Assessment of the Impact of Decis 2.5 EC on the Growth of Hippuris vulgaris          下载免费PDF全文

Małgorzata Gałczyńska  Maria Swarcewicz  Waldemar Paździoch  Teresa Lewandowska 《洁净——土壤、空气、水》2016,44(10):1329-1334

  相似文献   

The distal segment of Etna’s 2001 basaltic lava flow     

Massimiliano Favalli  Andrew J. L. Harris  Alessandro Fornaciai  Maria Teresa Pareschi  Francesco Mazzarini 《Bulletin of Volcanology》2010,72(1):119-127

Etna’s 2001 basaltic lava flow provided a good example of the distal flow segment between the flow front and stable channel, across which the flow evolves from channel-contained to dispersed. This zone was mapped with meter precision using LIDAR data collected during 2004 and 2005. These data, supported by field mapping, show that the flow front comprised eight lobes each 10 to 20 m high. The flow front appears to have advanced not as a single unit, but as a series of lobes moving forward one lobe at a time. Primary lobes were centered on the channel axis and marginal lobes were off-axis. The lobes advanced as breakouts of low-yield-strength lava from the flow core of the stalled flow front. Marginal lobes were abandoned and contributed to marginal levees flanking the transitional channel. For Etna’s 2001 flow, the transitional channel is 140 m wide, 700 m long and fed a 240-m-long zone of dispersed flow; the change from stable to transitional channel occurred at a major reduction in slope. Above this, the stable channel is 5.2 km long, 55 to 105 m wide and bounded by 15- to 25-m-high levees, and the stable channel is located over a previous channel. In a final stage of activity, lava ponding at the break-in-slope that marks the terminus of the stable channel put pressure on the eastern levee, causing it to fail. Liberated lava then fed a final break-out to the east. Similar flow front-features occur at other volcanoes, indicating that similar processes are characteristic of dispersed flow zones.  相似文献   

Comparison of marine and river water humic substances in a Patagonian environment (Argentina)     

María del Carmen Scapini  Víctor Hugo Conzonno  Vilma Teresa Balzaretti  Alicia Fernández Cirelli 《Aquatic Sciences - Research Across Boundaries》2010,72(1):1-12

Structural aspects of humic substances (HSs) in marine waters of Engaño Bay (Atlantic Ocean) and water from the Chubut River (Patagonia, Argentina) were compared. The HSs were isolated, purified, and analyzed using a multiple-method approach for structural characterization: elemental analysis, nuclear magnetic resonance (¹³C and ¹H NMR), infrared spectroscopy (FTIR), UV-visible absorption and fluorescence. Similarities between the marine and freshwater components were evaluated on the basis of N and O contents, H/C and C/N atomic ratios, infrared bands from nitrogen-containing and carboxylic groups, percentage of functional groups obtained from NMR spectra, spectral slope coefficient of absorption spectra, absorbance ratios at 250 and 365 nm (E ₂/E ₃), aromaticity, excitation–emission matrices and fluorescence quantum yield. Both the Engaño Bay and Chubut River waters have HSs that are mainly composed of fulvic acids (FAs); although they are very similar, they may be distinguished from one another. Similarities include the predominance of aliphatic carbon content (low aromatic content); however, the water bodies differed in their content of proteins and carboxylic acids. The Engaño Bay FAs have mainly an aquatic origin; although the Chubut River FAs suggest a similar aquagenic origin, there is also evidence of contributions from pedogenic FAs.  相似文献   

A case study on fuel oil contamination in a mangrove swamp in Hong Kong   总被引：5，自引：0，他引：5  

Tam NF  Wong TW  Wong YS 《Marine pollution bulletin》2005,51(8-12):1092-1100

Mangroves commonly found along tropical and subtropical coastlines are susceptible to oil pollution. In December 2000, around 500 1 m tall Kandelia candel saplings at the age of 3–5 years old located at the foreshore region of Sheung Pak Nai swamp, Hong Kong SAR, were found to be damaged by oil pollution. More than 80% of the saplings were either dead or washed away and leaving less than 5% healthy saplings with dense green leaves. Elevated concentrations of light n-alkanes (ranging from n-C₁₄ to n-C₂₀), pristane and phytane were recorded in surface sediments collected in December 2000. The ratio between light and total n-alkanes was 0.4. The total petroleum hydrocarbons (60–80 μg g⁻¹ TPH) and unresolved complex mixtures (60–70 μg g⁻¹ UCM) were higher than the background values of other mangrove sediments in Hong Kong, which were 40 and 20 μg g⁻¹, respectively. In certain root zone sediments, TPH concentrations were above 1000 μg g⁻¹. These results suggest that surface sediments in Sheung Pak Nai were contaminated by petroleum oil, most likely by illegal discharge of fuel oil which occurred between 1998 and 2002. One year later, in December 2001, unhealthy saplings had recovered and re-grown. The concentrations of TPH and UCM in sediments declined to around 40 μg g⁻¹, pristane and phytane dropped by 80%, and the ratio of light to total n-alkanes was 0.15, suggesting that residual oil in sediments was weathered leading to a remarkable recovery of the unhealthy saplings.  相似文献   

