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排序方式: 共有419条查询结果,搜索用时 31 毫秒
51.
Inga Golbeck Xin Li Frank Janssen Thorger Brüning Jacob W. Nielsen Vibeke Huess Johan Söderkvist Bjarne Büchmann Simo-Matti Siiriä Olga Vähä-Piikkiö Bruce Hackett Nils M. Kristensen Harald Engedahl Ed Blockley Alistair Sellar Priidik Lagemaa Jose Ozer Sebastien Legrand Patrik Ljungemyr Lars Axell 《Ocean Dynamics》2015,65(12):1603-1631
52.
Yoana Del-Pilar-Ruso Jose Antonio de-la-Ossa-Carretero Francisca Giménez-Casalduero Jose Luis Sánchez-Lizaso 《Marine pollution bulletin》2010,60(11):1930-1938
The European Water Framework Directive (WFD) and the Urban Wastewater Treatment Directive (UWWTD) aim to improve water quality and reduce the environmental impact of wastewater, by requiring member states to introduce better treatment levels. This study was carried out in order to detect the most suitable treatment type or flow level for reducing benthic environmental impact. Therefore, soft-bottom polychaete assemblages affected by discharges of six treatment plants, with different treatment technologies and flow rates, were analysed over three consecutive years. Polychaete assemblages changed as a result of sewage discharge. These changes were related to treatment level and flow rates. Both disposal quality and quantity are important since changes in soft-bottom assemblages in stations affected by pre-treated sewage with medium and high flow rates are observed. However, the location with a low-flow pre-treated effluent has similar polychaete assemblages with regard to locations with biological treatment or controls. 相似文献
53.
In the paleogeographic reconstruction of Mexico and northern Central America, an ever-increasing amount of evidence shows
that the entire region is a collage of suspect terranes transported from abroad, whose timing and sense of motion are now
beginning to be understood. Among these, the Chortis block (nuclear Central America) and the Baja California Peninsula have
been proposed as pieces of continent separated from the Pacific coast of southwestern Mexico, that have moved either southeastward
by the Farallon plate or northwestward by the Kula plate. Previous studies mainly confined to the northern margin of the Chortis
block, confirmed a left-lateral displacement of 130 km in Neogene time. Further studies made northwestward along the Mexican
coast provided a better understanding of magmatic and metamorphic processes in the area, and suggested times of detachment
increased to 30 Ma, 40 Ma, and 66 Ma. The pre-detachment westernmost position of the block has changed, depending on the model
chosen, from Puerto Vallarta and beyond, to the current position. Here we show that the isotopic mineral ages from coastal
granites along the coast from Puerto Vallarta, Jalisco (80 Ma) to Puerto Angel, Oaxaca (11 Ma) record systematic decrease
of cooling ages from NW to SE. This pattern is interpreted to result from the progressive uplift of rocks exposed at the present-day
coast in that direction, such uplift occurred in response to the development of the Middle America Trench at the newly formed
continental margin when the Chortis block was sliding at an average rate of 1.5 cm/year in a sinistral sense to its present
position. Our results also constrain the position of the Kula-Farallon spreading axis north of Puerto Vallarta. These observations
led us to conclude that several indicators point to this time and region for the onset of strike-slip drifting of the Chortis
block toward its current position. Here, we also present several view points in terms of other possilble interpretations to
different tectonic, geologic and isotopic data sets published recently by different authors. 相似文献
54.
55.
Carlos Sainz Ismael Fuente Luis Quindós Jose Luis Gutierrez Jose Luis Arteche Luis Santiago Quindós 《Acta Geophysica》2010,58(5):957-962
People working with ionising radiation are receiving radiation coming from artificial and natural sources. In Spain, as in
many other countries, there is a serious control by the national authorities, Spanish Nuclear Safety Council, of the dose
the workers receive from artificial sources. However, until the publication of the European Basic Safety Standards Directive,
96/29/EURATOM, the old criteria referring to the “above natural background” were widely used. This directive was incorporated
to the Spanish legislation in July 2001 (BOE 178); in its Title VII it recommends to evaluate the dose coming from natural
sources and take it into account for establishing the safety criteria. It is noteworthy to assess the natural doses received
at homes and the dose received by workers of radioactive installations subject to regulations, and to compare the two results.
The social and economical implications of the results derived can be important in the practical application of the recommendations
included in the above-mentioned BOE 178 Directive. 相似文献
56.
