Finance and Alluvial Mining in Papua 1878 to 1920     

W.A. McGee  G.R. Henning 《Asia Pacific viewpoint》1991,32(1):78-87

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Factors influencing atmospheric deposition,stream export,and landscape accumulation of trace metals in forested watersheds     

S. E. Lindberg  R. R. Turner 《Water, air, and soil pollution》1988,39(1-2):123-156

Wet and dry deposition inputs and streamflow output of Cd, Mn, Pb, Zn, and Al were measured intermittently at four deciduous forested watersheds in the southeastern United States between 1976 and 1982. Atmospheric inputs to each site were similar, varying by factors of 1.1 to 2.2 for the different metals. Metal levels in precipitation indicate that these sites are representative of rural, continental areas. Metals in rain exhibit significant temporal and spatial trends, with concentrations generally higher during summer than winter at all sites and generally lowest at the more remote site. The concentrations of Cd and Pb in both wet and dry deposition decreased between the period 1976 to 1977 and 1981 to 1982. Ion ratios and enrichment factors suggest that Mn is largely soil derived in atmospheric samples while Cd, Pb, and Zn are enriched over typical soil levels. Factor analysis indicates that soil components influence both Al and Mn while fine aerosol components influence Cd in wet and dry deposition. Both components influence the behavior of Pb. Dry deposition dominated the input of Mn and Al to each site, while wet deposition was the major input process for the other metals (54 to 85% of total). On an annual basis, deposited Cd, Pb, and Zn are strongly retained in each watershed: 2% of the Pb, 8 to 29% of the Cd, and 8 to 34% of the Zn inputs were transported in stream flow. Deposited Mn and Al are retained to a lesser degree and show a net loss from two sites. Metal export is controlled by stream pH, organic carbon, bedrock geology, and hydrologic characteristics of each site.  相似文献   

Starch Blue     

Turner NC 《Science (New York, N.Y.)》1948,108(2803):302-303

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The flight from the arts and sciences: trends in degrees conferred   总被引：2，自引：0，他引：2  

Turner SE  Bowen WG 《Science (New York, N.Y.)》1990,250(4980):517-521

After rising steadily between 1954 and 1968, the percentage of all bachelor's degrees awarded in the arts and sciences declined dramatically. These swings cannot be explained by demographic variables; however, they have been affected by changes in the academic profiles of educational institutions that were in turn related to trends in enrollment. Even more important have been the changing choices of fields of study made by men and women (particularly in the case of the humanities), in part as a consequence of widening opportunities for women. The flight from the arts and sciences now appears to be over, and in the future gender-related variables can be expected to have less impact on the distribution of degrees conferred.  相似文献   

Lymphocytic-choriomeningitis virus in hamster tumor: spread to hamsters and humans   总被引：6，自引：0，他引：6  

A M Lewis  W P Rowe  H C Turner  R J Huebner 《Science (New York, N.Y.)》1965,150(694):363-364

A passage line of a spontaneous hamster fibrosarcoma is contaminated by the virus. of lymphocytic choriomeningitis. Tumors from animals receiving implants when newborn contain high titers of infectious lymphocytic-choriomeningitis virus and complement-fixing antigen, and hamsters receiving implants when weanlings develop high titers of complement-fixing antibody against lymphocytic-choriomeningitis virus. In contrast with the specific reactions of tumorous hamsters to the initiating virus in virus-induced tumors, the development of complement-fixing antibody to lymphocytic-choriomeningitis virus does not depend on the development of tumors. Infant hamsters bearing the tumor have a generalized subclinical infection and seem able to spread virus to other hamsters and to humans.  相似文献   

A CULTURE MEDIUM FOR EUGLENA     

Turner CL 《Science (New York, N.Y.)》1917,45(1158):239

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Policy forum: genetics. Ethical considerations in synthesizing a minimal genome     

Cho MK  Magnus D  Caplan AL  McGee D 《Science (New York, N.Y.)》1999,286(5447):2087, 2089-2087, 2090

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Testing cosmogonic models with gravitational lensing     

Wambsganss J  Cen R  Ostriker JP  Turner EL 《Science (New York, N.Y.)》1995,268(5208):274-276

Gravitational lensing provides a strict test of cosmogonic models because it is directly sensitive to mass inhomogeneities. Detailed numerical propagation of light rays through a universe that has a distribution of inhomogeneities derived from the standard CDM (cold dark matter) scenario, with the aid of massive, fully nonlinear computer simulations, was used to test the model. It predicts that more widely split quasar images should have been seen than were actually found. These and other inconsistencies rule out the Cosmic Background Explorer (COBE)-normalized CDM model with density parameter Omega = 1 and the Hubble constant (H(o)) = 50 kilometers second(-1) megaparsec(-1); but variants of this model might be constructed, which could pass the stringent tests provided by strong gravitational lensing.  相似文献   

Extinct 244Pu in ancient zircons   总被引：2，自引：0，他引：2  

Turner G  Harrison TM  Holland G  Mojzsis SJ  Gilmour J 《Science (New York, N.Y.)》2004,306(5693):89-91

We have found evidence, in the form of fissiogenic xenon isotopes, for in situ decay of 244Pu in individual 4.1- to 4.2-billion-year-old zircons from the Jack Hills region of Western Australia. Because of its short half-life, 82 million years, 244Pu was extinct within 600 million years of Earth's formation. Detrital zircons are the only known relics to have survived from this period, and a study of their Pu geochemistry will allow us to date ancient metamorphic events and determine the terrestrial Pu/U ratio for comparison with the solar ratio.  相似文献   

CLASSIFICATION OF IGNEOUS ROCKS     

Turner HW 《Science (New York, N.Y.)》1898,7(175):622-625

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