泡沫电介质中高压脉冲放电的破岩机理研究

针对水介质中压力冲击波在破碎岩石方面的应用,研究高压脉冲放电在泡沫电介质中的放电机理。根据不同电介质的电离特性配比了两种阴阳离子的泡沫电介质,数值模拟分析了在不同电介质环境下高压脉冲放电时的冲击压力变化规律。运用气泡动力学方程分析了气泡在放电过程中的爆破形态,分析了不同放电电压、放电间隙等条件对气泡爆破形态的影响规律。并进行了初步室内实验,验证了泡沫作为电介质实现高压脉冲放电破碎岩石的可行性。由于泡沫可产生空泡效应,能增加爆破效果,而且泡沫在防漏、密封性能要求等方面都优于水介质,具有更广阔的应用前景。     

氮氧混合气体高压脉冲电晕放电等离子体的分子束质谱诊断研究

利用具有三级差分抽气系统的分子束质谱仪为检测手段，对N2，O2混合气体的线板式高压脉冲电晕放电等离子体阴极板区的正离子成分进行了诊断研究。实验结果表明：在放电反应室N2,O2混合气体压力1330～3325Pa，峰值电压4～10kV及放电重复频率10～100Hz范围内，N2^ 和O^ 流强相当，N^ 流强约为N2^ 流强的2～10倍，N^ 、N2^ 和O^ 流强随脉冲峰值电压、放电重复频率的升高而增大，随放电气压的变化则存在一极值。     

高压脉冲电晕放电氮等离子体的分子束质谱诊断研究

克服强电磁场干扰，以具有三级差分抽气系统的分子束质谱为手段，对线板式高压脉冲电晕放电Ｎ２等离子体阴极板区的正离子成分进行了首次诊断研究。发现在各种实验条件下，Ｎ＾＋离子流强度均显大于Ｎ２＾＋；Ｎ＾＋及Ｎ２＾＋离子流强度随放电电压、放电频率升高而增大，随放电室气压变化则存在一极值。对Ｎ２等离子体中所包含的主要基元物理－化学过程进行了讨论。     

氮氧混合气体高压脉冲电晕放电等离子体的分子束质谱诊断研究

利用具有三级差分抽气系统的分子束质谱仪为检测手段 ,对N2 ,O2 混合气体的线板式高压脉冲电晕放电等离子体阴极板区的正离子成分进行了诊断研究。实验结果表明 :在放电反应室N2 ,O2 混合气体压力 1330～ 332 5Pa ,峰值电压 4～10kV及放电重复频率 10～ 10 0Hz范围内 ,N+ 2 和O+ 流强相当 ,N+ 流强约为N+ 2 流强的 2～ 10倍。N+ ,N+ 2 和O+ 流强随脉冲峰值电压、放电重复频率的升高而增大 ,随放电气压的变化则存在一极值     

高电压脉冲放电破岩系统建模分析

等离子体通道是高电压脉冲放电破岩的“工具”,通道形成及膨胀使岩石破碎过程伴随着通道阻抗的急剧变化。为更好地分析高电压脉冲放电破岩系统的能量利用效率,结合破岩空腔的脱模分析获得了通道的穿透深度及实际长度,基于能量平衡方程建立了等离子体通道阻抗模型,建立了高电压脉冲放电破岩系统的电路分析模型,仿真计算与试验结果对比表明该模型能够准确分析高电压脉冲放电破岩系统的输出特性,为系统优化提供理论指导。     

高压脉冲电晕放电氮等离子体的分子束质谱诊断研究

克服强电磁场干扰 ,以具有三级差分抽气系统的分子束质谱为手段 ,对线板式高压脉冲电晕放电N2 等离子体阴极板区的正离子成分进行了首次诊断研究。发现在各种实验条件下 ,N 离子流强度均显著大于N 2 ;N 及N 2 离子流强度随放电电压、放电频率升高而增大 ,随放电室气压变化则存在一极值。对N2 等离子体中所包含的主要基元物理 化学过程进行了讨论     

高压对高功率脉冲磁控放电等离子体注入与沉积氧化钒薄膜的影响

利用高功率脉冲磁控放电等离子体注入与沉积技术制备了氧化钒薄膜,分别采用X射线衍射仪、原子力显微镜、扫描电子显微镜和电化学分析仪研究了不同高压幅值对氧化钒薄膜的相结构、表面形貌、截面形貌以及耐腐蚀性能的影响。结果表明制备的氧化钒薄膜以VO2(-211)相为主,还含有少量的VO2(111)、VO(220)、VO(222)相。不同高压下氧化钒薄膜表面致密、平整,其表面粗糙度仅为几个纳米,显示出良好的表面质量。氧化钒薄膜表现出典型致密的柱状晶生长形貌,且随着高压增加,氧化钒薄膜膜层厚度有所下降。氧化钒薄膜耐腐蚀性能较纯铝基体有较大提高,腐蚀电位提高0.093V,腐蚀电流下降1～2个数量级;当高压为-15kV时,氧化钒薄膜腐蚀电位最高,腐蚀电流最低,表现出最佳的耐蚀性能。     

