全文获取类型
收费全文 | 472篇 |
免费 | 7篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 42篇 |
环保管理 | 45篇 |
综合类 | 44篇 |
基础理论 | 101篇 |
污染及防治 | 155篇 |
评价与监测 | 66篇 |
社会与环境 | 27篇 |
出版年
2023年 | 5篇 |
2022年 | 29篇 |
2021年 | 29篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 20篇 |
2017年 | 24篇 |
2016年 | 33篇 |
2015年 | 27篇 |
2014年 | 30篇 |
2013年 | 48篇 |
2012年 | 28篇 |
2011年 | 43篇 |
2010年 | 26篇 |
2009年 | 23篇 |
2008年 | 26篇 |
2007年 | 22篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有486条查询结果,搜索用时 15 毫秒
91.
X. L. Otero M. A. Huerta-Díaz S. De La Peña T. O. Ferreira 《Environmental monitoring and assessment》2013,185(10):7945-7959
Soil and sediment samples from several intertidal environment exposed to different types of contamination were studied to investigate the importance of grain size in relation to the capacity of the substrates to retain trace metals. The unfractionated samples (referred to as bulk samples) were separated into the following grain/size fractions: fine–coarse sand (2?0.100 mm), very fine sand (0.100?0.050 mm), silt (0.050?0.002 mm), and clay (0.002 mm). The sample into its fractions was carried out was in a glove box under high-purity N2 atmosphere in order to minimize any alterations to the samples. The bulk samples were characterized in terms of physicochemical properties such as pH, redox potential, and grain size. The total organic carbon (TOC), total sulfur (S), iron (Fe) pyrite, Fe, and manganese (Mn), and trace metals lead (Pb), mercury (Hg), chromium (Cr), and nickel (Ni) were analyzed in the bulk samples and in each fraction. The sand fractions were also examined by scanning electron microscopy (SEM). Comparisons of the above parameters were made between fractions and between each fraction and the corresponding bulk sample. The fine–coarse sand fraction contained high levels of the primary elements of the geochemical processes that occur in marine sedimentary environments such as TOC, total Fe, Mn, and S. The net concentrations of these four elements were higher in the fine-coarse sand fraction than in the very fine sand fraction and were similar to the net concentrations in the silt and clay fractions. Detailed SEM analysis of the sand coarse fraction revealed the presence of Fe and aluminum oxyhydroxide coatings in the oxic layers, whereas the framboidal pyrites and coatings observed in the anoxic layers were Fe sulfides. The presence of the various coatings explains why the trace metal concentrations in the sand fine–coarse fraction were similar to those in the clay fraction and higher than those in the very fine sand fraction. The present results highlight the importance of the sand fraction, which is generally disregarded in geochemical and environmental studies of sedimentary layers. 相似文献
92.
Silva Marcio Roberto Ferreira Fernando César Maranhão Adriana Gonçalves Lanzarini Natália Maria de Carvalho Castro Karina Neboo Miagostovich Marize Pereira 《Food and environmental virology》2021,13(4):528-534
Food and Environmental Virology - Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a... 相似文献
93.
José Fortes Lopes Ana Cristina Cardoso Maria Teresa Moita Alfredo C. Rocha Juan A. Ferreira 《Ecological modelling》2009
The main objective of this paper is to implement a coupled three-dimensional physical and ecological model for the Aveiro coast, and to apply it to study the temperature and the phytoplankton biomass spatial distributions along the coastal ecosystem. The Aveiro coast is located at Portugal within the upwelling system of the Atlantic Iberian coast, characterized by nutrients availability and phytoplankton biomass accumulation, from April to October. In order to implement the ecological model, its validation was assessed by comparing simulations to data relative to the horizontal and vertical distributions of the temperature, nutrients and phytoplankton biomass, obtained during the CICLOS I survey off the Portuguese coast [Moita, M.T., 2001. Estrutura, Variabilidade e Dinâmica do Fitoplâncton na Costa de Portugal Continental. PhD Thesis. Faculdade de Ciências da Universidade de Lisboa, 272 pp.]. A sensitivity analysis of the model has been performed in order to assess the influence of the main ecological model variables. The simulation results show that the model is capable of predicting realistic the temperature, the nutrients and the chlorophyll-a distributions for the study area. The scenarios evidence the setup of a thermal stratification pattern resulting from the upwelling of deep and rich in nutrients water to the surface layer and a chlorophyll-a maxima extending offshore, along the picnocline and the nutricline. The results confirm the crucial role played by the physical processes in the phytoplankton bloom along the Aveiro coast. They also evidence the close link between the surface phytoplankton distribution and the surface temperature distribution. 相似文献
94.
95.
Ferreira Felipe Silva Brito Samuel Vieira de Oliveira Almeida Waltécio Alves Rômulo Romeu Nóbrega 《Regional Environmental Change》2016,16(2):543-551
Regional Environmental Change - The use and trade of animals in traditional medicine involves many different species, some of which are threatened with extinction. Thus, evaluating biological and... 相似文献
96.
Collection and recycling of electronic scrap: a worldwide overview and comparison with the Brazilian situation 总被引:1,自引:0,他引:1
Recycling and the related issue of sustainable development are increasing in importance around the world. In Brazil, the new National Policy on Solid Wastes has prompted discussion on the future of electronic waste (e-waste). Over the last 10 years, different e-waste collection systems and recycling processes have been applied globally. This paper presents the systems used in different countries and compares the world situation to the current Brazilian reality. To establish a recycling process, it is necessary to organize efficient collection management. The main difficulty associated with the implementation of e-waste recycling processes in Brazil is the collection system, as its efficiency depends not only on the education and cooperation of the people but also on cooperation among industrial waste generators, distributors and the government. Over half a million waste pickers have been reported in Brazil and they are responsible for the success of metal scrap collection in the country. The country also has close to 2400 companies and cooperatives involved in recycling and scrap trading. On the other hand, the collection and recycling of e-waste is still incipient because e-wastes are not seen as valuable in the informal sector. The Brazilian challenge is therefore to organize a system of e-waste management including the informal sector without neglecting environmentally sound management principles. 相似文献
97.
