在放电间隙较大的介质阻挡放电中， 利用高速照相机， 同时观察到了体放电（VD）和沿面放电(SD)。 采用光谱法， 研究了VD和SD的光谱线形随放电参数的变化。 在氩气介质阻挡放电中， 测量了VD和SD的Ar Ⅰ（2P2→1S5）谱线展宽和频移随气压及放电间隙的变化。 结果发现： SD的展宽和频移均比VD的大， 说明SD的电子密度高于VD的电子密度； 随着压强从40 kPa增大到60 kPa， VD和SD的谱线展宽及频移均增加， 表明它们的电子密度均随压强的增大而升高； 随着d值从3.8 mm增大到4.4 mm， VD和SD的谱线展宽也增加， 反映它们的电子密度均随d值的增大而增加。

The volume discharge (VD) and surface discharge (SD) were observed in dielectric barrier discharge with a relatively large discharge gap simultaneously by using a high-speed camera. The variations of the spectral line profiles of VD and SD as a function of the discharge parameters were studied by using optical emission spectra. The changes in the width and shift of Ar Ⅰ（2P2→1S5）spectral lines of VD and SD with gas pressure and discharge gap were measured in dielectric barrier discharge in argon. It was found that both the width and shift of SD are bigger than those of VD, indicating that the electron density of SD is higher than that of VD. The width and shift of VD and SD increase with the gas pressure increasing, indicating that the electron density of VD and SD increases with the gas pressure increasing. The width of VD and SD increases with the gas gap d increasing from 3.8 to 4.4 mm, reflecting that the electron density of VD and SD increases with d increasing.