氧气/煤油发动机燃气热物理参数及输运系数计算

为了给氧气/煤油发动机设计和热防护设计提供必要的设计参数,针对氧气/煤油燃气进行热力学计算。运用吉布斯最小自由焓计算模型得到燃气平衡组成,通过拟合公式的方法得到燃气的热物理参数及输运系数。通过计算,得到氧气/煤油燃气的组分及比焓、密度、比熵、粘性系数等热物理参数和输运系数随温度和压力的变化特性。分析结果表明:水离解对氧气/煤油燃气组分变化存在显著影响,压力增大会导致水离解起始温度升高;氧气/煤油燃气比焓、比熵、定压比热、粘性系数、热传导系数变化在温度较低时受压力影响较小,当水开始离解后,压力的影响显著增强;组分在燃气中的扩散系数同时受到了温度和组分摩尔分数的影响;燃气普朗特数变化受热传导系数变化的影响较大,水离解后,热传导系数的迅速增大使燃气的普朗特数迅速减小。     

基于泡沫型干扰幕的多波段无源干扰技术

武器系统制导方式已越来越多地由单一制导转向复合制导,现有的多波段无源干扰技术已不能满足作战需求。基于泡沫型干扰幕的新型多波段无源干扰技术在技术和战术上较好地解决了这一问题。分析研究了现有多波段干扰技术存在的问题和泡沫型干扰幕的干扰原理及实现方法,寻求提高此技术干扰效应的途径,最后阐述该技术具有的优点。     

The Mars Environment Analogue Platform long duration balloon flight

The MEAP (Mars Environment Analogue Platform) mission was to fly a stratospheric balloon on a semicircular trajectory around the North Pole in summer 2008. The balloon platform carried the high-resolution neutral gas mass spectrometer P-BACE (Polar Balloon Atmospheric Composition Experiment) as scientific payload. MEAP/P-BACE is a joint project between the Esrange Space Center, Sweden, the University of Bern, Switzerland and the Swedish Institute of Space Physics (IRF), Kiruna, Sweden. Mission objectives were to validate the platform for future long duration flights around the North pole, to validate the P-BACE instrument design for planetary mission applications (conditions in the Earth stratosphere are similar to the conditions at the Mars surface), to study variation of the stratospheric composition during the flight and to gain experience in balloon based mass spectrometry. All objectives were fulfilled.     

The thermospheric composition different responses to geomagnetic storm in the winter and summer hemisphere measured by “SZ” Atmospheric Composition Detectors

Three “SZ” Atmospheric Composition Detectors (ACDs) on board spacecraft “SZ-2”, “SZ-3” and “SZ-4” were launched on 10th January 2001, 26th March 2002 and 31st December 2002 separately. A large quantity of thermospheric composition data at the orbital altitude ranging from 330 to 362 km were collected from the in-situ measurement of ACDs. The spacecrafts’ lifetime was just in the second peak period of the 23rd solar cycle which includes two peaks and the solar activity value F_10.7 was from 89 to 228. During this period, several intense geomagnetic disturbances happened.     

The X-Ray Spectrometer on the MESSENGER Spacecraft

NASA’s MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) mission will further the understanding of the formation of the planets by examining the least studied of the terrestrial planets, Mercury. During the one-year orbital phase (beginning in 2011) and three earlier flybys (2008 and 2009), the X-Ray Spectrometer (XRS) onboard the MESSENGER spacecraft will measure the surface elemental composition. XRS will measure the characteristic X-ray emissions induced on the surface of Mercury by the incident solar flux. The Kα lines for the elements Mg, Al, Si, S, Ca, Ti, and Fe will be detected. The 12° field-of-view of the instrument will allow a spatial resolution that ranges from 42 km at periapsis to 3200 km at apoapsis due to the spacecraft’s highly elliptical orbit. XRS will provide elemental composition measurements covering the majority of Mercury’s surface, as well as potential high-spatial-resolution measurements of features of interest. This paper summarizes XRS’s science objectives, technical design, calibration, and mission observation strategy.     

主成分分析法在宏观经济评价中的应用

文章主要介绍了主成分分析方法基本思想及其计算步骤,并用主成分分析方法在综合评价方面进行了实证分析,最后提出了在实际应用中应该注意的问题.     

The Transition Between Fast and Slow Solar Wind from Composition Data

The transition between coronal hole associated fast solar wind and slow solar wind is studied using data from the high resolution mass spectrometer SWICS on ACE. We discuss the data in the framework of a recent theory about the global heliospheric magnetic field and conclude that the data are consistent with magnetic connections between field-lines in the fast and in the slow wind. This revised version was published online in June 2006 with corrections to the Cover Date.     

Exploring The Saturn System In The Thermal Infrared: The Composite Infrared Spectrometer

The Composite Infrared Spectrometer (CIRS) is a remote-sensing Fourier Transform Spectrometer (FTS) on the Cassini orbiter that measures thermal radiation over two decades in wavenumber, from 10 to 1400 cm^{− 1} (1 mm to 7μ m), with a spectral resolution that can be set from 0.5 to 15.5 cm^{− 1}. The far infrared portion of the spectrum (10–600 cm^{− 1}) is measured with a polarizing interferometer having thermopile detectors with a common 4-mrad field of view (FOV). The middle infrared portion is measured with a traditional Michelson interferometer having two focal planes (600–1100 cm^{− 1}, 1100–1400 cm^{− 1}). Each focal plane is composed of a 1× 10 array of HgCdTe detectors, each detector having a 0.3-mrad FOV. CIRS observations will provide three-dimensional maps of temperature, gas composition, and aerosols/condensates of the atmospheres of Titan and Saturn with good vertical and horizontal resolution, from deep in their tropospheres to high in their mesospheres. CIRS’s ability to observe atmospheres in the limb-viewing mode (in addition to nadir) offers the opportunity to provide accurate and highly resolved vertical profiles of these atmospheric variables. The ability to observe with high-spectral resolution should facilitate the identification of new constituents. CIRS will also map the thermal and compositional properties of the surfaces of Saturn’s icy satellites. It will similarly map Saturn’s rings, characterizing their dynamical and spatial structure and constraining theories of their formation and evolution. The combination of broad spectral range, programmable spectral resolution, the small detector fields of view, and an orbiting spacecraft platform will allow CIRS to observe the Saturnian system in the thermal infrared at a level of detail not previously achieved.This revised version was published online in July 2005 with a corrected cover date.     

DD402单晶合金在小发涡轮工作叶片上的应用

论述了所研制DD402单晶合金的化学成分、显微组织、热处理及长期组织稳定性、物理性能、力学性能、化学性能等。通过考核试车和试飞证明，用该合金制造的小型航空发动机涡轮工作叶片工作正常。这一成果可供航空发动机设计人员和工艺人员在新机研制和生产中借鉴。     

烟火药水下燃烧的声辐射机理与实验研究（英文）

烟火药水下燃烧能够形成低频的水下声。法国烟火集团拉克鲁瓦防御公司研制出了一种＂烟火——声电＂声诱饵（1995）,但是至今还没有进行深入的研究与报道。本文就烟火药水下燃烧的声辐射机理进行了探讨。结果显示,其所辐射的噪声主要包括喷注噪声和气泡噪声,进一步的分析发现主要以气泡噪声为主,喷注湍流噪声为辅。为了证明此观点,实验研究了具有脉动燃烧效应的烟火药水下燃烧时的声辐射特性。