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   114篇
  免费   0篇
废物处理   6篇
环保管理   11篇
综合类   19篇
基础理论   16篇
污染及防治   36篇
评价与监测   22篇
社会与环境   3篇
灾害及防治   1篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2018年   1篇
  2017年   3篇
  2016年   9篇
  2015年   8篇
  2014年   6篇
  2013年   8篇
  2012年   8篇
  2011年   11篇
  2010年   6篇
  2009年   8篇
  2008年   2篇
  2007年   9篇
  2006年   7篇
  2005年   5篇
  2004年   3篇
  2003年   2篇
  2002年   3篇
  2000年   1篇
  1995年   1篇
  1994年   1篇
  1992年   2篇
  1990年   1篇
  1976年   1篇
  1954年   1篇
  1934年   1篇
排序方式: 共有114条查询结果,搜索用时 15 毫秒
91.
The effects of air pollution on lichen biodiversity (LB) were monitored in Liguria (northwest Italy). A systematic sampling strategy was adopted in order to avoid the influence of spatial autocorrelation on the results. An eight LB class scale permitted to point out the levels of naturality/alteration in the region. The comparison of these results with the ones obtained by mean of physico-chemical methodologies shows a good accordance. The results of this study suggest the possibility of designing an integrated monitoring network, in which biological monitoring will allow to estimate the level of alteration in remote areas, which account for most of this region and which are currently not covered by measurements with automatic systems.  相似文献   
92.
A totally protected di-O-benzyl derivative of triacetonlactose dimethyl acetal was transformed into a 4'-hexeno disaccharide by elimination of acetone with t-BuOK in DMF and subsequently in 5'-C-methoxy derivative by oxidation with MCPBA in methanol as a solvent. The hydrolysis of this latter compound affords 2,6-di-O-benzyl-L-arabino-aldohexosos-5-ulose, which by intramolecular aldol condensation with DBU gives an inosose that was stereoselectively reduced to epi-inositol. Therefore our synthetic strategy offers a new and simple method to transform lactose into carbocyclic monosaccharide analogues.  相似文献   
93.
This study assessed coastal erosion vulnerability along a 90-km sector, which included both erosional and accretionary beaches, and different levels of human occupation. Two aerial photogrammetric flights were used to reconstruct coastal evolution between 1977 and 1999. During this period, extensive accretion was recorded updrift of human structures at harbors and ports, e.g., Scoglitti (105.6 m), Donnalucata (52.8 m), and Pozzallo (94.6 m). Conversely, erosion was recorded in downdrift areas, with maximum values at Modica Stream mouth (63.8 m) and Point Castellazzo (35.2 m). Assessments were subsequently divided into four categories ranging from “high erosion” to “accretion.” Several sources were examined to assess human activities and land use. The latter was mapped and divided into four categories, ranging from “very high” to “no capital” land use. Subsequently, coastal erosion vulnerability was assessed by combining land use categories with recorded coastline behavior. Results showed “very high” to “high” vulnerability along 5.8% and 16.6%, respectively, of the littoral, while 20.9% and 56.7%, respectively, was found to exhibit “medium” and “low/very low” vulnerability. A very good agreement between predicted coastal vulnerability and coastal trend had been observed over recent years. Furthermore, several human structures and activities are located within the “imminent collapse zone (ICZ)” which reached maximum values of 17.5 m at Modica Stream and 13.5 m at Point Braccetto.  相似文献   
94.
This paper presents the results of an intensive monitoring activity of the particulate, fall-out and soil of selected living areas in Italy with the aim to detect the asbestos concentration in air and subsequent risk of exposure for the population in ambient living environments, and to assess the nature of the other mineral phases composing the particulate matrix. Some areas were sorted out because of the presence of asbestos containing materials on site whereas others were used as blank spots in the attempt to detect the background environmental concentration of asbestos in air. Because the concentration of asbestos in ambient environments is presumably very low, and it is well known that conventional low–medium flow sampling systems with filters of small diameter (25 mm) may collect only a very small fraction of particulate over a short period, for the first time here, an intense monitoring activity was conducted with a high flow sampling system. The high flow system requires the use of large cellulose filters with the advantage that, increasing the amount of collected dust, the probability to collect asbestos fibers increases. Both the protocol of monitoring and analysis are novel and prompted by the need to increase the sensitivity towards the small number of expected fibers. With this goal, the collection of fall-out samples (the particulate falling into a collector filled with distilled water during the monitoring shift) and soil samples was also accomplished. The analytical protocol of the matrix particulate included preliminary X-ray powder diffraction (XRPD), optical microscopy and quantitative electron microscopy (SEM and TEM). Correlations with climatic trends and PM10 concentration data were also attempted.The surprising outcome of this work is that, despite the nature of the investigated site, the amount of dispersed asbestos fibers is very low and invariably lower than the theoretical method detection limits of the SEM and TEM techniques for identification and counting of asbestos fibers. The results are compared to the literature data worldwide and an updated model for asbestos fibers dispersion in ambient environments is proposed.  相似文献   
95.
A novel multivariate method based on principal component analysis of pre-processed sections of chromatograms is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil. Five distinct sources of 3- to 6-ring PAHs could be revealed. The harbour is the most contaminated site in the bay, its plume stretches in a South West to North East direction and the chemical profile indicates mainly pyrogenic sources mixed with a fraction of high-molecular-weight petrogenic PAHs. Rio São João de Meriti is the second largest source of PAHs, and introduces mainly a fraction of low-molecular-weight petrogenic PAHs from the western region of Rio de Janeiro. The sites close to the ruptured pipeline at the Duque de Caxias Refinery show a distinctive pollution pattern indicating a heavy petroleum fraction. The method also led to the identification of new potential indicator ratios also involving coeluting peaks (e.g., triphenylene and chrysene).  相似文献   
96.
Among the compounds discussed for anti-microbial and anti-fungal use allicin (allylthiosulfinate, diallyl disulfide-S-monoxide), an active ingredient of garlic, has attracted considerable attention. The objective of this study is to determine the antifungal activity of a local garlic ecotype (Voghiera) extracts against different pathogens. Primary screening was carried out by the agar plates technique using ethanol garlic extract at four final concentrations against the following organisms: Alternaria alternata, Aspergillus spp., Colletotrichum acutatum, Didymella bryoniae, Fusarium culmorum, Fusarium avenaceum, Fusarium gramineareum, Gliocladium roseum 47, Pythium splendens, Rhizoctonia solani, Sclerotium rolfsii, Stemphylium vesicarium, Trichoderma longibranchiatum, and Botrytis cinerea. Secondary screening was carried out using a lyophilized and a spray-dried preparation at different concentrations against the organisms selected for the high inhibition garlic effect in the primary screening and compared with the commercial fungicides mancozeb and iprodione. The best results were observed for the spray-dried garlic compound that showed a good fungicidal activity at the concentration of 1.5 g/10 mL while lyophilized garlic at the same concentration exhibited less inhibition activity against the four fungi analyzed in the second screening.  相似文献   
97.
ABSTRACT

