Probing Titan's Surface     

Eshleman VR  Tyler GL  Simpson RA  Marouf EA 《Science (New York, N.Y.)》1984,223(4638):772

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Bistatic-radar detection of lunar scattering centers with lunar orbiter I     

Tyler GL  Eshleman VR  Fjeldbo G  Howard HT  Peterson AM 《Science (New York, N.Y.)》1967,157(3785):193-195

Continuous-wave signals transmitted from Lunar Orbiter I have been received on Earth after they have been reflected from the surface of the moon. The frequency spectrum of the reflected signals is used to locate discrete, heterogeneous, scattering centers on the lunar surface. The scattering centers are probably distinguished from the surrounding terrain by a higher surface reflectivity. Continuous-wave bistatic radar could provide an important new method for the study and mapping of planetary surfaces.  相似文献   

Growth of SiO2 at room temperature with the use of catalyzed sequential half-reactions     

JW Klaus  O Sneh  SM George 《Science (New York, N.Y.)》1997,278(5345):1934-1936

Films of silicon dioxide (SiO2) were deposited at room temperature by means of catalyzed binary reaction sequence chemistry. The binary reaction SiCl4 + 2H2O --> SiO2 + 4HCl was separated into SiCl4 and H2O half-reactions, and the half-reactions were then performed in an ABAB ellipsis sequence and catalyzed with pyridine. The pyridine catalyst lowered the deposition temperature from >600 to 300 kelvin and reduced the reactant flux required for complete reactions from approximately 10(9) to approximately 10(4) Langmuirs. Growth rates of approximately 2.1 angstroms per AB reaction cycle were obtained at room temperature for reactant pressures of 15 millitorr and 60-second exposure times with 200 millitorr of pyridine. This catalytic technique may be general and should facilitate the chemical vapor deposition of other oxide and nitride materials.  相似文献   

A sporadic third layer in the ionosphere of Mars   总被引：1，自引：0，他引：1  

Pätzold M  Tellmann S  Häusler B  Hinson D  Schaa R  Tyler GL 《Science (New York, N.Y.)》2005,310(5749):837-839

The daytime martian ionosphere has been observed as a two-layer structure with electron densities that peak at altitudes between about 110 and 130 kilometers. The Mars Express Orbiter Radio Science Experiment on the European Mars Express spacecraft observed, in 10 out of 120 electron density profiles, a third ionospheric layer at altitude ranges of 65 to 110 kilometers, where electron densities, on average, peaked at 0.8 x 10(10) per cubic meter. Such a layer has been predicted to be permanent and continuous. Its origin has been attributed to ablation of meteors and charge exchange of magnesium and iron. Our observations imply that this layer is present sporadically and locally.  相似文献   

Chesapeake bay anoxia: origin, development, and significance     

Officer CB  Biggs RB  Taft JL  Cronin LE  Tyler MA  Boynton WR 《Science (New York, N.Y.)》1984,223(4631):22-27

Anoxia occurs annually in deeper waters of the central portion of the Chesapeake Bay and presently extends from Baltimore to the mouth of the Potomac estuary. This condition, which encompasses some 5 billion cubic meters of water and lasts from May to September, is the result of increased stratification of the water column in early spring, with consequent curtailment of reoxygenation of the bottom waters across the halocline, and benthic decay of organic detritus accumulated from plankton blooms of the previous summer and fall. The Chesapeake Bay anoxia appears to have had significant ecological effects on many marine species, including several of economic importance.  相似文献   

STUDIES ON THE ETIOLOGY OF EGYPTIAN TRACHOMA     

Olitsky PK  Tyler JR 《Science (New York, N.Y.)》1933,78(2010):18

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PHLEBOTOMUS AND OROYA FEVER AND VERRUGA PERUANA     

Noguchi H  Shannon RC  Tilden EB  Tyler JR 《Science (New York, N.Y.)》1928,68(1769):493-495

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BACTERIUM GRANULOSIS AND TRACHOMA OF AN URBAN WHITE POPULATION     

Olitsky PK  Tyler JR 《Science (New York, N.Y.)》1930,71(1836):263-264

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Recovery from retrograde amnesia: a learning process     

A M Schneider  J Tyler  D Jinich 《Science (New York, N.Y.)》1974,184(132):87-88

Retrograde amnesia was produced in rats by electroconvulsive shock. Memory recovered if the animals were given repeated test trials. Memory did not recover if steps were taken to reduce the conditioning properties of the test trials; the manipulations included eliminating the response, altering the apparatus cues, or extinguishing conditioned "fear" by confining animals to the apparatus during the first test trial.  相似文献   

Human voice recognition depends on language ability     

Perrachione TK  Del Tufo SN  Gabrieli JD 《Science (New York, N.Y.)》2011,333(6042):595

The ability to recognize people by their voice is an important social behavior. Individuals differ in how they pronounce words, and listeners may take advantage of language-specific knowledge of speech phonology to facilitate recognizing voices. Impaired phonological processing is characteristic of dyslexia and thought to be a basis for difficulty in learning to read. We tested voice-recognition abilities of dyslexic and control listeners for voices speaking listeners' native language or an unfamiliar language. Individuals with dyslexia exhibited impaired voice-recognition abilities compared with controls only for voices speaking their native language. These results demonstrate the importance of linguistic representations for voice recognition. Humans appear to identify voices by making comparisons between talkers' pronunciations of words and listeners' stored abstract representations of the sounds in those words.  相似文献