The Stark structures in a cesium atom around n=18 are numerically calculated. The results show that the components of 20D states with a small azimuthal quantum number ｜m｜ shift upward a lot, and those with a large ...The Stark structures in a cesium atom around n=18 are numerically calculated. The results show that the components of 20D states with a small azimuthal quantum number ｜m｜ shift upward a lot, and those with a large ｜m｜ shift downward a little within 1100 V/cm. All components of P states shift downward. Experimental work has been performed in ultracold atomic cesium. Atoms initially in 6P3/2 state are excited to high-n Rydberg states by a polarization light perpendicular to the field, and Stark spectra with ｜m｜=1/2,3/2,5/2 are simultaneously observed with a large linewidth for the first time. The observed spectra are analyzed in detail. The relative transition probability is calculated. The experimental results are in good agreement with our numerical computation.展开更多
振动斯塔克效应(vibrational Stark effect)是指振动光谱在外加电场作用下发生移动的现象,该效应在现代化学中有广泛的应用。为了增进对振动斯达克效应的理解,本文选择了水的单分子H_(2)O和二聚体分子(H_(2)O)_(2),通过密度泛函理论计...振动斯塔克效应(vibrational Stark effect)是指振动光谱在外加电场作用下发生移动的现象,该效应在现代化学中有广泛的应用。为了增进对振动斯达克效应的理解,本文选择了水的单分子H_(2)O和二聚体分子(H_(2)O)_(2),通过密度泛函理论计算展示了外加定向电场对这两个分子的振动频率的影响。计算显示,外加定向电场直接影响分子的几何结构、电荷密度、偶极矩、能量,以及振动频率。随着电场强度的增大,H_(2)O和(H_(2)O)_(2)分子的红外振动光谱都出现了收缩现象,即高频的O―H伸缩振动红移,而低频的H―O―H弯曲振动蓝移,这与文献中模拟结果一致。本文为理解振动斯塔克效应提供了一个简单清晰的理论计算案例。展开更多
基于介质阻挡放电工作原理,设计了气体-液体两相放电装置。采用发射光谱诊断技术,结合Stark展宽理论,系统研究了工作电压、气体流量、液体高度等参数对气体-液体两相放电发射光谱及电子密度的影响规律。结果表明,氢氦混合气-生物油两相...基于介质阻挡放电工作原理,设计了气体-液体两相放电装置。采用发射光谱诊断技术,结合Stark展宽理论,系统研究了工作电压、气体流量、液体高度等参数对气体-液体两相放电发射光谱及电子密度的影响规律。结果表明,氢氦混合气-生物油两相界面放电时,氢发射光谱特征谱线Hα强度最高,而巴耳末系的另外三条特征谱线未检出,放电低温等离子体的电子能量介于12.09-12.75 e V间;氢发射光谱α特征峰强度和电子密度随工作电压的增加而增加,随气体流量、液体高度的增加而减小。展开更多
We have studied highly excited sodium in various electric fields, parallel electric and magnetic fields, with one σ andπ photon irradiation, and even in a magnetic field with a complex laser polarization configurati...We have studied highly excited sodium in various electric fields, parallel electric and magnetic fields, with one σ andπ photon irradiation, and even in a magnetic field with a complex laser polarization configuration. The σ spectra shows a simple linear Stark effect with the applied electric field, while the π spectra exhibits a strong non-linear dependence on the electric field. The π transitions in parallel fields show a similar behavior to that in a pure electric field but the spectra get more smooth due to the magnetic field. The diamagnetic spectrum with laser polarization angles between 0 and π /2 proves that it can be reproduced by simple linear combination of π and σ components, indicating there is no interference between the π and σ channels. A full quantum calculation considering the quantum defects accounts for all the observations. The quantum defects, especially for the channel np, play an important role in the spectral profile.展开更多
The arc spectrum of TIG welding in high pressure was analyzed by Stark broadening. Using the characteristic line of Arl in welding arc, a study of electron density in high pressure revealed that the electron density o...The arc spectrum of TIG welding in high pressure was analyzed by Stark broadening. Using the characteristic line of Arl in welding arc, a study of electron density in high pressure revealed that the electron density of the welding arc had an upward trend with the pressure increase. According to data analysis, a curve of relationship between electron density alwl environmental pressure was established. It has a universal significance for change of electron density in high pressure. Through the analysis of electron density changing in time-domain in different pressure, a theoretical basis was provided for the problem of poor arc stability in high pressure.展开更多
基金the National Basic Research Program of China(Grant No.2012CB921603)the National Natural Science Foundation of China(Grant Nos.61078001,61178009,11274209,and 60778008)+2 种基金the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China(Grant No.J1103210)the Natural Science Foundation of Shanxi Province,China(Grant No.2012011003-2)the Shanxi International Collaboration Program(Grant No.2010081046)
文摘The Stark structures in a cesium atom around n=18 are numerically calculated. The results show that the components of 20D states with a small azimuthal quantum number ｜m｜ shift upward a lot, and those with a large ｜m｜ shift downward a little within 1100 V/cm. All components of P states shift downward. Experimental work has been performed in ultracold atomic cesium. Atoms initially in 6P3/2 state are excited to high-n Rydberg states by a polarization light perpendicular to the field, and Stark spectra with ｜m｜=1/2,3/2,5/2 are simultaneously observed with a large linewidth for the first time. The observed spectra are analyzed in detail. The relative transition probability is calculated. The experimental results are in good agreement with our numerical computation.
