全文获取类型
收费全文 | 107篇 |
免费 | 0篇 |
国内免费 | 3篇 |
专业分类
废物处理 | 8篇 |
环保管理 | 7篇 |
综合类 | 5篇 |
基础理论 | 23篇 |
污染及防治 | 42篇 |
评价与监测 | 15篇 |
社会与环境 | 10篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 9篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 6篇 |
2011年 | 3篇 |
2010年 | 9篇 |
2009年 | 8篇 |
2008年 | 3篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1994年 | 1篇 |
1989年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有110条查询结果,搜索用时 546 毫秒
1.
Determinants of Farmers’ Adoption of Improved Soil Conservation Technology in a Middle Mountain Watershed of Central Nepal 总被引:2,自引:0,他引:2
This study explores different socio-economic and institutional factors influencing the adoption of improved soil conservation technology (ISCT) on Bari land (Rainfed outward sloping terraces) in the Middle Mountain region of Central Nepal. Structured questionnaire survey and focus group discussion methods were applied to collect the necessary information from farm households. The logistic regression model predicted seven factors influencing the adoption of improved soil conservation technology in the study area including years of schooling of the household head, caste of the respondent, land holding size of the Bari land, cash crop vegetable farming, family member occupation in off farm sector, membership of the Conservation and Development Groups, and use of credit. The study showed that technology dissemination through multi-sectoral type community based local groups is a good option to enhance the adoption of improved soil conservation technology in the Middle Mountain farming systems in Nepal. Planners and policy makers should formulate appropriate policies and programs considering the farmers' interest, capacity, and limitation in promoting improved soil conservation technology for greater acceptance and adoption by the farmers. 相似文献
2.
A. K. Srivastava D. S. Bisht K. Ram S. Tiwari Manoj K. Srivastava 《Environmental science and pollution research international》2014,21(14):8610-8619
The mass concentration of carbonaceous species, organic carbon (OC), and elemental carbon (EC) using a semicontinuous thermo-optical EC-OC analyzer, and black carbon (BC) using an Aethalometer were measured simultaneously at an urban mega city Delhi in Ganga basin from January 2011 to May 2012. The concentrations of OC, EC, and BC exhibit seasonal variability, and their concentrations were ~2 times higher during winter (OC 38.1?±?17.9 μg m?3, EC 15.8?±?7.3 μg m?3, and BC 10.1?±?5.3 μg m?3) compared to those in summer (OC 14.1?±?4.3 μg m?3, EC 7.5?±?1.5 μg m?3, and BC 4.9?±?1.5 μg m?3). A significant correlation between OC and EC (R?=?0.95, n?=?232) indicate their common emission sources with relatively lower OC/EC ratio (range 1.0–3.6, mean 2.2?±?0.5) suggests fossil fuel emission as a major source of carbonaceous aerosols over the station. On average, mass concentration of EC was found to be ~38 % higher than BC during the study period. The measured absorption coefficient (babs) was significantly correlated with EC, suggesting EC as a major absorbing species in ambient aerosols at Delhi. Furthermore, the estimated mass absorption efficiency (σabs) values are similar during winter (5.0?±?1.5 m2 g?1) and summer (4.8?±?2.8 m2 g?1). Significantly high aerosol loading of carbonaceous species emphasize an urgent need to focus on air quality management and proper impact assessment on health perspective in these regions. 相似文献
3.
Sivaji Patra Manish Tiwari VishnuVardhan Kanuri Pradipta R. Muduli R. S. Robin 《Chemistry and Ecology》2017,33(8):708-724
The spatial distribution of the C/N ratios and variations in δ13C and δ15N of suspended particulate matter were used to characterise their source in Asia’s largest brackish water lagoon, Chilika, India. In addition, the significance of re-mineralised nutrients in the primary productivity of the shallow lagoon was also determined through quantification of the subsurface nitrogen uptake conditions at two relatively stable locations in the lagoon. The results indicated that the influence of terrestrial organic matter was the maximum in the northern sector and was relatively limited at the central and southern part of the lagoon. In situ 15N uptake experiments (daytime) under biogeochemically stable conditions revealed that the N uptake by phytoplankton ranged between 0.24 and 1.01?mM?m?3?h?1 during pre-monsoon and post-monsoon seasons. New production and regenerated production in the shallow lagoon was also estimated by calculating f-ratios (ratio of nitrate assimilation by phytoplankton to total nitrogenous nutrient assimilation, have been estimated), which varied from 0.52 in the post-monsoon to 0.38 in the pre-monsoon. Lowering of the f-ratio from post- to pre-monsoon indicated a dominance of mineralisation over the new production. 相似文献
4.