Drying of salt-contaminated masonry: MRI laboratory monitoring     

Teresa Diaz Gonçalves  Leo Pel  José Delgado Rodrigues 《Environmental Geology》2007,52(2):293-302

Drying of masonry specimens was monitored by means of a two-dimensional (2D) magnetic resonance imaging (MRI) technique. The external surfaces stayed wet for longer if NaCl was present instead of pure water only. This corroborates many practical observations that salts aggravate dampness in masonry. A slower evaporation process and not hygroscopicity was the cause. That suggests that salt-induced dampness may, in general, arise simply from changes in the drying process of masonry materials. That also implies that the height and depth at which crystallization occurs in walls may depend on the relative equilibrium humidity (RHeq) and other properties of salts that influence drying of porous materials. Evaporation rates of free surfaces of pure water and saturated NaCl solution were measured by a gravimetric technique. The results indicate that slow drying of salt-contaminated materials is not due only to the lower RHeq of salt solutions. The effective surface of evaporation is likely to be reduced perhaps due to blocking of pores by salt crystals. Final salt-distribution maps of the specimens show that: (a) salts may affect the inner materials of the masonry, even in evaporation-induced processes that lead crystallization to occur predominantly on the external surface; (b) distinct internal distribution patterns occur if masonry composition varies. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.  相似文献   

Geochronology of a composite granitoid pluton: a high-precision ID-TIMS U–Pb zircon study of the Variscan Karkonosze Granite (SW Poland)     

Ryszard Kryza  Urs Schaltegger  Teresa Oberc-Dziedzic  Christian Pin  Maria Ovtcharova 《International Journal of Earth Sciences》2014,103(3):683-696

Resolving time differences between successive magmatic pulses in composite granitoid plutons is often a difficult task. High-precision CA-ID-TIMS zircon ages obtained from such a pluton, the Variscan Karkonosze Granite (NE part of the Bohemian Massif), provide evidence that the crystallization of the two main granite facies, porphyritic and equigranular, happened between 312.5 ± 0.3 and 312.2 ± 0.3 Ma, thus unresolvable at the 0.08–0.1 % precision level of a single ²⁰⁶Pb/²³⁸U age. This finding is at odds with most other previous dating attempts and asks for a re-evaluation of the previous scattered geochronological data. The main reasons for the scatter of the earlier dates obtained by various techniques can include analytical causes, the presence of older inheritance and disturbance of the U–Pb isotopic system, due to zircon metamictization (enhanced by high-U content in zircon) or late- and post-magmatic alteration.  相似文献   

Asbestos and other fibrous minerals contained in the serpentinites of the Gimigliano-Mount Reventino Unit (Calabria,S-Italy)   总被引：1，自引：1，他引：0  

Andrea Bloise  Teresa Critelli  Manuela Catalano  Carmine Apollaro  Domenico Miriello  Alessandro Croce  Eugenio Barrese  Francesca Liberi  Eugenio Piluso  Caterina Rinaudo  Elena Belluso 《Environmental Earth Sciences》2014,71(8):3773-3786

Serpentinites are metamorphic rocks with good technological properties and valuable ornamental characteristics, which have been exploited since ancient times. Actually, their use is limited and monitored in several countries worldwide because they can contain fibrous asbestos minerals that may be carcinogenic. Furthermore, certain types of fibrous minerals can be confused with asbestos, and must therefore be carefully investigated. We have investigated the possible presence of the asbestos and non-asbestos fibrous phases contained in serpentinitic rocks in a meta-ophiolitic sequence from the Gimigliano-Mount Reventino Unit (Southern Italy), which had not been previously assessed. The detection and quantification of asbestos and the correct distinction of the fibrous non-asbestos minerals are very important not only from a scientific point of view, but also from a legislative one. This is especially the case for the administrative agencies that have to take decisions with regards to the implementation of public and occupational health protection measures (e.g., in road yards and quarry excavations). As a consequence of this, serpentinitic rock samples have been characterized in detail through X-ray powder diffraction, scanning and transmission electron microscopy combined with energy-dispersive spectrometry, analytical electron microscopy (SEM–EDS and TEM–AEM), differential scanning calorimetry, thermogravimetry and micro-Raman spectroscopy. Two kinds of asbestos and four kinds of non-asbestos fibrous silicates have been detected in the examined samples. In order of decreasing abundance these are polygonal serpentine, chrysotile, fibrous antigorite, tremolite, gedrite and magnesiohornblende. The size, morphology, crystallinity and chemical composition of the fibres were also discussed, in the light of the possible role these properties could play in the carcinogenic effect on human health.  相似文献   

Alteration kinetics of natural stones due to sodium sulfate crystallization: can reality match experimental simulations?     

