Study of Solid Oxide Fuel Cell Electrolytes Based on Lanthanum Gallate

Sr、Mg双掺杂的镓酸镧具有高氧离子电导率、高氧离子迁移数与较好的稳定性，是目前研究广泛的中温固体氧化物燃料电池(ITSOFC)电解质材料。本文采用交流阻抗和Hebb-Wagner极化法研究了氧化铝掺杂的La0.9Sr0.1Ga0.8Mg0.2O3-d和钴掺杂的La0.8Sr0.2Ga0.8Mg0.2O3-d材料的电导特性，利用热重分析法考察了钴掺杂的La0.8Sr0.2Ga0.8Mg0.2O3-d中钴离子的价态以及氧空位浓度随氧分压的变化，并用电动势法测定了系列镓酸镧材料的平均氧离子迁移数。首次系统研究了氧化铝掺杂的La0.9Sr0.1Ga0.8Mg0.2O3-d的电导特性。发现其总电导率与...Lanthanum gallate doped with Sr and Mg exhibits high oxygen ion conductivity, high oxygen ion transference number and good stability. There are growing interests in study this kind of promising electrolytes for intermediate temperature solid oxide fuel cells (ITSOFCs). In this study, four-probe impedance spectrometry and Hebb-Wagner polarization were applied to study the electrical conductivities ...学位：理学硕士院系专业：化学化工学院化学系_化学学号：20032510

Comparison between the Electrical Conductivities of La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_3 and La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05)O_3

采用固相合成法制备了La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282)和La0.8Sr0.2Ga0.8Mg0.15Co0.05O3(LSGMC5),利用四电极交流阻抗法和Hebb-Wagner极化法对比研究了两种材料的总电导率和电子电导率.实验结果表明,LSGM8282的总电导率与氧分压无明显依赖关系,而LSGMC5的总电导率在高氧分压区随氧分压降低而增加,在中等氧分压区域基本保持不变.在973～1173K的温度范围内,LSGM8282的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和1/4.在1073～1173K的温度范围内,LSGMC5的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和约为1/8,表明LSGMC5的空穴产生机制可能与LSGM8282不同.LSGM8282的氧离子电导率与氧分压无关,而LSGMC5的氧离子电导率在高氧分压区随氧分压的减小而增加.La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282) and La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (LSGMC5) are two kinds of excellent electrolytes for intermediate temperature solid oxide fuel cells (ITSOFCs ). LSGM8282 and LSGMC5 were prepared using solid state reaction in this study. Total electrical conductivities and electronic conductivities of LSGM8282 and LSGMC5 were comparatively studied using four-probe AC impedance spectrometry and Hebb-Wagner polarization. The results showed that the total electrical conductivity of LSGM8282 had no dependency on oxygen partial pressures. However, the total electrical conductivity of LSGMC5 increased with the decrease in oxygen partial pressures under high oxygen partial pressures. Within the temperature range of 973～1173 K, the orders of dependency of the electron conduction and hole conduction of LSGM8282 on the oxygen partial pressure was -1/4 and 1/4, respectively. Within the temperature range of 1073～1173 K, the orders of dependency of the electron conduction and hole conduction of LSGMC5 on the oxygen portial pressure was -1/4 and about 1/8, respectively. The oxygen ion conductivity of LSGM8282 had no dependency on oxygen partial pressures, while that of LSGMC5 increased with the decrease in oxygen partial pressures under high oxygen partial pressures.福建省科技攻关计划重点项目(NO.2003H046);; 留学回国人员基金资

小儿沙门菌感染临床特点及耐药性分析

目的探讨儿童沙门菌感染的临床特点和耐药情况,为临床诊疗提供帮助。方法收集2013～2017年经粪便培养出沙门菌阳性的163例住院患儿的临床特征、沙门菌血清型分布情况及药敏试验结果,并进行回顾性分析。结果 163例沙门菌阳性患儿中,≤1岁患儿79例(48.5%);临床表现以发热、腹泻为主,体温>39℃达121例(74.2%),腹泻超过10次/d有52例(31.9%),且合并呼吸道感染多见,共56例(34.4%);沙门菌感染好发于夏秋季,5～10月共检出131例(80.4%)。血清分型以鼠伤寒沙门菌、肠炎沙门菌为主,分别为100例(61.3%)、15例(9.2%);不同血清型沙门菌对头孢噻肟耐药率均在20%以上,对β内酰胺酶抑制剂(阿莫西林/克拉维酸、哌拉西林/他唑巴坦)敏感性较高,尚未出现对碳青霉烯类(亚胺培南)耐药株。结论≤1岁婴儿夏秋季易感染沙门菌,常见血清型为鼠伤寒沙门菌;临床表现以发热、腹泻为主,合并呼吸道感染多见;沙门菌对三代头孢菌素类的耐药率有所增加,临床治疗应根据药敏试验结果合理使用抗菌药物。厦门市青年创新创业人才项目(2015-A-03

