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1.
石油污染土壤中石油含量对玉米的影响   总被引:25,自引:1,他引:24  
为了弄清石油污染土壤中石油类对农作物的影响,吉林油田进行了一年的田间玉米种植试验,在不同浓度水平,分别对玉米出苗率,可见外观特性、百粒重、产量和品质进行了较系统的观察、监测、类比分析。结果表明,土壤中石油含量的不同,对玉米生长过程各项指标有不同的影响并找出吉林油田土壤-玉米系统中影响玉米生长及其产 量的土壤临界含油量。  相似文献
2.
Soil pollution by lead, zinc, cadmium and copper was characterized in the mine tailings and surrounding soils (arable and pasture lands) of an old Spanish Pb-Zn mine. Sixty soil samples were analyzed, determining the total metal concentration by acid digestion and the chemical fractionation of Pb and Zn by the modified BCR sequential extraction method. Samples belonging to mine waste areas showed the highest values, with mean concentrations of 28,453.50 mg kg(-1) for Pb, 7000.44 mg kg(-1) for Zn, 20.57 mg kg(-1) for Cd and 308.48 mg kg(-1) for Cu. High concentrations of Pb, Zn and Cd were found in many of the samples taken from surrounding arable and pasture lands, indicating a certain extent of spreading of heavy metal pollution. Acidic drainage and wind transport of dust were proposed as the main effects causing the dispersion of pollution. Sequential extraction showed that most of the Pb was associated with non-residual fractions, mainly in reducible form, in all the collected samples. Zn appeared mainly associated with the acid-extractable form in mine tailing samples, while the residual form was the predominant one in samples belonging to surrounding areas. Comparison of our results with several criteria reported in the literature for risk assessment in soils polluted by heavy metals showed the need to treat the mine tailings dumped in the mine area.  相似文献
3.
层次分析法在环境质量评价中的不足与改进   总被引:14,自引:0,他引:14  
孟宪林 《四川环境》2001,20(1):50-52
本文针对应用层次分析法进行环境质量评价中存在的不足作了必要的改进, 并应用于环境空气质量与土壤重金属污染的评价中。评价结果表明;改进层次分析比一般层次分析法更为合理。  相似文献
4.
我国煤炭开采和燃烧过程中的硫污染对土壤环境的影响   总被引:13,自引:0,他引:13  
我国煤炭在开采和燃烧过程中形成的硫污染物主要是酸性矿井水和二氧化硫,由煤炭燃烧造成的硫的干湿沉降以及煤炭开采过程中形成的酸性矿井水使土壤的物理化学性质发生变化,从而对土壤造成严重的破坏。主要表现在造成土壤中可溶性硫酸盐的大幅度升高;引起土壤的pH值下降;植物营养元素特别是K、Na、Ca、Mg等产生淋失;活性铝溶出量增加;有毒重金属活化;抑制土壤酶的活性等方面。可以通过脱硫除尘、加强绿化、建立合理的工业布局、加入土壤改良剂等措施来减少硫污染物的排放量和改善其对土壤环境的影响,但总量控制是关键,是最根本的途径。  相似文献
5.
土壤重金属污染的全过程控制   总被引:13,自引:2,他引:11  
殷捷  陈玉成 《四川环境》2000,19(1):27-30
在介绍土壤环境重金属污染的特点及其在土壤中的赋存形态、迁移转化特征的基础上,阐述了土壤重金属污染的全过程控制措施,从源头到治理可分为:产前控制、产中控制和产生控制;同时阐述了各类措施的适用条件、范围、效果和费用,并对今后的治理研究提出了一些见解。  相似文献
6.
