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61.
In the Western Mediterranean Sea, the gorgonian Eunicella singularis (Esper, 1794) is found at high densities on sublittoral bottoms at depths from 10 to 70 m. Shallow colonies have symbiotic zooxanthellae that deeper colonies lack. While knowledge of the ecology of the shallow populations has increased during the last decades, there is almost no information on the ecology of the deep sublittoral populations. In October and November 2004 at Cap de Creus (42°19′12″ N; 03°19′34″ E), an analysis of video transects made by a remotely operated vehicle showed that shallow populations (10–25 m depth) were dominated by small, non-reproductive colonies, while deep sublittoral populations (50–67 m depth) were dominated by medium-sized colonies. Average and maximum colony heights were greater in the deeper populations, with these deeper populations also forming larger patch sizes and more extensive regions of continuous substrate coverage. These results suggest that shallow habitats are suitable for E. singularis, as shown by the high recruitment rate, but perturbations may limit or delay the development of these populations into a mature stage. This contrasts with the deep sublittoral habitats where higher environmental stability may allow the development of mature populations dominated by larger, sexually mature colonies.  相似文献   
62.
Environmental Science and Pollution Research - The growing demand for products with lower environmental impact and the extensive applicability of cellulose nanofibrils (CNFs) have received...  相似文献   
63.
As in many lekking anurans, Italian treefrog males use two mating tactics: they can attract females by calling vigorously or be satellites, that is, they can remain silent in proximity of a calling male and try to intercept females attracted by their neighbour. We investigated the factors that affected the expression of this mating tactic. Consistent with the conditional mating tactic hypothesis, satellites were smaller than average and smaller than their parasitised calling males. They spent a larger-than-average number of nights at the breeding site, where most of them were also observed calling. Moreover, satellites showed lower call rates and lower mating success than those of males they parasitise but not lower than those of males they did not parasitise. Overall, these results, together with those derived from the analyses of the seasonal and spatial distribution of males, provide evidence for a non-random association between satellites and calling males and are consistent with the hypothesis that satellites have spectral and temporal acoustic preferences that parallel those of females. By adopting the less-successful satellite mating tactic, competitively inferior males can nevertheless maximise their potential reproductive fitness by sexually parasitising the most attractive chorusing males.  相似文献   
64.
The complex performance of newly synthesized CoNiMnB electrodeposits in base-stabilized sodium borohydride solutions was examined. The rate of hydrogen generation due to borohydride hydrolysis was determined at different temperatures. Activation energy of approximately 33 kJ/mol was estimated, which is lower than the values reported for other catalysts. At electrochemical conditions, there is a competition between borohydride hydrolysis and electrooxidation reactions. The electrooxidation of borohydride takes place with low overpotentials at relatively high current densities. The long-term discharge at galvanostatic conditions as well as possibilities for partial storage of generated hydrogen indicates potentials for application of studied electrodeposits as anode material in direct borohydride fuel cells (DBFC).  相似文献   
65.
The importance of open mineral storage piles in bulk solids port terminals have increased considerably in recent years in Europe and USA (in Spain, great extensions of transoceanic ports are being made) to address the increasing demand of raw material importation due to local mining operation closure. These storage piles are affected by the climatologically processes and the dust emission to the atmosphere, causing repercussions to health and environmental, which is intimately related to the air velocity, according to USEPA studies, maximum ratio of dust emission emitted from CFD and software Ansys CFX 10.0 is determined. In addition, an emission variability study based on the pile distance of different height solid barriers is developed, reducing the emission to 66%. The studies have been contrasted by published investigations and industrial measurement.  相似文献   
66.
The Lagoon Olho d'Água in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants.  相似文献   
67.
This paper presents results of the AQL2004 project, which has been develope within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLatif). The project intended to obtain monthly burned-land maps of the entire region, from Mexico to Patagonia, using MODIS (moderate-resolution imaging spectroradiometer) reflectance data. The project has been organized in three different phases: acquisition and preprocessing of satellite data; discrimination of burned pixels; and validation of results. In the first phase, input data consisting of 32-day composites of MODIS 500-m reflectance data generated by the Global Land Cover Facility (GLCF) of the University of Maryland (College Park, Maryland, U.S.A.) were collected and processed. The discrimination of burned areas was addressed in two steps: searching for "burned core" pixels using postfire spectral indices and multitemporal change detection and mapping of burned scars using contextual techniques. The validation phase was based on visual analysis of Landsat and CBERS (China-Brazil Earth Resources Satellite) images. Validation of the burned-land category showed an agreement ranging from 30% to 60%, depending on the ecosystem and vegetation species present. The total burned area for the entire year was estimated to be 153 215 km2. The most affected countries in relation to their territory were Cuba, Colombia, Bolivia, and Venezuela. Burned areas were found in most land covers; herbaceous vegetation (savannas and grasslands) presented the highest proportions of burned area, while perennial forest had the lowest proportions. The importance of croplands in the total burned area should be taken with reserve, since this cover presented the highest commission errors. The importance of generating systematic products of burned land areas for different ecological processes is emphasized.  相似文献   
68.
