氯丁橡胶滚动密封圈密封不严及其解决措施

对水下振源体的滚动密封圈密封不严问题产生的原因进行了分析,选择高抗结晶性能的氯丁橡胶DCR114和DCR213并用（75/25）代替原来的氯丁橡胶CR232,通过了硬度变化试验,改进后的滚动密封圈未再出现漏水现象。     

Buoyancy driven flow of two stratified liquids in a cavity

A two dimensional study on the transient natural convection of two stratified liquids in a cavity is presented. We studied the motion of the fluids when one wall of the cavity is quickly heated up at a certain required temperature, the stratified liquids being initially at rest and in thermal equilibrium. The experiments were done at different inclination angles of the hot wall so that its influence on the dynamics of the process could be observed. Also, several initial concentrations for the denser liquid were tested for each inclination, and the global effect of the initial concentration investigated. It was possible to monitor the advance of the thermal intrusions by means of careful measurements of their thermal fronts.     

CeO2-promotion of NiAl2O4 reduction via CeAlO3 formation for efficient methane reforming

NiAl₂O₄ is readily formed during preparing conventional Ni/Al₂O₃ catalysts, and its low reducibility causes the re-formation of inactive NiAl₂O₄ due to the presence of oxidant during methane partial oxidation, which decreases catalyst activity and stability. CeO₂ effectively promotes NiAl₂O₄ reduction via forming CeAlO₃, which prevents the NiAl₂O₄ re-formation. A critical CeO₂ ratio of 35.0 wt% CeO₂/(CeO₂+Al₂O₃) was found to favor CeAlO₃ formation, which is corresponding to the stoichiometric composition of NiAl₂O₄. The pathway of CeAlO₃ formation via NiAl₂O₄ reduction has been proposed and thermodynamically confirmed for the first time. The factors affecting CeAlO₃ formation have been identified: the presence of Ni in the composite promotes CeAlO₃ formation via solid reaction between CeO₂ and NiAl₂O₄ during reduction; high reduction and reaction temperatures favor the CeAlO₃ formation and stabilization. The thermally stable structure of fibrous catalysts enables the study of the temperature effects.