全文获取类型
收费全文 | 16430篇 |
免费 | 177篇 |
国内免费 | 137篇 |
专业分类
安全科学 | 455篇 |
废物处理 | 627篇 |
环保管理 | 2298篇 |
综合类 | 2587篇 |
基础理论 | 4490篇 |
环境理论 | 5篇 |
污染及防治 | 4309篇 |
评价与监测 | 1006篇 |
社会与环境 | 860篇 |
灾害及防治 | 107篇 |
出版年
2022年 | 112篇 |
2021年 | 133篇 |
2020年 | 108篇 |
2019年 | 151篇 |
2018年 | 229篇 |
2017年 | 230篇 |
2016年 | 364篇 |
2015年 | 243篇 |
2014年 | 364篇 |
2013年 | 1267篇 |
2012年 | 447篇 |
2011年 | 638篇 |
2010年 | 543篇 |
2009年 | 523篇 |
2008年 | 693篇 |
2007年 | 699篇 |
2006年 | 661篇 |
2005年 | 506篇 |
2004年 | 588篇 |
2003年 | 521篇 |
2002年 | 483篇 |
2001年 | 703篇 |
2000年 | 471篇 |
1999年 | 282篇 |
1998年 | 241篇 |
1997年 | 217篇 |
1996年 | 227篇 |
1995年 | 247篇 |
1994年 | 271篇 |
1993年 | 219篇 |
1992年 | 247篇 |
1991年 | 222篇 |
1990年 | 254篇 |
1989年 | 238篇 |
1988年 | 193篇 |
1987年 | 173篇 |
1986年 | 159篇 |
1985年 | 168篇 |
1984年 | 192篇 |
1983年 | 180篇 |
1982年 | 185篇 |
1981年 | 179篇 |
1980年 | 137篇 |
1979年 | 153篇 |
1978年 | 131篇 |
1977年 | 117篇 |
1975年 | 118篇 |
1974年 | 115篇 |
1973年 | 111篇 |
1972年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
911.
Analysis of the concentrations of chemical elements and the composition of diatoms in the surface layer of bottom sediments has been performed in a small reservoir at the mouth of dammed river to evaluate the levels of pollution and the impact of toxicants on diatom communities of the river ecosystem. Data on interrelations between the concentrations of chemical elements and the relationship between inorganic pollution and accumulation of diatoms in bottom sediments as an indicator of development of the diatom assemblage have been obtained using linear correlation analysis and graphical plotting. 相似文献
912.
I. A. Prokop’ev G. V. Filippova A. A. Shein D. V. Gabyshev 《Russian Journal of Ecology》2014,45(1):18-23
It has been shown that the growth of technogenic dust pollution is accompanied by the accumulation of heavy metals in soil and plant phytomass, compared to the control, and that the morphometric and reproductive characteristics of Matricaria chamomila are most sensitive to the impact of these pollutants. The response of plants is manifested in increased variation in morphological characters, mobilization of compensatory protective biochemical mechanisms, and production of more viable seed progeny. 相似文献
913.
Yu. I. Novitskii G. V. Novitskaya D. R. Molokanov Yu. A. Serdyukov 《Russian Journal of Ecology》2014,45(3):201-208
Experiments have been performed to evaluate the impact of weak permanent horizontal magnetic field of about 400 A/m on seed formation in the main magnetic orientation types of radish, the north-south (NS) and west-east (WE) types. The results show that external magnetic field exposure retards plant progression through all stages of ontogeny but does not alter the ratio of NS and WE types. Under its effect, the numbers of pods and seeds and seed weight decrease in the NS-type but increase in the WS-type plants. Therefore, external magnetic field acts as an ecological factor that differentiates the responses of radish plants depending on the type of their magnetic orientation. Differences in the sensitivity of plants to magnetic field exposure are explained by specific features of their physiological status. 相似文献
914.
