Life-history strategies of calanoid congeners under two different climate regimes: a comparison   总被引：5，自引：0，他引：5  

Halsband-Lenk  Claudia; Carlotti  Francois; Greve  Wulf 《ICES Journal of Marine Science》2004,61(4):709-720

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Nonlinear wave propagation on a sphere: Interaction between Rossby waves and gravity waves; stability of the Rossby waves     

Jacques Vanneste  Francois Vial 《地球物理与天体物理流体动力学》2013,107(1-4):121-144

Abstract

An analytical spectral model of the barotropic divergent equations on a sphere is developed using the potential-stream function formulation and the normal modes as basic functions. Explicit expressions of the coefficients of nonlinear interaction are obtained in the asymptotic case of a slowly rotating sphere, i.e. when the normal modes can be expressed as single spherical harmonics.  相似文献   

A pollen–climate calibration from western Patagonia for palaeoclimatic reconstructions     

Vincent Montade  Odile Peyron  Charly Favier  Jean Pierre Francois  Simon G. Haberle 《第四纪科学杂志》2019,34(1):76-86

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Meteorological aspects associated with dust storms in the Sistan region,southeastern Iran     

D. G. Kaskaoutis  A. Rashki  E. E. Houssos  A. Mofidi  D. Goto  A. Bartzokas  P. Francois  M. Legrand 《Climate Dynamics》2015,45(1-2):407-424

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Bioaccumulation of heavy metals and radionuclides from seawater by encased embryos of the spotted dogfish Scyliorhinus canicula     

Jeffree RA  Warnau M  Oberhansli F  Teyssie JL 《Marine pollution bulletin》2006,52(10):1278-1286

Encased embryos of spotted dogfish Scyliorhinus canicula absorbed six radio-isotopes (241Am, 109Cd, 57Co, 134Cs, 54Mn and 65Zn) directly from seawater during short-term experimental exposure, demonstrating the permeability of the egg-case to these contaminants. Embryo to water concentration factors (CFs) ranged from 0.14 for 134Cs to 7.4 for 65Zn. The 65Zn and 57Co CFs increased exponentially with embryo length, whereas the CF for 109Cd declined with length. Among different components of the encased embryo the egg case was the major repository (69-99%) of all six radio-isotopes that were distributed throughout its wall. Egg-case CFs were as high as 10(3) for 57Co and 65Zn, making it the major source of gamma radiation exposure to the embryo and potentially of radio-isotopes for continued absorption by the embryo, following the uptake phase of the experiment. The patterns of uptake by the egg-case approximated linearity for most isotopes and loss rates were isotope-specific; egg-case biokinetics were not greatly affected by the viability of the contained embryo. Within the embryo initial data on radio isotopic distribution show that the skin is their major site of uptake, as previously demonstrated for juveniles.  相似文献   

星系金属丰度的研究进展(Ⅱ):光度-金属丰度关系     

梁艳春  HAMMER Francois  邓李才  赵刚 《天文学进展》2007,25(1):22-35

金属丰度与星系光度是星系的重要特征参量,研究它们之间的关系有助于理解星系中恒星质量与金属成分的累积过程。评述了星系的光度-金属丰度关系的最新研究进展,包括对近邻星系、中等红移星系(0．42)的研究结果．由于观测样本跨越较宽的宇宙学时标,可以由此来探讨这一关系的演化过程,从而帮助理解星系演化的整体图景。  相似文献   

A model-based evaluation of Marine Protected Areas: the example of eastern Baltic cod (Gadus morhua callarias L.)     

