Depth dependency of neutron density produced by cosmic rays in the lunar subsurface

Depth dependency of neutrons produced by cosmic rays (CRs) in the lunar subsurface was estimated using the three-dimensional Monte Carlo particle and heavy ion transport simulation code, PHITS, incorporating the latest high energy nuclear data, JENDL/HE-2007. The PHITS simulations of equilibrium neutron density profiles in the lunar subsurface were compared with the measurement by Apollo 17 Lunar Neutron Probe Experiment (LNPE). Our calculations reproduced the LNPE data except for the 350–400 mg/cm² region under the improved condition using the CR spectra model based on the latest observations, well-tested nuclear interaction models with systematic cross section data, and JENDL/HE-2007.     

一种基于空芯光子晶体光纤的气体检测装置研究

光谱分析技术在大气污染检测领域具有广泛的应用前景。文章从吸收光谱的测量原理出发,提出一种基于空芯光子晶体光纤的气体检测装置实验方案,通过对不同浓度的甲醇和三氯乙烯样品进行测量,并根据3标准对测量结果进行分析,发现系统对甲醇和三氯乙烯的检测灵敏度可以达到ppmv量级。     

电弧加热射流O2激光诱导荧光技术温度测量

采用ArF准分子激光器作为激发光源来激励O2-Schumann-Runge带系(B3Σ-u←X3Σ-g)193.3nm附近的转动吸收谱线,用紫外光电倍增管探测该带系256nm附近的荧光信号,建立了ArF准分子激光器O2激光诱导荧光流场测试系统.在建立O2单带测温模型和软件的基础上,利用Schumann-Runge带系(10,2)带的荧光信号、测量了氧氩混合电弧加热射流的径向温度分布.结果表明我们建立的ArF准分子激光器O2-LIF测试系统是成功的.     

用于火星表面生命信息探测的激光拉曼技术进展

生命信息探测一直是深空探测中重要的一个部分。简要介绍了拉曼光谱技术探测有机物的优势和火星生命信息探测进展,以及常见的火星生命信息探测技术;重点概述了国内外用于火星有机物和生命信息探测的激光拉曼光谱技术的进展,分析总结了火星表面有机物质探测技术的发展趋势;最后简要概述了拉曼光谱技术在火星探测领域的发展前景。     

空间成像光谱信息的处理与分析

信息处理和分析是空间成像光谱技木中涉及最终取得地物目标识别结果的两个重要步骤。按照信息处理流程,阐述了存档处理、数据压缩、检索处理、辐射与几何校正等关键技术;并在评述图像恢复与增强处理及多光谱数据信息分析方法的基础上,对成像光谱数据人工目视解译与计算机分析解译技术进行了研究与探讨。     

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.     

Molecular Hydrogen

Observations of H₂ line emission in galactic and extragalactic environments obtained with the Infrared Space Observatory (ISO) are reviewed. The diagnostic capability of H₂ observations is illustrated. We discuss what one has learned about such diverse astrophysical sources as photon-dominated regions, shocks, young stellar objects, planetary nebulae and starburst galaxies from ISO observations of H₂ emission. In this context, we emphasise use of measured H₂ line intensities to infer important physical quantities such as the gas temperature, gas density and radiation field and we discuss the different possible excitation mechanisms of H₂. We also briefly consider future prospects for observation of H₂ from space and from the ground. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands, and the United Kingdom), and with the participation of ISAS and NASA.     

热障涂层残余应力的拉曼光谱测量及数值分析

 为了研究航空发动机热障涂层(TBCs)制备过程中残余应力的分布问题,采用大气等离子喷涂技术(APS)在镍基高温合金GH99上制备了热障涂层(CoCrAlY粘结层和ZrO₂陶瓷面层),对热障涂层进行了100~3 500 cm^-1激光拉曼光谱扫描,并采用有限元方法计算了与之对应的热障涂层有限元模型应力分布.分析了涂层系统内部轴向残余应力的分布情况并对比分析了激光拉曼光谱频移及有限元计算结果.激光拉曼分析结果表明:轴向陶瓷层内部呈现压应力,在陶瓷层/粘结层界面处应力达到最大值14.8 MPa,粘结层内呈现拉应力;数值分析应力变化趋势与激光拉曼测试分析结果相吻合.     

PAN基碳纤维表面液相氧化改性研究

利用拉曼光谱(Raman),红外光谱(IR)和扫描电镜(SEM)对经过KClO3/H2SO4液相改性处理的碳纤维(CF)表面结构进行了研究,并初步讨论了微观结构对碳纤维单丝力学性能的影响.结果表明:纤维表面的沟槽随改性处理时间增加逐渐加深;表面处理的刻蚀作用会使晶粒边界活性增大,石墨微晶变小;改性处理能够增加CF表面活性官能团(羧酸(-C=O)和酚羟基(-OH)),降低碳纤维表面惰性;表面处理后纤维的力学性能均有所下降,液相氧化处理60min和120min后,拉伸强度分别降低约15％和50％.     

物质对X射线的吸收系数和散射系数的计算

介绍了物质对X射线的光电吸收系数和康普顿散射系数的计算方法。作为算例，在约1keV～1MeV的X射线能量范围内，计算了聚四氟乙烯、某双基推进剂和人体鲜骨对X射线的光电吸收系数和康普顿散射系数。