全文获取类型
收费全文 | 3171篇 |
免费 | 5篇 |
国内免费 | 35篇 |
专业分类
安全科学 | 69篇 |
废物处理 | 149篇 |
环保管理 | 327篇 |
综合类 | 405篇 |
基础理论 | 1160篇 |
污染及防治 | 671篇 |
评价与监测 | 233篇 |
社会与环境 | 197篇 |
出版年
2023年 | 7篇 |
2022年 | 17篇 |
2021年 | 21篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 128篇 |
2017年 | 126篇 |
2016年 | 210篇 |
2015年 | 65篇 |
2014年 | 39篇 |
2013年 | 50篇 |
2012年 | 440篇 |
2011年 | 235篇 |
2010年 | 40篇 |
2009年 | 37篇 |
2008年 | 64篇 |
2007年 | 81篇 |
2006年 | 74篇 |
2005年 | 398篇 |
2004年 | 532篇 |
2003年 | 406篇 |
2002年 | 45篇 |
2001年 | 44篇 |
2000年 | 21篇 |
1999年 | 33篇 |
1998年 | 4篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 3篇 |
1961年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有3211条查询结果,搜索用时 15 毫秒
991.
Raud M Tutt M Jõgi E Kikas T 《Environmental science and pollution research international》2011,19(7):3039-3045
Introduction
Two semi-specific microbial biosensors were constructed for the analysis of biochemical oxygen demand (BOD) in high-cellulose-content pulp and paper industry wastewaters. The biosensors were based on living cells of Bacillus subtilis and Paenibacillus sp. immobilized in an agarose gel matrix. Semi-specific microorganisms were isolated from various samples (decaying sawdust and rabbit manure) and were chosen based on their ability to assimilate cellulose.Materials &; methods
The biosensors were calibrated with the Organization for Economic Cooperation and Development synthetic wastewater, and measurements with different wastewaters were conducted.Results
The response time of biosensors using the steady-state method was 20?C25 min, and the service life of immobilized microorganisms was 96 days. Detection limit was 5 mg/l of BOD7 while linear ranges extended up to 55 and 50 mg/l of the BOD7 for B. subtilis- and Paenibacillus sp.-based biosensors, respectively. Repeatability and reproducibility of both biosensors were within the limits set by APHA??less than 15.4%. In comparison, both biosensors overestimated the BOD7 values in paper mill wastewaters and underestimated the BOD7 in aspen pulp mill wastewater.Conclusions
The semi-specific biosensors are suitable for the estimation of organic pollution derived from cellulose, while the detection of pollution derived from tannins and lignins was minor. Better results in terms of accuracy and repeatability were gained with Paenibacillus sp. biosensor. 相似文献992.
H Segner M Wenger AM Möller B Köllner A Casanova-Nakayama 《Environmental science and pollution research international》2011,19(7):2465-2476
Numerous environmental chemicals, both long-known toxicants such as persistent organic pollutants as well as emerging contaminants such as pharmaceuticals, are known to modulate immune parameters of wildlife species, what can have adverse consequences for the fitness of individuals including their capability to resist pathogen infections. Despite frequent field observations of impaired immunocompetence and increased disease incidence in contaminant-exposed wildlife populations, the potential relevance of immunotoxic effects for the ecological impact of chemicals is rarely considered in ecotoxicological risk assessment. A limiting factor in the assessment of immunotoxic effects might be the complexity of the immune system what makes it difficult (1) to select appropriate exposure and effect parameters out of the many immune parameters which could be measured, and (2) to evaluate the significance of the selected parameters for the overall fitness and immunocompetence of the organism. Here, we present - on the example of teleost fishes - a brief discussion of how to assess chemical impact on the immune system using parameters at different levels of complexity and integration: immune mediators, humoral immune effectors, cellular immune defenses, macroscopical and microscopical responses of lymphoid tissues and organs, and host resistance to pathogens. Importantly, adverse effects of chemicals on immunocompetence may be detectable only after immune system activation, e.g., after pathogen challenge, but not in the resting immune system of non-infected fish. Current limitations to further development and implementation of immunotoxicity assays and parameters in ecotoxicological risk assessment are not primarily due to technological constraints, but are related from insufficient knowledge of (1) possible modes of action in the immune system, (2) the importance of intra- and inter-species immune system variability for the response against chemical stressors, and (3) deficits in conceptual and mechanistic assessment of combination effects of chemicals and pathogens. 相似文献
993.
Rožič PŽ Dolenec T Baždarić B Karamarko V Kniewald G Dolenec M 《Environmental science and pollution research international》2011,19(7):2708-2721
Introduction and purpose
Studies examining the environmental impact of marine aquaculture have increased significantly in number during the last few decades. The present paper investigates a region of rapid growth in intensive aquaculture and its influence on the local marine ecosystem.Discussion
This study was undertaken with the specific aim of assessing the effect of fish farming on marine sediment at a farm near the island of Vrgada in the Central Adriatic. Data obtained regarding major (Si, Al, K, Na, Fe, Ca, Mg), minor (Mn, P, Ti) and trace (As, Au, Ba, Cd, Co, Cr, Cs, Cu, Ga, Hf, Hg, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Se, Sr, Ta, Th, Tl, U, V, Y, Zn, Zr) elements were used to estimate the spatial and temporal distribution of metals in the sediment and their possible relationship with local aquacultural activity.Results
Although the measured concentrations of heavy metals in sediment below fish cages were notably different and potentially a result of farming activity, the values were generally lower than background concentrations observed in the Central Adriatic. In contrast, concentrations of heavy metals at a reference site unaffected by aquaculture varied from lower levels to values even higher than those observed below the high-production cages. Furthermore, calculated environmental index values indicate that the sediment below the farm is either uncontaminated or suffers from only low levels of contamination.Conclusion
Such results suggest that the effect of observed fish farm activity on the local marine ecosystem is practically negligible. 相似文献994.
