塞式喷管模拟实验及数据采集系统

为了了解塞式喷管性能,采用固体推进剂对塞式喷管单元发动机进行了模拟实验。重点介绍了塞式喷管单元发动机模拟实验的实验系统和高精度测量系统以及数据采集软件。同时,简单说明了数据处理的方法。最后给出了典型的实验结果,该结果对塞式喷管的设计、理论研究以及数值计算有重要的参考价值。     

挤压油膜阻尼器转子系统非线性动力特性分析

为了对挤压油膜阻尼器（SFD）-转子系统非线性动力特性进行分析，提出了油膜力数据库方法，即将挤压油膜阻尼器轴颈沿径向和周向的速度变化范围从（-∞, ∞）转化到（-1, 1)，给定阻尼器的长径比，用有限差分法建立了挤压油膜阻尼器轴颈在各离散运动状态下的油膜力数据库，直接或通过插值求得对应运动状态下的非线性油膜力，从而有效地解决了非线性油膜力的快速计算问题。实际算例计算结果表明，该方法无论在速度还是在精度上都能满足要求，对实际转子系统的动力特性分析及优化设计具有一定的应用价值。     

液体火箭发动机动态数据处理的小波分析方法

研究了基于小波分析的液体火箭发动机动态数据处理方法，给出了数据处理模型，应用小波奇异性检测和误差滤波理论，分析了动态数据的处理过程，并用某液体火箭发动机某次地面试车的动态测试数据进行了验证。结果表明，小波分析方法不需要过程误差的先验知识，能够同时完成异常数据的检测及相应误差的滤除任务，非常适合于液体火箭发动机的动态工作过程。     

International scientific optical network for space debris research

A joint team of researchers under the auspices of the Center for Space Debris Information Collection, Processing and Analysis of the Russian Academy of Sciences collaborates with 15 observatories around the world to perform observations of space debris. For this purpose, 14 telescopes were equipped with charge-coupled device (CCD) cameras, Global Positioning System (GPS) receivers, CCD frame processing and ephemeris computation software, with the support of the European and Russian grants. Many of the observation campaigns were carried out in collaboration with the Astronomical Institute of the University of Bern (AIUB) team operating at the Zimmerwald observatory and conducting research for the European Space Agency (ESA), using the Tenerife/Teide telescope for searching and tracking of unknown objects in the geostationary region (GEO). More than 130,000 measurements of space objects along a GEO arc of 340.9°, collected and processed at Space Debris Data Base in the Ballistic Center of the Keldysh Institute of Applied Mathematics (KIAM) in 2005–2006, allowed us to find 288 GEO objects that are absent in the public orbital databases and to determine their orbital elements. Methods of discovering and tracking small space debris fragments at high orbits were developed and tested. About 40 of 150 detected unknown objects of magnitudes 15–20.5 were tracked during many months. A series of dedicated 22-cm telescopes with large field of view for GEO survey tasks is in process of construction. 7 60-cm telescopes will be modernized in 2007.     

Italian polar data center for capacity building associated with the IHY

The International Heliophysical Year offers a good opportunity to develop and coordinate studies on the Sun–Earth system by using a large variety of simultaneous data obtained by satellite/spacecraft and ground based instruments. Among these data we recall the ones coming from solar and interplanetary medium observations, auroral, neutron monitor, geomagnetic field, ionospheric, meteorological, and other atmospheric observatories. In this context, an Information System for the Italian Research in Antarctica has started in 2003, aiming to collect information on the scientific research projects funded by the National Antarctic Research Program of Italy since its establishment (1985). It belongs to Joint Committee on Antarctic Data Management of Scientific Committee on Antarctic Research as Italian Antarctic Data Center. This project, as the Italian Polar Database, gathers also information on research activities conducted in North Pole regions. This Information System can be a relevant resource for capacity building associated with the International Heliophysical Year, especially for people involved in interdisciplinary researches. We describe the present status of the Italian Polar Data Center and its potential use.     

微波带通滤波器的时域分析法研究

文章介绍了一种利用微波带通滤波器的时域反射损耗(即S11)曲线分析和调试滤波器的方法,运用此法在调试滤波器时可以快速地分析出具体是哪一个谐振电路或耦合器需要调试,以便对其进行专门的修正和调试,从而节省调试时间,简化调试过程。同时也介绍了3种方法作为把频域数据转换为时域数据的理论基础,即傅里叶级数法、快速傅里叶变换法和Chirp-z变换法,并对这3种方法作了相应的评价。     

SMT车间的数据采集

数据采集技术是实现制造执行系统(MES)的关键。针对MES在表面贴装技术(SMT)行业的应用,分别介绍了SMT车间数据采集的要求,实现的方法及其优劣比较。同时,叙述了数据采集系统在传输稳定性方面的注意事项,展望了数据采集技术的发展前景。     

我国早期原子钟研制历程回顾

“2019全国时间频率学术会议”是由四个专业委员会联合每两年举办一次的20周年纪念会。20年来，我国原子钟事业已有长足发展，成为世界上原子钟研制与开发的大国。但总体上说，我们的工作还是以跟随为主，真正属于自主创新的较少。不改变这种局面，我们还难以成为独立自主的时间频率强国，为国家经济和国防建设作出应有贡献。本文回顾了我国原子钟研发的情况，提到一些从基础研究上属于原始创新的案例。阐述了这些案例是在简陋的实验条件下依靠对原子钟内各类实验现象进行深入的物理分析基础上出现的。同时，也指出了在比较粗糙的工艺条件下实现精细的技术指标中能工巧匠所起的特殊作用。文章也约略提到国内各单位间无私协作的崇高精神。本文将讲述一些故事，并就原子钟产业的问题表示一点看法。中国要实现“强国梦”，阻力和困难还很多很艰巨，我们必须拥有丰富的原始创新来加以克服。为此，坚韧的奋斗钻研精神和传统仍不失借鉴与继承意义。