共沉淀法合成La_(0.7)Sr_(0.3-x)Ca_xCo_(0.9)Fe_(0.1)O_(3-)及其性能表征

以金属硝酸盐、氨水为沉淀剂,采用化学共沉淀法合成了La0.7Sr0.3-xCaxCo0.9Fe0.1O3-"(简称LSCCF,x=0.05,0.10,0.15,0.20)粉料。借助差示扫描量热法-热重分析法(DSC-TG)、X射线衍射法(XRD)和扫描电子显微镜法(SEM)对600℃,800℃,1000℃热处理4h后LSCCF粉料的形成过程、晶体结构和粒度形貌进行了研究。实验结果表明,LSCCF粉料的形成过程分为4个阶段——脱水阶段、分解阶段、LaCoO3基氧化物形成阶段和LSCCF固溶体形成阶段;适宜热处理制度为800℃下保温4h,且制备出的LSCCF粉料为均一的钙钛矿结构。使用直流四极探针法测定了LSCCF样品在空气气氛下的电导率,发现该体系材料在600～800℃范围的电导率都超过了250S·cm-1,其导电机制符合p型小极化子绝热孔隙理论,且能够满足中温固体氧化物燃料电池(ITSOFC)阴极材料的要求。     

奶粉中羟基磷灰石成分的检测

将奶粉溶于超纯水中,经超声、离心、真空冷冻干燥提取奶粉中无机成分富含物,再经X射线粉末衍射(Xray powder diffraction,XRD)和傅里叶红外光谱法对其进行定性鉴别分析;于空白奶粉样品中加入不同浓度的针状纳米羟基磷灰石标准品,经与样品相同处理后进行XRD分析,利用扫描电子显微镜(Scanning electrons microscopy, SEM)、透射电子显微镜—能谱仪(Transmission electron microscopy-energy spectrometer,TEM-EDS)对样品及加标样品中提取成分进行了形貌和纳米尺寸表征。结果表明,加标样品XRD检测中确定含有羟基磷灰石成分,电镜下能观察到纳米尺寸的针状羟基磷灰石,因此验证了此方法检测纳米羟基磷灰石的可行性;5种样品中1种样品含有羟基磷灰石,并含有未知结构的类似于球状的纳米成分(元素组成为碳、氧、磷、氯),3种样品含有晶体状的方解石,1种样品不含有晶体状羟基磷灰石。     

HPR20PLUS在线气体分析质谱仪低压测试性能观察

To obtain data for experiments and applications of HPR20^PLUS on-line mass spectrometer in low pressure. The gas, standard gas, and breath gas of low pressure cabin were analyzed respectively in unman and manned experiments under different low pressure. The accuracy and stability of HPR20^PLUS On-line Mass Spectrometer in unman experiments under different low pressure were conformed to the requirements of HPR20^PLUS on-line mass spectrometer, and the changes of breath gas in manned experiments were accorded with the laws of human experiments . Performance tests of HPR20^PLUS on-line mass spectrometer in low pressure is excellent , and HPR20 ^PLUS on-line mass spectrometer can be used for human experiments under low pressure .