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111.
计算和研究了1988年云南澜沧-耿马Ms7.6地震产生的完全库仑破裂应力变化的时空演化图像, 对继澜沧地震13 min后发生的耿马M7.2地震的应力触发问题进行了分析, 同时也对澜沧-耿马地震后24 d内发生的Ms5.0~6.9后续强余震的应力触发问题进行了探讨. 结果显示, 澜沧地震断层破裂产生的完全库仑破裂应力变化空间分布图像具有很强的非对称性, 正值的动态和静态库仑破裂应力变化区域均具有与强余震分布位置吻合较好的现象. 耿马Ms7.2地震受到了澜沧Ms7.6地震产生动态和静态库仑破裂应力的触发作用; 绝大多数后续强余震受到了动、静态库仑破裂应力的综合触发作用.  相似文献   
112.
We demonstrate the possibility to improve the signal-to-noise ratio of superconducting gravity time-series by correcting for local hydrological effects. Short-term atmospheric events associated with heavy rain induce step-like gravity signals that deteriorate the frequency spectrum estimates. Based on 4D modeling constrained by high temporal resolution rain gauge data, rainfall admittances for the Vienna and Membach superconducting gravity stations are calculated. This allows routine correction for Newtonian rain water effects, which reduces the standard deviation of residuals after tidal parameter adjustment by 10%. It also improves the correction of steps of instrumental origin when they coincide with step-like water mass signals.  相似文献   
113.
The SOLSPEC instrument has been built to carry out solar spectral irradiance measurements from 200 to 3000 nm. It consists of three spectrometers designed to measure the solar spectral irradiance in ultraviolet, visible, and infrared domains. It flew with the ATLAS I mission in March 1992. This paper is dedicated to the visible part of the solar spectrum. Comparisons with recent data are shown and differences below 450 nm are discussed.  相似文献   
114.
The deep drill hole SG6 in western Siberia (66°N, 78.5°E) penetrated 1.1  km of lower Triassic basalts, which are possibly an extension of the central Siberian Permo– Triassic flood basalt province. About 300 samples of these basalts were progressively demagnetized and measured. Principal component analysis often shows multiple magnetizations carried by haematite and magnetite. The corrected mean inclinations are +77° and −77° for the haematite component. A magnetostratigraphic scale was derived and showed a N–R–N–R–N succession. This is quite different from the Noril'sk and Taimyr typical polarity scale, R–N.
  The basalts found in the SG6 deep drill hole are slightly younger than those of central Siberia and Taimyr. They correspond to middle–upper Induan age, whereas the Noril'sk and Taimyr sections correspond to an uppermost Permian and lower Induan age. Altogether they indicate that, after a high output rate of volcanic material near the Permo–Triassic boundary, this activity slowed down drastically on the Siberian platform and Taimyr, but persisted for several million years in western Siberia.  相似文献   
115.
116.
Cosmogenic nuclides in extraterrestrial matter provide a wealth of information on the exposure and collision histories of small objects in space and on the history of the solar and galactic cosmic radiation. The interpretation of the observed abundances of cosmogenic nuclides requires detailed and accurate knowledge of their production rates. Accelerator experiments provide a quantitative basis and the ground truth for modeling cosmogenic nuclide production by measurements of the relevant cross sections and by realistic simulations of the interaction of galactic protons with meteoroids under completely controlled conditions, respectively. We review the establishment of physical model calculations of cosmogenic nuclide production in extraterrestrial matter on the basis of such accelerator experiments and exemplify this approach by presenting new experimental and theoretical results for the cosmogenic nuclide44Ti. The model calculations describe all aspects of cosmogenic nuclide production and allow the determination of long-term solar and galactic cosmic ray spectra and a consistent interpretation of cosmogenic nuclides in extraterrestrial matter.  相似文献   
117.
Matheron (1971) proposed an approximation of the extension variance in IR. We propose in this note an extension of this formula in IR 2 , based on a MacLaurin formula. Its application is shown in an example, the estimation of the maximum depressional storage of a soil surface.  相似文献   
118.
An experimental study of the effect of boron in the water saturated Q-Or-Ab-B2O3-H2O system has been performed at P=1 Kbar to provide experimental data and explain the role of boron in some late magmatic and early hydrothermal events. Experiments were conducted between 500° C and 800° starting from a gel, or a previously crystallized gel, and variable amounts of boron (0 to 18% B2O3) added to water. The phases obtained were: quartz, sanidine, albite, silicate liquid quenched to glass, and aqueous vapour phase. Boric acids, borates and isotropic low index materials were found in the quenched vapour phase. An aluminium silicate-like mineral, not yet fully identified, is also present.The solidus temperature of the Q-Or-Ab composition is lowered by 60° C when 5 wt. % B2O3 is added and by more than 130° C when 17wt. % B2O3 is added. Compositions of equilibrated silicate melts and vapours were obtained between 780° C and 750° C for various B2O3 concentrations. The vapour phase is B and Si rich. It is also enriched in Na with respect to K, and in alkalis with respect to Al. Its silicate solute content is higher than in experiments with pure water. The solubility of water is increased by the addition of boron in Q-Or-Ab melts. Microprobe data show that the melts equilibrated with vapour phases become hyperaluminous and more potassic than sodic. The partition coefficient of boron is in favour of the vapour (k D=B2O3% in melt/B2O3% in vapour=0.33±0.02). The effect of the interaction between the silicate phases and the vapour is discussed. Comparison is made between the behaviour of boron and that of chlorine and fluorine. Geological applications are also provided, which concern the influence of boron on minimum melting, on muscovite stability and on the hypersolvus-subsolvus transition.  相似文献   
119.
Samples from the MANOP Santa Barbara Basin sediment trap intercomparison were analyzed for the isotopes of uranium, thorium, radium, lead, and polonium. All of the traps showed approximately the same compositions and isotopic ratios, indicating that they trapped similar materials. The234Th flux via falling particles was very close to the flux predicted from the production and scavenging rates of234Th from the water column. The210Pb content of the trapped particles and the surface sediments were the same, however, the measured flux of210Pb was seven times greater than the predicted flux. Predicted and measured fluxes of228Th and210Po were similarly out of balance. To explain this apparent inconsistency, we suggest (as others have done) that the Santa Barbara Basin is an area where scavenging from the water column is intensified and where sediments deposited initially on the margins may be physically remobilized on a short time scale. These two effects increase the apparent area from which the basin derives the longer-lived isotopes but does not increase significantly the supply of the short-lived234Th.  相似文献   
120.
Mathematical Geosciences - In mineral deposit evaluation, the estimation of block values can involve the solution of as many as 100,000 systems of linear equations. To minimize computing costs it...  相似文献   
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