N503为载体的支撑液膜体系中汞(Ⅱ)的迁移研究

研究了以多孔聚偏氟乙烯为支撑体,N503为膜载体,煤油为膜溶剂的支撑液膜体系中Hg(Ⅱ)的迁移行为,测定了Hg(Ⅱ)与N503在煤油溶剂中的萃合物组成和条件萃取常数,考察了料液相pH值、载体浓度、料液相及反萃相中Cl-浓度等因素对Hg(Ⅱ)迁移的影响,获得Hg(Ⅱ)迁移的最佳条件:料液相pH=2.5～3.0,Cl-浓度为0.1 mol/L,载体浓度为0.706 mol/L,反萃相中Cl-浓度为0.8 mol/L.在最佳实验条件下,当Hg(Ⅱ)起始浓度为5.0×10-5 mol/L时,迁移120 min,Hg(Ⅱ)的迁移率可达99.6%.Hg(Ⅱ)在N503-煤油支撑液膜体系中的扩散层厚度δa为1.57×10-5 m,膜内扩散系数d0为7.26×10-13 m2/s,确立了Hg(Ⅱ) 的渗透系数P方程.     

Splitting Modulus Finite Element Method for Orthogonal Anisotropic Plate Benging

ＩｎｔｒｏｄｕｃｔｉｏｎＡｃｃｏｒｄｉｎｇｔｏｔｈｅｄｉｆｆｅｒｅｎｃｅｏｆｉｎｄｅｐｅｎｄｅｎｔｖａｒｉａｂｌｅ,ａｌｌｔｈｅｐｒｏｐｏｓｅｄｆｉｎｉｔｅｅｌｅｍｅｎｔｍｏｄｅｌｓｃａｎｂｅｄｉｖｉｄｅｄｉｎｔｏｆｉｖｅｃｌａｓｓｅｓ:1 )Ｄｉｓｐｌａｃｅｍｅｎｔｍｏｄｅｌ[1- 4],ｗｈｉｃｈａｓｓｕｍｅｓｄｉｓｐｌａｃｅｍｅｎｔｉｓｃｏｎｔｉｎｕｏｕｓｉｎｔｈｅｅｎｔｉｒｅｆｉｅｌｄ ;2 )Ｅｑｕｉｌｉｂｒｉｕｍｍｏｄｅｌ[4 ],ｗｈｉｃｈａｓｓｕｍｅｓｓｔｒｅｓｓｉｓｂａｌａｎｃｅｏｎｅａｃｈｅｌｅｍ…     

Research on reverse recovery characteristics of SiGeC p-i-n diodes

This paper analyses the reverse recovery characteristics and mechanism of SiGeC p-i-n diodes. Based on the integrated systems engineering (ISE) data, the critical physical models of SiGeC diodes are proposed. Based on heterojunction band gap engineering, the softness factor increases over six times, reverse recovery time is over 30% short and there is a 20% decrease in peak reverse recovery current for SiGeC diodes with 20% of germanium and 0.5% of carbon, compared to Si diodes. Those advantages of SiGeC p-i-n diodes are more obvious at high temperature. Compared to lifetime control, SiGeC technique is more suitable for improving diode properties and the tradeoff between reverse recovery time and forward voltage drop can be easily achieved in SiGeC diodes. Furthermore, the high thermal-stability of SiGeC diodes reduces the costs of further process steps and offers more freedoms to device design.     

High Current Operation of a Semi-insulating Gallium Arsenide Photoconductive Semiconductor Switch Triggering a Spark Gap

A transient peak current as high as 5.6 kA is obtained by a GaAs photoconductive semiconductor switch （PCSS） in series with a spark gap. Based on the characteristics of the GaAs PCSS, mechanisms of discharge between the PCSS and the spark gap are discussed. It is implied that a hybrid operation mode of photo-activated charge domain occurs due to the superposition of the bias voltage and the instantaneous radio frequency voltage.     

Stability Analysis of Maxwell Viscoelastic Pipes Conveying Fluid with Both Ends Simply Supported

ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｉｓｗｅｌｌ＿ｋｎｏｗｎｔｈａｔｓｉｍｐｌｙｓｕｐｐｏｒｔｅｄｐｉｐｅｓｃｏｎｖｅｙｉｎｇｆｌｕｉｄａｒｅｎａｍｅｄａｓｇｙｒｏｓｃｏｐｉｃｃｏｎ ｓｅｒｖａｔｉｖｅｓｙｓｔｅｍｂｅｃａｕｓｅｉｔｓｅｎｅｒｇｙａｔｔｈｅｅｘｉｔｉｓｅｑｕａｌｔｏｔｈａｔａｔｔｈｅｅｎｔｅｒ[1].Ｔｈｉｓｓｙｓｔｅｍｗａｓｓｔｕｄｉｅｄｂｙｓｏｍｅｓｃｈｏｌａｒｓａｔｈｏｍｅａｎｄａｂｒｏａｄ .Ｐａｉｄｏｕｓｓｉｓ[2 ]ｓｔｕｄｉｅｄｔｈｅｐｒｏｂｌｅｍｏｆｄｙｎａｍｉｃｓａｎｄｓｔａｂｉ…