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891.
Evaluating pollution potential of leachate from landfill site, from the Pune metropolitan city and its impact on shallow basaltic aquifers 总被引:3,自引:0,他引:3
Sanjay S. Kale Ajay K. Kadam Suyash Kumar N. J. Pawar 《Environmental monitoring and assessment》2010,162(1-4):327-346
Leachate produced by municipal solid waste dumping site near the metropolitan city of Pune, India was examined for its pollution potential and impact on surrounding shallow basaltic aquifers. Twenty-eight physico-chemical parameters during post- and pre-monsoon seasons (Nov 2006 and May 2007) were determined to assess the seasonal variation in the leachate pollution index (LPI) as well as in the groundwater quality. The leachate demonstrated higher LPI value during pre-monsoon, comparable to those at other metropolises outside India. Potentially toxic leachates derived from the dumping site have largely influenced the adjoining basaltic aquifers through two different modes of transport. Despite high contents of heavy metals (Al, Cd, Cr, Cu, Co, Fe, Mn, Ni, Pb and Zn) in the leachate, the aquifers in the close proximity of landfill site are least polluted by metallic contaminants possibly due to redox controls. Various geoenvironmental features governing the dispersal of leachate contaminants in the basaltic aquifers under semi-arid climatic regime have been identified and discussed. Although a few remedial measures have been suggested to mitigate the impact of leachate percolation and dispersion, the present study demands for a proper solid waste management in metropolitan cities. 相似文献
892.
Chromium speciation in groundwater of a tannery polluted area of Chennai City, India 总被引:2,自引:0,他引:2
Chromium speciation in groundwater of a tannery polluted area was investigated for the distribution of chromium species and the influence of redox couples such as Fe(III)/Fe(II) and Mn(IV)/Mn(II). Speciation analysis was carried out by ammonium pyrolidinedithiocarbamate (APDC)–methylisobutylketone (MIBK) procedure. The groundwater samples were analyzed for Cr(III), Cr(VI), and Cr(III)-organic complexes. The APDC could not extract the Cr(III)-organic complexes, but HNO3 digestion of the groundwater samples released the Cr(III)-organic complexes. The groundwater of the area is relatively oxidizing with redox potential (E h) and dissolved oxygen (DO) ranged between 65 and 299 mV and 0.25 and 4.65 mg L???1, respectively. The Fe(II) reduction of Cr(VI) was observed in some wells, but several wells that had Fe(II)/Cr(VI) concentrations more than the stoichiometric ratio (3:1) of the reduction reaction also had appreciable concentration of Cr(VI). This could partly be due to the oxidation of Fe(II) to Fe(III) by DO. It appears that the occurrence of Mn more than the Fe(II) concentration was also responsible for the presence of Cr(VI). Other reasons could be the Fe(II) complexation by organic ligands and the loss of reducing capacity of Fe(II) due to aquifer materials, but could not be established in this study. 相似文献
893.
Prabhat Kumar Rai 《Environmental monitoring and assessment》2010,165(1-4):407-433
Assessment of seasonal changes in surface water quality is an important aspect for evaluating temporal variations of lentic ecosystem (lakes and reservoirs) pollution due to industrial effluent discharge. In this study, nine metals and 15 physicochemical parameters, collected from four sampling sites in a tropical lake receiving the discharge from thermal power plant, coal mine, and chloralkali industry, during the years from 2004 to 2005, were analyzed. For greater efficacy in monitoring of heavy metals, particle-induced X-ray emission has been used during present investigation. Different statistical techniques like analysis of variance, Pearson correlation, principal component analysis, and factor analysis were employed to evaluate the seasonal correlations of physicochemical parameters. Most of the metals and physicochemical parameters monitored in the present study exhibited high spatial and temporal variability. Pertaining to metal pollution, the most polluted site was Belwadah, i.e., waters and sediments had the highest concentration of all the relevant metals. The reference site was characterized by the presence of low concentrations of metals in waters and in sediments. Based on the high metal concentration recorded in lake ambient, drinking, bathing, and irrigation water should not be used by the local people at the effluent discharge points. 相似文献
894.
A field study was conducted in the fly ash lagoons of Santandih Thermal Power Plant located in West Bengal (India) to find
out total, EDTA and DTPA extractable metals in fly ash and their bioaccumulation in root and shoot portion of the naturally
growing vegetation. Fly ash sample has alkaline pH and low conductivity. The concentration of total Cu, Zn, Pb and Ni were
found higher than weathered fly ash and natural soil, where as Co, Cd and Cr were found traces. Five dominant vegetation namely,
Typha latifolia, Fimbristylis dichotoma, Amaranthus defluxes, Saccharum spontaenum and Cynodon dactylon were collected in the winter months (November–December). Bioaccumulation of metals in root and shoot portions were found
varied significantly among the species, but all concentration were found within toxic limits. Correlation between total, DTPA
and EDTA extractable metals viz. root and shoot metals concentration were studied. Translocation factor (TF) for Cu, Zn and
Ni were found less than unity, indicates that these metals are immobilized in the root part of the plants. Metals like Mn
have TF greater than unity. The study infers that natural vegetation removed Mn by phytoextraction mechanisms (TF > 1), while
other metals like Zn, Cu, Pb and Ni were removed by rhizofiltration mechanisms (TF < 1). The field study revealed that T. latifolia and S. spontaenum plants could be used for bioremediation of fly ash lagoon. 相似文献
895.
