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11.
Wet and dry atmospheric depositions and soil chemical and microbiological properties were determined in a Mediterranean natural ecosystem of Central Italy near Rome (Castelporziano Estate). The monitoring of depositions permitted us to quantify the exceedances of S and N compounds (expressed as eqH(+)ha(-1)year(-1)) over the critical loads of acidity. Critical loads, i.e. the quantity of a substance which a part of the environment can tolerate without adverse effects occurring, were determined adopting the level 0 methodology following the UN/ECE Convention on Long-range Transboundary Air Pollution. Deposition data were available for the period 1992-1997, and acidity exceedances were referred to the main vegetation types present in the area. Results showed that most part of the Estate has a medium degree of vulnerability to acidification, and the corresponding risk of acidification deriving from the exceedances of atmospheric deposition was rather low. The study of soil chemical and microbiological properties included mainly total soil organic carbon (SOC), microbial biomass-C, biomass-C/SOC, soil respiration, and metabolic quotient (qCO2). Soil organic C metabolism has been discussed on the basis of the results from eight sampling sites.  相似文献   
12.
The routes of five satellite-tracked loggerhead turtles (Caretta caretta), subjected to an experimental translocation away from their usual migratory routes, have been analysed in relation to the concurrent oceanographic conditions. Remote sensing data on sea surface temperature and height anomalies, as well as trajectories of surface drifters were used, to get simultaneous information on the currents encountered by the turtles during their long-range oceanic movements. Turtles mostly turned out to move in the same direction as the main currents, and their routes were often influenced by circulation features they encountered. A comparison between turtle ground speeds with that of drifters shows that in several instances, the turtles did not drift passively with the currents but contributed actively to the overall movement. Two turtles embarked on an oceanic crossing, probably induced by seasonal changes in surface temperatures, a crossing that was largely determined by the main currents existing in the area.  相似文献   
13.
The relationship between whole effluent toxicity (WET) and chemical-based effluent quality assessment across a range of effluent types was examined for the first time in Serbia. WET was determined by Daphnia magna acute tests, while chemical-based toxicity was taken as theoretical for concentrations of priority chemicals and effluent quality assessment based on the valid Serbian regulations. A poor correlation was found between WET and chemical-based effluent quality assessment: positive toxicity tests were found, in general, in cases where samples satisfied the requirements of mandatory effluent monitoring. Statistically insignificant correlation between the predicted and observed toxicity indicated that the presence of priority substances accounted to the overall toxicity only to a certain degree, most probably due to a rather short list of priority pollutants regularly analysed in effluents. Current monitoring requirements neglect hazards that derive from potentially present toxicants and unpredictable toxicity of complex mixtures, which led to poor correlation between the WET and chemical-based results in this study.  相似文献   
14.
The Sava River is the biggest tributary to the Danube River. As a part of the 6th FW EU project, Sava River Basin: Sustainable Use, Management and Protection of Resources (SARIB), ecological status of sediments was investigated. In order to assess the geographical distribution in sediment contamination of the Sava River, inorganic and persistent organic pollutants were analyzed in sediments at 20 selected sampling sites along the Sava River from its spring to its outfall into the Danube River. For comparability of data to other river basins the sediment fraction below 63 μm was studied. Due to complexity of the work performed, the results are published separately (“Part I: Selected elements” and “Part II: Persistent organic pollutants”). In the present study, the extent of pollution was estimated by determination of the total element concentrations and by the identification of the most hazardous highly mobile element fractions and anthropogenic inputs of elements to sediments. To assess the mobile metal fraction extraction in 0.11 mol L???1, acetic acid was performed (first step of the Community Bureau of Reference extraction procedure), while anthropogenic inputs of elements were estimated on the basis of normalization to aluminum (Al) concentration. According to the Water Framework Directive, the following elements were investigated in sediments: cadmium (Cd), lead (Pb), nickel (Ni), and mercury (Hg). Furthermore, copper (Cu), zinc (Zn), chromium (Cr), arsenic (As), and phosphorous (P) were determined. The analyses of sediments demonstrated slightly elevated values for Hg, Cr, and Ni in industrially exposed sites (concentrations up to 0.6, 380, and 210 mg kg???1, respectively). However, the latter two elements exist in sparingly soluble forms and therefore do not represent an environmental burden. P concentrations were found in elevated concentrations at agricultural areas and big cities (up to 1,000 mg kg???1).  相似文献   
15.