洗涤法处理含油土壤的研究   总被引:13,自引:1,他引:12  
研究了用洗涤法处理含油土壤,考察了洗涤剂种类与浓度、洗涤温度、液固比、洗涤时间、表面活性剂、洗涤液直接循环使用次数对洗涤效果的影响,结果表明:当混合减浓度为10000mg/L、洗涤温度为70℃、液固比2:1、洗涤时间20min时,可将含油量为30%的土壤洗至残油率仅为0.3%左右。OP、EL型表面活性剂的加入对洗涤效果没有改善,特别有意义的是洗涤液能够直接循环使用而对洗涤效果基本无影响,这不仅能够减少用水量,还可以大大减少废水的排放量,降低操作费用及废水处理费用。该洗涤法不涉及物质的相变过程,混合碱由廉价的无机碱和无机盐组成,故能量消耗低,处理费用也低,且洗脱下来的原油可回收。  相似文献
7.
Soil erosion under different vegetation covers in the Venezuelan Andes   总被引:12,自引:0,他引:12  
This comparative study of soil erosion considered different environments in an ecological unit of the Venezuelan Andes. The soils belong to an association of typic palehumults and humic dystrudepts. Soil losses were quantified by using erosion plots in areas covered by four types of vegetation, including both natural and cultivated environments. The highest soil erosion rate evaluated corresponded to horticultural crops in rotation: reaching a value of 22 Mg ha–1 per year. For apple tree (Malus sylvestris Miller) plots, soil losses reached values of 1.96 Mg ha–1 per year. Losses from pasture (Pennisetum clandestinum Hochst. ex Chiov.) plots, without livestock grazing, were as high as 1.11 Mg ha–1 during the second year of the experiment. The highest soil losses generated from plots under natural forest were equal to 0.54 Mg ha–1 per year. Environmental factors such as total and effective rainfall, runoff, and some soil characteristics as those related to soil losses by water erosion were evaluated. The type of management applied to each site under different land use type and the absence of conservation practices explain, to a large extent, the erosive processes and mechanisms.  相似文献
8.
Soil Characteristics and Management in an Urban Park in Hong Kong   总被引:9,自引:0,他引:9  
3   threshold. With diminished porosity, transmission of air and water, storage of plant-available moisture, and root growth suffer. Chemically, the samples have an unnatural alkaline pH; inadequate organic matter, nitrogen, phosphorus, exchangeable cations; and limited cation exchange capacity. The results can help park-soil management, including the need to evaluate soil in planned park sites, salvage high-grade soil parcels, prevent construction damage, ameliorate structure by mechanical operations and suitable amendments, and replace site soil of very poor quality. Edaphic problems can be forestalled or solved by treating soil as an integral component of park planning and management based on scientific principles and methods.  相似文献
9.
Soil Characteristics and Management in an Urban Park in Hong Kong   总被引:9,自引:0,他引:9  
3   threshold. With diminished porosity, transmission of air and water, storage of plant-available moisture, and root growth suffer. Chemically, the samples have an unnatural alkaline pH; inadequate organic matter, nitrogen, phosphorus, exchangeable cations; and limited cation exchange capacity. The results can help park-soil management, including the need to evaluate soil in planned park sites, salvage high-grade soil parcels, prevent construction damage, ameliorate structure by mechanical operations and suitable amendments, and replace site soil of very poor quality. Edaphic problems can be forestalled or solved by treating soil as an integral component of park planning and management based on scientific principles and methods.  相似文献
10.
Soil erosion in developing countries: a socio-economic appraisal   总被引:9,自引:0,他引:9  
Soil erosion is the single most important environmental degradation problem in the developing world. Despite the plethora of literature that exists on the incidence, causes and impacts of soil erosion, a concrete understanding of this complex problem is lacking. This paper examines the soil erosion problem in developing countries in order to understand the complex inter-relationships between population pressure, poverty and environmental-institutional dynamics. Two recent theoretical developments, namely Boserup's theory on population pressure, poverty and soil erosion and Lopez's theory on environmental and institutional dynamics have been reviewed. The analysis reveals that negative impacts of technical change, inappropriate government policies and poor institutions are largely responsible for the continued soil erosion in developing countries. On the other hand, potential for market-based approaches to mitigate the problem is also low due to the negative externalities involved. A deeper appreciation of institutional and environmental dynamics and policy reforms to strengthen weak institutions may help mitigate the problem.  相似文献
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