搜索结果: 46-60 共查到“知识库 光谱学”相关记录1477条 . 查询时间(3.406 秒)
偏振光谱仪偏振探测精度分析
偏振光谱仪 退偏器 偏振度 偏振测量精度
2018/3/7
用于野外地物偏振光谱测量的偏振光谱仪，其偏振探测精度直接影响到地物偏振光谱信息获取的准确性，进而影响到目标偏振特性的解译水平。设计了适用于光栅光谱仪的偏振测量组件，将两种型号的光栅光谱仪改装成偏振光谱仪。基于可调偏振度光源验证偏振光谱仪的偏振光谱测量精度，首先分析了偏振光谱仪的偏振敏感性，然后给出了偏振光谱仪对可调偏振度光源输出不同偏振度谱的实验测量结果。实验结果表明：在460~920 nm波长范...
基于蒙特卡罗模拟的α能谱拖尾分析
α能谱 蒙特卡罗 241Am
2018/10/8
α能谱测量是通过对放射性核素释放α粒子能量的测量来实现核素识别和定量分析的技术.α能谱易受测量样品形态的影响,存在着向低能拖尾的现象,这降低了α能谱测量的准确性.为了分析α能谱谱形特点,采用蒙特卡罗程序Geant4模拟了241Am源的α能谱,并对可能造成241Amα能谱峰拖尾的因素进行了模拟分析.结果表明,241Am源上沉积的灰尘是其α能谱峰拖尾的主要原因；采用最小二乘法拟合可以对沉积灰尘的粒径分...
三维旋转滑动弧等离子体助燃激励器的光谱特性实验
助燃激励器 光谱特性 振动温度
2018/2/8
为研究不同射流流量和放电电压下三维旋转滑动弧等离子体助燃激励器的光谱特性规律,对3种不同几何结构的电极，在大气压下进行了交流滑动弧放电等离子体的光谱信号测量。结果表明:当流量和电压越大时,三维旋转滑动弧放电等离子体的振动温度越高,即振动激发强度越强。同时,比较A、B、C 3种滑动弧放电等离子体电极结构的光谱特性后发现,A型电极在滑动弧放电过程中产生的等离子体的振动温度最高,最有利于激发产生等离子体...
基于高斯伪谱法的碰撞规避策略研究
高斯伪谱 空间碎片 空间碰撞 规避策略
2018/5/4
为保证在轨卫星运行安全，对于碰撞概率较高的空间交会情况需要进行规避机动，防止在轨卫星与空间碎片碰撞.选取连续推力策略进行规避机动，将空间碰撞规避过程转化为满足复杂约束的最优控制问题，采用高斯伪谱法对最优控制律进行求解，求解结果满足相应约束.研究结果为航天器有效规避空间碰撞威胁提供了有力支持.
光谱连续可调星敏感器地面标定系统设计
星模拟器 定标 光谱匹配 光谱连续可调 消彗差Czerny-Turner结构
2018/5/4
为解决由于色温不匹配对星敏感器光信号定标精度产生的影响，提出一种光谱连续可调星敏感器地面标定系统设计方案.该高精度准直光学系统的光谱范围为500~800nm，像质测试结果表明，全视场畸变小于0.08%，MTF在60lp·mm-1处大于0.6.基于DMD光源系统的组成和工作原理，对光谱分辨率和光谱曲线模拟精度进行分析，设计了一套光谱分辨率全谱段优于2nm的Czerny-Turner分光系统.测试结果...
碘甲烷在外电场下的光谱和解离特性
碘甲烷 外电场 降解 红外光谱
2019/4/18
碘甲烷是一种有毒的甲基化试剂和土壤消毒剂，应用十分广泛，研究其基本的物理性质和使其降解的有效措施很有必要。使用密度泛函理论（density functional theory，DFT），在B3LYP/LANL2DZ水平上研究在外电场（0~0.04a.u.）作用下碘甲烷分子的解离特性以及多种物理性质。计算结果表明，在C—I键连线Z方向上，外电场从0逐渐增加到0.04a.u.时，分子体系能量逐渐减小，...
USABILITY OF A SUNLIT - SHADED AREA SEPARATION IN INDIVIDUAL TREE SPECIES CLASSIFICATION
Aerial Classification Forestry Fusion Imagery Multispectral
2016/2/29
Individual tree species classification can be done using Light Detection and Ranging (LIDAR) and aerial multichannel images
simultaneously. LIDAR is typically used to derive shape features and aeria...
OBJECT-ORIENTED CHANGE DETECTION OF RIPARIAN ENVIRONMENTS FROM HIGH SPATIAL RESOLUTION MULTI-SPECTRAL IMAGES
Object-Oriented Change Detection Definiens Developer Rule Sets Riparian Zones
2015/11/16
The objectives of this research were to: (1) develop rule sets in Definiens Developer 7® for mapping and monitoring riparian zone
land-cover classes within two QuickBird images; and (2) compare...
Spectral analysis of the clinometric data at the Phlegraean Fields from 1992 to 1998
Spectral analysis Phlegraean Fields clinometric data
2015/9/29
Ground deformation is one of the most important precursors for volcanic eruptions. In this respect, the surveillance of volcanoes has greatly benifited from the continuous recording of clinometric dat...
Basic results in the rigorous theory of weighted dynamical zeta functions
or dynamically defined generalized Fredholm determinants are presented. Analytic
properties of the zeta functions or d...
Seismological aspects of the Cairo earthquake, 12th October 1992
Cairo earthquake source parameters spectral magnitude focal mechanism aftershock stress tensor inversion
2015/9/28
On 12 October 1992 a significant earthquake (MB = 5.8) occurred southwest of Cairo in the vicinity of the Dahshour region. For the mainshock, an average moment release M 0 = 9.70E17 n-m; a fault lengt...
Sensitivity experiments to mountain representations in spectral models
spectral models mountain representations
2015/9/28
This paper describes a set of sensitivity experiments to several formulations of orography. Three sets are considered: a "Standard" orography consisting of an envelope orography produced originally fo...
便携式能量色散X射线荧光光谱仪(EDXRF)具有大型XRF光谱仪的分析性能,在矿产资源勘查中具有广阔的应用前景,特别是在勘查难度大、找矿工作周期长的覆盖区的现场快速分析具有重要意义,但在野外快速分析方面亟需进一步开发。本文采用手工压制样片,建立了Minipal 4便携式能量色散XRF光谱仪现场测定新疆东天山浅覆盖区浅钻化探样品中的铜铅锌砷钴镍锰7种元素的野外快速分析方法,各元素的检出限分别为2、2...
Emission Fourier transform spectroscopy for remote sensingof the Earth's atmosphere
Fourier transform spectroscopy emissionspectroscopy Earth observation stratospheric chemistry
2015/9/16
Fourier transform emission spectroscopy can make an important contribution in the observation of the Earth's atmosphere and in the investigation of atmospheric physics and chemistry. In this paper, we...
Aerosol optical thickness of Mt. Etna volcanic plume retrieved by means of the Airborne Multispectral Imaging Spectrometer (MIVIS)
aerosol optical thickness volcanic plume MIVIS DEM radiative transfer model 6S inversion technique
2015/9/16
Within the framework of the European MVRRS project (Mitigation of Volcanic Risk by Remote Sensing
Techniques), in June 1997 an airborne campaign was organised on Mt. Etna to study different character...