AC-PDP中等离子体电场的实验研究

用激光荧光技术直接测量了AC PDP单元高气压He和He Xe0 1%放电中的电场行为,估算了由放电电场产生的AC PDP单元上的壁电压。选用高气压下寿命较长的氦的亚稳态2s3S,比较主量子数n=8和n=9的Stark分裂谱,使电场的测量精度提高到10%。电场和壁电压的时间分布描述了PDP单元的放电行为。

电场增强催化甲烷合成碳二烃催化剂影响研究(英文)

本研究提出了在常温、常压电场增强等离子体条件下甲烷直接转化合成碳二烃的洁净工艺 ,在不同的放电电压、放电功率、甲烷进料流量和不同的催化剂作用下 ,甲烷能够以不同的转化率和选择性转变为碳二烃。对影响甲烷转化率和碳二烃选择性的因素 :放电电压、放电功率、甲烷进料流量和催化剂进行了研究 ,对催化剂性能进行了比较 ,并探讨了反应机理。结果表明 ,适宜的工艺条件 :放电电压 2 0kV～ 4 0kV ;输入功率 :2 0W～ 4 0W ;合适的甲烷进料流量 :30mL/min～ 70mL/min。在该条件下 ,碳二烃的选择性可以达到 95 % ;催化剂对甲烷转化率的影响顺序为MnO2 /Al2 O3 >Ni/Al2 O3 >MoO3 /Al2 O3 >Ni/NaY >Pd/ZSM 5 >Ni/H4Mg2 Si3 O4>Ni/ZSM 5 >Co/ZSM 5 >无催化剂。

Characteristics of fulvic acid by high voltage pulse discharge plasma

High voltage pulse natural organic matter （NOM） toxic by-products. Fulvic acid discharge plasma can remove and produce no production of solution was treated by high voltage pulse discharge plasma in this paper. It was shown that： for the reason of thermolysis and oxidation, the pH and Oxidation Reduction Potential （ORP） of solution decreased gradually with the increase of peak voltage and fulvic acid solution concentration, meanwhile the temperature and turbidity of solution increased gradually. Adding hydrochlorid acid in the treatment could amplify the effect of plasma. When the concentration of NOM as the surrogate parameter, Ultraviolet Absorbancy Degree （UV254） increased slowly by the effect of plasma, while the degradation of Total Organic Carbon （TOC） was first-order reaction. The removal rate of TOC increased from 22.6% to 33.4% by high voltage pulse electrical field of 35 kv, and from 25.6% to 36.7% with the addition of hydrochlorid acid. This paper may provide some basis for the scale-up design of water treatment process by high voltage pulse discharge plasma with other technologies.

Action of Runaway Electron Preionized Diffuse Discharges on Steel： Composition, Structure, and Properties

In the work, we studied the effect of the plasma of a runaway electron preionized （REP） diffuse discharge （DD） on the composition, structure, and properties of ST3PS steel surface layers. Voltage pulses with an incident wave amplitude of up to 30 kV, FWHM of around 4 ns, and rise time of around 2.5 ns were applied to the gap in an inhomogeneous electric field. The ST3PS steel specimens exposed to this type of discharge revealed changes in their defect subsystem, suggesting that the runaway electron preionized diffuse discharge provides surface hardening of the steel.

The relations between density of FACs in the Plasma Sheet Boundary Layers and Kp index

We have studied 172 field-aligned currents （FACs） cases observed by the ClusterlI satellites when they crossed the plasma sheet boundary layer （PSBL） in the magnetotail from July to October 2001. We mainly analyzed the relationship between the characteristic of FACs at the PSBL in magnetotail and the Kp index. The main results indicated the followings： 1） In the different geomagnetic activity levels, the relative occurrence of FACs in PSBL increased monotonically with geomagnetic activity. 2） The density of FACs in PSBL increased monotonically with Kp index. In the storm main phase, the density of FACs increased dramatically, the maximum FACs approximately equaled 19.05 nA m-2 while Kp equaled 5.3） The variation of FACs density in PSBL was consistent with the variation of the Kp index. However, when AE〈800 nT, FACs density in PSBL increased with increasing AE, and when AE〉800 nT, it decreased with increasing AE. Therefore, our results suggested that the FACs density in PSBL had a closer correlation with Kp index.

Physical characteristics with SPP in the metallic nanowires structure

In this work, the terahertz （THz） electromotive force （EMF） of the surface plasmon （SP） electric field and field strength was investigated in its propagation direction. Based on the nanowires structure, we introduced physical models which were light wave energy of surface plasmon polariton （SPP） pulse and the variation of EMF changes in the active condition. Results of theory and verification showed SPP generated EMF with 10-2-10 V among wire radii of 5-30 nm; the electric field was up to 10^5-1066V/cm in the radius of 5 nm; the electric field intensity induced localization at λ=850 nm, and at the same time light intensity amplified 40 times. The characteristics which are femtosecond SPP pulse response and force-field amplifier in this work are significant for nonlinear spectroscopy research.

Characteristics of low altitude ionospheric electric field over Hainan Island,China

A sounding rocket experiment undertaken by the Chinese Meridian Project from a low latitude station on Hainan Island(19.5°N,109.1°E),China,measured the DC electric field during 05:45-05:52 LT on April 5,2013.The data observed using a set of electric field double probes,as part of the rocket's scientific payload,revealed the special profile of how the vectors of the DC electric field vary with altitude between 130 and 190 km.During the experiment,the vertical electric field was downward,and the maximum vertical electric field was nearly 5.1 mV/m near the altitude of 176 km.The zonal electric field was eastward and slightly less than 0.6 mV/m.The plasma drift velocity was estimated from the E×B motion,and the zonal drift velocity was eastward and of the order of 100 m/s.The zonal wind velocity was also estimated using the drift velocity near the maximum density height in the F1-region,and it was found to be nearly 120 m/s.This work constituted the first in situ measurement of the DC electric field conducted within the Fl-region(between 130 and 190 km) in the East Asian Sector.

Investigation on 3D flow field induced by a plasma actuator with serrated electrode

This paper presents an experimental investigation on flow field induced by a dielectric barrier discharge(DBD) plasma actuator with serrated electrodes in still air to further improve its flow control effectiveness. For comparison, the actuator with widely used linear electrodes was also studied. Experiments were carried out using 2D particle image velocimetry. Particular attention was given to the flow topology, discharge phenomenon, and vortex formation mechanism. Results showed that a 2D wall jet was induced by the linear actuators, whereas the plasma actuators with serrated electrode introduced a series of streamwise vorticities, which might benefit flow control(e.g., enhancing the momentum transport in the separated boundary flow). In addition, the mechanism of 3D flow topology induced by the serrated DBD actuator was analyzed in detail.

Modified Bubble Core Fields and Bubble Shape in Laser Driven Plasma

Bubble core fields as well bubble shape modification due to the nondepleted electrons inside the bubble is investigated theoretically. It is found that the Mope of transverse fields are reduced significantly, however, the slope of longitudinal electric field, which plays a key role on electrons acceleration in bubble, changes little. Moreover a modified longitudinal compressed bubble shape leads to a shorter dephasing distance which makes the electrons acceleration energy reduced to some extent. As a comparison we perform particle-in-cell simulations whose results are consistent with that of our theoretical consideration.