操作本文详细介绍了固体氧化物燃料电池各元件的材料，包括稳定化ＺｒＯ２电解质，Ｎｉ／稳定化ＺｒＯ２阳极，掺杂的ＬａＭｎＯ３阴极以及掺杂的ＬａＣｒＯ３双极分离器等。     

对称固体氧化物燃料电池电极材料Sm0.9Pr0.1FeO3-δ的制备及性能研究

采用柠檬酸-硝酸盐自蔓延燃烧法合成了Sm_(0.9)Pr_(0.1)FeO_(3-δ)(SPF)粉体。以YSZ为电解质,SPF同时作为阴极和阳极,构建了对称固体氧化物燃料电池SPF|YSZ|SPF。利用X射线衍射法研究材料的成相以及相互间的化学稳定性,交流阻抗法记录界面极化行为,热膨胀仪评估材料的热膨胀系数,用扫描电子显微镜观察电池的断面微观结构,用自组装的测试系统评价电池输出性能。结果表明,合成的SPF粉体呈钙钛矿结构,且在还原条件下仍保持不变,与电解质YSZ间有良好的化学及热稳定性;800℃时空气及氢气气氛下的电解质|电极间的极化阻抗分别为0.15和15.80Ω·cm2;以加湿H2(含体积分数3%的水蒸气)为燃料气,空气为氧化气时,单电池SPF|YSZ|SPF输出功率密度为168mW/cm2。结果显示SPF是对称固体氧化物燃料电池良好的候选电极材料。     

Gender differences in publication productivity in psychology in India

An analysis of gender differences in psychology in India provides quantitative and qualitative assessment of R&D output contributed by psychologists with the indication of the trend of growth, skewness, relatedness, co-authorship pattern of productivity.     

Metrology in Chemistry in Germany

The system for Metrology in Chemistry in Germany is described. At the national standards level, a network of high-level chemistry institutes coordinated by the national metrology institute, PTB, provides the primary references for chemical measurements. A dissemination mechanism employs chemical calibration laboratories accredited within the framework of the German Calibration Service (DKD). They act as “multipliers” between the national standards level and the user level by providing the user with calibration means which are traceable to the SI via national standards. Traceability structures in clinical chemistry, electrochemistry, elemental analysis and gas analysis are described     

Natural radioactivity in drinking water in private wells in Finland

Natural radioactivity in drinking water was determined in population-based random study of 472 private wells. The mean concentrations of (222)Rn, (226)Ra, (234)U, (238)U, (210)Pb and (210)Po in drilled wells were 460, 0.05, 0.35, 0.26, 0.04 and 0.05 Bq l(-1), and in wells dug in the soil were 50, 0.016, 0.02, 0.015, 0.013 and 0.007 Bq l(-1), respectively. Approximately 10% of the drilled wells exceeded a radon concentration of 1000 Bq l(-1) and 18% a uranium concentration of 15 microg l(-1). The mean annual effective dose from natural radionuclides for a drilled well user was 0.4 mSv and 0.05 mSv for a user of a well dug in the soil. The effective dose arising from (222)Rn was 75% of the total of all natural radionuclides for drilled well users. As regards long-lived radionuclides, (210)Po and (210)Pb caused the largest portion of the effective dose. The dose arising from (238)U, (234)U and (226)Ra was only 8% of the total of all natural radionuclides.     

Natural radioactivity in drinking water in private wells in Finland

Radiation Protection Dosimetry     

Radioactivity in building materials in Iraq

Activity concentrations of (226)Ra, (232)Th and (40)K in 45 samples of different building materials used in Iraq were measured using gamma-spectroscopy system based on high-purity germanium detector with an efficiency of 40 %. Radium equivalent activity, air-absorbed dose rate, annual effective dose, external and internal hazard indices and alpha index due to radon inhalation originating from building materials were measured to assess the potential radiological hazard associated with these building materials. The activity concentrations of the natural radionuclides (226)Ra, (232)Th and 40K were found to range from below detection limit (BDL) to 223.7 ± 9, BDL to 93.0 ± 3 and BDL to 343.1 ± 12, respectively. Values of average radium equivalent activity, air-absorbed dose rate, indoor and outdoor annual effective doses, external and internal hazard indices and alpha index ranged from 6.5 to 124.9, 16.2 to 89.5 (nGy h(-1)), 0.08 to 0.44 mSv, 0.02-0.11 mSv, 0.09 to 0.53, 0.13 to 0.69 and 0.03 to 0.62, respectively. These values indicate a low dose. Therefore, the building materials used in the current study are quite safe to be used as building materials.     

Optische in situ Schichtdickenmessung in Bedampfungsanlagen. Optical in situ film thickness monitoring in coating systems

Optical film thickness monitoring is more precise than crystal monitoring. The optical measurement makes use of the fact that the intensity of a monochromatic light beam which is reflected on a film will change periodically with increasing film thickness. The measurement is performed at an exchangeable test glass that is positioned beside the substrates and is therefore coated in the same way as the substrates. The accuracy of cut‐off is achieved by a “fit” of a theoretical curve shape to the measured values. Order filters are used to ensure that, at a certain wavelength, higher deflection orders do not influence the measurement when a monochromator grating is used.