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221.
The radioecological situation in Lake Tygish is described. The lake is situated on the central axis of the Eastern Ural Radioactive Trace (EURT), which was formed after the nuclear accident in the Southern Urals in 1957. The distributions of 90Sr and 137Cs among the main components of the water body and the results of the measurement of tritium concentration in the water are presented. Mathematical models are described that have made it possible to estimate changes in the concentrations of radionuclides and their amounts accumulated in the water and bottom sediments of the lake during the long period after the accident and to predict the development of the radioecological situation in the lake until 2057. Based on the mathematical models, more accurate data on the initial ecological situation in the lake in the year of the accident have been obtained.  相似文献   
222.
Seven sediment samples from mangrove sediments of the Red Sea were taken in order to evaluate the possible contamination of the sediments by trace metals (iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd)). Sequential extraction techniques were performed to study the different geochemical forms of these metals. X-ray diffraction analysis has been performed to correlate the mineralogical composition with the geochemical forms of the studied elements. The results of Fe and Mn contents indicate that they are in large part from lithogenous origin. The elevated concentrations are associated with the residual form ranged from 70 to 93% for Fe and 46 to 70% for Mn. The percentage of Zn, Cu, Cd and Pb in the non-residual form was much greater than that of the residual fractions. This reflects the high mobility and bioavailability of these metals in mangrove sediments of the Red Sea. X-ray diffraction analysis revealed the presence of silicate components including quartz, feldspars and clay minerals in some locality. Non-silicate components recorded in the study area as calcite as well as, Mg-calcite. Quantitatively both components i.e. silicate and carbonate varied according to their source material.  相似文献   
223.
This study characterises the sediment dredged from a lagooning system composed of a settling pond and three lagoons that receive leachates from a municipal solid waste (MSW) landfill in France. Organic carbon, carbonate, iron oxyhydroxides, copper (Cu) and zinc (Zn) concentrations were measured in the sediment collected from upstream to downstream in the lagooning system. In order to complete our investigation of sedimentation mechanisms, leachates were sampled in both dry (spring) and wet (winter) seasonal conditions. Precipitation of calcite and amorphous Fe-oxyhydroxides and sedimentation of organic matter occurred in the settling pond. Since different distributions of Zn and Cu concentrations are measured in sediment samples collected downstream in the lagooning system, it is suggested that these elements were not distributed in a similar way in the leachate fractions during the first stage of treatment in the settling pond, so that their sedimentation dynamics in the lagooning system differ. In the lagoons, it was found that organic carbon plays a major role in Cu and Zn mobility and trapping. The presence of macrophytes along the edges provided an input of organic matter that enhanced Cu and Zn scavenging. This edge effect resulted in a two-fold increase in Cu and Zn concentrations in the sediment deposited near the banks of the lagoons, thus confirming the importance of vegetation for the retention of Cu and Zn in lagooning systems.  相似文献   
224.
The aim of this study is to investigate the trace elements (TE) contents of potential biomonitors in a historical Zn–Pb mining district: apiary products (honey, royal-jelly and beeswax) lichen and moss were sampled and analysed. In spite of high TE concentrations in mining waste and soil, apiary products are free of TE contamination originating from historical mining. Lichen/moss show high TE levels, which suggest atmospheric input of local dust. Pb isotopes analysis proved the origin of TE found in lichen/moss to be mainly mining waste. These results help discuss the choice of relevant organisms for monitoring TE in the environment and bring additional data on the potential impacts of brownfields left after mining, especially on food products from apiaries.  相似文献   
225.
