虚阴极振荡器中微波产生的解析理论

 用解析方法研究了虚阴极振荡器中微波产生的机理, 给出了小信号增益公式和饱和功率的标度。由此得到的结论是: 虚阴极振荡器的辐射一般情况下是由相位受到RF场调制的从虚阴极反射的电子束流产生的, 当注入电流稍大于第一临界电流时，有最高辐射增益区，但反射电流较小；当注入电流稍大于第二临界电流时，有较高辐射增益区，反射电流也较大。     

氢化物-原子吸收光谱法测定冶金企业废水中的砷

采用HNO3/HClO4(体积比10∶1)消解冶金废水样品,经6mol.L-1 HCl溶液酸化后,加入碘化钾(3%)、抗坏血酸(1%)及硫脲(1%)混合溶液进行还原,用氢化物-原子吸收光谱法(HG-AAS)测定了样品中的As含量.结果表明,该方法的检出限为0.297μg/L,相对标准偏差RSD为5.463%,样品加标回收率为93%～108%;其操作方便、选择性好、灵敏度高、干扰少,适合于复杂废水中微量和痕量As的测定.     

Conversion of CH4, steam and O2 to syngas and hydrocarbons via dielectric barrier discharge

The conversion of CH4 with oxygen and steam in a dielectric barrier discharge (DBD) was studied in the paper to discuss the effects of different factors,such as the content of feed-in gas,the applied voltage and frequency.The results showed that a lower ratio of CH4 to O2 always resulted in a higher conversion of CH4.When it was 2,the conversion reached 32.43% without steam introduced into the system.The main effect of steam was increasing the selectivity to CO.The reaction was accelerated and the selectivities to CO and hydrocarbons were enhanced by increasing the applied voltage.It was also observed that a higher frequency led to a lower current and then restrained the reaction.     

ENTROPY PRODUCTION RATE OF THE MINIMAL DIFFUSION PROCESS

The entropy production rate of stationary minimal diffusion processes with smooth coefficients is calculated. As a byproduct, the continuity of paths of the minimal diffusion processes is discussed, and that the point at infinity is absorbing is proved.     

基于回声增强高次谐波产生的双色自由电子激光

基于回声增强高次谐波产生，提出了能够产生软X射线波段双色自由电子激光脉冲的方案，并对该方案进行了理论模拟和关键技术研究。研究给出了双色种子激光的产生方案，搭建了双色种子激光系统，该系统可以产生中心波长分别为264.8 nm和265.3 nm、脉冲延时可调的双色种子激光。基于该双色种子激光，在模拟中最终可以得到波长分别为5.884 nm和5.894 nm、峰值功率约为300 MW、脉冲延时可调的软X射线双色自由电子激光辐射脉冲。     

超氧阴离子

介绍了超氧阴离子 O-·2 的产生、检测、化学性质、反应动力学、生物学研究、应用等方面的研究进展。