Abandoned industrial sites and mines may constitute possible hazards for surrounding environment due to the presence of toxic compounds that may contaminate soils and waters. The possibility to remove metal contaminants, specifically nickel (Ni), by means of fungi was presented exploiting a set of fungal strains isolated from a Ligurian dismissed mine. The achieved results demonstrate the high Ni(II) tolerance, up to 500 mg Ni l?1, and removal capability of a Trichoderma harzianum strain. This latter hyperaccumulates up to 11,000 mg Ni kg?1, suggesting its possible use in a bioremediation protocol able to provide a sustainable reclamation of broad contaminated areas.  相似文献   
98.
Remediation actions at contaminated sites are based on multiple numerical model scenarios considering different parameter distributions, source positions and contaminant transport paths. In some cases the excess of scenarios is due to uncertainties in the conceptual model as a result of the spread of contamination through heterogeneities in the physical system. Reduction of project hypotheses and conceptual model uncertainty is therefore needed. This result can be achieved by coupling hydrogeological investigations with environmental forensic techniques, better localization of the source and understanding of contamination history. In this respect, in the present study, compositional fingerprinting and groundwater flow modeling were applied to a former oil storage facility where, even though a hydraulic barrier had been built to stop the hydrocarbon plume, the presence of some hydrocarbons was still found in downgradient monitoring wells. The final aim was to evaluate the efficacy of the hydraulic barrier and identify of the source of pollution. Fingerprinting results indicated pollution with a gasoline-diesel mixture much altered by water washing and/or biodegradation. Comparison of seven groundwater samples collected in wells and monitoring wells was performed by analyzing the volatile fraction (BTEX) and the total ion chromatogram (TIC), focusing attention on: n-alkanes (m/z 85), alkylcyclohexanes (m/z 83), isoprenoids (m/z 113), C4-alkylbenzenes (m/z 134), C3-C6 alkylbenzenes and polycyclic aromatic hydrocarbons (PAHs). The most probable scenario was then identified by combining the results of fingerprinting with different contaminant paths obtained using the numerical model.  相似文献   
99.

Supported Fe2O3/WO3 nanocomposites were fabricated by an original vapor phase approach, involving the chemical vapor deposition (CVD) of Fe2O3 on Ti sheets and the subsequent radio frequency (RF)-sputtering of WO3. Particular attention was dedicated to the control of the W/Fe ratio, in order to tailor the composition of the resulting materials. The target systems were analyzed by the joint use of complementary techniques, that is, X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDXS), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and optical absorption spectroscopy. The results showed the uniform decoration of α-Fe2O3 (hematite) globular particles by tiny WO3 aggregates, whose content could be controlled by modulations of the sole sputtering time. The photocatalytic degradation of phenol in the liquid phase was selected as a test reaction for a preliminary investigation of the system behavior in wastewater treatment applications. The system activity under both UV and Vis light illumination may open doors for further material optimization in view of real-world end-uses.

  相似文献   
100.
Health sector recovery in post‐conflict settings presents an opportunity for reform: analysis of policy processes can provide useful lessons. 1 The case of southern Sudan is assessed through interviews, a literature review, and by drawing on the experience of former technical advisers to the Ministry of Health. In the immediate post‐conflict phase, the health system in southern Sudan was characterised by fragmentation, low coverage of health services, dismal health outcomes and limited government capacity. Health policy was extensively shaped by the interplay of context, actors and processes: the World Bank and the World Health Organization became the primary drivers of policy change. Lessons learned from the southern Sudan case include the need for: sustained investment in assessment and planning of recovery activities; building of procurement capacity early in the recovery process; support for funding instruments that can disburse resources rapidly; and streamlining the governance structures and procedures adopted by health recovery financing mechanisms and adapting them to the local context.  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