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   255篇
  免费   1篇
安全科学   7篇
废物处理   16篇
环保管理   28篇
综合类   61篇
基础理论   36篇
污染及防治   70篇
评价与监测   24篇
社会与环境   12篇
灾害及防治   2篇
  2023年   3篇
  2022年   6篇
  2021年   5篇
  2020年   4篇
  2019年   5篇
  2018年   8篇
  2017年   13篇
  2016年   15篇
  2015年   12篇
  2014年   17篇
  2013年   21篇
  2012年   21篇
  2011年   17篇
  2010年   7篇
  2009年   13篇
  2008年   8篇
  2007年   10篇
  2006年   10篇
  2005年   10篇
  2004年   13篇
  2003年   6篇
  2002年   6篇
  2001年   1篇
  2000年   1篇
  1997年   3篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   2篇
  1990年   3篇
  1989年   1篇
  1986年   1篇
  1984年   1篇
  1961年   1篇
  1958年   1篇
  1943年   1篇
  1941年   1篇
  1938年   1篇
排序方式: 共有256条查询结果,搜索用时 15 毫秒
111.
Environmental issues related to swine production are still a major concern for the general public and represent a key challenge for the swine industry. The environmental impact of higher livestock concentration is particularly significant where it coincides with weaker policy standards and poor manure management. Effective tools for environmental monitoring of the swine sewage management process become essential for verifying the environmental compatibility of farming facilities and for defining suitable policies aimed at increasing swine production sustainability. This research aims at the development and application of a model for a quick assessment of the environmental effectiveness of the pig farming sewage management process. In order to define the model, multicriteria techniques, and in particular, Saaty’s analytic hierarchy process, were used to develop an iterative process in which the various key factors influencing the process under investigation were analyzed. The model, named EASE (Environmental Assessment of Sewages management Effectiveness), was optimized and applied to the Lake Trasimeno basin (Umbria, Italy), an area of high natural, environmental and aesthetic value. In this context, inadequate disposal of pig sewage represents a potential source of very considerable pollution. The results have demonstrated how the multicriteria model can represent a very effective and adaptable tool also in those decision-making processes aimed at the sustainable management of livestock production.  相似文献   
112.
Environmental Science and Pollution Research - Atmospheric pollutants, such as NOx, SO2, and particulate matter, together with water percolation inside the stone pores, represent the main causes of...  相似文献   
113.
ABSTRACT: The analysis of the sea depth in the vicinity of a thermal power plant is important in view of the heat dispersion and transport of the cooling water discharged from the energy production processes. The bathymetry of the Tyrrhenian Sea in the area facing the thermoelectric plant being built at Montalto di Castro, Italy, is reconstructed with the aid of the kriging technique. The large number of measurements (2038) precludes the use of a global interpolation model. At the same time, the steepness of the variogram suggests that the stochastic process is likely non-stationary. The latter problem is managed by detrending the observed records with a fourth-order polynomial drift determined with the least squares method. The global approach is replaced with local models with an influence radius of 70 m and a minimal number of interpolation records equal to 10. The detrended residuals appear to be second-order stationary having an isotropic vaniogram that is fitted equally well by a linear or a spherical function. The average size of the local interpolation models is 28, which ensures a high cemputational efficiency. The bathymetry of the sea area of interest is then reconstructed over a regular grid with a total of 3570 nodes. The estimation standard deviation maps show that the accuracy of the prediction is even greater than the prescribed tolerance (= 0.2 m) and indicate that future data collection campaigns require a less dense and, therefore, less expensive recording network. The redundant measurement profiles are identified. Their elimination still allows for bathymetry estimates affected by interpolation errors that fall within the project specifications.  相似文献   
114.
To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2–3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.  相似文献   
115.
Dichlorodiphenyltrichloroethane (DDT) is still used in Africa for the indoor control of malaria and it may represent a potential hazard for wildlife. The littoral sediments of two alkaline-saline lakes, Natron (Tanzania) and Bogoria (Kenya), in the Eastern Rift Valley, supporting large populations of lesser flamingos (Phoeniconaias minor), were analysed for DDT residues. Physical–chemical analyses (temperature, conductivity, pH and dissolved oxygen) were also performed on the water of the two lakes and in the tributaries of Lake Natron, to evaluate the influence of the environmental variables on pollutant occurrence. At Lake Natron, around 1 km from the sediment collection sites, tree leaves of Acacia tortilis were also collected. The main metabolite found in all sediment samples was pp’DDE, whilst equal concentrations of pp’DDT and pp’DDE were measured in acacia leaves. The levels of DDTs measured in the sediments were within 5.9–30.9 ng g−1 d.w., reaching the maximum value in a tributary of Lake Natron. On the whole, the contamination of Lake Natron and Lake Bogoria basins seems to be quite moderate. Nevertheless, the pp’DDE/pp’DDT ratio equals 1 in the Acacia tortilis leaves, which makes one suppose that the input of the parent compound was rather recent and could have been from aerial transport or dust from relatively close-by old pesticides storage sites.  相似文献   
116.
