双燃式(超燃)冲压发动机中激波与边界层之间相互作用对内部流动的影响

在激波风洞中研究了激波与边界层之间相互作用对双燃式（超燃）冲压发动机进气道和燃烧室冷态内部流场的影响,实验发现在进气道中,激波与边界层之间的相互作用产生了两侧均为超声速流的滑移面。实验结果表明内涵道（亚燃室）中流动状态的变化与激波－边界层之间相互作用密切相关。     

通过矩形喷嘴的非稳定液体射流

绍了关于用矩形喷嘴进行的瞬态液体射流的实验研究结果。流动显示演示了在喷流过程中液体射流的种种不稳定现象。笔者推广了Ryhming的理论模型，计算了喷嘴出口的射流速度，并与实验结果进行了比较。     

双向电脉冲激励压电超声换能器实验研究

本文对双向电脉冲激励压电陶瓷超声换能器进行实验研究。对两种类型的换能器进行了实验,进而利用迭加原理对换能器所产生的脉冲超声波波形进行了讨论。结果证明,双向电脉冲是激励压电超声换能器比较理想的电脉冲波形,可以得到幅值大、脉冲持续时间短的超声波,有广泛的应用前景。     

The response of sporadic E-layer to the total solar eclipse of July 22, 2009 over the equatorial ionization anomaly region of the Indian zone

The digital ionosonde located in Bhopal (23.2°N, 77.2°E), India has been used to investigate the responses of the Es layer in the equatorial ionization anomaly (EIA) crest to the total solar eclipse (TSE) of July 22, 2009. Results show the presence of intense Es layer during and after the eclipse period. The gravity waves induced by the solar eclipse propagated upward in the Es layer and produced the periodic disturbance. The results of the wavelet analysis display the presence of dominant oscillation of about 24–32, 16–20 and 8 min. The appearance of intense sporadic-E concomitantly with the signatures of gravity wave suggests that the wind shear introduced by the solar eclipse induced gravity wave might be the plausible mechanism behind the intensification of Es-layer ionization.     

Wave emissions at half electron gyroharmonics in the equatorial plasmasphere region: CLUSTER observations and statistics

Intense (n + 1/2) f_ce emissions are a common phenomenon observed in the terrestrial inner magnetosphere. One of their interests is their possible effect in the pitch angle scattering of plasmasheet keV-electron, leading to diffuse auroras. In this paper, we present CLUSTER’s point of view about this topic, in the equatorial region of the plasmasphere, via a statistical study using 3 years of data. Spectral characteristics of these waves, which represent an important clue concerning their generation mechanism, are obtained using WHISPER data near perigee. Details on the wave spectral signature are shown in an event study, in particular their splitting in fine frequency bands. The orbit configuration of the four spacecraft offers a complete sampling on all MLT sectors. A higher occurrence rate of the emissions in the dawn sector and their confinement to the geomagnetic equator, pointed out in previous studies, are confirmed and described with additional details. The proximity of emission sites, both to the plasmapause layer and to the geomagnetic equator surface, seems to be of great importance in the behaviour of the (n + 1/2) f_ce wave characteristics. Our study indicates for the first time, that both the intensity of (n + 1/2) f_ce emissions, and the number of harmonic bands they cover, are increasing as the observation point is located further away outside from the plasmapause layer. Moreover, a study of the wave intensity in the first harmonic band (near 3/2 f_ce) shows higher amplitude for these emissions than previous published values, these emissions can play a role in the scattering of hot electrons. Finally, geomagnetic activity influence, studied via time series of the D_st index preceding observations, indicates that (n + 1/2) f_ce emission events are observed at CLUSTER position under moderate geomagnetic activity conditions, no specific D_st time variation being required.     

Various methods of calibration of the STEREO/WAVES antennas

On October 25th, 2006, NASA’s two STEREO spacecraft were launched which are designed to increase our knowledge of the physics of the solar system. On board they carry a sophisticated radio experiment, called S/WAVES. The key technology, used by S/WAVES is the direction finding capability in addition to the use of two spacecraft which makes it possible to triangulate radio sources. Direction finding requires the reception properties of the antennas to be known very accurately. We applied several different methods to calibrate the S/WAVES antennas. In this paper the methods are described and compared and the results are presented and discussed with respect to advantages and disadvantages of the different methods.     

纤维素甘油醚硝酸酯在双基推进剂中的应用

纤维素甘油醚硝酸酯NGEC是一种改性硝化棉,以NGEC为粘合剂代替NC,采用传统的无溶剂法制备了NGEC基改性双基推进剂。研究了以NGEC为粘合剂的改性双基推进剂的力学、燃烧和弹道性能及燃烧波结构。结果表明,NGEC具有较好的热塑性,NGEC基改性双基推进剂加工性能优良,其低温-40℃延伸率可达相同配方NC基改性双基推进剂的1.5倍以上,其推进剂弹道性能稳定,燃烧性能和燃烧波结构与NC基推进剂相似。因此,NGEC作为含能粘合剂代替NC,可用于改善改性双基推进剂性能的研究。     

大塑性变形时裂纹稳定扩展的有限元模拟计算

采用8结点等参元并在裂纹尖端采用三角形奇异元对三点弯曲试样在单调加载过程中的裂纹扩展进行了有限元模拟计算。并与实验结果进行了对比。     

分层流体中运动物体与自由面相互作用的实验研究

在静水槽中进行了分层流体中运动物体生成的内重力波与自由面相互作用的实验研究。分层介质为水-盐水以及柴油-盐水两种情形。研究的重点是物体在密度突跃层附近运动时导致的自由面的特定变形,讨论了物体的位置和运动速度等因素对变形形态的影响。对密度突跃层本身的变形特征也作了描述。     

The Solar Wind - Inner Heliosphere

The solar wind in the inner heliosphere, inside ~ 5 AU, has been almost fully characterized by the addition of the high heliographic latitude Ulysses mission to the many low latitude inner heliosphere missions that preceded it. The two major omissions are the high latitude solar wind at solar maximum, which will be measured during the second Ulysses polar passages, and the solar wind near the Sun, which could be analyzed by a Solar Probe mission. Here, existing knowledge of the global solar wind in the inner heliosphere is summarized in the context of the new results from Ulysses.