全文获取类型
收费全文 | 2148篇 |
免费 | 94篇 |
国内免费 | 653篇 |
专业分类
安全科学 | 128篇 |
废物处理 | 138篇 |
环保管理 | 255篇 |
综合类 | 1012篇 |
基础理论 | 415篇 |
环境理论 | 2篇 |
污染及防治 | 650篇 |
评价与监测 | 109篇 |
社会与环境 | 69篇 |
灾害及防治 | 117篇 |
出版年
2023年 | 31篇 |
2022年 | 89篇 |
2021年 | 93篇 |
2020年 | 59篇 |
2019年 | 52篇 |
2018年 | 69篇 |
2017年 | 74篇 |
2016年 | 101篇 |
2015年 | 110篇 |
2014年 | 138篇 |
2013年 | 169篇 |
2012年 | 130篇 |
2011年 | 182篇 |
2010年 | 140篇 |
2009年 | 127篇 |
2008年 | 132篇 |
2007年 | 96篇 |
2006年 | 122篇 |
2005年 | 77篇 |
2004年 | 81篇 |
2003年 | 69篇 |
2002年 | 76篇 |
2001年 | 59篇 |
2000年 | 76篇 |
1999年 | 61篇 |
1998年 | 62篇 |
1997年 | 67篇 |
1996年 | 55篇 |
1995年 | 55篇 |
1994年 | 37篇 |
1993年 | 42篇 |
1992年 | 28篇 |
1991年 | 20篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 16篇 |
1987年 | 15篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 15篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1973年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有2895条查询结果,搜索用时 15 毫秒
81.
82.
83.
Ian D. Leith Lucy J. Sheppard David Fowler J. Neil Cape Matt Jones Alan Crossley Ken J. Hargreaves Y. Sim Tang Mark Theobald Mark R. Sutton 《Water, Air, & Soil Pollution: Focus》2005,4(6):207-218
Providing an accurate estimate of the dry component of N deposition to low N background, semi-natural habitats, such as bogs and upland moors dominated by Calluna vulgaris is difficult, but essential to relate nitrogen deposition to effects in these communities. To quantify the effects of NH3 inputs to moorland vegetation growing on a bog at a field scale, a field release NH3 fumigation system was established at Whim Moss (Scottish Borders) in 2002. Gaseous NH3 from a line source was released along of a 60 m transect, when meteorological conditions (wind speed >2.5 m s?1 and wind direction in the sector 180–215°) were met, thereby providing a profile of decreasing NH3 concentration with distance from the source. In a complementary study, using a NH3 flux chamber system, the relationships between NH3 concentrations and cuticular resistances were quantified for a range of NH3 concentrations and micrometeorological conditions for moorland vegetation. Cuticular resistances increased with NH3 concentration from 11 s m?1 at 3.0 μg m?3 to 30 s m?1 at 30 μg m?3. The NH3 concentration data and the concentration-dependent canopy resistance are used to calculate NH3 deposition taking into account leaf surface wetness. The implications of using an NH3 concentration-dependent cuticular resistance and the importance for refining critical loads are discussed. 相似文献
84.
85.
The Ethics of Constrained Choice: How the Industrialization of Agriculture Impacts Farming and Farmer Behavior 总被引:3,自引:0,他引:3
Mary?K.?HendricksonEmail author Harvey?S.?James 《Journal of Agricultural and Environmental Ethics》2005,18(3):269-291
The industrialization of agriculture not only alters the ways in which agricultural production occurs, but it also impacts the decisions farmers make in important ways. First, constraints created by the economic environment of farming limit what options a farmer has available to him. Second, because of the industrialization of agriculture and the resulting economic pressures it creates for farmers, the fact that decisions are constrained creates new ethical challenges for farmers. Having fewer options when faced with severe economic pressures is a very different situation for farmers than having many options available. We discuss the implications of constrained choice and show that it increases the likelihood that farmers will consider unethical behavior. 相似文献
86.
The challenges of sustainability in mining regions: The coal mining region of Santa Catarina, Brazil 总被引:1,自引:0,他引:1
Throughout history, mining communities have invariably found themselves striving for a good quality of life and a long‐term future. In the 21st century, problems of maintaining the economic vitality of mining regions are now compounded by concerns about the biophysical integrity of the local environment. In regions of the world where the economic viability of the resource is marginal and achieving a reasonable quality of life is a daily struggle, sustainable mining may seem to be a dubious prospect at best. Yet the twin imperatives of global political forces and burgeoning environmental concerns are requiring industry, governments and other interests to re‐conceptualize the way in which mining takes place in communities. Although mining itself may not be seen as an industry that contributes to the achievement of environmental objectives, it could — with careful planning — be used as a tool to foster a more sustainable and healthier community. This argument is considered in the context of the coal mining region of Santa Catarina, Brazil. 相似文献
87.
