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伊利石层间钾释放的远红外光谱研究 总被引:1,自引:0,他引:1
本文介绍了新近研究层间交换的远红外方法,并用该方法研究了金砂伊早石层间交换的性质,随着温度的升高,伊利石的远红外谱段从108cm^-1向低波数方向偏移,300C时为107cm^-1,500℃时为1000cm^-1,700℃时为98cm^-1,同时,伊利石的释钾程度也伴随着增加,远红外谱同释放钾的能力有一清楚对比,因此可以用远红外方法预言伊利石释钾的能力,最后,利用量子化学计算的PM3方法首次从理论 相似文献
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J. Fischer M.L. Luhman S. Satyapal M.A. Greenhouse G.J. Stacey C.M. Bradford S.D. Lord J.R. Brauher S.J. Unger P.E. Clegg H.A. Smith G. Melnick J.W. Colbert M.A. Malkan L. Spinoglio P. Cox V. Harvey J.-P Suter V. Strelnitski 《Astrophysics and Space Science》1999,266(1-2):91-98
Based on far-infrared spectroscopy of a small sample of nearbyinfrared-bright and ultraluminous infrared galaxies (ULIRGs) with theISO Long Wavelength Spectrometer we find adramatic progression in ionic/atomic fine-structure emission line andmolecular/atomic absorption line characteristics in these galaxiesextending from strong [O III]52,88 m and [N III]57 m lineemission to detection of only faint [C II]158 m line emissionfrom gas in photodissociation regions in the ULIRGs. The molecularabsorption spectra show varying excitation as well, extending fromgalaxies in which the molecular population mainly occupies the groundstate to galaxies in which there is significant population in higherlevels. In the case of the prototypical ULIRG, the merger galaxy Arp220, the spectrum is dominated by absorption lines of OH, H2O, CH,and [O I]. Low [O III]88 m line flux relative to the integratedfar-infrared flux correlates with low excitation and does not appear tobe due to far-infrared extinction or to density effects. A progressiontoward soft radiation fields or very dusty H II regions may explainthese effects. 相似文献
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为揭示大质量星形成及早期演化中的一些重要特征,根据IRAS的流量,选择了一批F100μ≥500Jy的强远红外源,它们大多是处于恒星形成或早期演化阶段中的大质量的天体,利用紫金山天文台青海观测站13.7米射电望远镜,对它们进行了22GHz水脉泽的搜寻,得最11个新的水脉泽源。 相似文献
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利用拉曼光谱和红外光谱研究了方解石、白云石和菱镁矿的光谱学特征,探究了影响三种矿物红外辐射性能的因素。三种矿物的拉曼光谱(Raman)、中红外吸收光谱(MIR)、远红外吸收光谱(FIR)显示随着矿物中镁含量的增大将会影响CO32-的面外弯曲振动(ν2)、反对称伸缩振动(ν3)和平面内弯曲振动(ν4),使各光谱特征峰均向高频端迁移。基于黑体辐射定律以及在80 ℃、400~2 000 cm-1矿物的辐射能量谱,结果显示方解石、白云石、菱镁矿的发射率依次减少(0.951,0.938,0.895)。三种矿物的红外吸收光谱和发射光谱中的振动位置均受CO32-基频的显著影响,在1 300~1 650 cm-1均产生宽的低吸收带,该吸收带与CO32-的反对称伸缩振动相关,且吸收带范围(202,236,272 cm-1)与发射率之间呈负相关关系。因此,当最强化学键的振动出现在发射光谱窄的吸收带范围内会产生相对较高的辐射能和发射率。此外,矿物的晶体结构也会影响发射率,大的离子半径、键长和晶胞体积将降低辐射过程中能量的吸收,增强辐射特性。综上研究结果,方解石、白云石和菱镁矿的拉曼光谱和红外光谱揭示了金属原子的相对质量对光谱学特征的显著影响,其发射率可能受到C—O键的反伸缩振动范围、最强吸收带控制的最低发射率以及矿物晶体结构的共同影响。这项研究呈现了必要的光谱信息和热发射率数据以识别特定的碳酸盐矿物,为类似矿物的光谱特征研究奠定了基础;同时为进一步认识地壳中大量的碳酸盐矿物提供了研究方法,也为地外勘探的深入研究给予相关的理论基础。 相似文献
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Dominic J. Benford Michael J. Amato John C. Mather S. Harvey Moseley Jr David T. Leisawitz 《Astrophysics and Space Science》2004,294(3-4):177-212
The Single Aperture Far-InfraRed (SAFIR) Observatory’s science goals are driven by the fact that the earliest stages of almost
all phenomena in the universe are shrouded in absorption by and emission from cool dust and gas that emits strongly in the
far-infrared (40μ–200μ) and submillimeter (200μ–1 mm). In the very early universe, the warm gas of newly collapsing, unenriched
galaxies will be revealed by molecular hydrogen emission lines at these long wavelengths. High redshift quasars are found
to have substantial reservoirs of cool gas and dust, indicative of substantial metal enrichment early in the history of the
universe. As a result, even early stages of galaxy formation will show powerful far-infrared emission. The combination of
strong dust emission and large redshift (1 < z < 7) of these galaxies means that they can only be studied in the far-infrared and submillimeter. For nearby galaxies, many
of the most active galaxies in the universe appear to be those whose gaseous disks are interacting in violent collisions.
The details of these galaxies, including the effect of the central black holes that probably exist in most of them, are obscured
to shorter wavelength optical and ultraviolet observatories by the large amounts of dust in their interstellar media. Within
our own galaxy, the earliest stages of star formation, when gas and dust clouds are collapsing and the beginnings of a central
star are taking shape, can only be observed in the far-infrared and submillimeter. The cold dust that ultimately forms the
planetary systems, as well as the cool “debris” dust clouds that indicate the likelihood of planetary sized bodies around
more developed stars, can only be observed at wavelengths longward of 20μ.