The significance of metal concentrations in marine mammals is not well understood and relating concentrations between stranded and free-ranging populations has been difficult. In order to predict liver concentrations in free-ranging dolphins, we examined concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, total Hg (THg), V, Zn) in skin and liver of stranded bottlenose dolphins (Tursiops truncatus) from the South Carolina (SC) coast and the Indian River Lagoon, Florida (FL) during 2000-2008. Significantly higher concentrations of Zn, Fe, Se, Al, Cu and THg were found in skin while liver exhibited significantly higher Cu, Fe, Mn and THg concentrations for both study sites. Mean skin concentrations of Cu and Mn were significantly higher in SC dolphins while higher concentrations of THg and V were found in FL dolphins. In addition, liver tissues in SC dolphins exhibited significantly higher As concentrations while higher Fe, Pb, Se, THg, and V levels were found in FL dolphins. Two elements (Cu and THg) showed significant age-related correlations with skin concentration while five elements (Cu, Se, THg, Zn and V) showed age-related correlations with liver concentrations. Geographic location influenced age-related accumulation of several trace elements and age-related accumulation of THg in hepatic tissue was observed for both sites to have the highest correlations (r2 = 0.90SC; r2 = 0.69FL). Mean THg concentration in liver was about 10 times higher in FL dolphins (330 μg g−1 dw) than those samples from SC dolphins (34.3 μg g−1 dw). The mean molar ratio of Hg to Se was 0.93 ± 0.32 and 1.08 ± 0.38 for SC and FL dolphins, respectively. However, the Hg:Se ratio varied with age as much lower ratios (0.2-0.4) were found in younger animals. Of the 18 measured elements, only THg was significantly correlated in skin and liver of stranded dolphins and skin of free-ranging dolphins from both sites suggesting that skin may be useful in predicting Hg concentrations in liver tissue of free-ranging dolphins. Results indicate that 33% of the stranded and 15% of the free-ranging dolphins from FL exceed the minimum 100 μg g−1 wet weight (ww) (∼400 dw) Hg threshold for hepatic damage while none from SC reached this level. Hepatic concentrations of As in SC dolphins and V in FL dolphins were also highly correlated with skin concentrations which may have some regional specificity predictive value. The present study provides the first application of trace element concentrations derived from stranded bottlenose dolphins to predict liver concentrations in free-ranging populations.  相似文献   
226.
Khunjar WO  Love NG 《Chemosphere》2011,82(6):917-922
The sorption of carbamazepine (CBZ), iopromide (IOP), trimethoprim (TMP) and 17α-ethinylestradiol (EE2) was evaluated using four biomass types (pure ammonia oxidizing bacterial culture, two heterotrophic enrichment cultures with varying levels of oxygenase activity, and a full-scale nitrifying activated sludge (NAS) culture). CBZ and IOP did not sorb to the four biomass types. EE2 did not sorb to the pure culture but sorbed significantly to the heterotrophic cultures and NAS. TMP sorbed to the heterotrophic cultures and NAS, and was not evaluated for the pure culture. Three floc characteristics (hydrophobicity, median particle size, organic matter content) correlated moderately well with the EE2 organic matter sorption coefficient (KOM,EE2). Zeta potential did not correlate well with KOM,EE2 but did with KOM,TMP, indicating that TMP sorption is more influenced by electrostatic factors than EE2. Once divalent cation-linked exocellular polymeric substances (EPS) were removed from flocs, EE2 and TMP sorption to the non-EPS (cellular) fraction decreased by approximately 50%. The correlation between KOM,EE2 for the non-EPS cellular fraction deteriorated while the correlation between KOM,TMP improved. EE2 seemed to sorb more strongly to EPS protein whereas TMP sorbed equally to polysaccharide and protein EPS. Attempts to develop predictive models were not successful. Pharmaceuticals that sorbed to biomass samples underwent biodegradation whereas those that did not sorb were not biodegraded, suggesting a relationship between sorption and pharmaceutical biotransformation.  相似文献   
227.
Seasonal variation of the concentrations of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES in the water and sediment from the Saricay Stream, Geyik Dam and Ortakoy Well in the same basin. Comparisons between trace metal concentrations in water and sediment in three sources (Stream, Dam and Well) were made. The concentrations of a large number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges (as mass ratio): Co: 5–476 μg g−1, Cr: 15–1308 μg g−1, Cu: 7–128 μg g−1, Fe: 1120–13210 μg g−1, Mn: 150–2613 μg g−1, Ni: 102–390 μg g−1, Pb: 0.7–31.3 μg g−1 and Zn: 18–304 μg g−1, whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5–20.7 μg L−1, Cr: 20.3–284 μg L−1, Cu: 170–840 μg L−1, Fe: 176–1830 μg L−1, Mn: 29.3–387 μg L−1, and Ni: 4.3–21.9 μg L−1. Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance (one-way ANOVA) and correlation matrix was employed for the sediment and water samples of the two field surveys (summer and winter) comparison. The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of metals during the dry season showed an anthropological effect from small industry firms, e.g.: an olive mill and a dairy farm or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges.  相似文献   
228.
