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101.
This paper provides a new reference line for municipal solid waste characterization in Kuwait. The baseline data were collected in accordance with the Standard Test Method for the Determination of the Composition of Unprocessed Municipal Solid Waste (ASTM). The results indicated that the average daily municipal waste generation level is 1.01 kg/person. Detailed waste stream surveys were conducted for more than 600 samples of municipal solid waste (MSW). The waste categories included paper, corrugated fibers, PET bottles, film, organic matter, wood, metal, glass, and others. The results indicated that organic waste dominated the characterization (44.4%), followed by film (11.2%) and then corrugated fibers (8.6%). Analysis of variance (ANOVA) was used to investigate the influence of season and governorate on waste composition. A significant seasonal variation was observed in almost all waste categories. In addition, significant differences in proportions between the current level and 1995 baseline were observed in most waste categories at the 95% confidence level. 相似文献
102.
Distribution, sources and potential toxicological significance of polycyclic aromatic hydrocarbons(PAHs) in Guanting Reservoir sediments, China 总被引:6,自引:0,他引:6
The Guanting Reservoir lost its function as the second biggest drinking water source for Beijing due to the pollutions from the upstream flow of Yongding River in 1997. From 1998, lots of studies were carryied out to renew the function of Guanting Reservoir as domestic drinking water source before 2008 Olympic Games. This is the first time that polycyclic aromatic hydrocarbon concentrations in the surface sediment of Guanting Reservoir have been analyzed. A distinctive spatial distribution of PAHs was observed. Sediments from four sites along Inlet of Yongding River to reservoir bam had PAHs concentrations of 1377--2855 μg/g dw in descending order. The composition of PAHs is investigated and used to assess patrogenic,combustion and naturally derived of the sediments samples of Guanting Reservoir. Special PAHs ratios, such as phenanthrene/anthracene(P/A) and fluoranthene/pyrene(Fl/Pyr) were calculated to assess the relative importance of different origins. The data confirmed a relatively high level of petrogenic contamination in four sites. These high PAHs levels were associated with the input of untreated and partially treated industrial sewage. In addition, the concentrations of PAHs compounds of samples indicated that sediments of reservoir were most likely to pose potential biological impairment. 相似文献
103.
104.
根据2002年至2010年我国群死群伤火灾的统计数据,分析了群死群伤火灾的总体形势、时空分布以及发生场所和起火原因的影响,得到了群死群伤火灾的发展趋势及其发生的规律和特点。结果表明,群死群伤火灾总体呈波动下降趋势,受经济因素影响明显;在发生时段上,年初和年末高于年中,晚上高于白天;在发生场所上,居住建筑发生的起数和死亡人数最多;在火灾原因上,电气火灾和用火不慎远远高于其他原因。 相似文献
105.
Assessing Mn, Fe, Cu, Zn, and Cd pollution in bottom sediments of Wadi Al-Arab Dam, Jordan 总被引:19,自引:0,他引:19
Thirty five bottom sediment samples were collected in a grid pattern from Wadi Al-Arab Dam. The present study focuses on the levels of Mn, Fe, Cu, Zn, Cd, total organic matter (TOM) and carbonate content (CO(3)(-2)) in order to assess the extent of environmental pollution and to discuss the origin of these contaminants in sediments of the dam. Concentration data were processed using correlation analysis and factor analysis. The results of correlation analysis and factor analysis show low positive and negative correlations among Mn, Fe, Cu, Zn, Cd, TOM, and CO(3)(-2) and indicate that heavy metals in sediments of Wadi Al-Arab have different anthropogenic and natural sources. The results also confirm the complicated behavior of these pollutants, that can be influenced by many factors. Sediments pollution assessment was carried out using enrichment factor and the geoaccumulation index. The calculation of enrichment factors showed that Mn and Cu are depleted by 0.76, and 1.33, respectively, whereas Cu, Zn, and Cd are enriched by 3.6, and 30, respectively. The results of geoaccumulation index reveal that sediments of Wadi Al-Arab are uncontaminated with Mn, Fe, and Cu, moderately contaminated with Zn, and strongly to extremely contaminated with Cd. Some of the elevated concentration of Zn and Cd are probably due to anthropogenic sources nearby the dam site. These sources mainly include fertilizers and pesticides used in agricultural activities, and the effluent of Irbid City treatment plant. Environmental risks of Cd and Zn were evaluated using the risk assessment code (RAC) and sequential extraction method. Zn poses a low environmental risk, whereas Cd poses a medium environmental risk. 相似文献
106.