Kraus  Gerd; Pelletier  Dominique; Dubreuil  Julien; Mollmann  Christian; Hinrichsen  Hans-Harald; Bastardie  Francois; Vermard  Youen; Mahevas  Stephanie 《ICES Journal of Marine Science》2009,66(1):109-121

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Experimental constraints on the storage conditions of phonolites from the Kerguelen Archipelago     

Marcus?FreiseEmail author  Francois?Holtz  Jürgen?Koepke  James?Scoates  Hervé?Leyrit 《Contributions to Mineralogy and Petrology》2003,145(6):659-672

Phase relations of a phonolite (K1) and a tephri-phonolite (K2) from the Upper Miocene lavas in the Southeast Province of the Kerguelen Archipelago have been investigated in the P/T range 100–500 MPa and 700–900 °C at two fO₂ conditions (~ NNO and ~ NNO+2.3) to clarify the differentiation and pre-eruptive conditions of these magmas. Crystallization experiments were performed in cold seal pressure vessels (CSPV) and internally heated pressure vessels (IHPV) at various X_H2O, under reducing (log fO₂ ~ NNO) and oxidizing conditions (log fO₂ ~ NNO+2.3). Under reducing conditions, the resulting phase assemblage for K1 was: titanomagnetite, nepheline, alkali feldspar, clinopyroxene and biotite; under oxidizing conditions, the assemblage was: magnetite, plagioclase, alkali feldspar, nepheline, titanite (minerals given in the order of appearance with decreasing T at 200 MPa for 4 wt% water in the melt). It is emphasized that an effect of fO₂ on the phase stability of feldspars and feldspathoides was observed. Comparison of the natural and experimental phase assemblages shows that the pre-eruptive conditions for K1 must have been in the log fO₂ range NNO+1–NNO+2, at pressures above 200–250 MPa. Assuming a temperature of 800 °C, the water content of the melt is constrained to be between 4 and 6 wt% H₂O. The pre-eruptive fO₂ conditions for the less evolved sample K2 are more oxidizing with log fO₂ close to NNO+2.3. The experimental results show that the enrichment of alkalis in residual melts during differentiation of tephri-phonolites is enhanced at high fO₂.Editorial responsibility: J. Hoefs  相似文献   

Near-Surface Coherent Structures and The Vertical Momentum Flux in a Large-Eddy Simulation of the Neutrally-Stratified Boundary Layer     

Ralph C. Foster  Francois Vianey  Philippe Drobinski  Pierre Carlotti 《Boundary-Layer Meteorology》2006,120(2):229-255

The near-surface flow of a well-resolved large-eddy simulation of the neutrally-stratified planetary boundary layer is used to explore the relationships between coherent structures and the vertical momentum flux. The near-surface flow is characterized by transient streaks, which are alternating bands of relatively higher and lower speed flow that form parallel to the mean shear direction in the lower part of the boundary layer. Although individual streaks are transient, the overall flow is in a quasi-equilibrium state in which the streaks form, grow, decay and regenerate over lifetimes on the order of tens of minutes. Coupled with the streaky flow is an overturning circulation with alternating bands of updrafts and downdrafts approximately centered on the streaks. The surface stress is dominated by upward ejections of slower moving near-surface air and downward sweeps of higher speed air from higher in the boundary layer. Conditional sampling of the ejection and sweep events shows that they are compact, coherent structures and are intimately related to the streaks: ejections (sweeps) preferentially form in the updrafts (downdrafts) of the three-dimensional streak flow. Hence, consistent with other recent studies, we propose that the streak motion plays an important role in the maintenance of the surface stress by establishing the preferential conditions for the ejections and sweeps that dominate the surface stress. The velocity fluctuation spectra in the model near the surface have a k ⁻¹ spectral slope over an intermediate range of wavenumbers. This behaviour is consistent with recent theoretical predictions that attempt to evaluate the effects of organized flow, such as near-surface streaks, on the variance spectra.  相似文献   

煤矸石堆周围土壤重金属污染特征分析--以焦作市中马村矿为例   总被引：15，自引：0，他引：15  

李东艳  方元元  任玉芬  胡斌 《煤田地质与勘探》2004,32(5):15-17

利用扇形布点法采集了焦作市中马村矿矸石堆周围土壤，对其中的Cr、Pb、Cu、Mn4种重金属含量进行了研究。结果表明：煤矸石的堆放对周围土壤造成不同程度的污染，重金属的含量随离矸石堆距离增大呈减小的趋势，主要受到风向的影响。  相似文献