Laser-induced breakdown spectroscopy (LIBS) has been applied for the determination of nutrients in the green house soil samples. We determined appropriate spectral signatures of vital nutrients and calibrated the method to measure the nutrients in a naturally fertilized plot, cultivated with tomato and cucumber plants. From the calibration curves we predicted the concentrations of important nutrients such as Ca, K, P, Mg, Fe, S, Ni and Ba in the soil. Our measurements proved that the LIBS method rapidly and efficiently measures soil nutrients with excellent detection limits of 12, 9, 7, 9, 7, 10, 8 and 12~mg/kg for Ca, K, P, Mg, Fe, S, Ni and Ba respectively with a precision of 2%, The unique features of LIBS for rapid sample analysis demonstrated by this study suggests that this method offers promise for precision measurements of soil nutrients as compared to conventional methods in short span of time.  相似文献   
229.
Rain water samples were collected to study the chemical composition of wet atmospheric precipitation (first event) over the Lucknow city in the northern Indo-gangetic alluvial plains. The samples were collected in the month of July, 2005 from different sites. The wet precipitation samples were analyzed for pH, EC, major ions (, Cl, , , , F, Na+, K+, Ca2+, Mg2+, ) and heavy metals (As, Cd, Al, Co, Cr, Cu, Fe, Mn, Mo, Ni, Hg, Pb, Se, Sn, Ti, V, Zn). The pH values of wet precipitation samples ranged between 6.5 and 8.7. The analysis of linear regression applied to the set of studied variables and computation of neutralization factors showed that neutralization occurred in precipitation samples and Ca2+ had the maximum neutralization capacity. It was found that Cl, , Ca2+, Mg2+, Na+ and K+ in the precipitation samples originated mainly from crustal/anthropogenic sources in the region. On an average Fe, and Al accounted for >72% of the total concentration of trace metals in the wet precipitation samples followed by Zn (>10%). Enrichment factors calculated for heavy metals over reference background level in seawater and Earth’s crust showed relatively higher enrichment of Zn. The principal component analysis (PCA) identified the possible sources of ionic species and heavy metals in the wet precipitation samples.  相似文献   
230.
Anthropogenic sources of pollution can significantly contribute to elevated concentrations of toxic elements in soils. A preliminary survey of trace elements content and their availability in residential soils from New Madrid County, Missouri was undertaken. Mean elemental concentrations (mg kg−1, dry wt) of sixty two soil samples were: As 6.6, Be 0.8, Cd 1.6, Co 9.7, Cr 24.5, Cu 18.1, Fe 9951, Mn 298, Ni 15.6, Pb 48.8, V 42.1, Zn 95.5 and Hg 0.05. The US EPA preliminary remediation goals (PRGs) was only exceeded by As (7 % of samples) and V (8% of samples). The Missouri average background values were exceeded by Pb (69%), Zn (31%), Cu (27%), As (23%), Be (19%), Co (18%), Ni (16%), V (8%) and Mn (2%). Crustal enrichments (EFc) for As (97), Cr (6), Cu (10), Pb (121), V (7), and Hg (17) were highest for North Lilbourn soils. Fractionation experiment revealed that Fe (54–79%) was in the residual phase while Zn (70–90%), Mn (88–92%), As (59–81%) and Pb (63–79%) were potentially available in soils. Factor loadings of the element concentrations on principal components 1, 2 and 3 accounted for over 81% variance of the data set. The factor loadings suggested that apart from natural contributions of trace elements to the soils, human activities possibly accounted for other inputs in soils.  相似文献   
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