复合高功率脉冲磁控溅射放电等离子体特性

高功率脉冲磁控溅射具有高的金属离化率,在薄膜制备表现出巨大的优势,成为当前磁控溅射技术领域一个新的发展趋势。高功率脉冲磁控溅射的放电特性、等离子体特性等微观参数对薄膜质量控制具有决定性作用,分析宏观参数如何影响微观参数,有利于提高薄膜质量,稳定工艺。因此,本文研究了脉冲与直流电源并联模式的复合高功率脉冲磁控溅射过程中,脉冲电压(400~800 V)对Ti、Cr靶在Ar气氛中的放电特性、等离子体参数(等离子体电势、电子温度、电子密度)、基体电流的影响。结果表明:复合高功率脉冲磁控溅射Ti、Cr靶放电过程中,脉冲电压的增加有利于脉冲作用期间的靶电压、靶电流、基体电流增加;当Ti靶脉冲电压为600 V或Cr靶脉冲电压为700 V时,电子密度出现较大值。Cr靶与Ti靶放电相比,前者的靶电流、基体电流、等离子体电势、电子温度比后者更高,而电子密度却更低。     

空气中脉冲电晕放电N2（C3Ⅱu—B3Ⅱg）发射光谱的实验研究

在常温常压下，利用发射光谱法测量了正脉冲、负脉冲及双极性脉冲电晕放电N2(C3Ⅱu-B3Ⅱg)发射光谱相对强度沿线一筒式反应器的径向分布，得到了高能电子(≥11．03eV)密度沿线一筒式反应器的径向分布情况和随电压升高而增大的线性变化关系，并对三种不同脉冲形式进行了比较。     

水下等离子体声源脉冲放电光谱测量与分析

本文采用HR4000CG-UV-NIR光纤光谱仪和NI-PCB压力传感器测量了水下等离子体声源脉冲放电光谱和强声波的压力幅值,分析了声与光之间的能量转换关系,并重点观察了不同放电参数对光谱特征的影响。实验结果表明,等离子体声源脉冲放电光谱为连续谱,能量主要集中在500 nm左右的谱段;放电产生的光能量和声波能量相互竞争,具有此消彼长的关系;提高放电电压,减小电极间隙距离可以提高光的辐射强度和半峰值谱宽度;增大电极间隙距离,将使发光能量向远紫外区移动;更换电极材料将明显改变光的谱分布和强度变化。     

Discharge dynamics and characteristics of atmospheric glow discharge excited by sub-microsecond high voltage pulses

A study of sub-microsecond high voltage pulse excited glow discharges in atmospheric helium is carried out here. The discharge is generated between the powered copper electrode and ground electrode covered with a ceramic sheet. The electrical and optical characteristics of two discharge events in each voltage pulse in terms of discharge current amplitude, current pulse duration, time instant at current peak and accumulated charge in discharge are investigated on voltage pulse duration and pulse voltage magnitude. The time-resolved imaging with 5 ns exposure time is used to demonstration the spatio-temporal evolution of discharge. It is found that the first discharge depends markedly on pulse voltage magnitude and space charge accumulation on ceramic sheet surface plays an important role on ignition of second discharge.     

直流高压标准装置国际近况

简单介绍电磁计量领域关键比对数据库中直流高压参数标准装置-直流高压分压器的原理,分析了电阻发热、电晕放电以及绝缘支架漏电对直流高压分压器的影响,归纳总结目前国际上先进计量机构的直流高压标准装置的结构型式以及在校准时引入的不确定度来源。给出了直流分压器达到10-6量级的必要条件。     

Study on formation process of surface plasma

A suitable equation group used to describe the establishment process and characteristics of induced dielectric barrier discharge (IDBD) plasma have been determined. Some experiments have been done which are used to examine whether the equation group is right or not. The examination results show that the equation groups are correct and can be used to design an IDBD device.     

Wall charge characteristics in accordance with square and ramped reset pulse in alternating current plasma display panels (AC-PDPs)

The characteristics of wall charge after squared and ramped reset pulse have been experimentally investigated in an AC-PDP with a versatile driving simulator (VDS) system, in which arbitrary driving waveforms and sequences can be edited. Rising or falling times of ramped reset pulse have been varied to be 0, 30, 70, 110 and 150 V under fixed zero falling or rising times, respectively, and the reset voltage is fixed to be 320 V. The longer rising (either falling) times under zero falling (either rising) time in reset pulse make the less IR intensity caused by weak self-discharge that occurred at falling (either rising) time in reset pulse. Generally, the ramped reset pulses have been observed to have large wall voltages of 100 to 200 V while the squared reset pulses are to be 4 V by the weak self-discharges at falling time of reset pulse in this experiment.     

