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COonrol of Formation Process of Water Clusters by Rotatilnal Energy

旋转能控制水团簇形成过程

基本信息

批准号：
01550185
负责人：
INOUE Takayoshi
金额：
$ 1.22万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550185/
关键词：
WATER CLUSTER CONDENSATION ROTATIONAL ENERGY ROTATIONAL TEMPERATURE MOLECULAR BEAM MICRO WAVE

项目摘要

The formation process of water clusters were investigated experimentally, especially noticing the effect of the rotational energy of water molecules. The experimental apparatus is a conventional molecular beam machine with three stages of differential pumping. Water vapor were expanded freely through the nozzle into the vacuum to form a supersonic free jet. In the free jet, clustering of gaseous molecules takes place. The terminal concentrations of water clusters formed through the free jet were measured with a quadruple mass spectrometer. In this formation process, micro wave were irradiated on water molecules to excite the rotational energy level of water molecules. The obtained results are as follows ;(1) The dimmer concentration is little affected by the solute species, Ar or N_2. The concentrations of larger clusters in H_2O-Ar mixtures are always larger than those in H_2O-N_2 mixtures. This results implies the possibility of the control of formation process of clusters by the con … More trol of the internal energies of molecules.(2) The marked effect of the excitation of the rotational energy of molecules on the cluster formation were not observed in these experiments.(3) To increase the power of micro wave, the nozzle was inserted into the wavegaide but the marked effect of the excitation of the rotational energy of molecules on the cluster formation were not observed.The reasons of this ineffectiveness of the rotational excitation were supposed as follows ;(1) As the energy of the micro wave of 22.235GHz corresponds to the temperature difference of a few degrees, the amount of the energy which a water molecule absorbs is too small to have marked influence on the cluster formation.(2) Even in the room temperature, the distribution of the rotational energy of water molecules is so wide that the J=5->6 excitation of the rotational energy of a water molecule only gives a very small effect on its distribution, then it cannot have marked influence on the cluster formation. Less

实验研究了水团簇的形成过程，特别注意了水分子旋转能的影响。实验装置为常规分子束机，采用三级差动泵浦。水蒸气通过喷嘴自由膨胀进入真空，形成超音速自由射流。在自由射流中，气态分子发生聚集。用四倍质谱仪测定了自由射流形成的水团的末端浓度。在这个形成过程中，微波照射在水分子上激发水分子的旋转能级。所得结果如下：(1)消光剂浓度受溶质种类Ar和N_2的影响较小。h2o - ar混合物中较大团簇的浓度总是大于h2o - n_2混合物。这一结果暗示了通过控制分子内能来控制团簇形成过程的可能性。(2)这些实验没有观察到分子旋转能激发对团簇形成的显著影响。(3)为了增加微波的功率，在波导中插入喷嘴，但没有观察到分子旋转能的激发对团簇形成的显著影响。转动激励无效的原因假定如下：(1) 22.235GHz的微波能量对应几度的温差，水分子吸收的能量太少，对团簇的形成没有明显的影响。(2)即使在室温条件下，水分子的旋转能分布也很广，当J=5->6激发时，水分子的旋转能对其分布的影响也很小，因此不能对团簇的形成产生显著的影响。少