Feasibility of Trace Alcohol Congener Detection and Identification Using Laser-Induced Breakdown Spectroscopy

In this paper, a feasible scheme is reported for the detection and identification of trace alcohol congeners that have identical elemental composition using laser-induced breakdown spectroscopy （LIBS）. In the scheme, an intensive pulsed laser is used to break down trace alcohol samples and the optical emission spectra of the induced plasma are collected for the detection and identifq ication of alcohol molecules. In order to prepare trace alcohol samples, pure ethanol or methanol is bubbled by argon carrier gas and then mixed into matrix gases. The key issue for the scheme is to constitute indices from the LIBS data of the alcohol samples. Two indices are found to be suitable for alcohol detection and identification. One is the emission intensity ratio （denoted as H/C） of the hydrogen line （653.3 nm） to the carbon line （247.9 nm） for identification and the other is the ratio of the carbon line （as C/Ar） or the hydrogen line （as H/Ar） to the argon lines （866.7 nm） for quantitative detection. The calibration experiment result shows that the index H/C is specific for alcohol congeners while almost being independent of alcohol concentration. In detail, the H/C keeps a specific constant of 34 and 23 respectively for ethanol and methanol. In the meanwhile, the C/Ar and H/Ar indices respond almost linearly to the alcohol concentration below 1300 ppm, and are therefore competent for concentration measurement. With the indices, trace alcohol concentration measurement achieves a limit of 140 ppm using a laser pulse energy of 300 mJ.     

脉冲等离子体推进系统模态分析和试验验证

利用HyperMesh建立脉冲等离子体推进系统的网格模型,应用Abaqus完成模态分析,采用力锤法进行模态试验,得到脉冲等离子体推进系统的模态和振型。有限元分析和试验测试数据的对比结果表明,脉冲等离子体推进系统有限元模型的模态与实际产品的模态误差在2%以内。分析结果验证推进系统有限元模型的合理性,可为后续正弦振动、随机振动和冲击谱响应分析的正确性提供保障。     

微电推进系统研制及应用现状

200kg以下的微小卫星的轨道维持、姿态控制、阻尼补偿、编队飞行等任务对微电推进技术及产品提出了明确的应用需求,不同类型的微电推进在不同功率范围内有着各自的优势。本文对中国微小卫星12U立方星LPPT-5脉冲等离子体电推进系统、150kg小卫星LPPT-25脉冲等离子体电推进系统、6U立方星LVAT-1真空弧电推进系统、引力波探测卫星LCT-10胶体电推进系统、低轨小卫星星座LHT-40霍尔电推进系统方案及研制进展进行了论述,最后对正在研制的LRIT-40射频离子电推进系统与LECR-50微波离子电推进系统研制情况及后续应用进行了展望。     

Study of beam divergence and thrust vector eccentricity characteristics of the Hall thruster based on dual Faraday probe array planes and its applications

The accurate knowledge of the thrust vector eccentricity and beam divergence characteristics of Hall thrusters are of significant engineering value for the beneficial integration and successful application of Hall thrusters on spacecraft. For the characteristics of the plume bipolar diffusion due to the annular discharge channel of the Hall thruster, a Gaussian-fitted method for thrust vector deviation angle and beam divergence of Hall thrusters based on dual Faraday probe array planes was propo...     

兰州空间技术物理研究所吸气式电推进技术进展

吸气式电推进技术是将超低轨空间的环境气体工质收集、增压、电离以及加速产生推力的技术,是一项具有里程碑意义的航天器动力技术.兰州空间技术物理研究所开展了近10年吸气式电推进技术研究.主要介绍了兰州空间技术物理研究所吸气式电推进技术的最新进展,包括吸气式电推进系统方案和应用分析;基于理论分析和数值计算进行的气体收集增压技术...     

变工况下自励磁模式LHT-60霍尔推力器放电特性试验研究

针对低轨互联网星座轨道维持、寿命末期轨道提升任务需求,兰州空间技术物理研究所研制了口径为60 mm的LHT-60霍尔推力器.研究了LHT-60霍尔推力器变工况下的放电特性,进行了自励磁模式下,放电电压200～350 V、质量流量1.1～2.0 mg/s工况的推力器工作特性试验.结果表明,推力器在各工况点均可稳定工作,工...