A chirped pulse fourier transform microwave spectrometer

啁啾脉冲傅立叶变换微波光谱仪

• 批准号: 358803-2008
• 负责人: Jäeger, Wolfgang
• 金额: $ 10.37万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=403670
• 关键词: chirped; pulse; fourier; transform; microwave

'Superfluidity' is a collective term for the fascinating properties (e.g. vanishing viscosity) and unusual effects (e.g. fountain effect) which bulk helium exhibits below its transition temperature of 2.17 K. Superfluidity is a manifestation of quantum effects on the macroscopic scale and requires that the microscopic constituents are bosons, i.e. have an integer composite spin. Besides helium, there is only one other system which may show superfluid effects, namely molecular hydrogen, H2. Hydrogen occurs as two spin modifications, paraH2 with total spin I=0 and orthoH2 with I=1. paraH2 is expected to have the higher transition temperature to superfluidity (7 K) because of its weaker intermolecular interactions compared to orthoH2. However, superfluidity in bulk paraH2 has thus far escaped experimental verification because it solidifies already at 13 K.

“超流性”是一个集合术语，用来描述大块氦在低于2.17 K的转变温度时所表现出的迷人特性（如粘度消失）和不寻常的效应（如喷泉效应）。超流性是量子效应在宏观尺度上的一种表现，它要求微观成分是玻色子，即具有整数复合自旋。除了氦之外，只有一个系统可能表现出超流体效应，即分子氢，H2。氢以两种自旋变体出现，总自旋I=0的paraH2和I=1的orthoH2。预计paraH2具有更高的转变温度超流性（7 K），因为它的分子间相互作用较弱orthoH2。然而，大量仲氢中的超流性迄今尚未得到实验验证，因为它已经在13 K凝固。