Abstract

In this study, we used two biochars (BC) produced from grapevine pruning residues (BCgv) and red spruce wood (BCrs), two hydrochars (HC) from urban pruning residues (HCup) and the organic fraction of municipal solid wastes (HCuw), and two vermicomposts (VC) obtained vermicomposting digestates from buffalo manure (VCbm) and mixed feedstock (VCmf). Adsorption kinetics and isotherms of metribuzin onto these materials were performed. Sorption kinetics followed preferentially a pseudo-second-order model, thus indicating the occurrence of chemical interactions between the sorbate and the adsorbents. Adsorption constants were calculated using the Freundlich and Langmuir models. Metribuzin sorption data on BCgv and both HC fitted preferentially the Freundlich equation, whereas on the other materials data fitted both isotherms well (r?>?0.95). Metribuzin sorption capacity of the materials followed the trend BC?>?HC?>?VC. Sorption constants of metribuzin normalised per organic carbon content (KOC) on BCgv, BCrs, HCup, HCuw, VCbm and VCmf were 561, 383, 251, 214, 102 and 84?L kg?1, respectively. A significant positive correlation (P?=?0.016) was calculated between distribution coefficients (Kd) of all materials and the corresponding organic carbon contents, thus indicating a prominent role of the organic fraction of these materials in the adsorption of metribuzin.  相似文献   
117.
Packaging is strictly connected to environmental issues as it is a product characterised by high material consumption rate; it is often transported over long distances and has a short life. Providing environmental analysis is, therefore, urgent to identify energy and resources efficient solutions. The paper, taking advantage of a real case study, presents a life cycle-based comparative analysis among three different food packaging systems. The paper compares the life cycle of tin steel, polypropylene and glass-based packaging of an Italian preserves producer. The analysis leads to the conclusion that, for the baseline scenario, polypropylene packaging represents the greenest solution, whereas glass packaging is the worst choice. The paper presents a scenario analysis varying both the method used for accounting for recycling as well as the recycling rates of the packaging materials. Changes in overall results with parameters analysis changing are calculated and highlighted throughout the paper. The impact of a reuse policy of the glass-based solution is also analysed; a model for disposable glass packaging is proposed and the obtained results are compared with the single use polypropylene and tin steel-based packaging. In order to analyse the impact of different End of Life scenarios on the present case study, collecting as well as recycling rates of some European countries have been used. The results revealed a significant fluctuation both in energy consumption and in CO2 emission as the nation changes. Summing up, a methodology for packaging environmental impact analysis is applied to a real case study, some crucial aspects of the methodology have been analysed in depth in order to give a contribution in packaging environmental impact analysis.  相似文献   
118.
In the present study the concentrations of cobalt, copper, iron, manganese, zinc were analysed and the speciation of copper and zinc performed, with a summer and winter sampling, for two areas in the Northern Adriatic Sea and crossing at the farthest zones of the Po river-sea water interface. Results show that when salinity increases the concentrations of all investigated metals (with the exception of cobalt) present some degree of biogeochemical cycling. Copper is the element whose dissolved phase has the highest importance in metal transport across the salinity gradient. Results of speciation analysis demonstrate that the presence of excess amounts (5-8 fold) of unbound ligands confers a buffering capacity for potential inputs of dissolved metals into the Northern Adriatic Sea. The speciation of both copper and zinc in the dissolved phase was dominated by organic complexation.  相似文献   
119.
Batch sorption experiments using a starch-based sorbent were carried out for the removal of heavy metals present in industrial water discharges. The influence of contact time, mass of sorbent and pollutant load was investigated. Pollutant removal was dependent on the mass of sorbent and contact time, but independent of the contaminant load. The process was uniform, rapid and efficient. Sorption reached equilibrium in 60 min irrespective of the metal considered (e.g. Zn, Pb, Cu, Ni, Fe and Cd), reducing concentrations below those permitted by law. The material also removed residual turbidity and led to a significant decrease in the residual chemical oxygen demand (COD) present in the industrial water discharge. The germination success of lettuce (Lactuca sativa) was used as a laboratory indicator of phytotoxicity. The results show that the sorption using a starch-based sorbent as non-conventional material, is a viable alternative for treating industrial wastewaters.  相似文献   
120.
The aim of this paper is to assess, through an empirical investigation, whether the performance of safety management systems (SMSs) adopting and non-adopting companies statistically differ. To achieve such aim, empirical data were collected on a sample of 116 companies, encompassing both SMSs adopters and non-adopters. Hypotheses testing was performed to assess whether SMSs adopters experience significantly higher performance against (i) definition of safety and security goals and their communication to employees; (ii) risk data updating and risk analysis; (iii) identification of risks and definition of corrective actions; (iv) employees training. Results show that companies adopting SMSs exhibit higher performance against all the topics identified. These outcomes could be the starting point for providing empirical evidence of benefits achievable thanks to SMSs implementation.  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