旋翼/机身组合模型试验台技术改进及验证

中国空气动力研究与发展中心研制的旋翼/机身组合模型试验台,具有阻塞度小、功率大、支架干扰小等优点.近年来,试验台通过配套研制标模系统、改进测量系统及旋翼操纵系统标定方法等工作,使试验台的水平和能力得到了进一步的提升.验证试验表明:该试验台技术先进、性能指标优良,安全稳定性好,试验数据精准度高,可作为直升机型号研制和课题研究可靠的试验平台.     

Development of thermal sensors and drilling systems for lunar and planetary regoliths

We consider some novel concepts for thermal properties experiments aboard lunar landers or rovers, that may lead to an improved understanding of both the structure of the lunar near surface layers and the lunar thermal history. The new instruments could be developed using the experience and heritage from recently developed systems, like the Rosetta Lander thermal conductivity experiment MUPUS and existing designs used for terrestrial measurements of thermal conductivity. We describe shortly the working principle of such sensors and the main challenges faced when using them in the airless regolith layers of the Moon or other airless bodies. In addition new concepts to create appropriate drill holes for thermal and other measurements in the lunar regolith are discussed.     

任意平面域的三角形网格和混合网格生成

本文以阵面推进法为基础,给出了一种可对任意平面域进行三角形网格和混合网格自动生成的方法。该方法包含了易于生成与调控的矩形背景网格技术,简便的外形输入和初始阵面划分技术,加速查寻的数据结构,以及节点松弛和基于Ｄｅｌａｕｎａｙ准则的对角线交换技术。网格生成的实例表明,方法能快速可靠地生成任意平面域的高质量三角形网格和适于粘性计算的三角形／四边形混合网格,具有较好的通用性与实用性。     

轴对称件超塑约束胀形过程FEM模拟

采用大变形刚粘塑性有限元 ( FEM)模拟了圆板轴对称超塑约束胀形的贴模过程。研究了胀形件几何尺寸 (胀形高宽比 HP/RD)、材料速率敏感指数 m、摩擦因子 Am 对胀形件贴模过程 ,以及贴模方式对厚度不均的影响     

高速磨削技术的发展趋势及其相关技术

回顾了国内外高速磨削技术的发展过程,从高速磨削机理,高速磨削速度及其高速磨削相关技术等方面介绍国外的发展水平和先进成果,预测了今后国外高速磨削研究的发展趋势,并从高速度磨床的一些技术特征和参数,以及人们对高速磨削的认识等方面分析和评价了我国在推广和应用高速磨削中尚存的差距,可为进一步深入研究提供参考.     

A strategic “viewfinder” for SETI research

One of the most important reasons why unsuccessful results have been obtained so far by the SETI Project is due to the fact that no sure targets to aim at have been available up-to the present state of research. All-sky surveys, even if very accurate and complete, might result to be time-consuming. SETI needs at least one effective “viewfinder” in order that a true targeted research is carried out with a possible success. The best foundation to get this can be identified with the search for the evidence of extraterrestrial astro-engineering activity in form of the Dyson spheres predicted by theory. The existence of such stellar objects can be ascertained by finding the evidence of two main signatures in stars of solar spectral type: infrared excess and anomalous light curves due to transiting artificial objects. These are probably the most powerful viewfinders in order to allow SETI techniques for intelligent signal search to be aimed at more appropriate targets. This paper is not intended to be a research paper but rather a review paper whose goal is not to present calculations and/or operational research but rather to be a research proposal for a more focused research in SETI just using Dyson Spheres as crucial markers.     

Near infrared studies of the massive X-ray binary 2S 0114+65

We present near-infrared spectroscopy of the massive X-ray binary 2S 0114+650. These observations covering the spectral range 1.08–2.35 μm span the region where Paschen and Brackett series recombination lines of hydrogen are expected to be seen, namely, Paβ , Brγ and Br 10–17 lines. The absence of any of these lines in emission supports earlier inferences that the optical component in 2S 0114+650 is unlikely to be a Be star but rather a B type supergiant. Near-IR photometry gives J = 8.78, H = 8.53 and K = 7.96; these values show marginal variations from earlier reported measurements.     

Physical characterization of the deep-space debris WT1190F: A testbed for advanced SSA techniques

We report on extensive ${\mathit{BVR}}_c{I}_c$ photometry and low-resolution ($\lambda /\mathrm{\Delta }\lambda ～250$) spectroscopy of the deep-space debris WT1190F, which impacted Earth offshore from Sri Lanka, on 2015 November 13. In spite of its likely artificial origin (as a relic of some past lunar mission), the case offered important points of discussion for its suggestive connection with the envisaged scenario for a (potentially far more dangerous) natural impactor, like an asteroid or a comet.Our observations indicate for WT1190F an absolute magnitude $R_c={32.45}_{\pm 0.31}$, with a flat dependence of reflectance on the phase angle, such as ${\mathit{dR}}_c/d?～{0.007}_{\pm 2}$?mag?deg^?1. The detected short-timescale variability suggests that the body was likely spinning with a period twice the nominal figure of $P_{\mathrm{flash}}={1.4547}_{\pm 0.0005}\mathrm{s}$, as from the observed lightcurve. In the ${\mathit{BVR}}_c{I}_c$ color domain, WT1190F closely resembled the Planck deep-space probe. This match, together with a depressed reflectance around 4000 and 8500 Å may be suggestive of a “grey” (aluminized) surface texture.The spinning pattern remained in place also along the object fiery entry in the atmosphere, a feature that may have partly shielded the body along its fireball phase perhaps leading a large fraction of its mass to survive intact, now lying underwater along a tight ($～1\times 80$?km) strip of sea, at a depth of 1500?m or less.Under the assumption of Lambertian scatter, an inferred size of ${216}_{\pm 30}/\sqrt{\alpha /0.1}$?cm is obtained for WT1190F. By accounting for non-gravitational dynamical perturbations, the Area-to-Mass ratio of the body was in the range $(0.006?\mathit{AMR}?0.011)$?m²?kg^?1.Both these figures resulted compatible with the two prevailing candidates to WT1190F’s identity, namely the Athena II Trans-Lunar Injection Stage of the Lunar Prospector mission, and the ascent stage of the Apollo 10 lunar module, callsign “Snoopy”. Both candidates have been analyzed in some detail here through accurate 3D CAD design mockup modelling and BRDF reflectance rendering to derive the inherent photometric properties to be compared with the observations.     

基于自联想网络的发动机传感器解析余度技术

本文提出了一种基于自联想神经网络的传感器解析余度技术。在这种网络中,冗余传感器的信息被压缩、重组进入网络的第一部分,网络的第二部分将压缩信息恢复出来。基于数据融合原理,若一个传感器发生故障,其它传感器仍可提供足够的信息代替发生故障的传感器。理论分析和用于涡轴发动机的仿真结果表明,这种特殊结构的自联想网络具有良好的过滤噪声和故障信号的作用,特别适合于用作不易建模的复杂对象的传感器信号重构