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71.
Nikolai F. Zobov Sergei V. Shirin Roman I. Ovsyannikov Oleg L. Polyansky Robert J. Barber Jonathan Tennyson Peter F. Bernath Michel Carleer Reginald Colin Pierre-François Coheur 《Monthly notices of the Royal Astronomical Society》2008,387(3):1093-1098
The high resolution laboratory spectrum of hot water vapour has been recorded in the 500–13 000 cm−1 wavenumber range and we report on the analysis of the 4750–13 000 cm−1 (0.769–2.1 μm) portion. The emission spectrum was recorded using an oxy-acetylene welding torch and a Fourier transform spectrometer. Line assignments in the laboratory spectrum as well as in an absorption spectrum of a sunspot umbra were made with the help of the BT2 line-list. Our torch spectrum is the first laboratory observation of the 9300 Å'steam bands' seen in M-stars and brown dwarfs. 相似文献
72.
给出了1993年8月8日关岛地震(Ms=7.1,深度60km)前后ULF(Ultra Low Frequency:超低频信号,频段为O.005～10Hz)地磁信号的分析结果.ULF观测系统位于日本关岛,距离震中约65km.对观测数据进行分析后得出以下结论:①建议用非常细致的统计分析(月均值,标准偏差)来判断ULF信号的强度和极化值(比如:Z/H比值);②ULF信号活动强度和∑Kp的对比,有助于区别空间地磁脉动和非空间源地磁辐射;③发现Z/H比值的使用在把可能来自震源的辐射从空间等离子波中识别出来非常重要;④从对极化值的时间序列的统计分析发现极化值在震前仅一个月时有一个显著的增强,表明这期间的电磁异常现象很可能是震磁前兆信号;⑤Z分量的时间变化类似于Loma Prieta地震前的变化,即在震前10天到两周有明显的增强,在震前几天出现另一次增强;⑥可能与地震有关的电磁辐射是一种类似噪音的自然现象,它们的主要频带范围0.02～0.05Hz(最大幅值约为0.1nT). 相似文献
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74.
Eric H. Oelkers Sergey V. Golubev Claire Chairat Oleg S. Pokrovsky Jacques Schott 《Geochimica et cosmochimica acta》2009,73(16):4617-6554
The surface chemistry of natural wollastonite, diopside, enstatite, forsterite, and albite in aqueous solutions was characterized using both electrokinetic techniques and surface titrations performed for 20 min in batch reactors. Titrations performed in such reactors allow determination of both proton consumption and metal release from the mineral surface as a function of pH. The compositions, based on aqueous solution analysis, of all investigated surfaces vary dramatically with solution pH. Ca and Mg are preferentially released from the surfaces of all investigated divalent metal silicates at pH less than ∼8.5-10 but preferentially retained relative to silica at higher pH. As such, the surfaces of these minerals are Si-rich and divalent metal poor except in strongly alkaline solutions. The preferential removal of divalent cations from these surfaces is coupled to proton consumption. The number of protons consumed by the preferential removal of each divalent cation is pH independent but depends on the identity of the mineral; ∼1.5 protons are consumed by the preferential removal of each Ca atom from wollastonite, ∼3 protons are consumed by the preferential removal of each Mg or Ca atom from diopside or enstatite, and ∼4 protons are consumed by the preferential removal of each Mg from forsterite. These observations are interpreted to stem from the creation of additional ‘internal’ adsorption sites by the preferential removal of divalent metal cations which can be coupled to the condensation of partially detached Si. Similarly, Na and Al are preferentially removed from the albite surface at 2 > pH > 11; mass balance calculations suggest that three protons are consumed by the preferential removal of each Al atom from this surface over this entire pH range. Electrokinetic measurements on fresh mineral powders yield an isoelectric point (pHIEP) 2.6, 4.4, 3.0, 4.5, and <1, for wollastonite, diopside, enstatite, forsterite, and albite, respectively, consistent with the predominance of SiO2 in the surface layer of all of these multi-oxide silicates at acidic pH. Taken together, these observations suggest fundamental differences between the surface chemistry of simple versus multi-oxide minerals including (1) a dependency of the number and identity of multi-oxide silicate surface sites on the aqueous solution composition, and (2) the dominant role of metal-proton exchange reactions on the reactivity of multi-oxide mineral surfaces including their dissolution rate variation with aqueous solution composition. 相似文献
75.
Sabine Roedelsperger Michael Kuhn Oleg Makarynskyy Carl Gerstenecker 《Pure and Applied Geophysics》2008,165(6):1131-1151
It is sometimes assumed that steric sea-level variations do not produce a gravity signal as no net mass change, thus no change
of ocean bottom pressure is associated with it. Analyzing the output of two CO2 emission scenarios over a period of 2000 years in terms of steric sea-level changes, we try to quantify the gravitational
effect of steric sea-level variations. The first scenario, computed with version 2.6 of the Earth System Climate Model developed
at the University of Victoria, Canada (UVic ESCM), is implemented with a linear CO2 increase of 1% of the initial concentration of 365 ppm and shows a globally averaged steric effect of 5.2 m after 2000 years.
In the second scenario, computed with UVic ESCM version 2.7, the CO2 concentration increases quasi-exponentially to a level of 3011 ppm and is hold fixed afterwards. The corresponding globally
averaged steric effect in the first 2000 years is 2.3 m. We show, due to the (vertical) redistribution of ocean water masses
(expansion or contraction), the steric effect results also in a small change in the Earth’s gravity field compared to usually
larger changes associated with net mass changes. Maximum effects for computation points located on the initial ocean surface
can be found in scenario 1, with the effect on gravitational attraction and potential ranging from 0.0 to −0.7·10−5 m s−2 and −3·10−3 to 6·10−3 m2 s−2, respectively. As expected, the effect is not zero but negligible for practical applications. 相似文献
76.
77.
This study is devoted to the numerical simulation of the artificial ground freezing process in a fluid-saturated rock mass of the potassium salt deposit. A coupled model of nonstationary thermal conductivity, filtration and thermo-poroelasticity, which takes into account dependence of the physical properties on temperature and pressure, is proposed on the basis of the accepted hypotheses. The considered area is a cylinder with a depth of 256 meters and diameter of 26.5 meters and includes 13 layers with different thermophysical and filtration properties. Numerical simulation was carried out by the finite-element method. It has been shown that substantial ice wall formation occurs non-uniformly along the layers. This can be connected with geometry of the freezing wells and with difference in physical properties. The average width of the ice wall in each layer was calculated. It was demonstrated that two toroidal convective cells induced by thermogravitational convection were created from the very beginning of the freezing process. The effect of the constant seepage flow on the ice wall formation was investigated. It was shown that the presence of the slow flow lead to the delay in ice wall closure. In case of the flow with a velocity of more than 30 mm per day, closure of the ice wall was not observed at all in the foreseeable time. 相似文献
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79.