Effect of temperature on the decomposition of trifluoromethane in a dielectric barrier discharge reactor

This study investigated the decomposition of trifluoromethane (HFC-23) by using nonthermal plasma (NTP) generated in a dielectric barrier discharge (DBD) reactor. The main problem of the NTP process may be its low decomposition efficiency for fluorinated carbons, which can be resolved by introducing a catalyst and operating the process at elevated temperatures. The effect of temperature on the HFC-23 decomposition was examined with alumina or glass beads as the packing material in the NTP reactor. With other conditions kept constant, higher temperature resulted in higher HFC-23 decomposition efficiency, and it was shown that the NTP reactor packed with alumina beads acting as a catalyst decomposed HFC-23 more effectively than that with glass beads. When the reactor temperatures were 300 °C and 250 °C (flow rate: 60 L h^− 1; HFC-23 concentration: 2000 ppm), the decomposition efficiency in the presence of the alumina catalyst approached 100% at input powers of 60 W and 100 W, respectively. The main products from HFC-23 were CO and CO₂, which nearly accounted for the amount of HFC-23 decomposed. With respect to the decomposition efficiency, the combination of the NTP and the catalyst was more advantageous than using them separately.     

高压电场下自然对流蒸发器结霜的试验研究

为研究高压电场下自然对流蒸发器表面结霜的过程及电压等参数对该结霜过程的影响，对其在肋片式换热器的结霜过程进行微细观可视化研究。试验中，在冷表面Tw=-14℃，湿空气温度为15℃至20℃，相对湿度为20％～90％，静电场电压为0-40kV范围内，受高压不均匀电场的作用，换热器铜管表面的结霜分布不均匀，高压电场有明显抑制结霜的作用。     

高频脉冲电镀镍钴合金工艺及性能的研究

采用高频脉冲电流，制备Ni-Co复合镀层。通过正交试验设计的方法，重点考察了脉冲频率、占空比、平均电流密度、镀液pH值、温度及CoSO4·7H2O的浓度对镀层在15％H2SO4溶液中的阳极极化行为的影响，从而遴选出最佳电镀工艺：脉冲频率140kHz，占空比0．25，平均电流密度3A／dm，镀液pH值3，温度45℃，硫酸钴浓度20g／L。同时，对高频脉冲电镀与直流电镀进行比较。     

Influence of electrode configuration on ozone synthesis and microdischarge property in dielectric barrier discharge reactor

Characteristics of a dielectric barrier discharge were investigated experimentally to clarify an influence of an electrode configuration on ozone synthesis and a microdischarge behavior. Three difference configurations: plane, trench and multipoint were employed as ground electrode. The alumina dielectric barrier coated plane electrode was used as a high-voltage electrode, to which a sinusoidal high-voltage was applied with 10 kHz frequency. Pure oxygen gas was fed into the reactor with gas flow rate of 5 L/min. The maximum yielding rate increased from 80 to 120 g/kWh by changing an electrode configuration from plane to multipoint, which has 528 number of a right-pyramid shape projection on a 6 cm × 22 cm plane electrode. The yielding rate was strongly dependent on a produced ozone concentration in the plane electrode case, whereas slightly depended on the concentration in the multipoint electrode case. The electrode configuration also affected a number of the microdischarges per one applied voltage cycle. The multipoint electrode showed the largest number of microdischarges at same input energy.     

高活性超低单醇含量聚醚多元醇合成高回弹聚氨酯泡沫塑料的研究

以双金属络合物 (DMC)为催化剂 ,首先制备出超低单醇含量、高相对分子质量的聚氧化丙烯醚多元醇 ,再采用碱金属化合物催化剂 ,用环氧乙烷封端 ,制得高活性聚醚多元醇。用这种聚醚采用全水发泡体系合成高回弹软质聚氨酯泡沫塑料 ,通过物理机械性能的检测 ,实验结果表明 ,用DMC聚醚多元醇比常规的PPG聚醚多元醇制备的高回弹软质聚氨酯泡沫塑料具有更优越的理化性能和开发应用价值     

La,Nb复合掺杂Sr2Ta2O7陶瓷高温介电性能研究

研究了La,Nb复合掺杂Sr2Ta2O7陶瓷的高温介电性能,A位镧掺杂提高了材料体系的电阻活化能,从而提高了高温电阻率,Sr1.98 La0.02Ta2O7在700℃电阻率为3.65×107,和Sr2Ta2O7相比(4.37×106)电阻率提高了一个数量级;Nb掺杂对Sr2Ta2O7结构影响不大,Nb取代Ta的位置后主要影响垂直于Ta-O线的O离子位移.铌掺杂有效地提高了材料体系的居里温度,从-173℃(Sr2Ta2O7)提高到-11℃(Sr1.98 La0.02Ta1.9Nb0.1O7).