The Open-source Project for a Network Data Access Protocol (OPeNDAP) software framework has evolved over the last 10 years to become a robust, high performance, service oriented architecture for the access and transport of scientific data from a broad variety of disciplines, over the Internet. Starting with version 4.0 of the server release, Hyrax, has at its core, the Back-End Server (BES). The BES offers ease of programming, extensibility and reliability allowing added functionality especially related to high-performance data Grids, that goes beyond its original goal of distributed data access. We present the fundamentals of the BES server as a component based architecture, as well as our experiences using the BES to distribute data processing in Grid-oriented intensive parallel computational tasks. 相似文献
57.
Pablo Otero Manuel Ruiz-Villarreal Luz García-García Gonzalo González-Nuevo Jose Manuel Cabanas 《Ocean Dynamics》2013,63(1):115-129
The consequences of a stormy winter period (2009/2010) on the shelf and coastal dynamics off Northwest Iberia are analysed by using model results in combination with the set of available observations in the frame of the Iberian Margin Ocean Observatory (RAIA), a cross-border infrastructure among North Portugal and Galicia (Spain). During the study winter, the frequent arrival of weather fronts forced river plumes to flow along the inner shelf in a fast (>1 m?s?1) jet-like structure. The buoyant current strongly influenced the outer rías, the name of the estuaries in the region, where a strong decay of surface salinity (<10.5) has been observed. Once the weather front has passed, the wind reversal forced the offshore expansion of river plumes and also the development of a winter upwelling event. Thermohaline patterns in both model and observations revealed an intrusion of warm (>15 °C) and salty (>35.9) waters into the rías associated with the Iberian Poleward Current. Finally, some Lagrangian modelling experiments were performed to analyse the transport ability of the plume and the effect that could have had in the biological material trapped on it. The experiments reveal that an overall northward displacement of surface particles will be expected after several alternate wind events. 相似文献
58.
Jose A. Carnicero M. Concepción Ausín Michael P. Wiper 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(8):1991-2002
This paper proposes a nonparametric approach to estimating the dependence relationships between circular variables and other circular or linear variables using copulas. The proposed method is based on the use of Bernstein copulas which are a very flexible class of non-parametric copulas which allows for the approximation of any kind of dependence structure, including non symmetric relationships. In particular, we present a simple procedure to adapt Bernstein copulas to the circular framework and guarantee that the constructed bivariate distributions are strictly continuous. We provide two illustrative case studies, the first on the relation between wind direction and quantity of rainfall in the North of Spain and the second on the dependence between the wind directions in two nearby buoys at the Atlantic ocean. 相似文献
59.
In this study we analyze water level data from coastal tide gauges and deep-ocean tsunameters to explore the far-field characteristics of two major trans-Pacific tsunamis, the 2010 Chile and the 2011 Japan (Tohoku-oki) events. We focused our attention on data recorded in California (14 stations) and New Zealand (31 stations) as well as on tsunameters situated along the tsunami path and proximal to the study sites. Our analysis considers statistical analyses of the time series to determine arrival times of the tsunami as well as the timing of the largest waves and the highest absolute sea levels. Fourier and wavelet analysis were used to describe the spectral content of the tsunami signal. These characteristics were then compared between the two events to highlight similarities and differences between the signals as a function of the receiving environment and the tsunami source. This study provides a comprehensive analysis of far-field tsunami characteristics in the Pacific Ocean, which has not experienced a major tsunami in nearly 50 years. As such, it systematically describes the tsunami response characteristics of modern maritime infrastructure in New Zealand and California and will be of value for future tsunami hazard assessments in both countries. 相似文献
60.
AbstractThe Hilhorst model was used to convert bulk electrical conductivity (σb) to pore water electrical conductivity (σp) under laboratory conditions by using the linear relationship between the soil dielectric constant (εb) and σb. In the present study, applying the linear relationship εb–σb to data obtained from field capacitance sensors resulted in strong positive autocorrelations between the residuals of that regression. We were able to derive an accurate offset of the relationship εb–σb and to estimate the evolution of σp over time by including a stochastic component to the linear model, rearranging it to a time-varying dynamic linear model (DLM), and using Kalman filtering and smoothing. The offset proved to vary for each depth in the same soil profile. A reason for this might be the changes in soil temperature along the soil profile.
Editor D. Koutsoyiannis; Associate editor M.D. Fidelibus 相似文献