Long-term changes in growth of Norwegian spring-spawning herring   总被引：3，自引：1，他引：2  

Toresen  R. 《ICES Journal of Marine Science》1990,47(1):48-56

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On the stability of particular solutions of the singly averaged Hill problem     

M. A. Vashkov’yak  N. M. Teslenko 《Astronomy Letters》2005,31(12):844-852

We consider the particular solutions of the evolutionary system of equations in elements that correspond to planar and spatial circular orbits of the singly averaged Hill problem. We analyze the stability of planar and spatial circular orbits to inclination and eccentricity, respectively. We construct the instability regions of both particular solutions in the plane of parameters of the problem.  相似文献   

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   

Modes to replace transitional asymptotic ray fields in a vertically inhomogeneous earth model     

E. Niver  A. Kamel  L. B. Felsen 《Geophysical Journal International》1985,80(2):289-312

Summary. Asymptotic ray theory (ART) fails in transition regions near critically reflected, bottom glancing or caustic-forming rays in a vertically inhomogeneous layered earth. These deficiencies are repaired here by replacing the transitional ray fields with guided modes plus truncation remainders. Exact ray-mode equivalences and their high-frequency asymptotic approximations are formulated, and their validity and efficiency are verified by numerical comparisons for SH motion in a two-layer earth model comprised of an inhomogeneous sediment above an homogeneous semi-infinite bedrock.  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   

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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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   

Physical parameters of near-Earth asteroid 1982 DV     

Faith Vilas  David J. Tholen  Larry A. Lebofsky  Humberto Campins  Glenn J. Veeder  Richard P. Binzel  Alan T. Tokunaga 《Icarus》1985,63(2):201-205

Visual and infrared observations were made of Amor asteroid 1982 DV during its discovery apparition. Broadband visual and near-infrared photometry shows that it is an S-class asteroid. Narrowband spectrophotometry shows an absorption feature due to olivine or pyroxene or both centered at 0.93 μm. Applying a nonrotating thermal model to 10-μm photometry, the geometric albedo is calculated to be approximately 0.27. The geometric albedo for a slowly rotating, rocky surface was calculated for 1 night to be 0.15, consistent with S-class asteroid albedos. Thus, 1982 DV is either one of the most reflective S-class asteroids known, or a significant amount of bare rock is exposed on the asteroid's surface. For the nonrotating model, ellipsoidal dimensions for 1982 DV are 3.5 × 1.4 × 1.4 km.  相似文献   

A transformation of the two-body problem     

Victor R. Bond 《Celestial Mechanics and Dynamical Astronomy》1985,35(1):1-7

A transformation of the differential equations of motion of the two-body problem in the spherical coordinates to oscillator form is derived. It is shown that the independent variable transformation dt/ds=r² is a transformation which makes the oscillator form possible.  相似文献   

OTEC cold-water pipe research     

Vadus  J. Taylor  B. 《Oceanic Engineering, IEEE Journal of》1985,10(2):114-122

Shelf-mounted Ocean Thermal Energy Conversion (OTEC) plants require installation of cold-water pipes (CWP) on slopes of40degto depths of 1000 m. In addition, tower platforms containing OTEC power systems may be located on lesser sloped terrain near shore and exposed to special environmental loading problems affecting foundation design. Shelf-mounted installations require careful attention to site selection and geotechnical considerations for foundation integrity on sloped surfaces. This paper primarily discusses research associated with cold-water pipe and foundation installations on steep slopes, although research continues on tower platforms located on the shelf. At least five nations are in various stages of development of OTEC systems for island applications. Each of their systems is either shelf mounted or land based and requires that a large diameter cold-water pipe be installed on a steep slope to provide cold water from 1000-m depths. In addition to the installation and deployment of the large cold-water pipe, the most significant problem is the design and installation of suitable foundations that will last for several decades. To date there is very little experience in the offshore industry for large installations on steep slopes. A major scale-model research project is underway on the slopes of the island of Hawaii. A section of pipe 2.4 m in diameter and 24 m long was installed using combination concrete foundations and joints. The pipe and foundations are fully instrumented to measure environmental loading forces due principally to currents and waves. Environmental measurements will also be taken in the test area. The measurement data will be used to validate available analytical models for subsequent use in aiding industry in providing more cost-effective designs for OTEC pipes and foundations.  相似文献