Development Potentials and Policy Options of Biomass in China   总被引:7,自引:0,他引:7  
Biomass, one of the most important renewable energies, is playing and will continue to play an important role in the future energy structure of the world. This article aims to analyze the position and role, assess the resource availability, discuss the geographic distribution, market scale and industry development, and present the policy options of biomass in China. The resource availability and geographical distribution of biomass byproducts are assessed in terms of crop residues, manure, forest and wood biomass byproducts, municipal waste and wastewater. The position of biomass use for power generation is just next to hydropower among types of renewable energy in China. The potential quantity of all biomass byproducts energy in 2004 is 3511 Mtce (Mtce is the abbreviation of million tons of coal equivalents and 1 Mtce is equal to106 tce.), while the acquirable quantity is 460 Mtce. Biomass energy plays a critical role in rural regions of China. The geographical distribution and quantity of biomass byproducts resources depends mainly on the relationship between ecological zones and climate conditions. Our estimation shows that the total quantity of crop residues, manure, forest and wood biomass byproducts, municipal waste and wastewater resources are 728, 3926, 2175, 155 and 48240 Mt (million tons), respectively. Crop residues come mainly from the provinces of Henan, Shandong, Heilongjiang, Jilin and Sichuan. All manure is mainly located in the provinces of Henan, Shandong, Sichuan, Hebei and Hunan. Forest and wood biomass byproducts are mainly produced in the provinces or autonomous regions of Tibet, Sichuan, Yunnan, Heilongjiang and Inner Mongolia, while most of municipal waste mainly comes from Guangdong, Shandong, Heilongjiang, Hubei and Jiangsu. Most of wastewater is largely discharged from advanced provinces like Guangdong, Jiangsu, Zhejiang, Shandong and Henan. Biomass byproducts’ energy distribution also varies from province to province in China. Based on the analysis of the market scale and industry development, the article argues that China’s biomass energy industry is still at a very early stage of development and that Feed-in Tariffs (FIT) might be the best policy option for China to promote its development of biomass energy. A successful enforcement of FIT in China needs some policy combination of special capital subsidies, R&D funding, tax incentives and pricing.  相似文献   
69.
The Water Erosion Prediction Project (WEPP) model has been tested for its ability to predict soil erosion, runoff, and sediment delivery over a wide range of conditions and scales for both hillslopes and watersheds. Since its release in 1995, there has been considerable interest in adding a chemical transport element to it. Total phosphorus (TP) loss at the watershed outlet was simulated as the product of TP in the soil, amount of sediment at the watershed outlet, and an enrichment ratio (ER) factor. WEPP can be coupled with a simple algorithm to simulate phosphorus transport bound to sediment at the watershed outlet. The objective of this work was to incorporate and test the ability of WEPP in estimatingTP loss with sediment at the small watershed scale. Two approaches were examined. One approach (P-EER) estimated ER according to an empirical relationship; the other approach used the ER calculated by WEPP (P-WER).The data used for model performance test were obtained from two side-by-side watersheds monitored between 1976 and 1980. The watershed sizes were 5.05 and 6.37 ha, and each was in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Measured and simulated results were compared for the period April to October in each year. There was no statistical difference between the mean measured and simulated TP loss. The Nash-Sutcliffe coefficient was 0.80 and 0.78 for the P-EER and P-WER methods, respectively. It was critical for both methods that WEPP adequately represent the biggest sediment yield events because sediment is the main driver for TP loss so that the model can adequately simulate TP losses bound to sediment. The P-WER method is recommended because it does not require use of empirical parameters to estimate TP loss at the watershed outlet.  相似文献   
70.
Scale-up of anodic oxidation system is critical to the practical application of electrochemical treatment in bio-refractory organic wastewater treatment. In this study, the scale-up of electrochemical flow system was investigated by treating petrochemical wastewater using platinized titanium (Ti/Pt) and boron-doped diamond (BDD) anodes. It was demonstrated that flow cell was successfully scaled-up because when it was compared with batch mode (Rocha et al. 2012b), higher performances on organic matter removal were achieved. Under the suitable operating conditions and better anode material, the chemical oxygen demand (COD) of petrochemical wastewater was reduced from 2,746 to 200 mg L?1 within 5 h with an energy consumption of only 56.2 kWh m?3 in the scaled-up BDD anode system. These results demonstrate that anode flow system is very promising in practical bio-refractory organic wastewater treatment.  相似文献   
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