首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   385篇
  免费   5篇
  国内免费   7篇
安全科学   10篇
废物处理   39篇
环保管理   39篇
综合类   42篇
基础理论   65篇
环境理论   2篇
污染及防治   134篇
评价与监测   49篇
社会与环境   16篇
灾害及防治   1篇
  2023年   5篇
  2022年   15篇
  2021年   15篇
  2020年   7篇
  2019年   11篇
  2018年   20篇
  2017年   10篇
  2016年   13篇
  2015年   19篇
  2014年   24篇
  2013年   44篇
  2012年   24篇
  2011年   27篇
  2010年   16篇
  2009年   14篇
  2008年   19篇
  2007年   12篇
  2006年   14篇
  2005年   19篇
  2004年   13篇
  2003年   11篇
  2002年   12篇
  2001年   4篇
  2000年   3篇
  1998年   4篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   4篇
  1989年   1篇
  1988年   2篇
  1985年   1篇
  1970年   1篇
排序方式: 共有397条查询结果,搜索用时 953 毫秒
21.
A soil sampling intercomparison exercise for the ALMERA network   总被引:1,自引:0,他引:1  
Soil sampling and analysis for radionuclides after an accidental or routine release is a key factor for the dose calculation to members of the public, and for the establishment of possible countermeasures. The IAEA organized for selected laboratories of the ALMERA (Analytical Laboratories for the Measurement of Environmental Radioactivity) network a Soil Sampling Intercomparison Exercise (IAEA/SIE/01) with the objective of comparing soil sampling procedures used by different laboratories. The ALMERA network is a world-wide network of analytical laboratories located in IAEA member states capable of providing reliable and timely analysis of environmental samples in the event of an accidental or intentional release of radioactivity. Ten ALMERA laboratories were selected to participate in the sampling exercise. The soil sampling intercomparison exercise took place in November 2005 in an agricultural area qualified as a “reference site”, aimed at assessing the uncertainties associated with soil sampling in agricultural, semi-natural, urban and contaminated environments and suitable for performing sampling intercomparison. In this paper, the laboratories sampling performance were evaluated.  相似文献   
22.
Cellular phones have high environmental impact potentials because of their heavy metal content and current consumer attitudes toward purchasing new phones with higher functionality and neglecting to return waste phones into proper take-back systems. This study evaluates human health and ecological toxicity potentials from waste cellular phones; highlights consumer, corporate, and government responsibilities for effective waste management; and identifies key elements needed for an effective waste management strategy. The toxicity potentials are evaluated by using heavy metal content, respective characterization factors, and a pathway and impact model for heavy metals that considers end-of-life disposal in landfills or by incineration. Cancer potentials derive primarily from Pb and As; non-cancer potentials primarily from Cu and Pb; and ecotoxicity potentials primarily from Cu and Hg. These results are not completely in agreement with previous work in which leachability thresholds were the metric used to establish priority, thereby indicating the need for multiple or revised metrics. The triple bottom line of consumer, corporate, and government responsibilities is emphasized in terms of consumer attitudes, design for environment (DfE), and establishment and implementation of waste management systems including recycling streams, respectively. The key strategic elements for effective waste management include environmental taxation and a deposit-refund system to motivate consumer responsibility, which is linked and integrated with corporate and government responsibilities. The results of this study can contribute to DfE and waste management policy for cellular phones.  相似文献   
23.