Thirty one soil samples were collected from south Jordan around the cement factory in Qadissiya area. The samples were obtained at two depths, 0-10 cm and 10-20 cm and were analyzed by atomic absorption spectrophotometery for Pb, Zn, Cd, Fe, Cu and Cr. Physicochemical factors believed to affect their mobility of metals in soil of the study area were examined such as; pH, TOM, CaCO3, CEC and conductivity. The relatively high concentrations of lead, zinc and cadmium in the soil samples of the investigated area were related to anthropogenic sources such as cement industry, agriculture activities and traffic emissions. It was found that the lead, zinc and cadmium have the highest level in area close to the cement factory, while the concentration of chromium was low. This study indicate that all of the metals are concentrated on the surface soil, and decreased in the lower part of the soil, this due to reflects their mobility and physical properties of soil and its alkaline pH values. The use of factor analysis showed that anthropogenic activities seem to be the responsible source of pollution for metals in urban soils. 相似文献
107.
夏光 《中国环境管理干部学院学报》2007,17(1):1-3
2006年,从中央到地方都大幅度强化了环境保护的施政力度。中央提出了环境保护与经济增长要并重、同步和综合的要求,这被称为“环境保护的历史性转变”。与此同时,国家出台了20多项以环境保护为重要内容或与环境保护有关的产业政策和其他经济政策。新成立了11个环境保护和核安全的区域督查机构,层层下达了主要污染物排放消减指标。各地也把主要精力放在了推动新型工业化和城市化进程上,出台了大量加强和支持环境保护的经济政策和管理措施。 相似文献
108.
Impact of Criticism of Null-Hypothesis Significance Testing on Statistical Reporting Practices in Conservation Biology 总被引:2,自引:0,他引:2
FIONA FIDLER§ MARK A. BURGMAN GEOFF CUMMING† ROBERT BUTTROSE NEIL THOMASON‡ 《Conservation biology》2006,20(5):1539-1544
Abstract: Over the last decade, criticisms of null-hypothesis significance testing have grown dramatically, and several alternative practices, such as confidence intervals, information theoretic, and Bayesian methods, have been advocated. Have these calls for change had an impact on the statistical reporting practices in conservation biology? In 2000 and 2001, 92% of sampled articles in Conservation Biology and Biological Conservation reported results of null-hypothesis tests. In 2005 this figure dropped to 78%. There were corresponding increases in the use of confidence intervals, information theoretic, and Bayesian techniques. Of those articles reporting null-hypothesis testing—which still easily constitute the majority—very few report statistical power (8%) and many misinterpret statistical nonsignificance as evidence for no effect (63%). Overall, results of our survey show some improvements in statistical practice, but further efforts are clearly required to move the discipline toward improved practices. 相似文献
109.
Sorichetta A Masetti M Ballabio C Sterlacchini S Beretta GP 《Journal of environmental management》2011,92(4):1215-1224
Statistical methods are widely used in environmental studies to evaluate natural hazards. Within groundwater vulnerability in particular, statistical methods are used to support decisions about environmental planning and management. The production of vulnerability maps obtained by statistical methods can greatly help decision making. One of the key points in all of these studies is the validation of the model outputs, which is performed through the application of various techniques to analyze the quality and reliability of the final results and to evaluate the model having the best performance. In this study, a groundwater vulnerability assessment to nitrate contamination was performed for the shallow aquifer located in the Province of Milan (Italy). The Weights of Evidence modeling technique was used to generate six model outputs, each one with a different number of input predictive factors. Considering that a vulnerability map is meaningful and useful only if it represents the study area through a limited number of classes with different degrees of vulnerability, the spatial agreement of different reclassified maps has been evaluated through the kappa statistics and a series of validation procedures has been proposed and applied to evaluate the reliability of the reclassified maps. Results show that performance is not directly related to the number of input predictor factors and that is possible to identify, among apparently similar maps, those best representing groundwater vulnerability in the study area. Thus, vulnerability maps generated using statistical modeling techniques have to be carefully handled before they are disseminated. Indeed, the results may appear to be excellent and final maps may perform quite well when, in fact, the depicted spatial distribution of vulnerability is greatly different from the actual one. For this reason, it is necessary to carefully evaluate the obtained results using multiple statistical techniques that are capable of providing quantitative insight into the analysis of the results. This evaluation should be done at least to reduce the questionability of the results and so to limit the number of potential choices. 相似文献
110.
Arsenic levels were determined in 62 stations utilized as drinking and potable water resources by local community for Turkey's Aksaray Province (4589 km(2); 980 m above sea level). The samplings were implemented every two months for 1 year. The arsenic values were found to be ranging between 10 and 50 μg/L in 22 points and were found to be >50 μg/L in 5 stations, according to the mean value of the 6 samples. WHO and the Turkish Standards have permitted an arsenic concentration of 10 μg/L in drinking waters. The multivariate statistical technique, cluster analysis (CA), followed by principal component analysis (PCA) were applied to the data on 17 water quality parameters in 47 stations that are used for drinking and other domestic resources. Two significant sampling locations were detected based on the similarity of their water quality. The chemical correlations were observed in the two sub-sampling locations by Principal Component Analysis. 相似文献