自组装DNA与[Co(phen)_3]~(2+/3+)相互作用的表面增强拉曼光谱法研究

对金基体上自组装 ss DNA及 ds DNA与钴邻菲啉配合物离子 ( [Co( phen) 3 ]2 +/ 3 +)相互作用进行电化学现场表面增强拉曼光谱 ( SERS)研究 ,获得相互作用位点及相互作用模式的信息 . ds DNA与 [Co( phen) 3 ]2 +/ 3 +存在一定的嵌插作用 ,即配合物通过配体邻菲啉 ( phen)环以嵌插模式结合在碱基 A-T及 G-C富集区 ,同时与磷酸二酯键 PO2 结合 ,并伴随 ds DNA螺旋构象由 B型向 A型转变 ;而 [Co( phen) 3 ]2 +/ 3 +则是以静电模式与 ss DNA的磷酸二酯键 PO2 及脱氧核糖组成的骨架相互作用

自组装DNA吸附取向的表面增强拉曼光谱法研究

对金基体上自组装寡聚核苷酸探针杂交前后进行电化学非现场及现场表面增强拉曼光谱 ( SERS)研究 .非现场 SERS研究表明 ,杂交形成的 ds DNA在基体表面以 A型和 B型两种构象同时存在 ,杂交过程可能伴随 DNA链在基体表面吸附取向的变化 .根据现场 SERS研究结果可知 ,ss DNA及 ds DNA的大多数SERS谱带强度随电极电位正移而降低 ,尤其是归属于碱基 A的两种面外振动模式 ,谱带变化更为明显 .利用 SERS表面选择定则判断出随着电极电位由负向正变化 ,ss DNA及 ds DNA螺旋吸附取向由垂直吸附向平躺吸附于金基体表面变化

3种B族链球菌筛查方法在孕晚期筛查中的应用

目的比较3种B族链球菌(GBS)的筛查方法在孕晚期孕妇GBS筛查中的临床应用价值。方法收集2017年9月至12月在厦门市妇幼保健院产科门诊产检的35～37孕周孕妇阴道/直肠拭子样本1 027例,用GBS运送增菌...厦门市第二批青年创新创业人才项目(2015-A-03

米非司酮对人耐药卵巢癌细胞增殖、凋亡及其对紫杉醇敏感性的影响

背景与目的:米非司酮是有效的孕酮受体拮抗剂。研究发现,米非司酮对体内外卵巢癌细胞均具有生长抑制作用,但机制尚不清楚。本研究旨在探讨米非司酮对人耐药卵巢癌细胞A2780/T增殖、凋亡及其对紫杉醇敏感性的影响,为临床应用米非司酮治疗耐药性卵巢癌提供实验依据。方法:体外培养人卵巢癌耐药细胞A2780/T,采用CCK-8法检测单用米非司酮及合用紫杉醇时对A2780/T细胞增殖的影响,分析米非司酮与紫杉醇在抑制耐药卵巢癌细胞增殖中的相互作用。采用流式细胞术分析米非司酮及米非司酮联合紫杉醇对A2780/T细胞凋亡的影响。结果:实验所选各种浓度(0.625～20μg/mL)米非司酮对A2780/T和A2780细胞均有一定程度的生长抑制作用,并呈浓度依赖性。当紫杉醇浓度为1.25或2.5μg/mL,合用米非司酮浓度为20、10、5、2.5、1.25或0.625μg/mL时,能显著抑制A2780/T细胞的增殖,并显示两种药物的协同作用(q>1.15)。当紫杉醇浓度为0.625或5μg/mL时,仅表现为两种药物的相加作用(0.85<q<1.15)。米非司酮可诱导A2780/T细胞凋亡。当米非司酮浓度为1.25、2.5和5μg/mL时,细胞凋亡率分别为(15.50±1.48)%、(26.28±0.76)%和(45.13±0.91)%。当以上3种浓度米非司酮与2.5μg/mL紫杉醇联合作用时,显示了两种药物在诱导A2780/T细胞凋亡作用上的协同效应。结论:米非司酮能够显著抑制人卵巢癌细胞A2780/T和A2780增殖,诱导A2780/T细胞凋亡,并能增强A2780/T细胞对紫杉醇的敏感性