Reddy KJ Kumar JR Ramachandraiah C Reddy SA Reddy AV 《Environmental monitoring and assessment》2008,136(1-3):337-346
N-Ethyl-3-cabazolecarboxaldehydethiosemicarbazone (ECCT) is proposed as a new, sensitive and selective complexing reagent
for the separation and extractive spectrophotometric determination of palladium(II) at pH: 4.0 to form a yellowish orange
colored 1:1 chelate complex, which is very well extracted in to n-butanol. The absorbance was measured at a maximum wavelength,
410 nm. This method obeys Beer’s law in the concentration range 0.0–6.6 μg mL−1 and the correlation coefficient of Pd(II)-ECCT complex is 0.998, which indicates an excellent linearity between the two variables
with good molar absorptivity and Sandell’s sensitivity, 1.647 × 104 l mol−1cm−1, 6.49 × 10−3 μg cm−2, respectively. The instability constant of complex calculated from Edmond’s method, 2.724 × 10−5 was in good agreement with the value calculated from Asmus’ method 2.624 × 10−5, at room temperature. The precision and accuracy of the method is checked with calculation of relative standard deviation
(n = 5), 0.839. Edmond’s method was observed to be a more selective method in the presence of EDTA, oxalate and phosphate ions.
The method was successfully applied for the determination of Pd(II) in water samples, synthetic mixtures and hydrogenation
catalysts, employing an atomic absorption spectrometer for comparing these results. 相似文献
896.
Deepak Kumar Avinash Kumar Vimal Kumar Jaivender Kumar P. M Ravi 《Environmental monitoring and assessment》2013,185(4):2887-2894
The atmosphere is an important pathway to be considered in assessment of the environmental impact of radioactivity releases from nuclear facilities. The estimation of concentration of released effluents in air and possible ground contamination needs an understanding of relevant atmospheric dispersion. This paper describes the meteorological characteristics of Narora Atomic Power Station (NAPS) Nuclear Power Project site by using the integral parameters developed by Allwine and Whiteman (Atmospheric Environment 28(4):713–721, 1994). Meteorological data measured during the period 2006–2010 were analysed. The integral quantities related to the occurrence of stagnation, recirculation and ventilation characteristics were studied for the NAPS site to assess the dilution potential of the atmosphere. Wind run and recirculation factors were calculated for a 24-h transport time using 5 years of hourly surface measurements of wind speed and direction. The occurrence of stagnation, recirculation and ventilation characteristics during 2006–2010 at the NAPS site is observed to be 33.8, 19.5 and 34.7 % of the time, respectively. The presence of strong winds with predominant wind direction NW and WNW during winter and summer seasons leads to higher ventilation (48.1 and 44.3 %) and recirculation (32.6 % of the summer season). The presence of more dispersed light winds during pre-winter season with predominant wind directions W and WNW results in more stagnation (59.7 % of the pre-winter season). Thus, this study will serve as an essential meteorological tool to understand the transport mechanism of atmospheric radioactive effluent release from any nuclear industry during the pre-operational as well as operational phase. 相似文献
897.
Swayamprabha Mishra Monalisa Mohanty Chinmay Pradhan Hemanta Kumar Patra Ritarani Das Santilata Sahoo 《Environmental monitoring and assessment》2013,185(5):4347-4359
The present investigation aims to assess the phytoremediation potential of six aquatic macrophytes, viz. Eichhornia crassipes, Hydrilla verticillata, Jussiaea repens, Lemna minor, Pistia stratiotes and Trapa natans grown in paper mill effluent of JK Paper mill of Rayagada, Orissa, for remediation of heavy metals. The experiment was designed in pot culture experiments. Assessment of physico-chemical parameters of paper mill effluent showed significant decrease in pH, conductivity, total dissolved solids, total suspended solids, chlorine, sulphur, biological and chemical oxygen demand after growth of macrophytes for 20 days. Phytoremediation ability of these aquatic macrophytic species for copper (Cu) and mercury (Hg) was indicated by assessing the decrease in the levels of heavy metals from effluent water. Maximum reduction (66.5 %) in Hg content of untreated paper mill effluent was observed using L. minor followed by T. natans (64.8 %). L. minor showed highest reduction (71.4 %) of Cu content from effluent water followed by E. crassipes (63.6 %). Phytoextraction potential of L. minor was remarkable for Hg and Cu, and bioaccumulation was evident from bioconcentration factor values, i.e. 0.59 and 0.70, respectively. The present phytoremediation approach was considered more effective than conventional chemical treatment method for removing toxic contaminants from paper mill effluent. 相似文献
898.
