Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electro...Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.展开更多
目的:评价小剂量类固醇激素治疗脓毒症休克的疗效。方法:通过检索1996年～2011年Pubmed、Cochrane Database of Systematic Reviews与EMbase中关于小剂量类固醇激素治疗脓毒症休克的随机对照研究(RCT),同时筛检纳入文献的参考文献,对纳...目的:评价小剂量类固醇激素治疗脓毒症休克的疗效。方法:通过检索1996年～2011年Pubmed、Cochrane Database of Systematic Reviews与EMbase中关于小剂量类固醇激素治疗脓毒症休克的随机对照研究(RCT),同时筛检纳入文献的参考文献,对纳入研究的方法学进行评价,对文献质量进行严格评价和资料提取,对符合质量标准的RCTs用Revman 5.0软件进行Meta分析。结果:7个RCTs共993名患者纳入研究,其中治疗组501例,对照组492例,Meta分析结果表明治疗组的28d死亡率低于对照组、治疗组的休克7d逆转率高于对照组,对于脓毒症休克患者的并发症如消化道出血、二重感染、高血糖方面相关的RCTs结果显示无显著差异。结论:小剂量类固醇激素治疗可以增加脓毒症休克患者的治疗成功率而不增加发生其他不良结局的危险性,可将此作为脓毒症患者的常规治疗方案。展开更多
为了更深入地探讨Zn Fe SiO2复合镀层的电沉积机理,采用三电极体系下的动电位法测定了电沉积Zn Fe SiO2复合镀层的阴极极化曲线,并研究了镀液成分对阴极极化的影响。结果表明,Zn Fe SiO2复合镀层的沉积属于异常共沉积,而且SiO2微粒的... 为了更深入地探讨Zn Fe SiO2复合镀层的电沉积机理,采用三电极体系下的动电位法测定了电沉积Zn Fe SiO2复合镀层的阴极极化曲线,并研究了镀液成分对阴极极化的影响。结果表明,Zn Fe SiO2复合镀层的沉积属于异常共沉积,而且SiO2微粒的加入对Zn Fe SiO2镀层复合电沉积的阴极极化行为影响不大。展开更多
基金Project(50964008)supported by the National Natural Science Foundation of ChinaProject(2010287)supported by Analysis and Testing Foundation of Kunming University of Science and Technology,China
文摘Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.
文摘 为了更深入地探讨Zn Fe SiO2复合镀层的电沉积机理,采用三电极体系下的动电位法测定了电沉积Zn Fe SiO2复合镀层的阴极极化曲线,并研究了镀液成分对阴极极化的影响。结果表明,Zn Fe SiO2复合镀层的沉积属于异常共沉积,而且SiO2微粒的加入对Zn Fe SiO2镀层复合电沉积的阴极极化行为影响不大。
文摘高温烟气颗粒、二氧化碳和水蒸气是烃类池火中火焰热辐射的主要来源,而点源模型、Shokri Beyler模型和Mudan模型是计算池火辐射最常用的方法。采用这3种模型计算了直径为2 m的乙醇池火的火焰特性,得出了目标位置接受辐射强度和与池火中心距离之间的关系。根据乙醇池火试验的光谱辐射强度,以及通过简化处理计算得到的火焰周围大气环境的衰减系数,采用辐射传热理论计算目标位置处的辐射强度。将不同模型的计算结果与基于试验数据的计算结果对比发现:当热辐射强度小于1.5 k W/m2时,点源模型计算结果比较准确;当热辐射强度大于4.5 k W/m2时,Shokri Beyler模型的计算结果比较合理。在工业火灾的实际应用中,计算辐射对人员的伤害可选用点源模型与Mudan模型;计算辐射对周围建筑物的破坏可选用Shokri Beyler模型。