The dissolved labile and labile particulate fractions (LPF) of Cu and Zn were analyzed during different seasons and salinity conditions in estuarine waters of marina, port, and shipyard areas in the southern region of the Patos Lagoon (RS, Brazil). The dissolved labile concentration was determined using the diffusive gradients in thin films technique (DGT). DGT devices were deployed in seven locations of the estuary for 72 h and the physicochemical parameters were also measured. The LPF of Cu and Zn was determined by daily filtering of water samples. Seasonal variation of DGT–Cu concentrations was only significant (p?<?0.05) at one shipyard area, while DGT–Zn was significant (p?<?0.05) in every locations. The LPF of Cu and Zn concentrations demonstrated seasonal and spatial variability in all locations, mainly at shipyard areas during high salinity conditions. In general, except the control location, the sampling locations showed mean variations of 0.11–0.45 μg?L?1 for DGT–Cu, 0.89–9.96 μg?L?1 for DGT–Zn, 0.65–3.69 μg?g?1 for LPF–Cu, and 1.35–10.87 μg?g?1 for LPF–Zn. Shipyard areas demonstrated the most expressive values of labile Cu and Zn in both fractions. Strong relationship between DGT–Zn and LPF–Zn was found suggesting that the DGT–Zn fraction originates from the suspended particulate matter. Water salinity and suspended particulate matter content indicated their importance for the control of the labile concentrations of Cu and Zn in the water column. These parameters must be taken into consideration for comparison among labile metals in estuaries.  相似文献   
24.
We sampled extensively (29 stations) at the Klang estuarine system over a 3-day scientific expedition. We measured physical and chemical variables (temperature, salinity, dissolved oxygen, total suspended solids, dissolved inorganic nutrients) and related them to the spatial distribution of phototrophic picoplankton (Ppico). Multivariate analysis of variance of the physicochemical variables showed the heterogeneity of the Klang estuarine system where the stations at each transect were significantly different (Rao’s F 18, 36?=?8.401, p?<?0.001). Correlation analyses also showed that variables related to Ppico abundance and growth were mutually exclusive. Distribution of Ppico was best explained by the physical mixing between freshwater and seawater whereas Ppico growth was correlated with temperature.  相似文献   
25.
Environmental Economics and Policy Studies - To test if tax return can effectively and efficiently increase the acceptance of externality taxation, a laboratory experiment with a negative...  相似文献   
26.
Due to high usage of tetracycline antibiotics, concerns have been raised about their environmental fate. In this study, potential changes in the pseudo-first-order hydrolysis rate constants for three tetracyclines, tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC), were evaluated by measuring the rate constants in batch and column leaching experiments. The first-order hydrolysis rate constants were measured at pH 5, 7, and 9 using batch tests. The values were highest at pH 7 for all three tetracyclines (0.0030 ± 0.0004, 0.0042 ± 0.0001, and 0.0323 ± 0.0003 h(-1) for TC, OTC, and CTC, respectively), indicating relatively short environmental half-lives of tetracyclines. Interestingly, it was found that the rates of degradation of the parent tetracyclines were much faster when silica sand was present in a batch solution or when the solution was passed through a silica column. For example, the ratios of the first-order degradation rate constants obtained in the column experiments to those in batch experiments were 13.2, 2.1, and 2.0 for TC, OTC, and CTC at a volumetric flow rate of 0.08 mL h(-1), with an observed tendency for this ratio to increase with an increased flow rate. This indicates that the silica surface may serve as a catalyst for hydrolysis and that the actual environmental half-lives of tetracycline antibiotics could be shorter than those estimated from laboratory hydrolysis rate constants using the standard batch protocol. Furthermore, the toxicity of the column effluent containing hydrolysis metabolites was assessed using bioluminescence inhibition in Vibrio fischeri. It was estimated that the toxicity of the metabolites of CTC was lower than that of their parent compound, whereas the toxicity of metabolites of TC and OTC was as high as or higher than that of their parent compounds.  相似文献   
27.