995.
Eduardo González María González-Sanchis Álvaro Cabezas Francisco A. Comín Etienne Muller 《Environmental management》2010,45(4):669-681
The structure of the floodplain forests of the Middle Ebro River (NE Spain) was examined at patch and landscape scales along
a three-step chronosequence defined according to the extent of flow regulation-induced hydrogeomorphic changes, with the ultimate
purpose of producing baseline information to guide through management and restoration plans. At patch scale, a total of 6,891
stems within 39 plots were registered for species, diameter and health status. The stem density, size class distribution,
canopy dieback and mortality were further compared by means of non-parametric tests. At landscape scale, the temporal evolution
of the area occupied by forest stands of different ages in the floodplain along the chronosequence was evaluated using four
sets of aerial photographs dated in 1927, 1957, 1981 and 2003. The within-patch structure of pioneer forests (<25–30 years old) was characterized by dense and healthy populations of pioneer species (Populus nigra, Salix alba and Tamarix spp.), but the area occupied by these forest types has progressively decreased (up to 37%) since the intensification of river
regulation (ca. 1957). In contrast, non-pioneer forests (>25–30 years old) were characterized by declining and sparse P. nigra–S. alba–Tamarix spp. stands, where late-seral species such as Ulmus minor and Fraxinus angustifolia were frequent, but only as small-size stems. At landscape scale, these type of senescent forests have doubled their surface
after river regulation was intensified. Populus alba only appeared in the oldest plots recorded (colonized before 1957), suggesting sexual regeneration failure during the last
five decades, but usually as healthy and dense stands. Based on these findings, measures principally aimed at recovering some
hydrogeomorphic dynamism are recommended to guarantee the self-sustainability of the floodplain forest ecosystem. 相似文献
996.
S. P. C. Gon?alves S. M. Martins-Franchetti 《Journal of Polymers and the Environment》2010,18(4):714-719
Poly(hydroxybutyrate-co-valerate) (PHBV) and poly(ε-caprolactone) (PCL) PCL/PHBV (4:1) blend films were prepared by melt-pressing.
The biodegradation of the films in response to burial in soil for 30 days was investigated by Fourier transform infrared spectroscopy
(FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetry (TG). The PHBV film
was the most susceptible to microbial attack, since it was rapidly biodegraded via surface erosion in 15 days and completely
degraded in 30 days. The PCL film also degraded but more slowly than PHBV. The degradation of the PCL/PHBV blend occurred
in the PHBV phase, inducing changes in the PCL phases (interphase) and resulting in an increase of its crystalline fraction. 相似文献
997.
We investigated lichen diversity in temperate oak forests using standardized protocols. Forty-eight sites were sampled in the Czech Republic, Slovakia and Hungary. The effects of natural environmental predictors and human influences on lichen diversity (lichen diversity value, species richness) were analysed by means of correlation tests. We found that lichen diversity responded differently to environmental predictors between two regions with different human impact. In the industrial region, air pollution was the strongest factor. In the agricultural to highly forested regions, lichen diversity was strongly influenced by forest age and forest fragmentation. We found that several natural factors can in some cases obscure the effect of human influences. Thus, factors of naturality gradient must be considered (both statistically and interpretively) when studying human impact on lichen diversity. 相似文献
998.
Patricia Zazeri Leite Tatiana Cristina Stefani Margarido Daína de Lima Denise de Cerqueira Rossa-Feres Eduardo Alves de Almeida 《Environmental science and pollution research international》2010,17(8):1411-1421
Purpose
Organophosphate pesticides (OPs) are among the most used insecticides in agriculture, causing the inhibition of esterases like acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and carboxylesterase (CbE). Pesticides can reach the aquatic environment, posing risks to non-target organisms, including tadpoles. 相似文献999.
Lara-Martín PA Gómez-Parra A González-Mazo E 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):36-45
Presence, distribution and transport mechanisms of the four major synthetic surfactants -linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES), nonylphenol ethoxylates (NPEOs) and alcohol ethoxylates (AEOs)- have been simultaneously studied in different aquatic ecosystems. Urban wastewater discharges and industrial activities were identified as the main sources for these compounds and their metabolites. LAS, AES and carboxylic metabolites remained in the dissolved form (87–99%). However, NPEOs and AEOs were mostly associated with particulate matter (65–86%), so their degradation in the water column was limited due to their lower bioavailability. It was also observed that sorption to the particulate phase was more intense for longer homologs/ethoxymers for all surfactants. With respect to surface sediments, AES levels were considerably below (<0.25 mg/kg) the values detected for LAS and NPEOs. Concentrations of AEOs, however, were occasionally higher (several tens of ppm) than those found for the rest of the target compounds in several sampling stations. 相似文献
1000.