Why Is the Climate Forcing of Sulfate Aerosols So Uncertain?   总被引：2，自引：0，他引：2  

Hu Rongming  Serge Planton  Michel Déque  Pascal Marquet  Alain Braun 《大气科学进展》2001,18(6):1103-1120

l. IntroductionAlthough the aerosol has been recognized as an important factor which has innuence onthe past, present and future climate for a long time, it still has much uncertainty in assessingits climate forcing. The direct radiative forcing of sulfate aerosols has been estimated rangingfrom --0.3 W/ m2 to --0.9 W/ m2 in recent publications (Charlson et al., l992, Kiehl andBriegleb l993; Taylor and Penner 1994, Boucher and Anderson l995, Kieh1 and Rodhe l995;Chuang et al., l997, Penne…  相似文献   

Composition and sources of dissolved and particulate PAH in surface waters from the Rhone delta (NW Mediterranean)     

Ioanna Bouloubassi  Alain Saliot 《Marine pollution bulletin》1991,22(12):588-594

PAH were determined in surface waters from the Rhone delta in winter and summer 1987. Both particulate and dissolved phases were analyzed by GC and GC/MS. Concentrations of major unsubstituted compounds associated with particles varied from a few to 20 ng l⁻¹, or from 0.42 to 6.0 μg g⁻¹. The seasonal variations reflected higher inputs in winter resulting from the presence of highly PAH-enriched particles. Tetra- and penta-cyclic PAH with MW 202 and 252 predominated, which reflected a significant origin from pyrolytic processes. A rapid decrease of the level of higher MW PAH was observed seawards in both seasons. Study of the tricyclic compounds and their alkylated homologues demonstrated a mainly fossil origin in winter, whereas in summer a high heterogeneity of particles was observed. PAH in the dissolved phase were found at concentrations up to 31 and 50 ng l⁻¹ in summer and winter, respectively. These levels were much higher than those encountered in the corresponding particulate phases. PAH with MW 178 and 202 predominated, and the alkylated homologues of the tricyclic compounds showed a major fossil orgin in winter and a mixed origin in summer. In winter dissolved PAH were transported through the delta into the marine environment without significant losses.  相似文献   

Pilot field experiment with canister-embedding clay under simulated repository conditions     

Rosemarie Atabek  Alain Lajudie  Jacques Lechelle  Roland Pusch 《Engineering Geology》1990,28(3-4):291-302

Precompacted annular clay blocks surrounding a casing with a heater were emplaced in a borehole with 20 cm diameter and 2.8 m depth in granite. The heater was in operation for 8 months and raised the temperature of the clay to 176°C close to the casing. At the extraction the clay was completely water-saturated close to the rock and it had experienced an increased water content also close to the hot casing.

Mineralogical changes of the Ca-smectite clay were indicated by a slight increase in CEC and by an XRD-based conclusion that the content of low-charge smectite increased, while the initial content of kaolinite was reduced.  相似文献   

Sedimentation, distribution and diagenesis of organic matter in a recent carbonate environment, Abu Dhabi, U.A.E.     

Fabien Kenig  Alain Y. Huc  Bruce H. Purser  Jean-Louis Oudin 《Organic Geochemistry》1990,16(4-6)

In the modern hypersaline carbonate lagoon and sabkha sedimentary environments of Abu Dhabi (United Arab Emirates), three types of organic matter originate respectively from microbial mat, Avicennia mangrove, and Halodule lagoonal seagrass. The study of recent sedimentary processes and cross sections through the sabkha sediments lead to the definition of organo-sedimentary facies based on geochemical and sedimentological criteria. This permits the construction of an organo-sedimentary sequence which expresses the Holocene sedimentary record involving a transgressive and a regressive sequence. The various organic facies occur in both sequences.Heterogeneity within the individual organic facies reflects several factors, including sedimentation dynamics, mineral matrix, oxidation and reduction, and selective organic and mineral diagenesis. These parameters are discussed in terms of depositional environment and location within the organo-sedimentary sequence. Changes in distribution, quantity, and preservation potential of the buried organic matter are discussed in terms of sea level changes and sedimentary accretion rates.  相似文献   

Structural,mineralogical, and paleoflow velocity constraints on Hercynian tin mineralization: the Achmmach prospect of the Moroccan Central Massif     

