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1.
Air pollution, bulk precipitation, throughfall, soil condition, foliar nutrients, as well as forest health and growth were studied in 2006–2009 in a long-term ecological research (LTER) network in the Bucegi Mountains, Romania. Ozone (O3) was high indicating a potential for phytotoxicity. Ammonia (NH3) concentrations rose to levels that could contribute to deposition of nutritional nitrogen (N) and could affect biodiversity changes. Higher that 50% contribution of acidic rain (pH?<?5.5) contributed to increased acidity of forest soils. Foliar N concentrations for Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), and European beech (Fagus sylvatica) were normal, phosphorus (P) was high, while those of potassium (K), magnesium (Mg), and especially of manganese (Mn) were significantly below the typical European or Carpathian region levels. The observed nutritional imbalance could have negative effects on forest trees. Health of forests was moderately affected, with damaged trees (crown defoliation >25%) higher than 30%. The observed crown damage was accompanied by the annual volume losses for the entire research forest area up to 25.4%. High diversity and evenness specific to the stand type’s structures and local climate conditions were observed within the herbaceous layer, indicating that biodiversity of the vascular plant communities was not compromised.  相似文献   
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Although female animals tend to be choosier than males in selecting mates, sexual selection theory predicts that males should also be choosy when female fecundity varies. Reproductive success among female spotted hyenas varies greatly with social rank. Our goals were therefore to determine whether male hyenas preferentially associate with high-ranking females, and whether male preferences are affected by female reproductive state. Interactions between adult males and females were observed intensively, and association indices calculated for all male-female pairs, over a 7-year period in one population of free-living hyenas. Males initiated most affiliative interactions with females, and males associated most closely with females that were likeliest to be fertile. High- and middle-ranking males associated most closely with high-ranking females, but low-ranking males associated equally closely with females in all rank categories. We used molecular markers to determine the paternity of cubs born during the study period, and found that sires associated more closely with the mothers of those cubs than did non-sires, particularly during the last months before conception. These association data indicate that male spotted hyenas do indeed exhibit selective mate choice, and that they prefer females likeliest to maximize male reproductive success.  相似文献   
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Bells Creek catchment in southeast Queensland (Australia) is a non-industrialised coastal plain limited to small settlements and agricultural land. A study was initiated to examine elevated metal concentrations and to assess horizontal and vertical distribution of those elements. Ninety-nine samples were analysed for Cr, V, Ni, Cu, Zn, Pb, As, Fe, Mn and Al. Total organic carbon, sulfur content and mineralogy of samples along with land-use practices across the catchment were used to identify processes which influence metal distribution. A comparison between metal concentration within the study area and mean heavy metal content of standard sandstone showed that except for Mn, all other metals showed elevated levels throughout the catchment. When metal concentrations were compared to parent bedrock, however, it was concluded that elevated levels are likely to be natural. A normalisation procedure was applied to the data set and this analysis validated that elevated trace metal concentrations in most samples are not due to artificial contamination. While surficial estuarine sediments were only enriched in V, soils were dominantly enriched in Cr, Zn and V. Overall, geochemistry and mineralogy of the samples show the effect of both natural and anthropogenic inputs to the catchment, however, natural processes are more dominant than anthropogenic inputs in concentrating metals.  相似文献   
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Participatory research in which experts and non-experts are co-researchers in addressing local concerns (also known as participatory action research or community-based research) can be a valuable approach for dealing with the uncertainty of social–ecological systems because it fosters learning among stakeholders and co-production of knowledge. Despite its increased application in the context of natural resources and environmental management, evaluation of participatory research has received little attention. The objectives of this research were to define criteria to evaluate participatory research processes and outcomes, from the literature on participation evaluation, and to apply them in a case study in an artisanal fishery in coastal Uruguay. Process evaluation criteria (e.g., problem to be addressed of key interest to local and additional stakeholders; involvement of interested stakeholder groups in every research stage; collective decision making through deliberation; and adaptability through iterative cycles) should be considered as conditions to promote empowering participatory research. Our research contributes to knowledge on evaluation of participatory research, while also providing evidence of the positive outcomes of this approach, such as co-production of knowledge, learning, strengthened social networks, and conflict resolution.  相似文献   
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A monitoring program of cyanobacteria and cyanotoxins in the framework of the surveillance of the Water Treatment Plant efficiency of the municipality of Santa Comba D?o (Portugal) was conducted from 1994 until 2007. With these data we aimed to answer the question, are MCs produced evenly over the years in a single water body? Samples were taken by the local health authorities in the site of the Water treatment plant and analyzed for total phytoplankton, cyanobacteria and the hepatotoxic cyanotoxins microcystins (MCs). Apart from 1999 and 2000, cyanobacteria represented a high proportion of total phytoplankton, attaining during several months of the year more than 90% of total phytoplankton density. A total of 24 cyanobacteria species were identified and Microcystis aeruginosa, Anabaena flos-aquae and Aphanizomenon flos-aquae were the main potentially toxic cyanobacteria species present throughout the period. MC concentration varied between 0.3 μg MC-LR eq l?1 in October 98 and 87.0 μg MC-LR eq l?1 in September 2001. The evolution of the average cell quota does not reveal any especial trend, although in 2001 the quota was the highest but not significantly different from the other years. The threshold limit of 5000 cells per ml of Microcystis aeruginosa should be taken into consideration in monitoring programs because the 10,000 cells per ml proposed by several other national programs might not be enough to prevent human health risks. Due to high annual variation in MC cell quota, monitoring programs of cyanobacteria and MC should be extended in time, since short term studies do not provide us the data needed for a safe management of a water body used for human purposes.  相似文献   
