高精度温度控制方式述评

对高精度温度控制系统中常用的模拟控制方式、数字控制方式和模拟/数字控制方式作了比较,目的在于找到既能满足计量检定恒温装置所需的技术指标、又方便实用的控制方式.     

Latitudinal variation of the topside electron temperature at different levels of solar activity

A database of electron temperature (T_e) measurements comprising of most of the available satellite measurements in the topside ionosphere is used for studying the solar activity variations of the electron temperature T_e at different latitudes, altitudes, local times and seasons. The T_e data are grouped into three levels of solar activity (low, medium, high) at four altitude ranges, for day and night, and for equinox and solstices. We find that in general T_e changes with solar activity are small and comparable in magnitude with seasonal changes but much smaller than the changes with altitude, latitude, and from day to night. In all cases, except at low altitude during daytime, T_e increases with increasing solar activity. But this increase is not linear as assumed in most empirical T_e models but requires at least a parabolic approximation. At 550 km during daytime negative as well as positive correlation is found with solar activity. Our global data base allows to quantify the latitude range and seasonal conditions for which these correlations occur. A negative correlation with solar activity is found in the invdip latitude range from 20 to 55 degrees during equinox and from 20 degrees onward during winter. In the low latitude (20 to −20 degrees invdip) F-region there is almost no change with solar activity during solstice and a positive correlation during equinox. A positive correlation is also observed during summer from 30 degrees onward.     

飞行中大气瞬时温度的获取

根据＊＊飞机上，ＣＷ－１００２和Ⅱ－５的试飞结果，对两种产品的性能做了对比分析；对飞行中大气温度的获取方法提出了的新意见。     

月面高温下推力器可靠性试验

嫦娥五号着陆上升组合体落月后将经历月昼强红外辐射环境，由于推力器喷管导热影响，使推进剂管路与电磁阀面临高温环境，推进系统存在管路内氧化剂汽化和推力器性能下降甚至无法正常工作的问题，影响上升器月面起飞正常姿态控制。为了研究高温下推力器的工作性能，进行了高温下氟塑料阀芯与氧化剂相容性调研，提出了电磁阀和推力器可靠性增长及可靠性验证试验方法，分析了温度与电磁阀阀芯行程的关系，获取了高温环境下推力器的稳态及脉冲工作性能，在小子样条件下评估了推力器可靠性置信下限及月面起飞上升推进系统可靠度，通过月面高温排气及月面起飞上升姿态控制对研究结果进行了航天器在轨飞行验证，圆满完成了上升器月面起飞上升任务。所提出的研究方法及思路具有很好的工程适用性。     

热管式表面温度计检定装置

叙述一种热管式表面温度计检定装置的原理、结构。该装置可用于航天领域在实验室条件下对表面温度计的检定。     

计算机模拟高温下温度波动对简化环氧分子结构参数的影响

对４００Ｋ下简化环氧分子结构的键长、键角、四原子扭转角及非键合原子间距离等结构参数在微小温度波动时进行动态模拟，分析了这些结构参数在该条件下的变形刚性。     

Tidal associated temperature disturbances observed at the middle atmosphere (30–65 km) by a Rayleigh lidar at 23°S

A lidar has been operated in São José dos Campos, Brazil (23.2°S, 45.8°W) since 1972, mainly dedicated to the study of mesospheric sodium at the 589 nm resonant line. The molecular Rayleigh scattering can also be used provided we limit the height to ∼75 km where the sodium scattering begins. Nevertheless, the weak signal obtained only permits the determination of density and temperature profiles by accumulating a large number of shots giving only nocturnal average profiles. Temporal variations in density and temperature on the scale of hours can however, be obtained by performing a superposed epoch analysis for a given time interval and covering a period of several days. In this way we obtained hourly mean profiles grouped by months, seasons and overall, with data acquired from 1993 to 2004. The difference between the hourly temperatures and the nocturnal means shows for some months, with enough data coverage, downward propagating structures that apparently have tidal origin. The seasonal averages show a recurrent feature with high temperatures before and low temperatures after midnight above 50 km. Some similarity is found with the GSWM model, but the observed temperature amplitudes are twice of that for the model.     

温度对油—气式起落架缓冲性能的影响研究

油—气式缓冲器内部的油液特性及充气压力会随环境温度而变化,进而影响起落架的缓冲性能。为了探究温度对油—气式起落架缓冲性能的影响,在起落架落震试验的基础上,提出一种缓冲器环境温度模拟方法,并分析油—气式起落架缓冲器在20~80℃环境温度下的缓冲性能。结果表明：在所研究的温度范围内,缓冲器初始充气压力对温度变化敏感,随着温...     

载人航天器空气环境参数控制非定常仿真分析

为支持乘员在轨驻留,载人航天器需通过空气环境控制系统将众多设计参数和空气环境参数控制在指标范围内。文章建立了一种载人航天器空气环境非定常控制仿真分析模型,包括舱体模块、航天员模块、舱压控制模块、温湿度控制模块以及CO2净化模块。利用该模型分析了载人航天器空气环境参数随乘员代谢水平的非定常变化趋势,并评估了控制系统的工作性能。结果表明:乘员代谢水平变化对空气环境参数有显著影响,通过调节控制系统运行参数可将各空气参数控制在有效指标范围内。人区温度与O2分压、CO2分压和人区湿度有密切的影响关系,不可孤立地进行分析。为载人航天器空气环境参数控制系统的设计和流程改进提供了依据。     

温度条件对碳纤维上浆剂与双马树脂反应及其复合材料界面粘结的影响

为了研究工艺温度对复合材料界面的调控作用,设计采用三阶段固化工艺(即扩散、固化和后固化),考察了不同温度制度下3种碳纤维/双马树脂(BMI)复合材料界面粘结性能的变化规律。采用原子力显微镜(AFM)和傅里叶变换红外光谱(FTIR)深入分析了上浆剂对纤维表面粗糙度和化学特性的影响,研究了上浆剂的反应活性及其与双马树脂的反应性,采用微珠脱粘方法测试了碳纤维/树脂的界面剪切强度(IFSSs)。结果表明,200℃处理2h后3种碳纤维上浆剂均发生部分反应,并且170℃,2h后上浆剂均与双马树脂发生化学反应。对比不同温度条件可以发现后固化阶段对碳纤维/双马体系的界面剪切强度影响显著,未经后固化的复合材料界面性能最低;110℃和140℃恒温扩散阶段对碳纤维/双马体系的界面剪切强度的影响不明显。同种温度条件下,CF1和CF3上浆剂与双马树脂的反应程度高于CF2,相应的CF1和CF3与双马树脂的界面剪切强度较高,表明上浆剂与双马树脂间的化学反应程度是影响其界面粘结性能的主要因素。该研究结果对我国碳纤维上浆剂的研制具有参考价值。