The Outer Part of the Scattered Disc from the Simulation of the Formation of Small-body Reservoirs     

Marián Jakubík  Tomáš Paulech  Luboš Neslušan  Piotr A. Dybczyński  Giuseppe Leto 《Earth, Moon, and Planets》2009,105(2-4):379-383

Considering the model of the initial disc of planetesimals consisting of 10,038 test particles, we simulated the formation of small-body reservoirs in the outer Solar System for the 2-Gyr period. We present the results from the simulation, which concern the part of the scattered disc with objects that have the semi-major axes larger than 50 AU and do not cross the Neptune’s orbit. A suitable border between the scattered disc and the inner Oort cloud, in terms of semi-major axis, appears to be no more than 2,500 AU. The simulated and observed values of perihelion distance and inclination to the Ecliptic typically cover the range between 30 and 40 AU and from 0° to 30°, respectively. No simulated or observed values of the inclination exceed 45°. The distributions of eccentricity and inclination in the simulation are more consistent with their observed counterparts, if the primary observational selection effects are imitated in the simulated distributions.  相似文献   

A study of the formation of N2O in the reaction of NO3(A2E′) with N2     

D. Marić  J. P. Burrows  G. K. Moortgat 《Journal of Atmospheric Chemistry》1992,15(2):157-169

The rate of formation of N₂O via the thermochemically favourable reaction of NO₃(A²E) with N₂, which would represent an additional source of stratospheric N₂O and therefore NO_x, has been investigated. Mixtures of NO₂+O₃ in synthetic air were photolysed at 662 nm. No evidence was found for the production of N₂O via this pathway, the upper limit for the quantum yield of nitrous oxide formation being % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiiYdd9qrFfea0dXdf9vqai-hEir8Ve% ea0de9qq-hbrpepeea0db9q8as0-LqLs-Jirpepeea0-as0Fb9pgea% 0lrP0xe9Fve9Fve9qapdbaqaaeGacaGaaiaabeqaamaabaabcaGcba% GaeqOXdy2aaSbaaSqaamaaBaaameaadaWgaaqaamaaBaaabaGaamOt% amaaBaaabaGaaGOmaiaad+eaaeqaaaqabaaabeaaaeqaaaWcbeaatu% uDJXwAK1uy0HMmaeHbfv3ySLgzG0uy0HgiuD3BaGqbaOGae8hzIqOa% aGimaiaac6cacaaI2aGaaiyjaaaa!4E60!\[\phi _{_{_{_{N_{2O} } } } } \le 0.6\% \]. However, a dark conversion of NO_x to N₂O was observed and is attributed tentatively to a heterogeneous reaction on the wall of the reaction vessel. This process, although most likely to be insignificant in the atmosphere, needs to be taken into consideration in laboratory investigations or field studies of N₂O emission or deposition.  相似文献   

The attenuation of tidal and subtidal oscillations in the Patos Lagoon estuary     

E. H. L. Fernandes  I. Mariño-Tapia  K. R. Dyer  O. O. Möller 《Ocean Dynamics》2004,54(3-4):348-359

The single, long and narrow channel that usually connects choked coastal lagoons to the ocean can serve as a natural hydraulic low-pass filter that reduces or eliminates tidal and subtidal effects inside the lagoon. This study proposes an alternative method of estimating the attenuation of the tidal and subtidal oscillations throughout the Patos Lagoon estuary. The attenuation is estimated for conditions of contrasting river runoff and weather (summer and winter). A high-pass/low-pass filter (fast fourier transformation technique – FFT) is applied to time series of sea-surface elevation (SSE) measured at the mouth of the Patos Lagoon. The resulting high-frequency (tidal) and low-frequency (subtidal) signals are used in independent simulations to force the TELEMAC-2D model. Attenuation of the tidal and subtidal signals throughout the estuary is estimated by applying cross-spectral analysis between the model-generated SSE time series at different locations throughout the estuary and the filtered SSE time series measured at the mouth. Results from the proposed method suggest that: (1) the low-frequency (subtidal) oscillations are less attenuated and propagate further than the high-frequency (tidal) oscillations in the Patos Lagoon estuary; (2) the filtering capability of the Patos Lagoon estuary is expected to follow a seasonal pattern, although further investigations on an interannual time scale are recommended in order to confirm this hypothesis; (3) the influence of the oceanic boundary processes on the SSE dynamics of the lagoon is restricted to the lower estuary. Further inland, the local forcing generated by the wind and freshwater input is likely to be the main forcing effect controlling the dynamics of the system. The proposed method proved to be an efficient and alternative way of estimating the attenuation of energy in the tidal and subtidal bands throughout the access channel of a choked coastal lagoon located in an area of reduced tidal influence.Responsible Editor: Iris Grabemann  相似文献   