Over the past several years, there has been an increasing recognition of the critical importance of the far-infrared to submillimeter
spectral region to addressing fundamental astrophysical problems, ranging from cosmological questions to understanding how
our own Solar System came into being. The development of large, far-infrared telescopes in space has become more feasible
with the combination of developments for the James Webb Space Telescope (JWST) of enabling breakthroughs in detector technology.
We have developed a preliminary but comprehensive mission concept for SAFIR, as a 10 m-class far-infrared and submillimeter
observatory that would begin development later in this decade to meet the needs outlined above. Its operating temperature
(≤4 K) and instrument complement would be optimized to reach the natural sky confusion limit in the far-infrared with diffraction-limited
performance down to at least the atmospheric cutoff, λ {>rsim} 40 {μ}. This would provide a point source sensitivity improvement of several orders of magnitude over that of the Spitzer
Space Telescope (previously SIRTF) or the Herschel Space Observatory. Additionally, it would have an angular resolution 12
times finer than that of Spitzer and three times finer than Herschel. This sensitivity and angular resolution are necessary
to perform imaging and spectroscopic studies of individual galaxies in the early universe. We have considered many aspects
of the SAFIR mission, including the telescope technology (optical design, materials, and packaging), detector needs and technologies,
cooling method and required technology developments, attitude and pointing, power systems, launch vehicle, and mission operations.
The most challenging requirements for this mission are operating temperature and aperture size of the telescope, and the development
of detector arrays. SAFIR can take advantage of much of the technology under development for JWST, but with much less stringent
requirements on optical accuracy. 相似文献
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B. Carli P. Ade M. Carlotti U. Cortesi A. Gignoli P. Hamilton M. Lanfranchi C. Lee A. R. MacKenzie A. Phillips 《Journal of Atmospheric Chemistry》2000,35(3):273-293
Far-infrared emission spectroscopy has beendemonstrated to be a valuable method for remotesensing of trace species in the stratosphere, with theability to simultaneously detect a number of keychemical species. SAFIRE-A is a new far-infraredFourier Transform (FT) spectrometer which has beenspecifically designed to operate on board of a highaltitude aircraft in the lower stratosphere and uppertroposphere regions where relatively few remotesensing measurements have been made. Using newtechnology, the sensitivity of the FT spectrometermethod has been substantially improved for the longwavelength region. Results are reported formeasurements of O3, HNO3 and N2O at 17and 19 km using a detection window near 23 cm-1.Geographical and altitude variability of the volumemixing ratio of these constituents and their relativecorrelation are discussed. Ozone measurements agreewell with in situ measurements, except in regions ofstrong stirring and mixing associated with deformationof the northern vortex edge. Whilst SAFIREmeasurements of trace gases do not capture all of thelocal variability seen by rapid in-situ techniques,they can indicate horizontal variability close to, butnot intercepted by, the aircraft's flight path. Apossible detection of ClO at the low background levelsexpected outside the polar vortex is also reported. 相似文献
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We have theoretically studied the influence of a far-infrared radiation (FIR) field from Hπ region on the cooling by C and O atoms, C+ ion and CO molecule in a photodissociation region, and a molecular cloud associated with Hπ region (hereinafter referred as HI region) at low temperatures (T
k≤200 K). Comparisons have been made for cooling with and without FIR for two extreme abundances (10−4 and 10−7) of the mentioned species for temperatures ranging between 10 and 200K and an hydrogen particle density range 10 cm−3≤n
o≤ 107 cm3.
The cooling by the species with low line-splitting (CI, Cπ and CO) is significantly influenced by the radiation field for temperaturesT
k < 100 K while the effect of radiation field on cooling by OI is significant even at higher temperatures (T
k > 100 K). The effect of FIR field on the cooling of CO from low rotational transitions is negligibly small, whereas it is
considerable for higher transitions. In general, the cooling terms related to the short-wavelength transitions are more affected
by FIR than those related to longer wavelengths.
It is also demonstrated here that in the determination of thermal structure of an HI region the dust grains play an important role in the heating of gas only through photoelectron emission following irradiation
by far-ultraviolet (FUV) radiation, as the infrared radiation from the dust is too small to have substantial effect on the
cooling. It is found that in the Hπ /HI interface the FIR field from grains in the Hπ region is not capable of modifying the temperature of the warmest regions but does so in the inner part where the temperature
is low enough. 相似文献
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以天然形成的方铅矿晶体为研究对象,说明方铅矿远红外反射光谱中低频端Plasmon反射边产生的物理原因,并根据不同反射边的斜率(Va)值大小与样品中所含杂质量的相关性,以解释不同样品中不同组分和结构上的特点对Plasmon反射边的影响。且根据不同杂质的正负相关性在自然成因上的因果关系,证明从反射光诸结构中获得对矿物成因有一定指导意义的信息的可行性。 相似文献
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Y. Doi S. Makiuti H. Okuda T. Nakagawa H. Shibai M. Kawada N. Hiromoto M. Fujiwara K. Okumura 《Experimental Astronomy》2000,10(2-3):393-401
We have developed a 4 × 8 array of stressed Ge:Ga detectors. This array detector has a high density format ofentrance pupils so that we can minimize the size of the cameraoptics. The cutoff wavelength of the detector is about 170 m, and the detector's NEP is better than 1016 WHz-1/2. We are going apply this array detector toballoon-borne astronomical observations. Furthermore, we aredeveloping this detector into a 5 × 15 array detector that will be placed onboard the IRIS satellite to be launched in 2003. 相似文献
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