Concept of wireless sensor network for future in-situ exploration of lunar ice using wireless impedance sensor

It is known that a wireless sensor network uses some sort of sensors to detect a physical quantity of interest, in general. The wireless sensor network is a potential tool for exploring the difficult-to-access area on the earth and the concept may be extended to space applications in future. Recently, lunar water has been detected by a few lunar missions using remote sensing techniques. The lunar water is expected to be in the form of ice at very low temperatures of permanently dark regions on the moon. To support the remote observations and also to find out potential ice bearing sites on the moon, in-situ measurement of the lunar ice is essential. However, a rover may not be able to reach the permanently shadowed regions due to terrain irregularity. One possibility to access such areas is to use a wireless sensor network on the lunar surface.     

基于FSK的测斜系统电路设计

本文重点阐述了测斜系统井下仪器数据采集单元和数据发送单元电路的设计及井上仪器解调电路的设计，给出了具体的电路设计结果及元器件参数。     

超音速混合及燃烧的强化技术

超音速气流中燃料与空气混合直接关系到燃烧效率，强化超音速混合及燃烧已成为各国专家正在解决的关键问题之一。本文在广泛搜集资料的基础上，归纳了已有的强化技术，为开展强化超音速混合及燃烧技术的研究作了必要的准备。     

用于压力传感器校准的高低温试验箱设计

基于压力传感器在高低温环境下的校准需求,设计了一种专用高低温试验箱。其控制温度范围可达到-120℃[KG-*4]~[KG-*7]500℃。提出了高低温试验箱的总体方案,介绍了宽温区温度的实现方法以及高温和低温系统不兼容的解决方法和控制流程。试验验证结果显示,高低温试验箱达到了实现宽温区温度的目的,满足设计指标要求。     

A Fast Global Node Selection Algorithm for Bearings-only Target Localization

In the target tracking, the nodes aggregate their observations of the directions of arrival of the target. The network then uses an extended Kalman filter （EKF） to combine the measurements from multiple snapshots to track the target. In order to rapidly select the best subset of nodes to localize the target with the minimum mean square position error and low power consumption, this paper proposes a simple algorithm, which uses the location information of the target and the network. The lower botmd of localization error is utilized according to the distances between the target and the selected active nodes. Furthermore, the direction likelihoods of the active nodes is predicted by way of the node/target bearing distributing relationships.     

基于Visual Basic6.0的功率传感器自动校准系统

从硬件组成和软件设计两方面介绍了功率传感器自动校准系统.着重介绍了该系统的软件设计思路,并就其特点进行说明.该自动校准系统在Visual Basic 6.0环境下完成编程,完整地实现了登录、设备信患登记、测试、报告文件输出及查询功能,使用简便、性能可靠且人机交互良好.     

MEMS惯性器件及系统发展研究综述

将MEMS惯性系统分为ISA、IMU和INS三级,分别介绍了国内外的研究概况,并对MEMS INS的发展趋势进行了讨论,供广大惯性导航研究人员参考。     

Gravitational wave detection on the Moon and the moons of Mars

The Moon and the moons of Mars should be extremely quiet seismically and could therefore become sensitive gravitational wave detectors, if instrumented properly. Highly sensitive displacement sensors could be deployed on these planetary bodies to monitor the motion induced by gravitational waves. A superconducting displacement sensor with a 10-kg test mass cooled to 2 K will have an intrinsic instrument noise of 10⁻¹⁶ m Hz^−1/2. These sensors could be tuned to the lowest two quadrupole modes of the body or operated as a wideband detector below its fundamental mode. An interesting frequency range is 0.1–1 Hz, which will be missed by both the ground detectors on the Earth and LISA and would be the best window for searching for stochastic background gravitational waves. Phobos and Deimos have their lowest quadrupole modes at 0.2–0.3 Hz and could offer a sensitivity h_min ? 10⁻²² Hz^−1/2 within their resonance peaks, which is within two orders of magnitude from the goal of the Big Bang Observer (BBO). The lunar and Martian moon detectors would detect many interesting foreground sources in a new frequency window and could serve as a valuable precursor for BBO.     

同步轨道遥感器热设计和热分析

为解决遥感器在同步轨道环境温度场分析中热传导与热辐射的综合处理问题,热传导模型温度计算采用控制容积方法建立有限差分方程;热辐射模型采用奥本海姆方法计算设备表面单元之间辐射换热;根据是否被遮挡,辐射换热中表面单元角系数的计算分别采用积分和数值方法。计算结果表明,采用上述方法进行温度场分析能够有效解决热传导模型与热辐射模型的耦合,求解精度较高,遥感器设备部件稳态分析温度分布和在轨瞬态分析温度曲线变化清楚,可作为进一步精密热控设计的依据。     

液体火箭发动机试验热电偶传感器测量工艺

热电偶传感器具有性能稳定、结构简单、使用安全、价格低廉、测温范围广等特点,在液体火箭发动机地面试验中得到了广泛应用。由于输出信号小,在发动机试验的恶劣环境中若使用不当,则容易造成测量不准或测不到数据。针对目前测量中存在的问题,提出了热电偶传感器使用中应注意的一些关键技术和使用工艺要求。工程实践表明,按此工艺操作,热电偶的测量可靠性和测量精度明显提高。