The diameter and thermal inertia of 433 Eros     

David Morrison 《Icarus》1976,28(1):125-132

Radiometry of Eros at 10 and 20 μm demonstrates that the thermal conductivity of the upper centimeter of the surface is approximately as low as that of the Moon, suggesting that the asteroid has a regolith of highly porous rocky material. When combined with photoelectric photometry, these infrared measurements yield an effective diameter of Eros at maximum light of D₀ = 22 ± 2 km and a geometric albedo of p_v = 0.18 ± 0.03.  相似文献   

Infrared radiometry of the rings of Saturn     

David Morrison 《Icarus》1974,22(1):57-65

Broad-band radiometry with a spatial resolution of 5 arc sec is presented of Saturn and its rings. The brightness temperature of the B ring is 96 ± 3°K at 20 μm and 91 ± 3°K at 11 μm. These values constrain the bolometric Bond albedo of the ring particles to be less than 0.6, thus requiring a phase integral of less than unity. From differences in the thermal emission of the ansae, I suggest that the leading side of the particles has higher albedo than the trailing side. A measured drop in temperature of the B ring following eclipse of 2.0 ± 0.5°K is consistent with radii for the ring particles of 2 cm or larger.  相似文献   

AAS division for planetary sciences: Fifth (1974) and sixth (1975) annual meetings     

David Morrison 《Icarus》1975,26(1):111-123

Visual estimates of total coma brightness define the light curve of Comet Kohoutek between November 24, 1973 and February 6, 1974. These data are well fitted by straight lines on the M-log r diagram. The preperihelion value of n is 2.2, and the post perihelion value is 3.8 up to January 16. A standstill in the decline is suspected between January 16 and 19. If the standstill is ignored the postperihelion data can be fitted less precisely by a single line with n = 3.3. From photoelectric measures on four nights between January 5 and 13 after perihelion, n is found to be 4.1.The average B-V with a 32.4 arc sec diaphragm for those four nights is 0.79 ± 0.04; no clear systematic variation with time is noted.  相似文献   

The Tucson revised index of asteroid data     

D. Bender  E. Bowell  C. Chapman  M. Gaffey  T. Gehrels  B. Zellner  D. Morrison  E. Tedesco 《Icarus》1978,33(3):630-631

Attention is called to the availability of the TRIAD computer file, a compilation of all reliable physical parameters for minor planets.  相似文献   

Asteroid sizes and albedos     

David Morrison 《Icarus》1977,31(2):185-220

The radiometric method of determining diameters of asteroids is reviewed, and a synthesis of radiometric and polarimetric measurements of the diameters and geometric albedos of a total of 187 asteroids is presented. All asteroids with diameters greater than 250 km are identified, and statistical studies can be carried out of the size distributions of different albedo classes down to 80-km diameter for the entire main asteroid belt (2.0–3.5 AU). The distribution of albedos is strongly bimodal, with mean albedos for the C and S groups of 0.035 and 0.15, respectively. The C asteroids outnumber the S at all sizes and all values of semi-major axis, increasing from a little over half the population inside 2.5 AU to more than 95% beyond 3.0 AU; for all objects with D > 70 km, the ratio C/(C+S) is 0.88 ± 0.04. More than half of all asteroids in this size range have a > 3.0 AU. The M asteroids constitute about 5% of the population for a < 3.0 AU, but no members of of this class have been identified in the outer belt. There are no significant differences between the distributions of C, S, and M asteroids for the largest asteroids (D > 200 km) and for those of intermediate size (200–270 km). The total mass in the belt, down to 70-km size, but excluding Ceres, is about 2 × 10²⁴ g. Evidence is presented that several large asteroids rotate in a prograde sense, and that a real difference existsbetween the bulk densities of Ceres and Vesta.  相似文献   

The Changing Geography of Full-Time Employment in New Zealand     

Philip S. Morrison 《New Zealand geographer》1984,40(2):78-88

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Zinc concentrations in marine macroalgae and a lichen from western Ireland in relation to phylogenetic grouping, habitat and morphology     

Stengel DB  Macken A  Morrison L  Morley N 《Marine pollution bulletin》2004,48(9-10):902-909

Zinc concentrations in 19 species of marine macroalgae and a lichen from western Ireland (Spiddal, Co. Galway) were analysed by atomic absorption spectrophotometry. Algae were collected from a single site but occupied different shore levels and belonged to distinct phylogenetic groupings and to different (previously recognised) morphological groups. Concentrations ranged from 15-115 microg g(-1) dry weight. The greatest variation in concentration occurred amongst the red algal species, containing both maximum and minimum concentrations. Zn concentrations in brown and green algae were generally lower than those in red algae. When grouped according to thallus morphology, thin, branched sheets (which consisted mainly of red algae) contained the highest Zn concentrations. In filamentous algae, Zn levels were higher than in thick-leathery or coarsely branched algae. However, all green algal species examined had similar Zn concentrations, despite their different morphologies. In brown algae, the highest Zn levels were detected in mid-shore fucoids (Fucus vesiculosus and Fucus serratus), while thicker, subtidal and low-shore brown algae (Laminaria digitata, Halydris siliquosa) exhibited lower Zn concentrations. The lowest Zn concentrations were detected in high-intertidal species (Fucus spiralis, Pelvetia canaliculata), the only marine lichen examined (Ramalina siliquosa) and a red crustose alga (Corallina officinalis). In all morphological groups, red algal representatives contained relatively higher levels of Zn, the exception being Corallina officinalis. Zn levels in 4 species from a second, estuarine site in Galway Bay exhibited the same relative differences amongst species, but were all consistently higher than in algae from Spiddal. It is concluded that Zn accumulation in macroalgae is closely related to ecological growth strategies, following a functional-form model. However, the phylogenetic origin of species which determines carbohydrate and phenol composition, and responses to ambient environmental conditions ultimately determine, the availability of binding sites for polyvalent cations.  相似文献   

Moons and planets: (2nd Ed.). William K. Hartmann. Wadsworth,Belmont, Calif., 1983. $29.95     

David Morrison 《Icarus》1983,56(1):192-193

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Modification of an equation of Szebehely     

Foster Morrison 《Celestial Mechanics and Dynamical Astronomy》1977,16(1):39-40

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Variation in the hatching length of spring-spawned herring larvae (Clupea harengus L.) on Ballantrae Bank in the Firth of Clyde     

Rankine  Paul W.; Cargill  Lindsay H.; Morrison  John A. 《ICES Journal of Marine Science》1990,46(3):333-339

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