Teresa Diaz Gonçalves  Vânia Brito 《Environmental Earth Sciences》2014,72(6):1789-1799

Salt decay is a very destructive mechanism that affects frequently the porous building materials of our architectural heritage. Sodium sulfate is one of the salts found in this context. It usually demonstrates high destructive power in salt crystallization tests because it can crystallize not only during evaporative processes but also when the temperature drops or when the salt solution comes into contact with pre-existing crystals. However, the use of extreme temperatures or successive wet/dry cycles also makes these tests unrepresentative of reality. To verify whether sodium sulfate can also be so destructive in field conditions, we have performed crystallization tests consisting of a single isothermal drying event. Three natural stones, relevant for the architectural heritage, were used for the purpose: Bentheimer sandstone, Ançã limestone, and a current Portuguese limestone of low porosity. The stones gave rise to distinct salt decay patterns: efflorescence, multilayer delamination and unilayer delamination, respectively. These morphological alterations were characterized at the micrometer scale by a new method based on what we have called the alteration kinetics curve. Such curve is calculated from topographic profiles obtained by a non-contact optical technique. The multilayer and unilayer delamination decay were also monitored by time-lapse photography. The work led us to conclude that sodium sulfate can indeed be also very destructive in field-representative conditions. Moreover, it showed that the optical method can be a valuable aid in the development of more realistic salt crystallization tests.  相似文献   

Can industrial pollution cause intersexuality in the amphipod, Echinogammarus marinus?     

Ford AT  Fernandes TF  Robinson CD  Davies IM  Read PA 《Marine pollution bulletin》2006,53(1-4):100-106

Following recent studies, in which intersex and/or reproductive abnormalities have been observed in a number of crustaceans in association with pollution, the prevalence of intersexuality in the amphipod, Echinogammarus marinus was monitored at sites receiving industrial discharges for one year in 2002/2003. Based upon reports of intersexuality occurring in amphipods due to feminising microsporidian parasites, the occurrence, and role of microsporidian parasites in causing intersex was investigated through histological examination. Results demonstrate a significantly higher prevalence of intersex organisms was found at sites receiving industrial discharges throughout the year when compared to a reference site, with the phenotype of intersex (intersex male and intersex female) varying in its dominance between impacted sites. Intersex specimens were significantly more likely to be infected with microsporidian parasites at sites receiving discharges than reference sites, however relatively few specimens (normal or intersex) were infected at reference sites suggesting parasitism is not the only cause of intersex. The direct/indirect role of pollution in the observed intersexuality is discussed.  相似文献   

Geomorphic indices and relative tectonic uplift in the Guerrero sector of the Mexican forearc     

Krzysztof Gaidzik  María Teresa Ramírez-Herrera 《地学前缘(英文版)》2017,8(4):885-902

Tectonically active areas, such as forearc regions, commonly show contrasting relief, differential tectonic uplift, variations in erosion rates, in river incision, and in channel gradient produced by ongoing tectonic deformation. Thus, information on the tectonic activity of a defined area could be derived via landscape analysis. This study uses topography and geomorphic indices to extract signals of ongoing tectonic deformation along the Mexican subduction forearc within the Guerrero sector. For this purpose, we use field data, topographical data, knickpoints, the ratio of volume to area (R_VA), the stream-length gradient index (SL), and the normalized channel steepness index (k_sn).The results of the applied landscape analysis reveal considerable variations in relief, topography and geomorphic indices values along the Guerrero sector of the Mexican subduction zone. We argue that the reported differences are indicative of tectonic deformation and of variations in relative tectonic uplift along the studied forearc. A significant drop from central and eastern parts of the study area towards the west in values of R_VA (from ～500 to ～300), SL (from ～500 to ca. 400), maximum SL (from ～1500–2500 to ～1000) and k_sn (from ～150 to ～100) denotes a decrease in relative tectonic uplift in the same direction. We suggest that applied geomorphic indices values and forearc topography are independent of climate and lithology. Actual mechanisms responsible for the observed variations and inferred changes in relative forearc tectonic uplift call for further studies that explain the physical processes that control the forearc along strike uplift variations and that determine the rates of uplift. The proposed methodology and results obtained through this study could prove useful to scientists who study the geomorphology of forearc regions and active subduction zones.  相似文献