文摘振动斯塔克效应(vibrational Stark effect)是指振动光谱在外加电场作用下发生移动的现象,该效应在现代化学中有广泛的应用。为了增进对振动斯达克效应的理解,本文选择了水的单分子H_(2)O和二聚体分子(H_(2)O)_(2),通过密度泛函理论计算展示了外加定向电场对这两个分子的振动频率的影响。计算显示,外加定向电场直接影响分子的几何结构、电荷密度、偶极矩、能量,以及振动频率。随着电场强度的增大,H_(2)O和(H_(2)O)_(2)分子的红外振动光谱都出现了收缩现象,即高频的O―H伸缩振动红移,而低频的H―O―H弯曲振动蓝移,这与文献中模拟结果一致。本文为理解振动斯塔克效应提供了一个简单清晰的理论计算案例。
文摘基于介质阻挡放电工作原理,设计了气体-液体两相放电装置。采用发射光谱诊断技术,结合Stark展宽理论,系统研究了工作电压、气体流量、液体高度等参数对气体-液体两相放电发射光谱及电子密度的影响规律。结果表明,氢氦混合气-生物油两相界面放电时,氢发射光谱特征谱线Hα强度最高,而巴耳末系的另外三条特征谱线未检出,放电低温等离子体的电子能量介于12.09-12.75 e V间;氢发射光谱α特征峰强度和电子密度随工作电压的增加而增加,随气体流量、液体高度的增加而减小。
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922003)the National Natural Science Foundation of China(Grant Nos.11174329 and 91121005)
文摘We have studied highly excited sodium in various electric fields, parallel electric and magnetic fields, with one σ andπ photon irradiation, and even in a magnetic field with a complex laser polarization configuration. The σ spectra shows a simple linear Stark effect with the applied electric field, while the π spectra exhibits a strong non-linear dependence on the electric field. The π transitions in parallel fields show a similar behavior to that in a pure electric field but the spectra get more smooth due to the magnetic field. The diamagnetic spectrum with laser polarization angles between 0 and π /2 proves that it can be reproduced by simple linear combination of π and σ components, indicating there is no interference between the π and σ channels. A full quantum calculation considering the quantum defects accounts for all the observations. The quantum defects, especially for the channel np, play an important role in the spectral profile.
基金Acknowledgement The authors wish to thank the financial support for this research from the National High Technology Research and Development Program of China （863 Program） （Grant No. 2002AA602012） and the National Natural Science Foundation of China （Grant No. 40776054）.
文摘The arc spectrum of TIG welding in high pressure was analyzed by Stark broadening. Using the characteristic line of Arl in welding arc, a study of electron density in high pressure revealed that the electron density of the welding arc had an upward trend with the pressure increase. According to data analysis, a curve of relationship between electron density alwl environmental pressure was established. It has a universal significance for change of electron density in high pressure. Through the analysis of electron density changing in time-domain in different pressure, a theoretical basis was provided for the problem of poor arc stability in high pressure.
