Metal Complexation with Different types of Soluble and Adsorbed Freshwater Ligands Followed by DPASV     

Cidália Maria Sousa Botelho  Rui Alfredo Rocha Boaventura  Maria de Lurdes Sadler Simões Gonçalves 《Aquatic Geochemistry》2007,13(2):173-186

In order to understand metal speciation in a polluted river (Este River, Northern Portugal) filtrate, freeze dried particles and organics desorbed from surfaces were titrated with Cd(II) and Zn(II), followed by differential pulse anodic stripping voltammetry (DPASV). The obtained results are compared with those previously published for Pb(II) and Cu(II). Due to the heterogeneity of the system, a continuous and a discrete ligand model were used to interpret the titration data. Two types of ligands could be detected and quantified by the discrete ligand model: small molecules with high affinities for cations such as Cd(II), Cu(I), and Zn(II) and macromolecules with higher affinities for Pb(II) and Cu(II). Small ligands were strongly adsorbed onto the particles, as inferred from the desorption of Zn(II) during titration with Pb(II) and Cd(II). The total concentrations of the different ligands and the complex formation constants with the different metals are reported.  相似文献   

Recent deformations and hydrothermal fields in the northern part of Paramushir Island     

O. R. Khubaeva  G. V. Bryantseva  L. A. Sim 《Moscow University Geology Bulletin》2007,62(4):229-233

This paper discusses application of a structural-morphologic method for interpreting covered territories; in the present case, covered by lava flows. The study resulted in recognizing a network of recent faults and in determining their strike-slip kinematics. The relation of volcanoes and thermal springs to these faults is discussed.  相似文献   

Interannual variability associated with ENSO: present and future climate projections of RegCM4 for South America-CORDEX domain     

Rosmeri Porfírio da Rocha  Michelle Simões Reboita  Lívia Márcia Mosso Dutra  Marta Pereira Llopart  Erika Coppola 《Climatic change》2014,125(1):95-109

Interannual variability over South America (SA) is mainly controlled by the El Niño-Southern Oscillation (ENSO) phenomenon. This study investigates the ENSO precipitation signal during austral spring (September–October–November-SON) over SA. Three global circulation models-GCMs-(MPI, GFDL and HadGEM2) are used for RegCM4 (Regional Climate Model version 4) downscaling of the present (1975–2005) near-future (2020–2050) and far-future (2070–2098) climates using two greenhouse gas stabilization scenarios (RCP4.5 and RCP8.5). For the present climate, only HadGEM2 simulates a frequency of El Niño (EN) and La Niña (LN) years similar to the observations. In terms of ENSO frequency changes, only in the far-future RCP8.5 climate there is greater agreement among GCMs, indicating an increase (decrease) of EN (LN) years. In the present climate, validation indicates that only the RegCM4 ensemble mean provides acceptable precipitation biases (smaller than ±20 %) in the two investigated regions. In this period, the GCMs and RegCM4 agree on the relationship between ENSO and precipitation in SA, i.e., both are able to capture the observed regions of positive/negative rainfall anomalies during EN years, with RegCM4 improving on the GCMs’ signal over southeastern SA. For the near and far future climates, in general, the projections indicate an increase (decrease) of precipitation over southeastern SA (northern-northeastern SA). However, the relationship between ENSO and rainfall in most of RegCM4 and GCM members is weaker in the near and far future climates than in the present day climate. This is likely connected with the GCMs’ projection of the more intense ENSO signal displaced to the central basin of Pacific Ocean in the far future compared to present climate.  相似文献   

Assessing SARAL/AltiKa Data in the Coastal Zone: Comparisons with HF Radar Observations     

Ananda Pascual  Arancha Lana  Charles Troupin  Simón Ruiz  Yannice Faugère  Romain Escudier 《Marine Geodesy》2015,38(3):260-276

We present an initial assessment of SARAL/AltiKa data in the coastal band. The study focuses on the Ibiza Channel where the north-south water exchanges play a key role in controlling the circulation variability in the western Mediterranean. In this area, the track 16 of SARAL/AltiKa intercepts the domain covered by a coastal high-frequency (HF) radar system, which provides surface currents with a range up to 60 km. We evaluate the performance of the SARAL/AltiKa Ssalto/Duacs delayed-time along-track products compared to the HF radar surface velocity fields. SARAL/AltiKa data are retrieved at a distance of only 7 km from the coast, putting in evidence the emerging capabilities of the new altimeter. The derived velocities resolved the general features of the seasonal mesoscale variability with reasonable agreement with HF radar fields (significant correlations of 0.54). However, some discrepancies appear, which might be caused by instrumental hardware radar errors, ageostrophic velocities as well as inaccurate corrections and editing in the altimeter data. Root mean square (rms) differences between the estimated SARAL/AltiKa and the HF radar velocities are about 13 cm/s. These results are consistent with recent studies in other parts of the ocean applying similar approaches to Topex/Poseidon and Jason-1 missions and using coastal altimeter corrections.  相似文献   