Acceleration Phase of Coronal Mass Ejections: I. Temporal and Spatial Scales     

Bojan Vršnak  Darije Maričić  Andrew L. Stanger  Astrid M. Veronig  Manuela Temmer  Dragan Roša 《Solar physics》2007,241(1):85-98

We study kinematics of 22 coronal mass ejections (CMEs) whose motion was traced from the gradual pre-acceleration phase up to the post-acceleration stage. The peak accelerations in the studied sample range from 40, up to 7000 m s⁻², and are inversely proportional to the acceleration phase duration and the height range involved. Accelerations and velocities are, on average, larger in CMEs launched from a compact source region. The acceleration phase duration is proportional to the source region dimensions; i.e., compact CMEs are accelerated more impulsively. Such behavior is interpreted as a consequence of stronger Lorentz force and shorter Alfvén time scales involved in compact CMEs (with stronger magnetic field and larger Alfvén speed being involved at lower heights). CMEs with larger accelerations and velocities are on average wider, whereas the widths are not related to the source region dimensions. Such behavior is explained in terms of the field pile-up ahead of the erupting structure, which is more effective in the case of a strongly accelerated structure.  相似文献   

Reactivity of transparent exopolymeric particles: A key parameter of trace metal cycling in the lagoon of Nouméa, New Caledonia     

X. Mari  C. Migon  E. Nicolas 《Marine pollution bulletin》2009,(12):1874-1879

Seawater samples were collected in the lagoon of Nouméa (New Caledonia) along two transects from coastal bays to the oligotrophic barrier reef. Dissolved (<0.2 μm) and sub-micrometer (0.2–0.8 μm) concentrations of chromium, nickel and zinc were measured. Concentrations in the 0.2–0.8 μm size range were correlated with transparent exopolymeric particles (TEP) turnover rates, suggesting that a TEP pool rapidly cycling in the system is more reactive toward metals. The role of TEP reactivity in the transfer efficiency of metals from dissolved to particulate phases was estimated through variations of the metal partitioning coefficient K between sub-micrometer TEP and solution, as a function of the water mass residence time. The log K (6.0–8.0) increased from high to low residence time, suggesting that TEP reactivity increases when water masses renew rapidly. This suggests that hydrodynamics control TEP reactivity toward metals. The characteristics (adsorption vs. complexation) of TEP-metal association are discussed.  相似文献   

Unconformity between a Late Miocene–Pliocene accretionary prism (Nishizaki Formation) and Pliocene trench‐slope sediments (Kagamigaura Formation), central Japan     

Yuzuru Yamamoto  Shun Chiyonobu  Toshiyuki Kurihara  Asuka Yamaguchi  Shoko Hina  Mari Hamahashi  Hugues Raimbourg  Romain Augier  Leslie Gadenne 《Island Arc》2012,21(4):231-234

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A practical review of geostatistical processing applied to geophysical data: methods and applications     

Matthieu Bourges  Jean‐Luc Mari  Nicolas Jeannée 《Geophysical Prospecting》2012,60(3):400-412

Nowadays, geostatistics is commonly applied for numerous gridding or modelling tasks. However, it is still under used and unknown for classical geophysical applications. This paper highlights the main geostatistical methods relevant for geophysical issues, for instance to improve the quality of seismic data such as velocity cubes or interpreted horizons. These methods are then illustrated through four examples. The first example, based on a gravity survey presents how a geostatistical interpolation can be used to filter out a global trend, in order to better define real anomalies. In the second case study, dedicated to refraction surveying, geostatistical filtering is used to filter out acquisition artefacts and identify the main geological structures. The third one is an example of porosity being integrated geostatistically with a seismic acoustic impedance map. The last example deals with geostatistical time to depth conversion; the interest of performing geostatistical simulations is finally discussed.  相似文献   

Influence of Olive Oil Mill Waste Amendment on Fate of Oxyfluorfen in Southern Spain Soils          下载免费PDF全文

María Jesús Calderón  Miguel Real  Alegría Cabrera  William C. Koskinen  Juan Cornejo  Mari Carmen Hermosín 《洁净——土壤、空气、水》2015,43(7):1107-1113

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UAV‐based mesoscale lithologic distribution map of a large shear zone in Jurassic accretionary complex (Ohwaki outcrop in the Mino Belt,central Japan)          下载免费PDF全文

Asuka Yamaguchi  Rina Fukuchi  Mari Hamahashi  Mayuko Shimizu 《Island Arc》2016,25(6):436-438

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研究发现慢滑断层不会引发地震     

Mari N Jensen  赵纪东 《国际地震动态》2010,(5):14-15

美国亚利桑那大学（University of Arizona）的一项最新研究表明,一些慢速移动的断层可能不会使意大利一些地区和世界上其他一些地方遭受破坏性地震的侵袭。  相似文献