El Mahjoub Mahjoubi  Alain Chauvet  Lakhlifi Badra  Stanislas Sizaret  Luc Barbanson  Abdelkader El Maz  Yan Chen  Méderic Amann 《Mineralium Deposita》2016,51(3):431-451

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Very hot,very shallow hydrothermal dolomitization: An example from the Maritime Alps (north‐west Italy–south‐east France)          下载免费PDF全文

Luca Barale  Carlo Bertok  Namam Salih Talabani  Anna d'Atri  Luca Martire  Fabrizio Piana  Alain Préat 《Sedimentology》2016,63(7):2037-2065

In the Maritime Alps (north‐west Italy – south‐east France), the Middle Triassic–lowermost Cretaceous platform carbonates of the Provençal Domain locally show an intense dolomitization. Dolomitized bodies, irregularly shaped and variable in size from some metres to hundreds of metres, are associated with tabular bodies of dolomite‐cemented breccias, cutting the bedding at a high angle, and networks of dolomite veins. Field and petrographic observations indicate that dolomitization was a polyphase process, in which episodes of hydrofracturing and host‐rock dissolution, related to episodic expulsion of overpressured fluids through faults and fracture systems, were associated with phases of host‐rock dolomitization and void cementation. Fluid inclusion analysis indicates that dolomitizing fluids were relatively hot (170 to 260°C). The case study represents an outstanding example of a fossil hydrothermal system, which significantly contributes to the knowledge of such dolomitization systems in continental margin settings. The unusually favourable stratigraphic framework allows precise constraint of the timing of dolomitization (earliest Cretaceous) and, consequently, direct evaluation of the burial setting of dolomitization which, for the upper part of the dolomitized succession, was very shallow or even close to the surface. The described large‐scale hydrothermal system was probably related to deep‐rooted faults, and provides indirect evidence of a significant earliest Cretaceous fault activity in this part of the Alpine Tethys European palaeomargin.  相似文献   

Assessment of balanced burden-sharing in the 2050 EU climate/energy roadmap: a metamodeling approach     

Frédéric Babonneau  Alain Haurie  Marc Vielle 《Climatic change》2016,134(4):505-519

In this paper we propose a non-cooperative meta-game approach to designing and assessing climate agreements among 28 European countries that will be compatible with the EU 2050 climate target. Our proposed game model is identified through statistical emulation of a large set of numerical simulations performed with the computable general equilibrium model GEMINI-E3. In this game, the players are the 28 European countries, the payoffs are related to welfare losses due to abatements and the strategies correspond to the supply of emission rights on the European carbon market. We show it is possible to design a fair burden-sharing rule that equalizes welfare losses between countries to approximately 1.2 % of their discounted household consumption. The associated European CO₂ price in 2050 reaches $1100, a figure in line with previous studies. Lastly, the paper discusses various implementation issues of these types of negotiations and evaluates the cost of non-cooperation among EU countries.  相似文献   

Influence du gypse sur la mesure de la teneur en eau et de la densite des marnes du keuper de lorraine     

Alain Thomas 《Engineering Geology》1971,5(4):313-329

Can we justifiably use a special drying process for measuring water content and dry density on marls containing gypsum so as to avoid errors due to the thermal dehydration of gypsum? In order to give an answer to this question, the author studied the variation of the systematic errors in the measures with measurable parameters such as temperature, length of drying time, gypsum content and water content. He also examined the incertitude due to the non-numerical parameters of dispersion, such as the nature of the tested marls and the size of the gypsum inclusions.

These investigations allowed the author, within the numerical parameters studied, to determine the regions where the precision of the corrections possible justifies the use of special methods of testing. He also shows that the usual way of desiccation below 55°C, is reliable only within a very limited range of water content.  相似文献   

Interpreting catch per unit effort data to assess the status of individual stocks and communities   总被引：3，自引：0，他引：3  

Maunder  Mark N.; Sibert  John R.; Fonteneau  Alain; Hampton  John; Kleiber  Pierre; Harley  Shelton J. 《ICES Journal of Marine Science》2006,63(8):1373-1385

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Modelling discard ogives from Irish demersal fisheries     

Borges  Lisa; Zuur  Alain F.; Rogan  Emer; Officer  Rick 《ICES Journal of Marine Science》2006,63(6):1086-1095

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