A high-resolution infrared spectral survey of Comet C/1999 H1 Lee     

Neil Dello Russo  Michael J. Mumma  Karen Magee-Sauer  Boncho P. Bonev  I.S. McLean 《Icarus》2006,184(1):255-276

We obtained high-resolution (λ/Δλ∼25,000) spectra of Comet C/1999 H1 (Lee) on UT 1999 August 19.6 and 21.6 using the cross-dispersed Near InfraRed SPECtrometer (NIRSPEC) at the Keck Observatory atop Mauna Kea, HI. Here we present spectra of Comet Lee between 2.874 and 3.701 μm (3479-2702 cm⁻¹) representing the most complete high-resolution infrared survey of a comet to date in this wavelength region. Using published line lists and laboratory spectra we have identified 444 of the 545 distinct emission features present in these spectra. We have tabulated the rest frequencies, assignments, relative intensities, and signal-to-noise ratios of all detected emissions. In addition to gaining insights into the chemistry of Comet Lee, this survey provides a valuable tool for planning future high-resolution infrared observations of comets and other astronomical targets, and for retrospective comparison to existing high-resolution infrared datasets.  相似文献   

The faint end of the galaxy luminosity function     

Neil Trentham  R. Brent Tully 《Monthly notices of the Royal Astronomical Society》2002,335(3):712-732

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Three-dimensional dust radiative-transfer models: the Pinwheel Nebula of WR 104     

Tim J. Harries  John D. Monnier  Neil H. Symington  Ryuichi Kurosawa 《Monthly notices of the Royal Astronomical Society》2004,350(2):565-574

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The timing and nature of recession of outlet glaciers of Hielo Patagónico Norte, Chile, from their Neoglacial IV (Little Ice Age) maximum positions   总被引：2，自引：1，他引：1  

Stephan Harrison  Vanessa Winchester  Neil Glasser 《Global and Planetary Change》2007,59(1-4):67

The dates of recession of eleven outlet glaciers of the Hielo Patagónico Norte (Northern Patagonian Icefield) from their recent maximum positions have been inferred from dendrochronology, lichenometry, radiocarbon dating and historical sources. We have refined the dating for part of the Little Ice Age period in this area placing a glacial advance to between AD 1650 and 1766 with the latter date favoured as conformable with historical records and an uncalibrated radiocarbon determination. Glacier recession from maximal positions began in the early 1860s–1870s. Recession was largely synchronous on the western and eastern sides of the Icefield. This synchronicity suggests that climate forcing over-rides second-order controls on glacier behaviour such as the nature of the terminal environment (e.g. calving/non-calving) or differences in glacier drainage basin area. We argue that this icefield-wide glacier recession represents a response to post-Little Ice Age warming, and provides further evidence for the global extent and near synchronous termination of the Little Ice Age.  相似文献   

Use of the frozen flux approximation in the interpretation of archaeomagnetic and palaeomagnetic data     

David Gubbins  Neil Roberts 《Geophysical Journal International》1983,73(3):675-687

Summary. The frozen flux approximation of Roberts & Scott is a constraint on the core field that can be used to aid interpretation of the very sparse datasets that palaeomagnetism and archaeomagnetism provide. It gives bounds on the size of the components of the magnetic field at a point, of the Gauss coefficients, and, if valid over such long time periods, limits the shape of the field during transitions between normal and reversed polarities. The maximum intensity at a point, consistent with the present flux, is 281 μT or 4 times the maximum field observed today. The present dipole is about 50 per cent of its upper bound. Polarity reversal is impossible if the transition field is purely axisymmetric. None of the measurements we consider violate the frozen flux approximation.  相似文献   

Tensiti: a social and physical development in Lae,Papua New Guinea     

Neil Kennan 《The Australian geographer》1988,19(2):284-289

The implementation of an ‘appropriate’ housing subdivision in Lae, Papua New Guinea represents a new approach in creating an acceptable environment for the urban poor. The unique hexagonal design of the Tensiti development and its aims and policy implications are discussed. It appears that at least some of the urban poor of Lae now live in a settlement which satisfies the demands of town planners, urban administrators and the realities of the settlers' basic needs and resources.  相似文献   

A Continuum Theory For Lattice Preferred Orientation     

Neil M. Ribe 《Geophysical Journal International》1989,97(2):199-207

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The termination of the solar wind     

Thomas R. McDonough  Neil M. Brice 《Icarus》1971

It has previously been suggested that the solar wind might terminate at distances of 5 AU to 20 AU from the Sun, and that the solar wind might be drastically slowed down by charge exchange and photoionization of interstellar hydrogen atoms which approach the Sun. However, recent satellite measurements of resonantly scattered Lyman alpha radiation, together with pulsar dispersion and Faraday rotation measures, imply very small values for the interstellar hydrogen density (0.05 cm⁻³) and magnetic field strength (3 μG). As a result, the solar wind is not expected to be slowed down by more than about 30% inside the termination distance, which is expected to be about 100 AU.  相似文献   

Invariant expressions for elastic radiation from a fault with prescribed slip     

L. Neil Frazer 《Geophysical Journal International》1982,70(2):529-533

Summary New formulae are obtained for the displacement potentials and displacements due to a point source with moment tensor, and for a fault with prescribed slip. These formulae, unlike previous formulae, are invariant, i.e. they are valid in any coordinate system, not just Cartesian coordinates or orthogonal curvilinear coordinates.
Apart from their invariance, these formulae have other advantages: they are exceedingly simple; the expressions for P -motion are nearly the same as those for S -motion; and the separation of far field motion from final static displacement is automatic.  相似文献   

A least-squares method for determining the best-fit point maximum, great circle, and small circle to nondirectional orientation data     

Neil S. Mancktelow 《Mathematical Geology》1981,13(6):507-521

Given a set of nondirectional orientation data (fold axes, lineations, dip and dip direction of bedding, universal stage readings of crystallographic axes, etc.),the best-fit line (point maximum),plane (great circle),or cone (small circle)can be determined by minimizing the sum of the squares of the angular residuals using a simplex convergence technique. Stereoplots of the angular deviation over the complete lower hemisphere for these distributions may also be generated when consideration of the constraint on the best-fit position is important; for example in comparing different data sets of the same structural element. The routines are available as a FORTRAN coded computer program.  相似文献