Cao Feiyan Zhang Xiaorong Hao Chunyu Tiwari Shani Chen Bing 《Environmental science and pollution research international》2021,28(7):8022-8035
Environmental Science and Pollution Research - Light absorption enhancement of black carbon due to the aerosol mixing states is an important parameterization for climate modeling, while emission... 相似文献
5.
In vitro Cr(VI) reduction by cell-free extracts of chromate-reducing bacteria isolated from tannery effluent irrigated soil 总被引:1,自引:1,他引:0
Sumit K. Soni Rakshapal Singh Ashutosh Awasthi Mangal Singh Alok Kalra 《Environmental science and pollution research international》2013,20(3):1661-1674
Four efficient Cr(VI)-reducing bacterial strains were isolated from rhizospheric soil of plants irrigated with tannery effluent and investigated for in vitro Cr(VI) reduction. Based on 16S rRNA gene sequencing, the isolated strains SUCR44, SUCR140, SUCR186, and SUCR188 were identified as Bacillus sp. (JN674188), Microbacterium sp. (JN674183), Bacillus thuringiensis (JN674184), and Bacillus subtilis (JN674195), respectively. All four isolates could completely reduce Cr(VI) in culture media at 0.2 mM concentration within a period of 24–120 h; SUCR140 completely reduced Cr(VI) within 24 h. Assay with the permeabilized cells (treated with Triton X-100 and Tween 80) and cell-free assay demonstrated that the Cr(VI) reduction activity was mainly associated with the soluble fraction of cells. Considering the major amount of chromium being reduced within 24–48 h, these fractions could have been released extracellularly also during their growth. At the temperature optima of 28 °C and pH?7.0, the specific activity of Cr(VI) reduction was determined to be 0.32, 0.42, 0.34, and 0.28 μmol Cr(VI)?min?1?mg?1 protein for isolates SUCR44, SUCR140, SUCR186, and SUCR188, respectively. Addition of 0.1 mM NADH enhanced the Cr(VI) reduction in the cell-free extracts of all four strains. The Cr(VI) reduction activity in cell-free extracts of all the isolates was stable in presence of different metal ions tested except Hg2+. Beside this, urea and thiourea also reduced the activity of chromate reduction to significant levels. 相似文献
6.
Sumit K. Soni Rakshapal Singh Ashutosh Awasthi Alok Kalra 《Environmental science and pollution research international》2014,21(3):1971-1979
Pot culture experiments were conducted in a glasshouse to evaluate the effects of four efficient Cr(VI)-reducing bacterial strains (SUCR44, SUCR140, SUCR186, and SUCR188) isolated from rhizospheric soil, and four arbuscular mycorrhizal fungi (AMF—Glomus mosseae, G. aggregatum, G. fasciculatum, and G. intraradices) alone or in combination, on Zea mays in artificially Cr(VI)-amended soil. Presence of a strain of Microbacterium sp. SUCR140 reduced the chromate toxicity resulting in improved growth and yields of plants compared to control. The bioavailability of Cr(VI) in soil and its uptake by the plant reduced significantly in SUCR140-treated plants; the effects of AMF, however, either alone or in presence of SUCR140 were not significant. On the other hand, presence of AMF significantly restricted the transport of chromium from root to the aerial parts of plants. The populations of AMF chlamydospores in soil and its root colonization improved in presence of SUCR140. This study demonstrates the usefulness of an efficient Cr(VI)-reducing bacterial strain SUCR140 in improving yields probably through reducing toxicity to plants by lowering bioavailability and uptake of Cr(VI) and improving nutrient availability through increased mycorrhizal colonization which also restricted the transport of chromium to the aerial parts. 相似文献
7.
Effects of soil amendments on the bioavailability of heavy metals from zinc mine tailings 总被引:2,自引:0,他引:2
A study was conducted to test the effects of soil amendments on the bioavailability of heavy metals in a zinc mine tailings containing soil to plants, using the Indian mustard plant (Brassica juncea) as a test organism. Zinc mine tailing containing soil was amended with humus soil (HS) and phosphatic clay (PC). The zinc mine tailing containing soil (ZMTS) was characterized for heavy metals. It was mixed with PC and HS, and four mixtures were prepared. The first mixture contained ZMTS, and served as a control. The second mixture contained ZMTS and PC in the ratio of 1:1 (w/w). The third mixture contained ZMTS and HS in the ratio of 1:1(w/w). The fourth mixture containing ZMTS, PC and HS in the ratio of (2:1:1) (w/w). A slight increase in the bioavailability of Pb, Cu, Zn and Mn was noticed with increase in the incubation time from 14 to 42 days. The bioavailability of Pb, Cu, Zn and Mn from ZMTS alone in Brassica plant was in the range of 94-99% up to 42 days. Addition of PC and HS to the ZMTS soil reduced the bioavailabilities of Pb by (15%), of Cu by (20%), of Zn by (20%) and of Mn by (25%) in the mustard plant. The data showed that PC in the presence of HS had a high affinity for the heavy metals in the order of Pb, Cu, Zn and Mn. 相似文献
8.
