排序方式： 共有30条查询结果，搜索用时 281 毫秒
1.
Jeremy Allington-Smith Graham Murray Robert Content George Dodsworth Bryan W. Miller James Turner Inger Jorgensen Isobel Hook 《Experimental Astronomy》2002,13(1):1-37
We describe the integral field unit (IFU) which converts the Gemini Multiobject Spectrograph (GMOS) installed on the Gemini-North telescope to an integral field spectrograph,which produces spectra over a contiguous field of view of 7 × 5 arcsec with spatial sampling of 0.2 arcsecover the wavelength range 0.4-1.0 μm.GMOS is converted to this mode by the remote insertion of the IFU into thebeam in place of the masks used for the multiobject mode. A separate fieldof half the area of the main field, but otherwise identical, is alsoprovided to improve background subtraction. The IFU contains 1500lenslet-coupled fibres and was the first facility of any type for integralfield spectroscopy employed on an 8/10 m telescope.We describe the design, construction and testing of the GMOS IFU and present measurements of the throughput both in the laboratory and at the telescope. We compare these with a theoretical prediction made before construction started. All are in good agreement with each other, with the on-telescope throughput exceeding 60% (averaged over wavelength). Finallywe show an example of data obtained during commissioning to illustrate the power of the device. 相似文献
2.
Mussel Periostracum from Deep-Sea Redox Communities as a Microbial Habitat: 3. Secondary Inhabitants
Abstract. Vacated microborings in periostracum of live mussels of the Florida Escarpment redox community (depth of 3266 m) become a habitat for a prolific secondary microbiota consisting of a variety of prokaryotic and a few eukaryotic organisms. Periostracum surface is also colonized by diverse microorganisms, dominated by presumed chemolithotrophic bacteria with stacks of intracellular lamellae. Unlike sheltered microflora within borings, the surface community is heavily grazed upon by numerous archaeogastropods and ciliates. 相似文献
3.
Derek Hook 《Geoforum》2005,36(6):688-704
This paper takes up the attempt to theorize the relation between the subjectivity of the political actor and the ideological aura of the monumental site. It does this with reference to the spatial history of Strijdom Square in Pretoria, South Africa, a cultural precinct and monumental space which was the site of a series of brutal racist killings committed by the Square’s unrelated namesake, militant right-winger Barend Strydom. This troubling intersection of subjectivity, space and ideology represents something of an explanatory limit for spatio-discursive approaches, certainly in as much as they are ill-equipped to conceptualize the powerfully affective, bodily and fantasmatic qualities of monumental spaces. In contrast to such approaches I offer a psychoanalytically informed account which grapples with the individualized and imaginative identities of space, with space as itself a form of subjectivity. I do this so as understand the ideological aura of monuments as importantly linked to the ‘intersubjectivity’ of subject and personified space. I then turn to Freud’s notion of the uncanny as a theory able to explain a series of disturbing affects of monuments, such as those of ‘embodied absence’ and ‘disembodied presence’. These and similar affects of ‘ontological dissonance’ (such as unexplained instances of doubling or repetition) may function in an ideological manner, both so as to impose a ‘supernaturalism of power’, and to effect an uncanny form of interpellation. 相似文献
4.
Dr. Stjepko Golubić 《Aquatic Sciences - Research Across Boundaries》1965,27(2):218-232
Ohne Zusammenfassung
Die vorliegende Arbeit entstand dank der Unterstützung der Alexander-von-Humboldt-Stiftung, Bad Godesberg. 相似文献
5.
Paul C. Hackley Edgar H. Guevara Tucker F. Hentz Robert W. Hook 《International Journal of Coal Geology》2009,77(3-4):294-309
Thermal maturity was determined for about 120 core, cuttings, and outcrop samples to investigate the potential for coalbed gas resources in Pennsylvanian strata of north-central Texas. Shallow (< 600 m; 2000 ft) coal and carbonaceous shale cuttings samples from the Middle-Upper Pennsylvanian Strawn, Canyon, and Cisco Groups in Archer and Young Counties on the Eastern Shelf of the Midland basin (northwest and downdip from the outcrop) yielded mean random vitrinite reflectance (Ro) values between about 0.4 and 0.8%. This range of Ro values indicates rank from subbituminous C to high volatile A bituminous in the shallow subsurface, which may be sufficient for early thermogenic gas generation. Near-surface (< 100 m; 300 ft) core and outcrop samples of coal from areas of historical underground coal mining in the region yielded similar Ro values of 0.5 to 0.8%. Carbonaceous shale core samples of Lower Pennsylvanian strata (lower Atoka Group) from two deeper wells (samples from ~ 1650 m; 5400 ft) in Jack and western Wise Counties in the western part of the Fort Worth basin yielded higher Ro values of about 1.0%. Pyrolysis and petrographic data for the lower Atoka samples indicate mixed Type II/Type III organic matter, suggesting generated hydrocarbons may be both gas- and oil-prone. In all other samples, organic material is dominated by Type III organic matter (vitrinite), indicating that generated hydrocarbons should be gas-prone. Individual coal beds are thin at outcrop (< 1 m; 3.3 ft), laterally discontinuous, and moderately high in ash yield and sulfur content. A possible analog for coalbed gas potential in the Pennsylvanian section of north-central Texas occurs on the northeast Oklahoma shelf and in the Cherokee basin of southeastern Kansas, where contemporaneous gas-producing coal beds are similar in thickness, quality, and rank. 相似文献
6.
