大气压针板介质阻挡放电中微流注、电晕和辉光放电相互转换研究（英文）

To discuss the modes of dielectric barrier discharge(DBD) between needle-to-plane electrodes in air,DBD is generated and observed on a needle-to-plane device at atmospheric pressure air.Fast images of the DBD are taken by using a charge couple device(CCD) cinema with a macro lens,while the electrical and photo-electricity waveforms of the DBD are recorded.The current waveforms show that under an applied voltage of 3 kV,there are numerous short current pulses in both positive and negative half-periods of discharges.However,under 6 kV,there are still the numerous short current pulses in the positive half-periods,but only one wide current pulse in each negative half-period.This difference is also found in the photoelectric signals.The streamer,corona and glow discharges are observed from the images of the discharges at different applied voltages.The structure of glow discharge in the negative period is exactly the same as that of the low pressure glow discharge.However,in the positive period of discharge there is always a streamer.In the negative period of discharge,while the applied voltage increases,the transition from corona to glow discharge is observed.The progress of a transition between streamer and glow discharge at 6 kV during one period is analyzed.The glow discharge appearance is determined by two factors: the discharge current is limited to a certain extent by the dielectric layer; the charges deposited on the dielectric layer during the last half period enhance the intensity of the electric field.At an insufficient applied voltage,the cathode drop leads to no glow discharge,but Trichel pulses.     

谷氨酸高产菌Zx-507菌株的选育报告

以钝齿棒状杆菌[Corynebacterinm crenanatum]T6-13为出发菌,经溶菌酶脱壁成原生质体后,用紫外线进行诱变培育得Zx—507谷氨酸高产菌。该菌株用于生产后,谷氨酸产量比原菌株提高27％,转化率提高15％,一次冷冻等电提取收率75%,取得了较大的经济效益。