Cyclic change in late triassic lacustrine communities     

Olsen PE  Remington CL  Cornet B  Thomson KS 《Science (New York, N.Y.)》1978,201(4357):729-733

A new type of lake and shore assemblage has been found in the Late Triassic age rocks of North Carolina and Virginia (Dan River group). It includes abundant aquatic reptiles, fishes, at least seven orders of insects, crustaceans, and a diverse flora. Cyclic changes in the fauna and flora correlate with sedimentary cycles, which together reflect the repetitive development and extinction of large meromictic lakes.  相似文献   

Lignin-like compounds and sporopollenin coleochaete, an algal model for land plant ancestry     

Delwiche CF  Graham LE  Thomson N 《Science (New York, N.Y.)》1989,245(4916):399-401

Unusual cell wall structure and resistance to microbial degradation led to an investigation of resistant biopolymers in Coleochaete (Chlorophyta, class Charophyceae), a green alga on the evolutionary lineage that led to land plants. In Coleochaete that are undergoing sexual reproduction, vegetative cell walls contain material similar to lignin, a substance generally thought absent from green algae, and the zygote wall includes sporopollenin. Knowledge of chemically resistant compounds in Coleochaete may facilitate interpretation of the fossil record. Placental transfer cells in Coleochaete orbicularis and in the hornwort Anthoceros survive acetolysis and contain lignin-like compounds, implying a close relation between these taxa.  相似文献   

Device Applications of Side-Chain Ferroelectric Liquid Crystalline Polymer Films     

KM Blackwood 《Science (New York, N.Y.)》1996,273(5277):909-912

Side-chain ferroelectric liquid crystalline polymers are currently used in a number of applications, including displays and electrical sensors. Comparisons with existing technologies and materials indicate that relative to ceramics, such polymers have lower figures of merit but offer greater durability in sensor applications.  相似文献   

Ablation, flux, and atmospheric implications of meteors inferred from stratospheric aerosol   总被引：1，自引：0，他引：1  

Cziczo DJ  Thomson DS  Murphy DM 《Science (New York, N.Y.)》2001,291(5509):1772-1775

Single-particle analyses of stratospheric aerosol show that about half of the particles contain 0.5 to 1.0 weight percent meteoritic iron by mass, requiring a total extraterrestrial influx of 8 to 38 gigagrams per year. The sodium/iron ratio in these stratospheric particles is higher and the magnesium/iron and calcium/iron ratios are lower than in chondritic meteorites, implying that the fraction of material that is ablated must lie at the low end of previous estimates and that the extraterrestrial component that resides in the mesosphere and stratosphere is not of chondritic composition.  相似文献   

THE AMERICAN CHEMICAL SOCIETY     

Thomson W 《Science (New York, N.Y.)》1881,2(28):2-3

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ACCLIMATIZATION IN NEW ZEALAND     

Thomson GM 《Science (New York, N.Y.)》1887,10(244):170-171

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THE HEALTH OF NEW YORK DURING SEPTEMBER     

Thomson GM 《Science (New York, N.Y.)》1886,8(197):426-430

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SUPPRESSION OF VITAL DATA     

Thomson DL  Hoff HE 《Science (New York, N.Y.)》1945,102(2655):513-514

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INFERENCES CONCERNING AURORAS     

Thomson E 《Science (New York, N.Y.)》1916,44(1145):818-819

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The seasons, global temperature, and precession   总被引：1，自引：0，他引：1  

Thomson DJ 《Science (New York, N.Y.)》1995,268(5207):59-68

Analysis of instrumental temperature records beginning in 1659 shows that in much of the world the dominant frequency of the seasons is one cycle per anomalistic year (the time from perihelion to perihelion, 365.25964 days), not one cycle per tropical year (the time from equinox to equinox, 365.24220 days), and that the timing of the annual temperature cycle is controlled by perihelion. The assumption that the seasons were timed by the equinoxes has caused many statistical analyses of climate data to be badly biased. Coherence between changes in the amplitude of the annual cycle and those in the average temperature show that between 1854 and 1922 there were small temperature variations, probably of solar origin. Since 1922, the phase of the Northern Hemisphere coherence between these quantities switched from 0 degrees to 180 degrees and implies that solar variability cannot be the sole cause of the increasing temperature over the last century. About 1940, the phase patterns of the previous 300 years began to change and now appear to be changing at an unprecedented rate. The average change in phase is now coherent with the logarithm of atmospheric CO(2) concentration.  相似文献