High-Energy Charged Particles in the Innermost Jovian Magnetosphere     

HM Fischer  E Pehlke  G Wibberenz  LJ Lanzerotti  JD Mihalov 《Science (New York, N.Y.)》1996,272(5263):856-858

The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of Io to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at approximately2.2RJ (where RJ is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (approximately62 megaelectron volts per nucleon) that peaked at approximately1.5RJ inside the bright dust ring. The abundances of all particle species decreased sharply at approximately1.35RJ; this decrease defines the innermost edge of the equatorial jovian radiation.  相似文献   

Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect     

Taylor PA  Margot JL  Vokrouhlicky D  Scheeres DJ  Pravec P  Lowry SC  Fitzsimmons A  Nolan MC  Ostro SJ  Benner LA  Giorgini JD  Magri C 《Science (New York, N.Y.)》2007,316(5822):274-277

Radar and optical observations reveal that the continuous increase in the spin rate of near-Earth asteroid (54509) 2000 PH5 can be attributed to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, a torque due to sunlight. The change in spin rate is in reasonable agreement with theoretical predictions for the YORP acceleration of a body with the radar-determined size, shape, and spin state of 2000 PH5. The detection of asteroid spin-up supports the YORP effect as an explanation for the anomalous distribution of spin rates for asteroids under 10 kilometers in diameter and as a binary formation mechanism.  相似文献   

Experimental demonstration of guiding and bending of electromagnetic waves in a photonic crystal   总被引：3，自引：0，他引：3  

SY Lin  E Chow  V Hietala  PR Villeneuve  JD Joannopoulos 《Science (New York, N.Y.)》1998,282(5387):274-276

The routing and interconnection of optical signals through narrow channels and around sharp corners are important for large-scale all-optical circuit applications. A recent computational result suggests that photonic crystals may offer a novel way of achieving this goal by providing a mechanism for guiding light that is fundamentally different from traditional index guiding. Waveguiding in a photonic crystal and near 100 percent transmission of electromagnetic waves around sharp 90 degree corners were observed experimentally. Bending radii were made smaller than one wavelength.  相似文献