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Summary This paper describes a simplified model which links the sedimentary concentration of selected biomarkers to their export primary production, their stability during transit to the anoxic sediment layer and the sediment bulk sedimentation rate. Manipulation of the biomarker data permits the individual effects of these processes to be separated. Examples demonstrate the use of this strategy in the evaluation of environmentally significant parameters. 相似文献
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Using a computer controlled microwave spectrometer, the self-broadened linewidth and -shift parameters have been simultaneously measured for the K = J inversion lines of ammonia. It is shown that the ΔF = ±1 quadrupole hyperfine components make appreciable contributions to the observed widths. With the exception of the J, K = 5, 5 line, the observed linewidths are in agreement with those calculated from both the Anderson and Murphy-Boggs theories. However, the line-shift parameters are not in agreement with the Anderson theory predictions. 相似文献
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H.M. Pickett R.L. Poynter E.A. Cohen 《Journal of Quantitative Spectroscopy & Radiative Transfer》1981,26(3):197-198
The line widths, pressure-induced shifts, and center frequency of the J = 1-0, K = 0 phosphine transition at 266.9 Ghz have been determined. The widths and shifts are reported for collisions with phosphine, H2 and He. 相似文献
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The functional Ito formula, in the form df() = f( + d ) f(),is formulated and proved in the context of a Lie algebra L associatedwith a quantum (non-commutative) stochastic calculus. Here fis an element of the universal enveloping algebra U of L, andf() + d() f() is given a meaning using the coproductstructure of U even though the individual terms of this expressionhave no meaning. The Ito formula is equivalent to a chaoticexpansion formula for f() which is found explicitly. 1991 MathematicsSubject Classification: primary 81S25; secondary 60H05; tertiary18B25. 相似文献
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Cottaz C Kleiner I Tarrago G Brown LR Margolis JS Poynter RL Pickett HM Fouchet T Drossart P Lellouch E 《Journal of Molecular Spectroscopy》2000,203(2):285-309
Line positions and intensities belonging to the vibrational system 2nu(2)/nu(4) of ammonia (14)NH(3) are measured and analyzed between 1200 and 2200 cm(-1) in order to improve the molecular database. For this, laboratory spectra are obtained at 0.006 and 0.011 cm(-1) unapodized resolution and with 4% precisions for the intensities using Fourier transform spectrometers located at the Kitt Peak National Observatory and the Jet Propulsion Laboratory. The observed data contain transitions of the nu(4) fundamental band near 1626.276(1) and 1627.375(2) cm(-1) (for s and a inversion upper states, respectively) and the 2nu(2) overtone band near 1597.470(3) and 1882.179(5) cm(-1) (for s and a inversion states, respectively). A total of 2345 lines with J' = 15 is assigned from which 2114 line positions with J' = 15 are fitted using an effective rotation-inversion-rotation Hamiltonian to achieve an rms of 0.003 cm(-1) with 57 molecular parameters. Over 1200 intensity measurements are modeled to +/-4.7% using 16 terms of the dipole moment expansion. A dyad model is used in order to model all the interactions expected within the 2nu(2)/nu(4) system. The bandstrengths of 2nu(2) (s <-- a), 2nu(2) (a <-- s), and nu(4) (s <-- s and a <-- a) are estimated to be 6.68(24), 0.201(5), and 116(3) cm(-2) atm(-1), respectively, at 296 K. The prediction generated by this study is available for planetary studies. Copyright 2000 Academic Press. 相似文献
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The frequencies and assignments of 50 lines in the pure inversion spectrum of 14NH3 in the 00011 vibrational state are reported in the microwave frequency region 18–53 GHz and in selected regions up to 58 GHz.The J = 0 inversion frequency, K-type doubling constant K, l = 2, ?1 and molecular dipole moment in this state are 32 904.7 ± 2.0 MHz, 1.958 ± 0.040 MHz and 1.459 ± 0.002 D, respectively, where model inadequacies are included in the uncertainties of the first two parameters. The dipole moment measurements for this and the ground state are in excellent agreement with Stark laser measurements. An expression containing the effective l-type doubling constant is obtained from the combination of frequencies . A preliminary value for the l-type doubling constant is 10 655 ± 20 MHz. 相似文献
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Bobeldijk I Bouwhuis M Ireland DG de Jager CW Jans E de Jonge N Kasdorp WJ Konijn J Lapikás L van Leeuwe JJ van der Meer RL Nooren GJ Passchier E Schroevers M van der Steenhoven G Steijger JJ Theunissen JA van Uden MA de Vries H de Vries R de Witt Huberts PK Blok HP van den Brink HB Dodge GE Harakeh MN Hesselink WH Kalantar-Nayestanaki N Pellegrino A Spaltro CM Templon JA Hicks RS Kelly JJ Marchand C 《Physical review letters》1994,73(20):2684-2687