Background, aim, and scope

The purpose of this study was to monitor and present the heavy metal concentrations in the blood of residents of areas near municipal waste incinerators (MWIs), who are more prone to environmental pollution. We also sought to compare and analyze the residents?? perception of environmental pollution as one of the factors affecting heavy metal concentrations in the blood using a survey about the perceived damage caused by the facilities. Since heavy metal levels in the blood can be affected not only by local environmental pollution but also by personal and occupational factors, heavy metal levels in the blood need to be verified and consistently monitored.

Methods

Residents who live within 300?m of MWIs in Seoul are acknowledged to be under indirect influence according to the Waste Disposal Act. A survey was given to 841 residents living within 300?m of a MWI from 2006 to 2009. The concentrations of heavy metals (lead, cadmium, and mercury) in the blood were measured in the 841 surveyed residents and in 105 residents in reference areas. Additionally, the perception of the damage caused by municipal waste incinerators was investigated using scores from 1 to 5 on a Likert scale.

Results

The measurements of the heavy metal concentrations in the blood showed that the mean concentrations of lead, cadmium, and mercury were 43.1, 1.7, and 1.3?ug/L, respectively. The blood levels of lead and cadmium were slightly higher in the group of the subjects who had resided the longest near the municipal waste incinerators. When compared with the domestic investigation by the Ministry of Environment, the concentrations of lead and cadmium were a little higher, while that of mercury was a little lower. Overall, there was no significant difference in the distribution of heavy metal levels in the blood among age groups. Additionally, the investigation of the perceived damage from municipal waste incinerators showed that the subjects  相似文献   
28.
Lindane removal by pure and mixed cultures of immobilized actinobacteria   总被引:1,自引:0,他引:1  
Stereoselective dissipation of epoxiconazole had been studied in grape and soil during plant growing under field conditions in this paper. A sensitive and rapid chiral method was developed and validated for the determination of epoxiconazole stereoisomers in grape and soil based on liquid chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS). Phenomenex Lux Cellulose-1 column was used for enantioseparation with a mixture of acetonitrile/water (90/10, v/v) as mobile phase at flow rate of 0.3 mL min−1. Fortified recoveries in grape and soil samples ranged from 76.0% to 91.9% and relative standard deviations were less than 11.4% with fortified levels of 0.025-1.0 mg kg−1. The limits of detection and quantification were 0.005 mg kg−1 and 0.025 mg kg−1, respectively, with linear calibration curves extending up to 5.0 mg kg−1. The field experimental results showed that dissipations of epoxiconazole stereoisomers in grape followed first-order kinetics (R2 > 0.92) and stereoselectivity occurred in 2 h after spraying. The (−)-stereoisomer with half-life of 9.3 d degraded faster than (+)-stereoisomer with that of 13.2 d, and resulted in relative enrichment of (+)-stereoisomer. However, the stereoisomeric dissipations in soil were triphasic (“increase-decrease-steady”) with lower dissipation rates, and also occurred with preferential degradation of (−)-stereoisomer under field condition. The results for stereoselective dissipations can be applied for food and environmental assessments of chiral pesticides.  相似文献   
29.
The present study investigates the effects of drill cutting discharges on the structure of meiofauna communities in an area of the shelf break at Campos Basin, Southeast Brazil. Drilling activities were operated, in a first phase, with water-based fluid and, in a second phase, with synthetic fluid paraffin-based (NAF-III). A total of 135 samples taken at a pre-drilling situation (MS1) and two post-drilling moments (MS2 and MS3—3 and 22 months post-drilling, respectively) were analyzed. Effects on meiofauna were dependent on two main factors: 1—the impact received during drilling operation, if water-based or synthetic/water-based drilling fluid and 2—the background state, if it already presented signs of previous drilling activities or not. Based on univariate and multivariate analysis, there were evidences that the most affected area after drilling was those under the influence of synthetic-based fluid and that already had signs of previous drillings activities. The region impacted only by water-based fluid was less affected and the only one that completely recovered after 22 months. Nematodes and copepods had different responses to the impact. While copepods flourish in the impacted area and recovered 22 months after drilling, nematodes were adversely affected shortly after drilling and the community structure only recovered where hydrocarbons had been depleted.  相似文献   
30.
An aquatic biomonitoring of Giardia cysts and Cryptosporidium oocysts in river water corresponding to five villages situated in three states in peninsular Malaysia was determined. There were 51.3 % (20/39) and 23.1 % (9/39) samples positive for Giardia and Cryptosporidium (oo)cysts, respectively. Overall mean concentration between villages for Giardia cysts ranged from 0.10 to 25.80 cysts/l whilst Cryptosporidium oocysts ranged from 0.10 to 0.90 oocysts/l. Detailed results of the river samples from five villages indicated that Kuala Pangsun 100 % (9/9), Kemensah 77.8 % (7/9), Pos Piah 33.3 % (3/9) and Paya Lebar 33.3 % (1/3) were contaminated with Giardia cysts whilst Cryptosporidium (oo)cysts were only detected in Kemensah (100 %; 9/9) and Kuala Pangsun (66.6 %; 6/9). However, the water samples from Bentong were all negative for these waterborne parasites. Samples were collected from lower point, midpoint and upper point. Midpoint refers to the section of the river where the studied communities are highly populated. Meanwhile, the position of the lower point is at least 2 km southward of the midpoint and upper point is at least 2 km northward of the midpoint. The highest mean concentration for (oo)cysts was found at the lower points [3.15?±?6.09 (oo)cysts/l], followed by midpoints [0.66?±?1.10 (oo)cysts/l] and upper points [0.66?±?0.92 (oo)cysts/l]. The mean concentration of Giardia cysts was highest at Kuala Pangsun (i.e. 5.97?±?7.0 cysts/l), followed by Kemensah (0.83?±?0.81 cysts/l), Pos Piah (0.20?±?0.35 cysts/l) and Paya Lebar (0.10?±?0.19 cysts/l). On the other hand, the mean concentration of Cryptosporidium oocysts was higher at Kemensah (0.31?±?0.19 cysts/l) compared to Kuala Pangsun (0.03?±?0.03cysts/l). All the physical and chemical parameters did not show significant correlation with both protozoa. In future, viability status and molecular characterisation of Giardia and Cryptosporidium should be applied to identify species and genotypes/subgenotypes for better understanding of the epidemiology of these waterborne parasites.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号