航空发动机用于地面燃煤差速联合循环的性能研究

提出一种新型燃煤联合循环发电技术—载热部分气化燃煤联合循环（ＣＧＣＣ），在这一系统中采用了由航机改型的ＦＴ－８燃气轮机。本文通过对燃气轮机系统性能的分析，采用模块化建模方法，全面地分析了燃气轮机在系统中设计工况和变工况下的工作情况，认为ＦＴ－８燃气轮机用于ＣＧＣＣ系统具有很大优越性。     

多股射流横向喷入有约束管流过程的模拟

用基于控制体的有限差分方法对一排射流横向喷入管流的流场进行了数值分析，以建立流场温度分布和上游流动条件及几何参数的关系，可变的参数包括：喷嘴直径，喷嘴数，圆柱管半径，射流与主流的体积流量比，温度比和动压比，结果发现，动压比，喷嘴个数和喷嘴间距是三个重要变量，通过对模拟结果的函数拟合，发现射流喷射深度与动压比除以喷嘴数的平方之间的关系可用一个对数函数很好地描述，给出了适用最佳混合的喷射深度和喷嘴间距，提出了可用于结构实设计的程序。     

Did life exist on Mars? Search for organic and inorganic signatures, one of the goals for “SAM” (sample analysis at Mars)

Observation of Mars shows signs of a past Earth-like climate, and, in that case, there is no objection to the possible development of life, in the underground or at the surface, as in the terrestrial primitive biosphere. Sample analysis at Mars (SAM) is an experiment which may be proposed for atmospheric, ground and underground in situ measurements. One of its goals is to bring direct or indirect information on the possibility for life to have developed on Mars, and to detect traces of past or present biological activity. With this aim, it focuses on the detection of organic molecules: volatile organics are extracted from the sample by simple heating, whereas refractory molecules are made analyzable (i.e. volatile), using derivatization technique or fragmentation by pyrolysis. Gaseous mixtures thus obtained are analyzed by gas chromatography associated to mass spectrometry. Beyond organics, carbonates and other salts are associated to the dense and moist atmosphere necessary to the development of life, and might have formed and accumulated in some places on Mars. They represent another target for SAM. Heating of the samples allows the analysis of structural gases of these minerals (CO₂ from carbonates, etc.), enabling to identify them. We also show, in this paper, that it may be possible to discriminate between abiotic minerals, and minerals (shells, etc.) created by living organisms.     

ΔDsat,a QB50 CubeSat mission to study rarefied-gas drag modelling

A CubeSat mission to study the impact of flow incidence angle, surface material and surface roughness on gas–surface interactions on spacecraft in low Earth orbits has been designed. To accomplish this scientific goal the CubeSat deploys a variable geometry aerofoil capable of exposing different surfaces to the flow at different incident angles. By using the on-board GPS measurements and an orbit determination technique the drag experienced by the CubeSat can be estimated. The CubeSat has been designed to be part of the QB50 mission, and hence it carries a sensor that can take in-situ measurements of the atmosphere. This is then used to estimate the atmospheric density and hence to extract information on the drag coefficient. To minimise any bias present in the measurement chain a differential approach is used. Therefore no absolute drag coefficients are estimated, instead, ratios of drag coefficients are computed. This allows direct comparisons of the drag coefficients of different materials, different surface roughness or different incident angles. Simulations indicate that this CubeSat mission will be able to obtain drag coefficient ratios with an uncertainty level of less than 5%.     

气相色谱测定偏二甲肼纯度方法的改进

研究了气相色谱内标法代替常规的标准工作曲线法测定偏二甲肼纯度（ＵＤＭＨ）。用内标与偏二甲肼混合样品,避免了微量进样不准确的缺陷。结果表明,该方法相对标准偏差接近于１％,回收率大于９８．０％。     

卫星推进系统气体流量探头的研制

介绍了卫星推进系统气体流量探头设计中的几个问题,该探头适用微波量气体流量的测量,采用了差压式孔板流量计的原理,设计轻巧,使用方便,能够进行远距离无失真传输,方便了现场测试。     

Theoretical investigation of shock stand-off distance for non-equilibrium flows over spheres

We derived a theoretical solution of the shock stand-off distance for a non-equilibrium flow over spheres based on Wen and Hornung’s solution and Olivier’s solution. Compared with previous approaches, the main advantage of the present approach is allowing an analytic solution without involving any semi-empirical parameter for the whole non-equilibrium flow regimes. The effects of some important physical quantities therefore can be fully revealed via the analytic solution. By combining the current solution with Ideal Dissociating Gas (IDG) model, we investigate the effects of free stream kinetic energy and free stream dissociation level (which can be very different between different facilities) on the shock stand-off distance.     

A method for automatic detection and characterization of plasma bubbles using GPS and BDS data

Detecting and characterizing Total Electron Content (TEC) depletion is important for studying the ionospheric threat due to the Equatorial Plasma Bubble (EPB) when applying the Ground-Based Augmentation System (GBAS) at low latitudes. This paper develops a robust method to automatically identify TEC depletion and derive its parameters. The rolling barrel algorithm is used to automatically identify the TEC depletion candidate and its parameters. Then, the depletion candidates are screened by several improved techniques to distinguish actual depletions from other phenomena such as Traveling Ionospheric Disturbance (TID) or abnormal data. Next, based on the depletion signals from three triangular receivers, the method derives EPB parameters such as velocity, width and gradient. The time lag and front velocity are calculated based on cross-correlation using TEC depletions and the geometrical distribution of three triangular receivers. The width and gradient of slope are then determined by using TEC depletion from a single receiver. By comparison, both the station-pair method and proposed method depend on the assumption that the EPB morphology is frozen during the short time when the plasma bubble moves between the receivers. However, our method relaxes the restriction that the baseline length should be shorter than the width of slope required by the station-pair. This relaxation is favorable for studying small-scale slope of depletions using stations of a longer baseline. In addition, the accuracy of the width and gradient is free of impact from hardware biases and small-scale disturbance, as it is based only on the relative TEC variation. The method is demonstrated by processing Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) data on 15 August, 2018, in a solar minimum cycle.     

硝基氧化剂废气污染治理

硝基氧化剂在使用过程中会产生大量的氮氧化物废气。对于氮氧化物的污染治理技术目前主要有化学吸收法，液膜法，催化脱除法，高能辐射法，冷冻法和吸附法等。这些方法各有其特点及合适的应用场合，在处理时要综合考虑废气的来源，组成，强度及费用，效果等各方面的因素，并在此 选择最佳处理方法。     

Optimisation of X-ray proportional counters for Scanning Sky Monitor (SSM) on ASTROSAT

The Scanning Sky Monitor (SSM) on ASTROSAT is a position-sensitive gas-filled proportional counter with a wide field of view. The scientific objective of SSM is to scan the sky within few hours to detect and locate transient X-ray sources in the outburst phase. Once detected, this information will be provided for studies in all energy bands. The energy range of operation of SSM is 2–10 keV. The optimisation of the parameters of the proportional counter such as the cell size, the gas mixture and the gas pressure for the SSM are discussed here.