Fumian Tulio Machado Ferreira Fernando César de Andrade Juliana da Silva Ribeiro Canal Natália Silva Gomes Gabriela Teixeira Lilian Borges Miagostovich Marize Pereira 《Food and environmental virology》2021,13(4):553-559
Food and Environmental Virology - Norovirus is a major cause of foodborne-associated acute gastroenteritis (AGE) outbreaks worldwide. Usually, food products are contaminated either during... 相似文献
98.
Elena Diaz-Almela Nuria Marbà Elvira Álvarez Elena Balestri Juan M. Ruiz-Fernández Carlos M. Duarte 《Marine Biology》2006,148(4):723-742
The intensive reconstructive sampling (1957–2004, 39 localities), a systematic direct observation (1992–2004, 1 locality)
and particular direct observations (66 localities) of Posidonia oceanica meadows were analysed together with temporal series of flowering available in the literature (19 localities). This allowed
the examination of temporal and spatial variability in annual flowering prevalence (FP, the fraction of meadows flowering
in a given year) and of annual meadow flowering intensity (FI, number of inflorescences per shoot) for the period 1979–2004
across the Western Mediterranean, as well as spatial variability of flowering frequency (FF, the fraction of years that a
given meadow has flowered) and shoot flowering probability (Pf, fraction of flowering stalks appeared per annual segment).
Each year, on an average 17% of the investigated meadows flowered, ranging from 3 to 86% of meadows among the years. The highest
annual FP and FI values were obtained in 2003 (FP=0.86 and mean FI=0.23±0.03 inflorescences shoot−1). A secondary peak of FP and mean FI occurred 9 years earlier, in 1994 (FP=0.44 and mean FI=0.08±0.02). Both peaks of flowering
occurred after hot summers. Flowering synchrony in particular years across the Western Mediterranean and clines of increased
meadow flowering frequency towards the North and East, suggests the existence of large-scale environmental mechanisms controlling
the floral induction. On the other hand, meadow FF and Pf were highly heterogeneous among and within the meadows, indicating
that local factors also may play a significant role in flowering induction. When flowering, the Western Mediterranean meadows
showed an average 0.11±0.02 inflorescences shoot−1, but FI greatly varied among and along the series (from 0.002 to 0.54 inflorescences shoot−1) and decreased significantly with depth but was independent of meadow shoot density and meadow latitude or longitude. The
shoot flowering probability was quite low (0.007±0.002 inflorescences shoot−1 year−1) and exponentially increased with shoot age. 相似文献
99.
Helton Nonato de Souza Ron G.M. de GoedeLijbert Brussaard Irene M. CardosoEdivania M.G. Duarte Raphael B.A. FernandesLucas C. Gomes Mirjam M. Pulleman 《Agriculture, ecosystems & environment》2012,146(1):179-196
Sustainable production and biodiversity conservation can be mutually supportive in providing multiple ecosystem services to farmers and society. This study aimed to determine the contribution of agroforestry systems, as tested by family farmers in the Brazilian Rainforest region since 1993, to tree biodiversity and evaluated farmers’ criteria for tree species selection. In addition, long-term effects on microclimatic temperature conditions for coffee production and chemical and biological soil characteristics at the field scale were compared to full-sun coffee systems. A floristic inventory of 8 agroforests and 4 reference forest sites identified 231 tree species in total. Seventy-eight percent of the tree species found in agroforests were native. The variation in species composition among agroforests contributed to a greater γ-diversity than α-diversity. Monthly average maximum temperatures were approximately 6 °C higher in full-sun coffee than in agroforests and forests. Total soil organic C, N mineralization and soil microbial activity were higher in forests than in coffee systems, whereas the chemical and biological soil quality in agroforests did not differ significantly from full-sun coffee after 13 years. Given its contribution to the conservation of biodiversity and its capacity to adapt coffee production to future climate change, coffee agroforestry offers a promising strategy for the area. 相似文献
100.
Previous studies in the Douro River estuary, based on occasional sampling, showed the presence of several estrogenic disrupting chemicals (EDCs). In sequence, we hypothesized that such type of pollution was more likely an enduring issue than an occasional phenomenon, and that it may even affect recreational beaches in each side of the estuarine mouth. Thus to conclude about the continuous influx of EDCs, water samples were taken twice a day, once per a week, from March to May of 2009, at four sites within the estuary and at two sites in the coastline. After solid-phase extraction, the extracts were prepared for GC-MS analysis of 11 reference EDCs. These embraced natural and pharmaceutical estrogens (17β-estradiol, estrone and 17α-ethynylestradiol) and xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol, and their mono and diethoxylates and bisphenol A). Data showed the ubiquitous presence of potentially hazardous amounts of natural estrogens (particularly of estradiol, ca 5.5?ng?L?1) and persistent organic pollutants such as nonylphenol mono (up to 550?ng?L?1) and diethoxylate (up to 2000?ng?L?1). It was concluded that the targeted area is continuously polluted by the assayed EDCs, and as a consequence, conditions exist for endocrine disturbance in the biota by chronic exposure to EDCs. 相似文献