Accurate laboratory wavelengths of some ultraviolet lines of Cr, Zn and Ni relevant to time variations of the fine structure constant     

J. C. Pickering  A. P. Thorne  J. E. Murray  U. Litzén  S. Johansson  V. Zilio  J. K. Webb 《Monthly notices of the Royal Astronomical Society》2000,319(1):163-167

The quality of astronomical spectroscopic data now available is so high that interpretation and analysis are often limited by the uncertainties of the laboratory data base. In particular, the limit with which space–time variations in the fine structure constant α can be constrained using quasar spectra depends on the availability of more accurate laboratory rest wavelengths. We recently measured some transitions in magnesium by high-resolution Fourier transform spectroscopy for this purpose, and we now report measurements on some ultraviolet resonance lines of Zn  ii (2062 and 2026 Å), Cr  ii (2066, 2062 and 2056 Å) and Ni  ii (1751, 1741, 1709 and 1703 Å). Apart from the last line, which is very weak, the uncertainty of these measurements is 0.002 cm⁻¹ (0.08 må) for the lines around 2000 Å and 0.004 cm⁻¹ (0.12 må) for the lines around 1700 Å.  相似文献   

An expectation maximization and smoothing approach for indirect acoustic estimation of fish size and density     

Hedgepeth  J. B.; Gallucci  V. F.; O'Sullivan  F.; Thorne  R. E. 《ICES Journal of Marine Science》1999,56(1):36-50

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Comparison of Depth Dependent Fault Zone Properties in the Japan Trench and Middle America Trench     

S. L. Bilek  T. Lay 《Pure and Applied Geophysics》1999,154(3-4):433-456

—Spatial variations in mechanical properties of the interplate thrust faults along the Japan and Middle America subduction zones are examined using teleseismic broadband earthquake recordings. Moment-normalized source duration is used to probe rigidity variations along the interface. We invert body waves to estimate source depth and source duration for 40 events in the Japan subduction zone and 38 events in the Middle America subduction zone. For both areas, there is a systematic decrease in source duration with increasing depth along the subduction zone interface. This is most likely a result of variation in properties of sediments on the plate contact. Variations in source duration are greatly reduced at depths greater than 18 km in both regions. Enhanced spatial heterogeneity at shallow depth may reflect variations in plate roughness, sediment distribution, permeability of the fault zone, and stress.  相似文献   

Herring and the "Exxon Valdez" oil spill: an investigation into historical data conflicts     

Thorne  Richard E.; Thomas  Gary L. 《ICES Journal of Marine Science》2008,65(1):44-50

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