P. M. S. Jayathilaka Peeyush Soni Sylvain R. Perret H. P. W. Jayasuriya Vilas M. Salokhe 《Regional Environmental Change》2012,12(1):55-68
Climate change is the main global challenge of this century; it is therefore imperative to identify its effects on agriculture
in developing countries. This research makes spatial assessment of climate change effect on major plantation crops in Sri
Lanka, with emphasis on crop suitability of tea, rubber, and coconut. Geo-referenced maps of spatial and temporal changes
in crop suitability and production potentials are generated and compared. Data pertaining to six agro-ecological zones under
the study area are analyzed for a period of 1980–2007. Crop suitability maps are generated amalgamating yield maps and climatic
factors maps using AHP in multi-criteria analysis under two time frames of 1980–1992 and 1993–2007. Percent change in crop
suitability and crop yield classes is calculated based on five crop suitability and five crop yield classes during two time
frames. Dynamics of climatic parameters and crop yield are recognized using geo-referenced maps. The suitability maps of the
two time frames are compared to identify the changes with each crop in conjunction with changes in the prevailing climate
and yield. Geographic shift of suitability, yield, and climate classes are examined. Net gain or loss in crop production is
quantified. Long-term annual rainfall significantly decreased in mid-country wet zone, whereas the mean temperature of the
study area increased by 1.4°C. Results clearly showed that the climate and yield can be meaningfully related to the crop suitability
and management. 相似文献
9.
Dwivedi S Tripathi RD Srivastava S Mishra S Shukla MK Tiwari KK Singh R Rai UN 《Chemosphere》2007,67(1):140-151
The disposal of fly-ash (FA) from coal-fired power stations causes significant economic and environmental problems. Use of such contaminated sites for crop production and use of contaminated water for irrigation not only decreases crop productivity but also poses health hazards to humans due to accumulation of toxic metals in edible grains. In the present investigation, three rice cultivars viz., Saryu-52, Sabha-5204, and Pant-4 were grown in garden soil (GS, control) and various amendments (10%, 25%, 50%, 75% and 100%) of FA for a period of 90 days and effect on growth and productivity of plant was evaluated vis-a-vis metal accumulation in the plants. The toxicity of FA at higher concentration (50%) was reflected by the reduction in photosynthetic pigments, protein and growth parameters viz., plant height, root biomass, number of tillers, grain and straw weight. However, at lower concentrations (10-25%), FA enhanced growth of the plants as evident by the increase of studied growth parameters. The cysteine and non-protein thiol (NP-SH) content showed increase in their levels up to 100% FA as compared to control, however, maximum content was found at 25% FA in Saryu-52 and Pant-4 and at 50% FA in Sabha-5204. Accumulation of Fe, Si, Cu, Zn, Mn, Ni, Cd and As was investigated in roots, leaves and seeds of the plants. Fe accumulation was maximum in all the parts of plant followed by Si and both showed more translocation to leaves while Mn, Zn, Cu, Ni and Cd showed lower accumulation and most of the metal was confined to roots in all the three cultivars. As was accumulated only in leaves and was not found to be in detectable levels in roots and seeds. The metal accumulation order in three rice cultivars was Fe > Si > Mn > Zn > Ni > Cu > Cd > As in all the plant parts. The results showed that rice varieties Saryu-52 and Sabha-5204 were more tolerant and could show improved growth and yield in lower FA application doses as compared to Pant-4. Thus, Sabha-5204 and Saryu-52 are found suitable for cultivation in FA amended agricultural soils for better crop yields. 相似文献
10.
Various aquatic plant species are known to accumulate heavy metals through the process of bioaccumulation. World’s most troublesome
aquatic weed water hyacinth (Eichhornia crassipes) has been studied for its tendency to bio-accumulate and bio-magnify the heavy metal contaminants present in water bodies.
The chemical investigation of plant parts has shown that it accumulates heavy metals like lead (Pb), chromium (Cr), zinc (Zn),
manganese (Mn) and copper (Cu) to a large extent. Of all the heavy metals studied Pb, Zn and Mn tend to show greater affinity
towards bioaccumulation. The higher concentration of metal in the aquatic weed signifies the biomagnification that lead to
filtration of metallic ions from polluted water. The concept that E. crassipes can be used as a natural aquatic treatment system in the uptake of heavy metals is explored. 相似文献