In the year 2000, organotin pollution was investigated in the Bay of Piran, Slovenia, at the northern extremity of the Adriatic Sea. Gas chromatography-mass spectrometry with single ion monitoring GC/MS-SIM was applied for speciation analysis of pentylated organotin compounds in water and mussels. Sampling of marine waters was performed in summer and autumn at 8 locations. Mussels Mytilus galloprovincialis were collected only in summer at 3 locations. The highest concentrations of tributyltin (TBT) in marine water ranged from 500 to 630 ng L(-1) (as Sn) in summer and from 180 to 230 ng L(-1) (as Sn) in autumn. TBT concentration in mussels varied from 500 to 3500 ng g(-1) dry weight (d.w.) (as Sn). The study indicated remarkable butyltin pollution of the Slovenian coastline. Accuracy of the analytical procedure was verified by BCR CRM 477.  相似文献   
16.
Objective. The objective of this study was to learn about the health and safety strategies in a sample of taxi drivers in Bucaramanga, Colombia. Methods. A cross-sectional study was conducted among 138 taxi drivers. A survey was used to identify the socio-demographic and working characteristics, knowledge, attitudes and practices according to their occupational risk. Results. Eighty-five percent of the workers labored 9–15?h/day. Of those who suffered accidents, 27% were not affiliated to an occupational risk administrator (p = 0.028). Of the workers who had a work-related accident, 58% considered that the use of a cell phone while driving would not always reduce their attention, 50% always used their seat belt and 7% took active breaks and wore their seat belt (p = 0.01). Conclusions. Within this group of taxi drivers, having or believing to possess knowledge regarding an occupational risk did not ensure that they had a safe attitude or safe working practices.  相似文献   
17.
Mass balance of contaminants can provide useful information on the processes that influence their concentrations in various environmental compartments. The most important sources, sinks and the equilibrium or non-equilibrium state of the contaminant in individual environmental compartments can also be identified. Using the latest mercury speciation data, the results of numerical models and the results of recent studies on mercury transport and transformation processes in the marine environment, we have re-evaluated the total mercury (HgT) mass balance in the Mediterranean Sea. New calculations have been performed employing three distinct marine layers: the surface layer, the thermocline and the deep sea. New transport mechanisms, deep water formation and density-driven sinking and upwelling, were included in the mass balance calculations. The most recent data have even enabled the calculation of an approximate methylmercury (MeHg) mass balance. HgT is well balanced in the entire Mediterranean, and the discrepancies between inputs and outputs in individual layers do not exceed 20 %. The MeHg balance shows larger discrepancies between gains and losses due to measurement uncertainties and gaps in our knowledge of Hg species transformation processes. Nonetheless, the main sources and sinks of HgT (deposition and evasion) and MeHg (fluxes from sediment, outflow through the Gibraltar Strait) are in accordance with previous studies on mercury in the Mediterranean Basin. Mercury in the Mediterranean fish harvest is the second largest MeHg sink; about 300 kg of this toxic substance is consumed annually with sea food.  相似文献   
18.
The manufacture of prefabricated building materials containing binding products such as ettringite (6CaO·Al2O3·3SO3·32H2O) and calcium silicate hydrate (CSH) can give, in addition to other well-defined industrial activities, the opportunity of using wastes and by-products as raw materials, thus contributing to further saving of natural resources and protection of the environment.Two ternary mixtures, composed by 40% flue gas desulfurization (FGD) gypsum or natural gypsum (as a reference material), 35% calcium hydroxide and 25% coal fly ash, were submitted to laboratory hydrothermal treatments carried out within time and temperature ranges of 2 h–7 days and 55–85 °C, respectively. The formation of (i) ettringite, by hydration of calcium sulfate given by FGD or natural gypsum, alumina of fly ash and part of calcium hydroxide, and (ii) CSH, by hydration of silica contained in fly ash and residual lime, was observed within both the reacting systems. For the FGD gypsum-based mixture, the conversion toward ettringite and CSH was highest at 70 °C and increased with curing time. Some discrepancies in the hydration behavior between the mixtures were ascribed to differences in mineralogical composition between natural and FGD gypsum.  相似文献   
19.
