Prospects for astrometry with the Hubble Space Telescope     

W. H. Jefferys  G. F. Benedict  P. D. Hemenway  P. J. Shelus  R. L. Duncombe 《Celestial Mechanics and Dynamical Astronomy》1985,37(3):299-305

The Hubble Space Telescope (HST), a large optical telescope having an aperture of 2.4 meters and a length of 8.8 meters, is being developed by the National Aeronautics and Space Administration. This telescope will be placed into earth orbit by the space shuttle. Astrometric observations with the HST are made using a Fine Guidance Sensor which is capable of measuring the position of one object relative to another with an accuracy of ±0.002 arcseconds. The astrometric user of HST will be provided with an Astrometric Data Reduction Software package (ADRS). The variety of astrometric problems to be investigated with HST is discussed.  相似文献   

Self-similar solutions for the blast wave problem in radiative gasdynamics,I     

J. B. Singh  K. S. Singh 《Astrophysics and Space Science》1985,111(1):79-85

Similarity solutions, describing the flow of a perfect gas behind spherical shock waves, are investigated including the radiation heat flux. The shock is assumed to be propagating in a medium at rest. Shock radius varies exponentially with time and density is inversely proportional to fifth power of the shock radius immediately ahead of the shock front.  相似文献   

Aircraft Observation of CO₂, CO, O₃ and H₂ over the North Pacific during the PACE-7 Campaign     

Y. SAWA  H. MATSUEDA  Y. MAKINO  H. Y. INOUE  S. MURAYAMA  M. HIROTA  Y. TSUTSUMI  Y. ZAIZEN  M. IKEGAMI  K. OKADA 《Tellus. Series B, Chemical and physical meteorology》2004,56(1):2-20

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Equilibrium response of thermohaline circulation to large changes in atmospheric CO2 concentration     

R. J. Stouffer  S. Manabe 《Climate Dynamics》2004,22(2-3):325-326

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沂水崔家峪玻璃用石英砂岩矿地质特征          下载免费PDF全文

李祥忠  程晓萍  杨学生  解庆岭 《山东国土资源》2004,20(2):34-40

沂水崔家峪玻璃用石英砂岩矿床赋存于早寒武世李官组砂岩段中．呈近水平的层状产出。因其岩石坚硬．矿体呈环山的平台状分布。矿体厚度大，矿石品级高，特级品矿石二氧化硅平均含量98．47％，铁杂质平均含量0．043％(选矿后，铁杂质含量可降至0．02％以下)，为一优质玻璃硅质原料矿床。矿石为细一中粒石英砂岩，粒度以中粒为主，矿石由碎屑颗粒和胶结物组成，碎屑成分含量为97％～98％．其中绝大部分是石英颗粒．具典型的砂屑结掏。该矿床属滨海陆源沉积矿床。  相似文献   

First Byurakan Spectral Sky Suvrvey. Blue stellar objects. III. Region δ=+43°     

G. V. Abramyan  V. A. Lipovetskii  A. M. Mikaelyan  D. A. Stepanyan 《Astrophysics》1990,33(3):493-500

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Kinematics of stars in Kovalsky-Kapteyn figures. II     

R. B. Shatsova  G. B. Anisimova 《Astrophysics》1990,33(3):518-527

Rostov State Pedagogical Institute; All-Union Scientific Research Institute Gradient. Translated from Astrofizika, Vol. 33, No. 3, pp. 379–393, November–December, 1990.  相似文献   

A note on the kinematics of the tachyon fluid     

T. Singh  G. Prasad 《Astrophysics and Space Science》1985,110(2):393-395

It is shown that the kinematical parameters associated with the congruence formed by tachyonic motion can be defined in the manner of Greenberg, but not that of Ehlers. The space-like counterpart of Raychaudhuri's equation has also been obtained.  相似文献   

地壳对海洋潮汐的响应   总被引：2，自引：2，他引：0  

郑文衡  王乘  何振  牛安福 《大地测量与地球动力学》2002,22(2):41-46

应用三维动态有限元方法研究了中国北部地区的地壳对邻近的渤海与黄海海平面变化的响应。虽然此应力场过于微弱不足以引发地震，但发现应力集中的位置及应力场变化较大的位置恰好与某些现代地震的震中一致。这一结果表明研究地壳对广泛分布的载荷的响应对研究区域地震构造是有帮助的。  相似文献   

A comparison of theoretical Sv emission line strengths with extreme ultraviolet observations of a sunspot     

F. P. Keenan  J. G. Doyle 《Solar physics》1990,128(2):345-351

Electron impact excitation rates for transitions in the S v ion, calculated with theR-matrix code, are used to derive the electron temperature sensitive emission line ratiosR ₁ =I(854.8 Å)/I(786.9 Å),R ₂ =I(852.2 Å)/I(786.9 Å),R ₃ =I(849.2 Å)/I(786.9 Å), andR ₄ =I(1199.1 Å)/I(786.9 Å), which are found to be significantly different from previous estimates. A comparison of the present results with observational data for a sunspot obtained with the Harvard S-055 spectrometer on boardSkylab reveals generally good agreement between theory and experiment, except in the case ofR ₁, which is probably due to blending in the 854.8 Å feature. The possible effects of Lyman continuum absorption on the observed line ratios is briefly discussed.  相似文献