高、低能扰动力函数对叶轮机阵发非定常气动力的影响(英文)

为了研究扰动力函数对多级叶轮机叶片排中基本的高、低能阵发非定常气动响应的影响,在研究用轴流压气机上进行了一系列的基础研究。      

振荡叶栅气动性能实验研究(英文)

为了提供双凸翼型叶栅在所有叶间相位角及实际折合频率下高亚音和跨音定常和振荡气动性能的基本数据,在 NASA路易斯研究中心的跨音振荡叶栅试验设备上进行了一系列试验。为了进行该试验,研制出并使用了非定常气动影响系数法,即叶栅中一次只有一个翼型振荡,测出该振荡翼型与邻近静止翼型上非定常压力的矢量和,藉此就能确定在特定叶间相位角下相当于全部叶片振荡的叶栅的非定常气动性能。      

Impact disruption and recovery of the deep subsurface biosphere

Although a large fraction of the world's biomass resides in the subsurface, there has been no study of the effects of catastrophic disturbance on the deep biosphere and the rate of its subsequent recovery. We carried out an investigation of the microbiology of a 1.76 km drill core obtained from the ～35 million-year-old Chesapeake Bay impact structure, USA, with robust contamination control. Microbial enumerations displayed a logarithmic downward decline, but the different gradient, when compared to previously studied sites, and the scatter of the data are consistent with a microbiota influenced by the geological disturbances caused by the impact. Microbial abundance is low in buried crater-fill, ocean-resurge, and avalanche deposits despite the presence of redox couples for growth. Coupled with the low hydraulic conductivity, the data suggest the microbial community has not yet recovered from the impact ～35 million years ago. Microbial enumerations, molecular analysis of microbial enrichment cultures, and geochemical analysis showed recolonization of a deep region of impact-fractured rock that was heated to above the upper temperature limit for life at the time of impact. These results show how, by fracturing subsurface rocks, impacts can extend the depth of the biosphere. This phenomenon would have provided deep refugia for life on the more heavily bombarded early Earth, and it shows that the deeply fractured regions of impact craters are promising targets to study the past and present habitability of Mars.