Abdalla Sirag Norashidah Mohamed Nor Siong Hook Law Nik Mustapha Raja Abdullah Miloud Lacheheb 《GeoJournal》2017,82(6):1247-1261
The current paper examines the relationship between health financing (public and out-of-pocket health financing), CO2 emission and health outcomes in 35 Sub-Saharan African countries for the period of 1995–2012. The panel unit root and cointegration tests are conducted as pre-tests, followed by the estimation of the parameters using the FM-OLS and DOLS techniques. The findings of the study show the importance of public health financing as one of the major factors that lead to better health outcomes, whereas the out-of-pocket expenditure is found to be harmful to population health since it leads to increase under-5 mortality rate. Although the results show a negative relationship between CO2 and health outcomes, still these results remain inclusive. In addition, the findings reveal the importance of socioeconomic factors such as income and education as key determinants of health outcomes. 相似文献
7.
Mussel Periostracum from Deep-Sea Redox Communities as a Microbial Habitat: 2. The Pit Borers 总被引：1，自引：0，他引：1
Abstract. Mussel periostracum from the Florida Escarpment redox community (3266 m depth) is extensively bored by a variety of microorganisms. Four different types of pit borings were observed and characterized on the basis of SEM images of their resin casts, and/or light and TEM reconstructions: two large, open-pit borers, a "button" borer, and a cone borer. These boring patterns represent distinctive feeding "strategies". The cumulative activities of periostracum borers remove the protective organic layer from the mussel shells, exposing the mineral to cndolith attack. 相似文献
8.
We examined the link between DNA strand breaks and hatching rates in grass shrimp, (Paleomonetes pugio), embryos exposed to 0.2 microM benzo[alpha] pyrene (BP), 5 microM cadmium (Cd) and 330 kJ/m(2) UV light, either alone or together. After exposure, embryos were transferred to clean seawater with or without 5 microM Cd. Hatching rates and DNA strand breaks (Comet Assay) were determined. DNA lesions caused by exposure to BP, UV light, or BP/cadmium were rapidly repaired and were not associated with any effects on hatching. Exposure to Cd after exposure to BP or UV did not affect embryological development or DNA repair. Exposure to BP/UV resulted in a high level of DNA lesions which were slowly repaired. Exposure to cadmium following BP/UV exposure inhibited hatching and DNA repair. Adducts formed during exposure to BP/UV exposure may be difficult to excise or may saturate the nucleotide excision repair system. 相似文献
9.
Abstract. A complex and highly unusual eukaryotic microorganism was discovered to be penetrating and removing the periostracum of deep-sea mussels from the Florida Escarpment brine seeps at a depth of 3266 m. These brine seeps support a chemolithoautotrophic redox community similar to those known from Pacific hydrotherma! vents. This microorganism of unknown taxonomic affinity is filamentous and coenocytic, with a simple plasma membrane and no cell wall. It forms prostrate, radiating systems of branched tunnels, 8–15 u.m in diameter. The surface of the tunnels is sculptured by helically organized, scale-like depressions, which are left as scars in the process of periostracum removal by the organism. Periostracum is removed in discrete pieces (scallops) at the ends of the tunnels. This organism has been found at three Atlantic deep-sea redox communities, but not in similar communities of the Pacific. 相似文献
10.
Dr. Stjepko Golubić Dr. Thérèse Le Campion-Alsumard 《Aquatic Sciences - Research Across Boundaries》1973,35(1):157-161
Boring patterns of two marine Cyanophytes,Mastigocoleus testarum Lagerheim, andKyrtuthrix dalmatica Ercegovi?, which actively penetrate carbonate substrates, have been compared. They show significant differences: 1. The course of penetration inMastigocoleus is arched to semicircular, inKyrtuthrix it is predominantly perpendicular to the surface. 2. Each boring tunnel inMastigocoleus contains only one single trichome, inKyrtuthrix it contains a looped trichome. 3. The tunnels are circular in cross section inMastigocoleus and elongated inKyrtuthrix. 相似文献