For (134/137)Cs, and many other soil contaminants, research into transfer to plants has focused on particular crops and phytoremediation candidates, producing uptake data for a small proportion of all plant taxa. Despite the significance of differences in uptake between plant taxa, the capacity of soil-to-plant transfer models to predict them is currently confined to those taxa for which data exist, there being no method to predict uptake by other taxa. We used residual maximum likelihood (REML) analysis on data from experiments (including 89 plant taxa from China plus 32 phytoremediation candidates) together with data from the literature, to construct a database of relative (134/137)Cs concentrations in 273 plant taxa. The REML (134/137)Cs concentrations in plants are not normally distributed but significantly clustered. Analysis of variance (ANOVA), coded with a recent ordinal phylogeny for flowering plants, showed that plant taxa do not behave independently for (134/137)Cs concentration because 42 and 15% of inter-taxa differences are associated with phylogeny above the species and ordinal level, respectively. In general, Eudicots, and especially the Caryophyllales, Asterales, and Brassicales, have high (134/137)Cs concentrations, while the Fabales and Magnoliids, in particular Poales, have low (134/137)Cs concentrations. Plants of the stress-tolerant ruderal (S-R) growth strategy sensu Grime have, in general, high concentrations of Cs, while those of the competitive (C) and generalist (C-S-R) strategies have low concentrations, although these effects are less pronounced than those of phylogeny. Plant phylogeny and growth strategy might thus be used to predict a significant portion of inter-taxa differences in plant uptake of (134/137)Cs. 相似文献
88.
Steven W. Effler Rakesh K. Gelda Mary Gail Perkins David M. O'Donnell 《Journal of the American Water Resources Association》2005,41(4):971-984
The development, testing, and application of a probabilistic model framework for the light attenuation coefficient for downwelling irradiance (Kd) and Secchi disc transparency (SD) that resolves the effects of several light attenuating constituents, including phytoplankton and nonliving particles (tripton), is documented. The model is consistent with optical theory, partitioning the magnitudes of the light attenuating processes of absorption and scattering according to the contributions of attenuating constituents as simple summations. The probabilistic framework accommodates variations in the character and concentrations of these constituents and ambient conditions during measurements, and recognizes a linear relationship between the magnitudes of absorption and scattering by tripton. The model is tested and applied for a 21 km reach of the Seneca River, New York, that features optical gradients caused by an intervening hypereutrophic lake and dam, and a severe infestation of the exotic zebra mussel. The model is applied to resolve the roles of phytoplankton and tripton in regulating measured longitudinal patterns of SD along the study reach of the river and increases in SD since the zebra mussel invasion, and to predict decreases in Kd since the invasion. 相似文献
89.
Mary B. Ogundiran Toyin Olujobi Oladele Osibanjo 《Journal of Material Cycles and Waste Management》2014,16(1):115-123
The consumption, disposal, material and chemical compositions of rechargeable electric torch wastes (RETWs) were investigated in Ibadan, Nigeria. Twenty-five RETWs of ten models were collected and disassembled. Their battery electrodes (BEs) and printed circuit boards (PCBs) were acid digested and leached using United States Environmental Protection Agency (USEPA) method 3050B and USEPA Method 1311, respectively. The digests and extracts were analysed for total and extractable Pb, Cd, Cr and Ni using atomic absorption spectrophotometer. The US Test method (CPSC-CH-E 1002-08) was used for digestion of the plastic components. Two hundred questionnaires were distributed to users in Ibadan to determine their usage of RETs and their management when spent. The results indicated that BEs contributed the highest percentage (44 %) component, followed by plastic (38 %). Other components include metal, PCBs, glass and wire. Of the respondents, 61.9 % dispose their spent torches in dumpsites. The mean ± SD concentrations of Pb, Cd, Cr and Ni in the BEs were 500 ± 109 g/kg, 3.94 ± 6.84 mg/kg, 0.33 ± 0.88 mg/kg, 1.68 ± 0.74 mg/kg respectively; in the PCBs, they were 684 ± 42 g/kg, 13.7 ± 17.8 mg/kg, 13.5 ± 10.2 mg/kg and 193 ± 437 mg/kg; and in the plastics, they were 14.1 g/kg, 5.33 mg/kg, 17 mg/kg, and 4.67 mg/kg respectively. The extractable Pb in BE (2670 mg/L) and PCBs (235 mg/L) exceeded the Toxicity Characteristics Leaching Procedure (TCLP) limit of 5 mg/L. RETWs present potential environmental problems in the absence of effective recycling. 相似文献
90.
Kang Huang He Zhang Chengliang Wang Rong Hou Pei Zhang Gang He Songtao Guo Shiyi Tang Baoguo Li Charles Oxnard Ruliang Pan 《Conservation biology》2021,35(6):1787-1796
A systematic understanding of dynamic animal extinction trajectories for different regions in a nation like China is critically important to developing practical conservation strategies. We explored historical and contemporary changes in terrestrial mammalian diversity to determine how diversity in each of the 5 regions in China has changed over time and to examine the conservation potential of these regions. We used records from databases on Pleistocene mammalian fossils and historical distribution records (1175–2020) for Primates (as a case study) to reconstruct evolutionary and historical distribution trajectories of the 11 orders of terrestrial mammals and to predict their prospective survival based on the national conservation strategy applied. The results indicated that since the Pleistocene, 4–5 mammalian orders have been lost in the northeast, 3 in central China, 2 along the coast, and 1 in the northwest. In the southwest, all 11 orders were maintained. Contemporarily, the coast and southwest had the highest and second-highest species densities. The southwest region and southeastern sections of the northwest region were the most historically and contemporarily diverse areas, which suggests that they should be the first priority for protected area (PA) designation. The central and coastal areas should be secondarily prioritized. In these 2 regions, conservation should focus on human coexistence with nature. Less attention should be paid to the PA in the northeast and western northwest because in these areas ecosystems are depauperate and the climate is harsh. Conservation in these areas should focus principally on avoiding further human encroachment on natural areas. Article impact statement: Historical and contemporary patterns of extinction can be a basis for mammalian conservation strategies. 相似文献