Young NE Stohlgren TJ Evangelista PH Kumar S Graham J Newman G 《Environmental monitoring and assessment》2012,184(9):5439-5451
Species distribution models are frequently used to predict species occurrences in novel conditions, yet few studies have examined the consequences of extrapolating locally collected data to regional landscapes. Similarly, the process of using regional data to inform local prediction for species distribution models has not been adequately evaluated. Using boosted regression trees, we examined errors associated with extrapolating models developed with locally collected abundance data to regional-scale spatial extents and associated with using regional data for predictions at a local extent for a native and non-native plant species across the northeastern central plains of Colorado. Our objectives were to compare model results and accuracy between those developed locally and extrapolated regionally, those developed regionally and extrapolated locally, and to evaluate extending species distribution modeling from predicting the probability of presence to predicting abundance. We developed models to predict the spatial distribution of plant species abundance using topographic, remotely sensed, land cover and soil taxonomic predictor variables. We compared model predicted mean and range abundance values to observed values between local and regional. We also evaluated model prediction performance based on Pearson's correlation coefficient. We show that: (1) extrapolating local models to regional extents may restrict predictions, (2) regional data can help refine and improve local predictions, and (3) boosted regression trees can be useful to model and predict plant species abundance. Regional sampling designed in concert with large sampling frameworks such as the National Ecological Observatory Network may improve our ability to monitor changes in local species abundance. 相似文献
899.
Chatterjee M Canário J Sarkar SK Branco V Godhantaraman N Bhattacharya BD Bhattacharya A 《Environmental monitoring and assessment》2012,184(9):5239-5254
This study was performed to elucidate the distribution, concentration trend and possible sources of total mercury (Hg(T)) and methylmercury (MeHg) in sediment cores (<63 μm particle size; n?=?75) of Sundarban mangrove wetland, northeastern part of the Bay of Bengal, India. Total mercury was determined by atomic absorption spectrometry (AAS) in a Leco AMA 254 instrument and MeHg by gas chromatography-atomic fluorescence spectrometry (GC-AFS). A wide range of variation in Hg(T) (0.032-0.196 μg g(-1) dry wt.) as well as MeHg (0.04-0.13 ng g(-1) dry wt.) concentrations revealed a slight local contamination. The prevalent low Hg(T) levels in sediments could be explained by sediment transport by the tidal Hugli (Ganges) River that would dilute the Hg(T) values via sediment mixing processes. A broader variation of MeHg proportions (%) were also observed in samples suggesting that other environmental variables such as organic carbon and microbial activity may play a major role in the methylation process. An overall elevated concentration of Hg(T) in surface layers (0-4 cm) of the core is due to remobilization of mercury from deeper sediments. Based on the index of geoaccumulation (I (geo)) and low effects-range (ER-L) values, it is considered that the sediment is less polluted by Hg(T) and there is less ecotoxicological risk. The paper provides the first information of MeHg in sediments from this wetland environment and the authors strongly recommend further examination of Hg(T) fluxes for the development of a detailed coastal MeHg model. This could provide more refine estimates of a total flux into the water column. 相似文献
900.
Vimal Kumar KG Dinesh Kumar PK Smitha BR Habeeb Rahman H Josia J Muraleedharan KR Sanjeevan VN Achuthankutty CT 《Environmental monitoring and assessment》2008,140(1-3):231-247
Seasonal variation of the hydrography along the southeast Arabian Sea is described using data collected onboard FORV Sagar
Sampada in September–October 2003 (later phase of Southwest monsoon, SWM) and March–April 2004 (Spring inter monsoon, SIM).
During the later phase of the SWM, upwelling was in the withdrawal phase and the frontal structure was clearer in the northern
sections (13 and 15°N lat) indicating strong upwelling in the area. The driving force of upwelling is identified as the combination
of alongshore wind stress and remote forcing with a latitudinal variability. Although a more prominent upwelling was found
in the north, a maximum surface Chlorophyll-a was found in the south (10°N). During the SIM, the area was characterized by oligotrophic water with relatively high Sea
Surface Temperature (>29°C) and low salinity (33.8 to 35.4). During March, the surface hydrography was found to be controlled
mainly by the intrusion of low-saline waters from the south, while during September by the high saline water from the north.
The presence of various water masses [Arabian Sea High Salinity Water (ASHSW), Persian Gulf Water (PGW), Red Sea Water (RSW)]
and their seasonal variations in the region is discussed and their decreasing influence towards the south is noted during
both periods of observation. During the SWM, the dynamic topography showed the equator-ward flow of the West India Coastal
Current (WICC) at the surface and a pole-ward coastal under current at sub-thermocline depth. During the SIM, surface circulation
revealed the WICC flowing pole-ward north of 13°N, but equator-ward flow in the south, with a clockwise circulation around
the Lakshadweep High. 相似文献