Comparison between the electrical conductivities of La0.8Sr0.2Ga0.8Mg0.2O3 and La0.8Sr0.2Ga0.8Mg0.15Co0.05O3

La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282) and La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (LSGMC5) are two kinds of excellent electrolytes for intermediate temperature solid oxide fuel cells (ITSOFCs). LSGM8282 and LSGMC5 were prepared using solid state reaction in this study. Total electrical conductivities and electronic conductivities of LSGM8282 and LSGMC5 were comparatively studied using four-probe AC impedance spectrometry and Hebb-Wagner polarization. The results showed that the total electrical conductivity of LSGM8282 had no dependency on oxygen partial pressures. However, the total electrical conductivity of LSGMC5 increased with the decrease in oxygen partial pressures under high oxygen partial pressures. Within the temperature range of 973 similar to 1173 K, the orders of dependency of the electron conduction and hole conduction of LSGM8282 on the oxygen partial pressure was -1/4 and 1/4, respectively. Within the temperature range of 1073 similar to 1173 K, the orders of dependency of the electron conduction and hole conduction of LSGMC5 on the oxygen portial pressure was -1/4 and about 1/8, respectively. The oxygen ion conductivity of LSGM8282 had no dependency on oxygen partial pressures, while that of LSGMC5 increased with the decrease in oxygen partial pressures under high oxygen partial pressures

Characteristics of PCBs in a Capacitor Storage Site and an Industrial Brownfield

研究了四川资阳机车厂废弃电力电容器封存点与旧工业场地土壤与降尘中28种多氯联苯(PCbS)的污染水平与组成特征.电容器封存山洞未封闭洞口处土壤中PCbS含量最高,28种PCbS的总含量(ΣPCbS)达227 502 ng.g-1,铸铁车间窗台降尘中也有高残留的PCbS,ΣPCbS在10μg.g-1以上,封存点和铸铁车间样品中PCbS单体含量之间均存在显著的正相关关系(P<0.01).高污染样品中PCbS的同族体分布均以四氯代PCbS为最高,其次为三氯代PCbS和五氯代PCbS.与封存点土壤相比,铸铁车间样品中高氯代PCbS的贡献更大.12种类二英PCbS的毒性当量(TEQ)介于75.43~24 027 Pg.g-1之间,远大于电子垃圾拆解区土壤,但普遍都以PCb126的毒性当量贡献占绝对优势.The levels and congener patterns of 28 PCBs compounds were investigated in soil and dust fallout collected in a capacitor storage site and an industrial brownfield,respectively in Sichuan Ziyang Locomotive Factory.The highest concentration of the total PCBs(PCBs=227 502 ng·g-1) was found in soil collected from the front gate(unsealed) of the capacitor storage tunnel.Very high levels of PCBs,exceed 10 μg·g-1,were also found in the dust collected from the window sill of an iron foundry.There were significant positive correlations(P<0.01) among PCB congener concentration in the storage site and the iron foundry samples.The major contribution to the total content of PCBs in the high contaminated samples was tetrachlorinated biphenyls,followed by tri-and penta-chlorinated biphenyls.Hexa-and higher chlorinated biphenyls contributed more to PCBs in the iron foundry than those in the storage site.The total toxicity equivalents(TEQ) of 12 dioxin-like congeners varied in the range of 75.43-24 027 pg·g-1 and were much higher than those in soils of e-waste recycling sites.However,PCB126 contribute the most to the TEQ in most cases.国家自然科学基金项目(40603020);福建省自然科学基金计划项目(2009J05106

单根聚苯胺纳米线导电性的研究

纳米线(管)的模板合成和导电原子力显微镜(C鄄AFM)结合是一种近期发展起来研究单根一维纳米结构及阵列导电性的有效方法.本文利用C鄄AFM测量了阳极氧化铝(AAO)模板电化学合成制备的单根聚苯胺纳米线的电导率,研究了直径、氧化还原态对单根聚苯胺纳米线电导率的影响.从I-V曲线可以看到,其导电性质与半导体类似,但又不同于半导体.尚未观察到反向击穿现象,可能原因是,在一定的反向偏压下的离子脱嵌使得它由部分氧化态(导电态)转变为还原态(绝缘态);电导率随纳米线直径减小而线性地增加;以ClO-4离子掺杂的氧化态和还原态比部分氧化态的电导率低二个数量级