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It is well known that adsorption is an efficient method of removal of various pollutants from wastewater. The present study examines the phenol removal from water by adsorption on a new material, based on zeolitic volcanic tuff. This compound contains zeolitic tuff and cellulose, another known adsorbent, in a mass ratio of 4 to 1. The performances of the new adsorbent composite were compared with those of a widely used adsorbent material, zeolitic volcanic tuff. The adsorbent properties were tested on batch synthetic solutions containing 1–10 mg L?1 (1–10 ppm) phenol, at room temperature without pH adjustment. The influence of the adsorbent dose, pH and contact time on the removal degree of phenol from water was investigated. The experimental data were modeled using the Langmuir, Freundlich, and Temkin adsorption isotherms. The Langmuir model was found to best represent our data revealing a monolayer adsorption with a maximum adsorption capacity between 0.12 and 0.53 mg g?1 at 25 °C, for 2.00 g of adsorbent, depending on the initial phenol concentration. The adsorption kinetic study was performed using a pseudo-first- and pseudo-second-order kinetic models illustrating that phenol adsorption on zeolite composite is well described by pseudo-first kinetic equations. Our results indicated that phenol adsorption on the new adsorbent composite is superior to that on the classic zeolite.  相似文献   
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The Pumicestone region is a unique catchment in northern Moreton Bay, southeast Queensland. The region supports a wide range of land-use activities as well as attractions such as nature conservation areas. One environmental aspect that has not previously been addressed in this area is the occurrence of minor and trace metals in estuarine sediments associated with the main estuaries of the region. The trace metals included in this investigation are: vanadium, chromium, molybdenum, cobalt, nickel, copper, zinc, cadmium, lead and arsenic. To determine and evaluate the occurrence and distribution of metals in the area, several components have been analysed: bedrock material, pre-industrial settings, recent estuarine sediments, soils of estuarine origin and mangrove pneumatophores. The 40 sites chosen for sediment and soil samples cover a variety of estuarine settings and represent a range of natural conditions in terms of channel and bank morphology, tidal energy, vegetation cover, relationship to bedrock, water salinity and land disturbance. The chemical, mineralogical and statistical analyses employed in this study enabled (a) establishment of background values for the area, (b) determination of relationships between metals and (c) identification of sites with anomalous metal concentrations. All the metals found in the sediments of the area are sourced from the geological bedrock. The dominant trace elements identified in sediments are Zn, V and Cr. The remaining metals are highly variable spatially. All trace metals are controlled by the presence of Fe and Mn oxides, and by the grainsize of the sediment. Typically, fine-grained Fe-rich materials tend to adsorb more trace metals than sandy sediments. In soils that have developed from estuarine muds, some metals such as Cr, Mo, Pb and As tend to be in larger quantities than in the estuarine counterparts. Some of the elements, which occur in significant amounts in the sediment, have been detected in mangrove tissue (Avicenniamarina) such as V, Cr, Zn, Fe and Mn. Of particular note is Cu, which is present in mangrove tissue in quantities many times exceeding the sediment concentration. The comparative analysis of pre-industrial settings and recent sediments and soils highlighted some areas of metal enrichment such as acid-affected sites where oxidation of pyrite has mobilised metals from sediments; these metals are then redistributed in Fe-rich surficial layers. Disturbed banks within the estuaries are also likely to have low levels of metal enrichment due to boating activities.  相似文献   
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Sarcophyton elegans is a common symbiotic (zooxanthellate) octocoral species in the shallow waters of the Great Barrier Reef (GBR). Study of a population at Lizard Island (14°40′S, 145°28′E) on the GBR from October 1991 to January 1994 revealed that, as is typical of tropical alcyonarian corals, S. elegans is a gonochoric broadcast spawner with a 1:1 sex ratio. Sexual reproduction was closely correlated with colony size, with first reproduction at 13-cm basal stalk circumference for females and 12 cm for males. Oogenesis took 19–24 months, with a new cycle commencing every year, and spermatogenesis took 10–12 months. The majority of gametes were released during the annual austral mass coral spawning event after the full moon in November, but gametes were also released after the full moon in each month between August and February. All autozooid polyps participated in reproduction, but those at the outer edge of a colony released their gametes first. During subsequent months, the polyps closer to the center of the colony released their gametes. This is a novel strategy of gamete release, reported here for the first time, which accommodates the demands of feeding and reproduction in a different way than other corals where individual polyps have separate feeding or reproductive roles. Colonies upstream in the prevailing current spawned up to 1 month earlier than those downstream and ceased 1 month earlier. The mechanism controlling this spatial differentiation in spawning time, repeatedly observed over three seasons, is unknown. Sarcophyton elegans appears to have a dual strategy of providing protection for its gametes by releasing most of them concurrently with the single, annual mass spawning of a large number of cnidarians, while also hedging its bets by individual colonies spawning a fraction of their gametes over an extended period of 6 months.  相似文献   
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