Déborah LeCorre Catharina Hohenthal Alain Dufresne Julien Bras 《Journal of Polymers and the Environment》2013,21(1):71-80
Fossil energy depletion and growing environmental concerns have brought up increasing interest in bio-based eco-efficient and high technology materials. Among them, starch nanocrystals (SNC) consist of crystalline nano-platelets produced from the hydrolysis of starch and mainly used as nano-fillers in polymeric matrix. New applications have brought up the need for scaling-up the SNC preparation process. However, for this new bio-based nano-material to be sustainable, its preparation and processing should have limited impacts on the environment. Thus, together with analyzing and making recommendations for the scaling-up of SNC production process, it is worth identifying “environmentally sensitive” steps using life cycle analysis (LCA). To that purpose, different scenarios have been proposed and compared according to different environmental impacts. Also, a comparison to its main competitor, i.e. organically modified nanoclay (OMMT), is proposed. From a LCA point of view, SNC preparation requires less energy than OMMT extraction, but global warming and acidification indicators were higher than for OMMT. However, SNC have the added advantages to be renewable and biodegradable contrary to OMMT which contribute to non-renewable energy and mineral depletion. Thus, used as filler, SNC have a positive impact on the end of life of the filled material. From these observations, recommendations for the scaling-up of the SNC preparation process are made and deal mainly with the use of land and water. 相似文献
915.
M. Ahmad Seyedabbasi Poonam R. Kulkarni James M. McDade Charles J. Newell Deepa Gandhi John D. Gallinatti Virgilio Cocianni DúBois J. Ferguson 《补救:环境净化治理成本、技术与工艺杂志》2013,23(2):93-109
The data mining/groundwater modeling methodology developed in McDade et al. (2013) was performed to determine if matrix diffusion is a plausible explanation for the lower‐concentration but persistent chlorinated solvent plumes in the groundwater‐bearing units at three different pump‐and‐treat systems. Capture‐zone maps were evaluated, and eight wells were identified that did not draw water from any of the historical source areas but captured water from the sides of the plume. Two groundwater models were applied to study the persistence of the plumes in the absence of contributions from the historical source zones. In the wells modeled, the observed mass discharge generally decreased by about one order of magnitude or less over 4 to 10 years of pumping, and 1.8 to 17 pore volumes were extracted. In five of the eight wells, the matrix diffusion model fit the data much better than the advection dispersion retardation model, indicating that matrix diffusion better explains the persistent plume. In the three other wells, confounding factors, such as a changing capture zone over time (caused by changes in pumping rates in adjacent extraction wells); potential interference from a high‐concentration unremediated source zone; and limited number of pore volumes removed made it difficult to confirm that matrix diffusion processes were active in these areas. Overall, the results from the five wells indicate that mass discharge rates from the pumping wells will continue to show a characteristic “long tail'' of mass removal from zones affected by active matrix diffusion processes. Future site management activities should include matrix diffusion processes in the conceptual site models for these three sites. © 2013 Wiley Periodicals, Inc. 相似文献
916.
F. Sarasini D. Puglia E. Fortunati J. M. Kenny C. Santulli 《Journal of Polymers and the Environment》2013,21(3):881-891
In the present study, Phormium Tenax fiber reinforced PLA composites were processed by injection molding and twin screw compounding with a fiber content ranging from 10 to 30 wt%. Three surface treatment methods have been used to improve the Phormium Tenax fiber-matrix interfacial bonding that are as follows: (1) aqueous alkaline solution, (2) silane coupling agent, and (3) a combination of alkaline and silane treatment. The mechanical, thermal and morphological properties of the resulting composites were investigated. The results have shown that the moduli of surface treated fiber reinforced composites are lower than the ones obtained for untreated composites (as a consequence of the decrease in fiber modulus caused by the chemical treatments) and no significant increase in strength was observed for any of the composites compared to neat PLA. SEM micrographs of composite fractured surfaces confirmed an improvement in the interfacial strength, which was insufficient nonetheless to significantly enhance the mechanical behavior of the resulting composites. Results from thermogravimetric analysis and differential scanning calorimetry suggest that surface treatment of Phormium affects the ability of PLA to cold crystallize, and the thermal stability of the composites at the different fiber contents was reduced with introduction of alkali and silane treated Phormium fibers. 相似文献
917.
