正激波后OH A~2∑~+──X~2∏瞬态光谱的测量

用光学多道分析仪（OMA光学系统）测量了氢氧燃烧驱动激波管中典型状态下正激波后高温空气不同时刻的瞬态光谱。光谱结果显示高温空气的光谱中有很强的OHA2∑＋─X2∏光谱。通过采用线线合成光谱的方法得到激波后不同时刻高温空气中OH分子的转动温度。     

Empirical analysis of airport network and critical airports

Air transport network, or airport network, is a complex network involving numerous airports. Effective management of the air transport system requires an in-depth understanding of the roles of airports in the network. Whereas knowledge on air transport network properties has been improved greatly, methods to find critical airports in the network are still lacking. In this paper, we present methods to investigate network properties and to identify critical airports in the network. A novel network model is proposed with airports as nodes and the correlations between traffic flow of airports as edges. Spectral clustering algorithm is developed to classify airports. Spatial distribution characteristics and intraclass correlation of different categories of airports are carefully analyzed. The analyses based on the fluctuation trend of distance-correlation and power spectrum of time series are performed to examine the self-organized criticality of the network. The results indicate that there is one category of airports which dominates the self-organized critical state of the network. Six airports in this category are found to be the most important ones in the Chinese air transport network. The flights delay occurred in these six airports can propagate to the other airports, having huge impact on the operation characteristics of the entire network. The methods proposed here taking traffic dynamics into account are capable of identifying critical airports in the whole air transport network.     

The Silicate Material in Comets

Silicates in comets appear to be a mix of high-temperature crystalline enstatite and forsterite plus glassy or amorphous grains that formed at lower temperatures. The mineral identifications from the 10 and 20 μm cometary spectra are consistent with the composition of anhydrous chondritic aggregate IDPs. The origin of the cometary silicates remains puzzling. While the evidence from the IDPs points to a pre-solar origin of both crystalline and glassy components, the signatures of crystalline silicates appear in the spectra of young stellar objects only at a late evolutionary stage, when comets are the likely source of the dust. This revised version was published online in June 2006 with corrections to the Cover Date.     

土地类型分类的人工神经网络方法

:研究了用人工神经网络对航空影像进行土地类型分类的方法 ,用选定窗口的平均值 ,标准差和傅利叶频谱平均值作为神经网络的输入 ,土地类型的标准值为神经网络的输出。将计算出来的未知土地类型标准值与已知土地类型的标准值相比较 ,可以确定出未知的土地类型。     

Boundary layer aerosol retrieval from thermal infrared nadir sounding – Preliminary results

A non-empirical algorithm is presented to retrieve the optical depth in the 750–1250 cm⁻¹ spectral range, of aerosol located in the boundary layer over the ocean, from nadir high-resolution radiance spectra in the thermal infrared. The algorithm is based on a line-by-line radiative transfer forward model and used the Optimal Estimation Method for the retrieval. Its performance strongly depends on the quality of the a priori temperature and H₂O atmospheric profiles. To demonstrate the relevance of the algorithm, distributions of maritime aerosol parameters have been retrieved from IMG/ADEOS data for December 1996, using the algorithm with the LBLRTM radiative transfer code, and ERA40 (ECMWF) a priori atmospheric profiles and surface conditions.     

Absorption and vibrational spectra of methylamine and its ions using quantum chemical methods

We present vibrational spectra of methylamine and its ions using the MP2 method and absorption spectra using time dependent density functional method. On the basis of these calculations electronic transitions of methylamine were successfully determined. We also have derived electron affinity and ionization potential for methylamine. The ionization potential 8.98 eV from this work is in excellent agreement with the experimental value of 9.04 eV. We found that like neutral methylamine, its cation also displays strong σ → σ∗ electronic transitions in the vacuum UV region whereas its anion shows strong electronic transitions in both the vacuum and far UV regions. The detection of methylamine in astronomical objects may benefit greatly from the accurate new data on its far-UV and near-IR lines.     

Solar prominence properties derived from the UV-EUV SUMER spectral atlas

In this paper, we summarize the work done to build a UV-EUV spectral atlas of a prominence and we introduce some recent scientific results obtained from these data.     

摆锤式冲击响应谱试验台的仿真研究

摆锤式冲击响应谱试验台是模拟爆炸冲击环境的一种较好手段,它能够模拟拐点频率在300Hz～2000Hz,峰值过载高达几千个g值的冲击谱型。根据该装置的结构和基本原理,本文应用有限元分析软件ANSYS,LS-DYNA等对其冲击响应谱产生过程进行了模拟,计算结果与试验数据吻合较好。此方法能够合理有效地模拟该装置的性能曲线,对摆锤式冲击试验台的设计具有指导意义。     

Radiation of accretion disks in quasars and galactic nuclei

The continuum spectra of accretion disks around supermassive Schvarzshild black hole are calculated for a set of accretion disk parameters. In every point of the disk surface the atmosphere is considered to be similar to the atmosphere of the star with the same values of the surface gravity and effective temperature. All important effects of general relativity affected the spectrum shape are taken into account.