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971.
The SAS® computer software system, widely used and respected for its capabilities in statistical analysis and data base management, now includes a new set of graphic and cartographic procedures called SAS GRAPH?. We have used these cartographic procedures in research on mapping ethno-cultural census data from metropolitan areas in Ontario and in undergraduate and graduate courses in computer cartography. On the basis of that experience, we describe and evaluate SAS/GRAPH'S cartographic capabilities and illustrate with maps drawn by various devices.  相似文献   
972.
973.
Severe rainfall in mid October, 2003 produced the largest floods in almost a century of record on rivers in the Cordillera of southwestern British Columbia. Sediment deposited in Lillooet Lake as a result of this event is clearly distinguished by stratigraphy, colour, texture, magnetic properties, and organic content. Each of these physical properties is related to the lacustrine processes, especially turbid underflow, that distributed the sediment through the lake. The flood, which lasted less than a week, delivered 8–12 times the amount of sediment that accumulates in most entire years in the deepest, central parts of the lake. Recognition of events of this type in the stratigraphic record offers a means of assessing the changing nature of extreme hydroclimatic events, and their relation to more ubiquitous, lower-energy processes.  相似文献   
974.
975.
976.
Suspended matter from the surface waters of the Amazon Estuary were collected during May and June 1976 on the ‘R/V Alpha Helix’, and their major-element compositions (Al, Si, Ti, K, Mg, Ca, P, Fe and Mn) were measured.Between salinities of 0 and 10%. the suspended material, predominantly terrigenous in derivation, decreases in load from 500 to 3 mg/l, but has a chemical composition which remains essentially constant. With the onset of a large amount of biological productivity at approximately 10%. salinity, there are large increases in the ratios of SiAl, PAl, CaAl, MgAl, TiAl and MnAl which are maintained at higher salinities. Calculations of “excess” concentrations of elements held in the non-terrigenous components of the suspended material further support our main conclusion that Si, P, Ca, Mg, Ti and Mn are incorporated into the skeletal and organic phases of marine phytoplankton (predominately diatoms) of the Amazon Estuary. The data suggest, but with less certainty, that Fe and K follow the above elements.This study has demonstrated that the chemical composition of river-introduced suspended matter can be significantly altered by biological activity within estuarine waters as can be the geochemical cycle of inorganic elements.  相似文献   
977.
The author describes the photogrammetric equipment in use by the Royal Commission on Historical Monuments (England), the methods used and the work that is being done in architectural recording. The difficulties and the possibilities of future architectural work in the United Kingdom are discussed and the achievements of some other countries in this field are reviewed.  相似文献   
978.
Spectro-polarimetric observations at 2231 nm were made of NOAA 10008 near the west solar limb on 29 June 2002 using the National Solar Observatory McMath–Pierce Telescope at Kitt Peak and the California State University Northridge – National Solar Observatory infrared camera. Scans of spectra in both Stokes I and Stokes V were collected; the intensity spectra were processed to remove strong telluric absorption lines, and the Stokes V umbral spectra were corrected for instrumental polarization. The sunspot temperature is computed using the continuum contrast and umbral temperatures down to about 3700 K are observed. A strong Tii line at 2231.0 nm is used to probe the magnetic and velocity fields in the spot umbra and penumbra. Measurements of the Tii equivalent width versus plasma temperature in the sunspot agree with model predictions. Zeeman splitting measurements of the Stokes I and Stokes V profiles show magnetic fields up to 3300 G in the umbra, and a dependence of the magnetic field on the plasma temperature similar to that which was seen using Fei 1565 nm observations of the same spot two days earlier. The umbral Doppler velocity measurements are averaged in 16 azimuthal bins, and no radial flows are revealed to a limit of ±200 m s–1. A Stokes V magnetogram shows a reversal of the line-of-sight magnetic component between the limb and disk center sides of the penumbra. Because the Tii line is weak in the penumbra, individual spectra are averaged in azimuthal bins over the entire penumbral radial extent. The averaged Stokes V spectra show a magnetic reversal as a function of sunspot azimuthal angle. The mean penumbral magnetic field as measured with the Stokes V Zeeman component splitting is 1400 G. Several weak spectral lines are observed in the sunspot and the variation of the equivalent width versus temperature for four lines is examined. If these lines are from molecules, it is possible that lines at 2230.67, 2230.77, and 2231.70 nm originate from OH, while the line at 2232.21 nm may originate from CN.  相似文献   
979.
Debris disks are found around some 15% of main sequencestars and their dust is thought to be continuallyreplenished in collisions between planetesimals inextrasolar Kuiper belts.While they were discovered in 1984 by IRAS, it is onlywith more recent imaging that their true nature has beenrevealed. This paper discusses recent debris disk images andtheir impact on our understanding of extrasolar systems.Importantly these images confirm the extrasolar Kuiper belthypothesis for most (but not all) debris diskcandidates and show that the planetesimals within thesedisks must have grown to at least a few km.Asymmetries in imaged disk structures also provide informationabout the planetary systems orbiting inside these planetesimalbelts. The impact of debris disk studies on our understandingof the evolution of our own Kuiper belt, as well as theirpotential to solve puzzles such as the origin of the missingmass and the outer edge of the Kuiper belt, is alsodiscussed.  相似文献   
980.
Pelitic units in the eastern Great Smoky Mountains of the North Carolina Blue Ridge contain rutile grains only in kyanite and higher zones. Adjacent non-pelitic rocks do not contain rutile at kyanite grade but commonly contain sphene. Detrital rutile breaks down at metamorphic grades lower than those at which metamorphic rutile forms. Similarly, pelitic rocks in southeastern Connecticut contain rutile grains above, but not below, the sillimanite isograd. Most non-pelitic rocks there contain rutile only in the hypersthene zone. The slight difference in behavior of rutile in the two terranes is attributed primarily to a slight difference in calcium content of the pelites. In both areas, rutile commonly appears first as inclusions in garnet. Geologic maps showing metamorphic and stratigraphic or compositional information should be useful as prospecting tools for placer deposits. A variety of rocks at granulite facies and pelitic rocks of the upper amphibolite facies contain rutile and these could provide an extensive source for rutile in rutile placer deposits.  相似文献   
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