Analysis of electromagnetic properties of superconducting suspension system for gravity measurement
A type of superconducting suspension system for gravity measurement was introduced, and the principle and feasibility was discussed. System modeling and simulation analysis was carried out by ANSOFT, and optimization of structural position was finally completed. Analysis shows that, the system was exceptionally stable with a magnetic force gradient small enough to observe gravity changes. For systems with a superconducting sphere weighed of 15 g, the gravity measurement accuracy could reach 1 nano-Gal.
Study on Superconducting Levitation System for Gravity Measurement
A high precision superconducting levitation system for gravity measurement has been developed, which used the levitation of a superconducting sphere by the magnetic field of two superconducting coils. The magnetic levitation is designed to provide independent adjustment of the levitating force and the force gradient. A Gifford-McMahon (GM) cryocooler is employed to cool down the system. This paper reviews the construction and operating characteristics of the system. The test results show that the earth tide signal was detected by the system.
Venus: Evolution of the Upper Atmospheric Clouds
Abstract The large number of UV photographs taken by different observatories throughout the world are grouped for analysis at the IAU Planetary Photograph Center of Meudon Observatory. Three horizontal V, Y, or psi-shaped dark-hued cloud features are usually aligned along the equator and move 110 m s−1 westward in a planetary-wide rotation. The more intense and distinctly V-Shaped features last several weeks. The smaller scale cloud structures usually show significant changes after each successive rotation in 4 days around the planet. The average UV contrast is 32% but can fluctuate from disappearance to 37%. For periods of several years, the polar areas are sometimes covered by a white cloud. According to a set of photographs taken at Pic-du-Midi, this never occurred between 1962 and 1966 but has happened during 25% of the time for at least one pole since 1967, and only when the planet was in a given half of its orbit. These polar clouds are ephemeral and usually last several weeks or months; they evolve...