超流氦噪声沸腾过程中的压力振动分析：小试样几何尺寸对噪声沸？…

小试样的几何形状尺寸是影响噪声沸腾状态的一个重要的因素. 对于不同几何尺寸的小试样, 沸腾发生时所产生的气泡的尺寸不同, 因而所产生的压力振动的幅度和特征频率就不同. 采用一个归一化因子将不同几何形状尺寸下的实验数据进行统一, 发现振动的特征频率与几何尺寸因子之间存在对数曲线的关系.     

Complex Formation of Cyclodextrins with Various Thiophenes and their Polymerization in Water: Preparation of Poly-pseudo-rotaxanes containing Poly(thiophene)s

Cyclodextrins (α-CD, β-CD and 2,6-di-O-dimethyl-β-CD (DM-β-CD)) were found to form inclusion compounds with thiophenes (thiophene (T), bithiophene (2T)) in water and in crystalline states. The structures of α-CD–T, β-CD–2T, and DM-β-CD–2T inclusion complexes were determined by X-ray crystallography. DM-β-CD forms a 1:1 cage type complex with 2T. In contrast, β-CD formed 2:3 (CD:guest) complexes with thiophene and α-CD formed 2:3 complexes, both of the channel type. These inclusion complexes were found to polymerize by FeCl₃ in the inclusion compounds in water. The products were formed poly-pseudo-rotaxane between cyclodextrins and poly(thiophene) characterized by IR, ¹H-NMR and ¹³C CP/MAS NMR. The molecular weights of the poly-pseudo-rotaxanes with poly(thiophene) were determined by the MALDI-TOF mass spectra to be 3000–5000. In comparison between poly-pseudo-rotaxane (DM-β-CD–poly(thiophene)), authentic poly(thiophene) and the washed DM-β-CD–poly(thiophene) which was washed with DMF to dethread DM-β-CD, these poly-pseudo-rotaxane was characterized by Raman, UV–vis and fluorescence spectra. The maximum emission band of DM-β-CD–poly(thiophene) shifted to a shorter wavelength. The hypsochromic shift was derived from poly-pseudo-rotaxane with DM-β-CD.     

超流氦噪声沸腾过程中的压力振动分析: 小试样几何尺寸对噪声沸腾状态的影响

小试样的几何形状尺寸是影响噪声沸腾状态的一个重要的因素. 对于不同几何尺寸的小试样, 沸腾发生时所产生的气泡的尺寸不同, 因而所产生的压力振动的幅度和特征频率就不同. 采用一个归一化因子将不同几何形状尺寸下的实验数据进行统一, 发现振动的特征频率与几何尺寸因子之间存在对数曲线的关系.