D. Balla A. Papageorgiou D. Voutsa 《Environmental science and pollution research international》2014,21(20):12062-12073
This study investigates the occurrence of carbonyl compounds in rainwater at the city of Thessaloniki, Northern Greece. The concentrations of carbonyl compounds (as sum of 14 compounds) ranged from 21.8 to 592 μg/L, mean concentration 119 μg/L. Formaldehyde, acetaldehyde, hexanal, glyoxal, and methylglyoxal were the dominant compounds. DOC concentrations in rainwater ranged from 0.46 to 21.3 mg/L. UV–Vis and fluorescence spectra characteristics showed variation among rain events. Carbonyl compounds were negatively correlated with temperature exhibited relatively higher concentrations in cold season. They also influenced by storm origin with higher concentrations under terrestrial air masses. Calm conditions enhance the concentrations of DOC. Wash out is an effective removal mechanism of DOC. 相似文献
918.
Amvrossios C. Bagtzoglou Eric D. Kenney April Hiscox David R. Miller 《Environmental Forensics》2014,15(2):147-158
This work applies optimization and an Eulerian inversion approach presented by Bagtzoglou and Baun in 2005 in order to reconstruct contaminant plume time histories and to identify the likely source of atmospheric contamination using data from a real test site for the first time. Present-day distribution of an atmospheric contaminant plume as well as data points reflecting the plume history allow the reconstruction and provide the plume velocity, distribution, and probable source. The method was tested to a hypothetical case and with data from the Forest Atmosphere Transfer and Storage (FACTS) experiment in the Duke experimental forest site. In the scenarios presented herein, as well as in numerous cases tested for verification purposes, the model conserved mass, successfully located the peak of the plume, and managed to capture the motion of the plume well but underestimated the contaminant peak. 相似文献
919.
Lance D. Yarbrough 《Environmental Forensics》2014,15(3):244-255
The consequences of erosion and subsequent sedimentation of lakes and streams are many and widespread. The natural process of erosion can be accelerated by land cover changes with an increase in areas of impervious surfaces. Sediment is continually being transported along all streams in nature and can come from anywhere in the watershed. Lakes slow the rate of velocity of the water and allow the entrained sediment to settle and accumulate. When sediment impacts water impoundments, legal actions may result. Even with evidence of specific sediment release, the forensic analysis may not be an open-and-shut case. The author presents a method to investigate the validity of a legal claim of a sediment-impacted lake at the outfall of a mixed rural/urban watershed. By combining land use change, soils, elevation and precipitation data, a maximum possible annual sediment loss was approximately 154 tonne per hectare (15.4 kg/m2). Lacking evidence of specific historic events of erosion and subsequent sedimentation, this method provides an equitable means of determining compensatory damages. Using aerial and satellite imagery provided historical evidence of land cover change and examples of significant erosion in the watershed and not named in the lawsuit. The focus of the litigation started with the property adjoining the effected lake. The analysis provides a method to investigate erosion and subsequent sedimentation claims at a watershed-scale. 相似文献
920.
Thomas M. Lewinsohn José Luiz Attayde Carlos Roberto Fonseca Gislene Ganade Leonardo Ré Jorge Johannes Kollmann Gerhard E. Overbeck Paulo Inácio Prado Valério D. Pillar Daniela Popp Pedro L. B. da Rocha Wesley Rodrigues Silva Annette Spiekermann Wolfgang W. Weisser 《Ambio》2015,44(2):154-162
Ecological science contributes to solving a broad range of environmental problems. However, lack of ecological literacy in practice often limits application of this knowledge. In this paper, we highlight a critical but often overlooked demand on ecological literacy: to enable professionals of various careers to apply scientific knowledge when faced with environmental problems. Current university courses on ecology often fail to persuade students that ecological science provides important tools for environmental problem solving. We propose problem-based learning to improve the understanding of ecological science and its usefulness for real-world environmental issues that professionals in careers as diverse as engineering, public health, architecture, social sciences, or management will address. Courses should set clear learning objectives for cognitive skills they expect students to acquire. Thus, professionals in different fields will be enabled to improve environmental decision-making processes and to participate effectively in multidisciplinary work groups charged with tackling environmental issues. 相似文献