Salt tectonics vs. inversion tectonics: The anticlines of the western Maestrazgo revisited (eastern Iberian Chain,Spain)     

Carlos L. Liesa  Antonio M. Casas-Sainz  Marcos Aurell  José L. Simón  Ana R. Soria 《Basin Research》2023,35(1):295-335

Many works in the last decades underline the role of evaporites, not just as a conditioning factor but as the engine for subsidence and eventually basin inversion. The western Mediterranean alpine ranges are being investigated in this regard because of the presence of discontinuous units of Permian to Triassic evaporites, deposited in the western Tethys basins. This work presents a thorough analysis of two particular structures (Cañada Vellida and Miravete anticlines) in the intraplate Maestrazgo basin (eastern Iberian Chain, Spain) in which evidence to support their reinterpretation as salt-driven structures have been recently reported. Our analysis includes (i) a comprehensive stratigraphic and structural study of the folds along their entire trace, (ii) the compilation of thickness and distribution of evaporite–bearing and supraevaporite units, paying special attention to changes in the thickness of units in relation to anticlines, and (iii) the study of fault patterns, sometimes in relation to the mechanical stratigraphy. All three aspects are also documented and discussed on a regional scale. The new data and interpretations reported here reinforce the extensional origin of the Late Jurassic–Early Cretaceous basins, and the role of regional extensional tectonics as the responsible for the development of first-order syn-sedimentary normal fault zones driving the formation and evolution of sub-basins. These basins were subsequently inverted and deformed, including the formation of complex, box-geometry anticlines that, in their turn, controlled deposition in Cenozoic basins. The review of the arguments that support the alternative of salt tectonics for the origin of such anticlines has allowed us to delve into the sedimentary and tectonic evolution of the inverted extensional basins and to propose a specific model for the development of these faulted anticlines. The role of salt levels and other interlayered detachments in the structuring of sedimentary basins and their inversion is also pondered. The observations in the eastern Iberian Chain reported here have implications to assess ongoing reinterpretations in terms of salt tectonics in other alpine basins and ranges of the western Mediterranean.  相似文献   

Older people’s psychosocial needs in a post-disaster rural community of China: an exploratory study     

Ke Cui  Timothy Sim 《Natural Hazards》2017,85(3):1577-1590

Older people are arguably one of the most vulnerable groups during a disaster. Existing studies either in China or in other countries predominantly focus on the more Western, pathology-based mental health approach in addressing the impact of disasters on older victims and their needs. However, the concept of ‘psychosocial’ recognises that problems caused by emergencies can simultaneously be of a social nature and a psychological one. This concept emerged from a growing critique on individual oriented mental health approach in disaster contexts. The present study was conducted to explore older people’s needs from a psychosocial perspective. The research site was a Chinese rural community located in the epicentre of ‘5.12’ Wenchuan earthquake (Ms = 8.0) occurred in 2008. The authors conducted content analyses on the qualitative in-depth interviews with 10 (5 males and 5 females) out of 30 older persons from this community. The findings revealed three major psychosocial problems: (1) constant fear of recurring debris flows; (2) sense of helplessness; and (3) disruption to previous social network. Indubitably, the participants reported family members and neighbours as their major sources of social support in emergency situations. This exploratory study argues that older people being exposed to disasters will not only develop psychological problems but also suffer disruption to their social support network and puts forward that empowering family and strengthening community cohesion are important initiatives for helping professionals to promote older people’s psychosocial well-being and enhance their resilience to natural disasters.  相似文献   

Neotectonic and modern stresses of South Sakhalin     

L. A. Sim  L. M. Bogomolov  O. A. Kuchai  A. A. Tataurova 《Russian Journal of Pacific Geology》2017,11(3):223-235

Tectonophysical studies are conducted in South Sakhalin for identification of temporal–spatial changes in the geodynamic settings of the formation of the local structures. Analysis of the field data reveals 11 local stress state (LSS) in the large newest megastructures, which were formed on geological basement of different ages. The parameters of the tectonic stresses are significantly distinct in each LSS, especially the orientations (up to reindexation) of the compression and extension axes in different fault wings. Tectonic stresses of two ages and constant latitudinal and horizontal compression axis are reconstructed. The earlier cofold shear stress field with a horizontal and longitudinal extension axis is post-Miocene and the later stress field of the reversed fault with a vertical extension axis is orogenic. The LSSs reconstructed for the first time by the displacement vectors on slickensides, along with the data on the earthquake mechanisms, substantiate the reindexation of the horizontal extension axis with the vertical intermediate axis of major normal stresses at the postfold orogenic stage of evolution of the territory. These results are in agreement with previous data on the transformation of the dextral to reverse thrust displacements along the longitudinal fault systems. The young stress field is more confidently interpreted in the activation fault zones, which limit the orogenic blocks, whereas the traces of cofold deformations without younger orogenic stress fields better remain inside the blocks which are composed of older and strongly dislocated Mesozoic rocks.  相似文献