顶吹浸没熔炼气泡和流体流动行为模拟研究

应用相似原理,建立水模型研究喷枪内旋流器位置和叶片数变化对于熔池搅拌和气泡后座的影响,应用高速摄影机和粒子成像测速系统对喷吹过程中的气泡生成和熔池内流体运动行为进行成像分析。水模拟研究表明,当旋流器叶片数为6片,在距离喷枪端部位置为9 cm时,获得最佳搅拌效果。试验结论比拟放大用于现场喷枪设计,效果改善明显。     

纯钨经高压扭转后韧性及热稳定性观察

采用高压扭转法,在440℃对纯钨进行大塑性变形(HPT)。硬度测试表明试样表面纯钨经高压扭转后硬度高达1150HV。差热分析(DSC)结果表明等效应变较小的试样再结晶温度较高(高于1450℃),等效应变较大的试样再结晶温度较低(约800℃)。XRD分析结果表明试样晶格应变达0.35%,晶格常数达0.3177 nm,位错密度达2.4 × 1015 m-2。高压扭转可以使纯钨在低温下实现固结并具有高强度,一定的韧性和热稳定性。     

补偿电网接地选线保护的研究

介绍一种既适合于中性点不接地电网,又适合于中性点经消弧线圈并电阻（或串电阻）接地电网（又称补偿电网）的接地选线保护,该选线保护装置解决了现有接地选线保护不能适应中性点经消弧线圈并电阻接地电网的问题．     

CSES GNSS ionospheric inversion technique,validation and error analysis

With the increased number of low Earth orbit (LEO) satellites equipped with global navigation satellite system (GNSS) receiver, the LEO based GNSS slant total electron content (TEC) and electron density profile (EDP) data play an increasingly important role in space weather and ionospheric research due to improved global coverage. China Seismo-Electromagnetic Satellite (CSES), which was launched in February 2018, is equipped with GNSS receiver for either precise orbit determination (POD) and ionospheric inversion. The purpose of the present paper is to validate CSES GNSS ionospheric inversion technique based on the real observations and verify the accuracy of TEC and EDP retrieval based on the simulated data. The following conclusions can be drawn: the epoch difference inversion (EDI) derived from CSES can successfully retrieve the EDPs without non-occultation side measurements; the technique of EDI and the calibrated TEC inversion (CTI) have similar behaviors in inversion errors, however, the retrieved NmF2 and hmF2 have a larger systematic error surrounding the equatorial ionization anomaly (EIA) where the assumption of spherical symmetry is often invalid; the precision and accuracy of retrieved TEC have been investigated in the paper based on the simulated data, and it is found that the accuracy of the retrieved TEC is relative to solar activity: the lower the F10.7 index, the higher the accuracy of retrieved TEC.