Articular cartilage is a complex tissue characterised by chondrocytes that are embedded within an organised dense extracellular matrix of collagen and proteoglycan. Under physiologic condition, articular metabolism is slow, but under pathological condition turnover can increase and the matrix undergoes faster mechanical failure and deterioration, resulting in cartilage degeneration. Moreover, modest damage of the articular cartilage, resulting from trauma or less invasive surgical procedure, produces an inflammatory reaction of the joint cartilage, which can cause irreversible degeneration through the increase in catabolic cytokines synthesis and the decrease in anabolic activity of chondrocytes. Pro-inflammatory cytokines increase the synthesis of matrix-degrading enzymes and limit the production of proteoglycans. It is known that physical stimuli modulate cartilage metabolism. In particular, pulsed electromagnetic fields (I-ONE therapy, Igea, Carpi, Italy) allow to treat homogenously the whole cartilage surface and thickness and the underlying subchondral bone. In vitro I-ONE therapy increases the binding between adenosine and A2A adenosine receptor on human neutrophils cell membrane, on bovine chondrocytes and on fibroblast-like synoviocytes. It has been shown that drugs with A2A adenosine receptor agonist activity prevent articular cartilage degeneration in animals. We hypothesised that the adenosine agonist effect of I-ONE therapy can also prevent cartilage degeneration. In a recent study, De Mattei et al. demonstrated how I-ONE therapy can strongly inhibit the release of PGE2 in bovine synovial fibroblasts exerting an anti-apoptotic effect on cells. Ex vitro, in bovine full thickness articular cartilage explants, I-ONE therapy induces the largest increase in proteoglycan synthesis and in IGF-1 synthesis, when cartilage is exposed to specific parameters of pulsed electromagnetic fields. These effective parameters were subsequently used in in vivo experiments. The effect of I-ONE therapy was investigated on Dunkin Hartley osteoarthritic knee by Mankin score and by histomorphometric and densitometric analysis; I-ONE therapy prevented cartilage degeneration and subchondral bone sclerosis. Osteochondral grafts were performed in the knees of sheep; I-ONE therapy favoured osteochondral grafts integration and prevented cyst-like resorption area formation, which can compromise the stability of graft and the success of the technique. To support the in vitro results, biochemical analyses of the synovial fluid were also performed in this animal model. The amount of inflammatory catabolic cytokines (IL-1β and TNF-α) in the synovial fluid of I-ONE treated animals was significantly lower than in control animals. On the contrary, TGF-β1 was significantly higher in stimulated animals than it was in controls. These results demonstrate not only the capability of I-ONE therapy to control the inflammatory reaction but also its capability to favour cartilage anabolic activity. These results provide the rational to design clinical studies to demonstrate the possibility to transfer the treatment to humans. Two randomised, prospective, double-blind clinical studies (Level I), one conducted to patients treated by arthroscopy with condroabrasion and/or perforations at the knee and the other after anterior cruciate ligament reconstruction, demonstrated that biophysical stimulation with I-ONE therapy leads to complete patient’s recovery in a significantly shorter time (P < 0.005). Moreover, a significant number of treated patients made lower use of anti-inflammatory drugs than the patients in the placebo group. We did not observe negative side effects, patient’s compliance was good and treatment was well accepted. I-ONE therapy significantly reduces patients’ recovery time, joint swelling and has a chondroprotective effect over articular cartilage. I-ONE treatment is a new therapy for the joint preservation.  相似文献   
20.
The role of volcanic ash as scavenger of atmospheric pollutants, in their transport and final deposition to the ground is examined. Attention is focused on polycyclic aromatic hydrocarbons (PAHs) and on particulate mercury (Hgp). The ash-fall deposits studied belong to the 2001 and 2002 eruptive activity of Mount Etna, Southern Italy, and were investigated at three (2001) and four (2002) sites downwind of the major tephra dispersal pattern. The dry deposition of mercury and PAHs was determined, and, in particular, a downward flux to the ground of PAHs (approximately 7.29 microg m(-2) per day) and mercury (750 ng m(-2) per day) was estimated in Catania from October 26 to October 28, 2002. Finally, evidence on the anthropogenic origin of PAHs scavenged from the troposphere by volcanic ash is supported by the analysis of PAH compositions in granulometrically homogeneous fractions.  相似文献   
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