全文获取类型
收费全文 | 109篇 |
免费 | 8篇 |
国内免费 | 27篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 21篇 |
环保管理 | 5篇 |
综合类 | 71篇 |
基础理论 | 17篇 |
污染及防治 | 11篇 |
评价与监测 | 16篇 |
社会与环境 | 1篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 3篇 |
2002年 | 11篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 1篇 |
排序方式: 共有144条查询结果,搜索用时 15 毫秒
61.
62.
湖北省酸雨控制区二氧化硫污染防治规划 总被引:1,自引:0,他引:1
在归纳湖北省酸雨控制区二氧化硫污染特征的基础上,对我省酸雨控制区二氧化硫的防治途径进行了分析。提出了全省“十五”期间二氧化硫总量控制规划,并从工业点源治理、城市清洁能源两大方面安排了二氧化硫污染防治的工程措施。“十五”期间全省共安排重点项目45项,计划投资960282万元,项目完成后削减二氧化硫19.19万t/a,实现“十五”规划目标。 相似文献
63.
在烟煤炭地下气化模型试验的基础上,研究了气化炉温度、气化工艺等对硫转化的影响;在纯氧气化工艺条件下,煤气中含硫气体的形态和含量主要受温度的影响,产生的H2S浓度在600~700℃达到最大值为7400mg·m-3,SO2在1000℃时达到最大值为270 mg·m-3.在纯氧-水蒸气工艺阶段,煤气中的含硫气体形态主要受煤气中氢气含量的影响,但在纯氧-水蒸气工艺后期,含硫气体量又转变为温度的函数.煤炭地下气化过程中,煤中的硫大部分以含硫气体的形式分布在煤气中;只有小部分硫分布在灰渣、焦油和冷凝水中. 相似文献
64.
65.
Changes in chemistry and vertical distribution of35S were investigated in column experiments using intact topsoil and repacked mineral soil horizons 1 to 20 weeks after tracer application (901 kBq35S-SO4
2– per column 6.5 cm in diameter). Horizons O, A, AE and Bvs of an Orthic Podzol were incubated at 20°C and wetted twice a week with 11 mm of natural throughfall precipitation (38.5 mg S04
2– L–1-, pH 3.3). The top 35 cm of the soil contained 1,290 kg S ha–1, or 18 times more than is the annual atmospheric S input (71.4 kg S ha–1 yr–1). Of this amount, 17.8 % was stored as inorganic sulphate S, 4.6 % as reduced inorganic S, and 77.6 % as organic S. In O + A and AE, free sulphate was the most abundant35S form, while in Bvs the 35S activity of free and adsorbed sulphate was similar. The proportion of adsorbed sulphate increased with depth, averaging 23, 30 and 47 % of total inorganic sulphate35S in O + A, AE and Bvs, respectively. Total specific activity of chemically transformed35S (i.e., of reduced inorganic S and organic S) constituted 3.4, 3.8 and 105 % of inorganic sulphate35S activity in O + A, AE and Bvs, respectively, in averaged weeks 2–4, and 7.5, 6.4 and 39.6 % in averaged weeks 11–13 in O+A, AE and Bvs, respectively. The turnover time of C-bonded35S was shorter than that of ester sulphate35S. An increase in FeS2–
35S with time indicated anaerobic conditions suitable for bacterial sulphate reduction. After 13 weeks, 68 % of the tracer was found deeper than 8 cm below soil surface. 相似文献
66.
67.
按国家关于清洁生产审核的具体环保要求,针对二氧化硫产出量与总量控制的相关标准,提出关于二氧化硫专项清洁生产审核研究的具体思路.根据对哈尔滨某集团有限公司SO2专项清洁生产审核,通过组织筹划、预评估,确定二氧化硫作为清洁生产审核的重点并制定清洁生产目标,评估过程中要依据具体的国家环保要求,对于确定的方案进行环境-经济-社会效益的分析.共提出10个清洁生产方案,其中无/低费方案8个,中/高费方案2个. 相似文献
68.
The critical loads concept is used by the UN-ECEConvention on Long Range Transboundary Air Pollution(CLRTAP) for setting pollution reduction targets.Increasing numbers of countries are adopting the SimpleMass Balance equation (SMB) to calculate critical loads ofacidifying S and N for forest soils. The equation is madeup of a series of mass balances each of which is used tocalculate a leaching flux. The assumptions in the SMBequation were investigated by testing its ability topredict current sulphur load and by comparing each of thecalculated leaching fluxes to measured rates. It was notpossible to predict current sulphur load at our sites usingthe SMB equation. The leaching tests demonstrated that,primarily due to its steady state assumptions, the SMBequation generates critical loads that are theoretical longterm estimates of risk, and are untestable. Thesimplifying assumptions sometimes lead to illogicalresults. Some of these can be improved by adding a final,simple but dynamic, calculation step to determine theexpected time until effects are observed. Theacceptability of combining annual average data, which bestapproximates steady state, with a biological indicator isquestionable. It is not possible to test critical loadscalculated using the SMB equation when applied with all ofits assumptions but it is possible to test its fundamentalapproach using non steady state data. 相似文献
69.
It is well established that wet deposition of sulphate in the UKhas fallen by a much smaller fraction than have emissions of sulphur dioxide. Dry deposition of sulphur has decreased in proportion to the decline in emissions. A number of suggestionshave been made which offer possible explanations for this non-linearity between emissions and wet deposition. In this paper amodel of the processing of sulphur dioxide by aqueous phase cloudchemistry in a cloudy boundary layer is presented. This work doesnot simulate all the details of the mechanisms by which sulphate is incorporated into precipitation. It does, however, explorethe non-linearity of this oxidation process. It is shown that theoxidation of sulphur dioxide, in these conditions, over the UK isdominated by oxidation by ozone. The rate of sulphate productionis then controlled by the availability of the one basic trace gasin the atmosphere ammonia. Using realistic concentrations of thereacting species this is found to simulate well the observed non-linearity. The model predicts that sulphate and sulphur dioxideconcentrations will be uncorrelated in the cloudy boundary layerbut that ammonium and sulphate will be well correlated. Fieldobservations at a cloudy site in Northern England are consistentwith these predictions. 相似文献
70.
The occurrence, distribution and nature of ambient thiobacilli along with their ability to oxidize different sulphur species under simulated natural and in vitro culture conditions were studied in the polluted and unpolluted sites of the River Ganga.
Thiobacillus thioparus, T. thiooxidans and T. denitrificans were isolated from the river water. the former two occurred in both polluted and unpolluted sites, while T. denitrificans occurred in polluted areas only. the paper pulp mill effluent discharge area contained the highest population of T. thioparus. the sewage drainage area showed relatively higher populations of T. thiooxidans and T. denitrificans.
The present study revealed that only biological oxidation of either thiosulphate or elemental sulphur occurred in the river water. All the thiobacilli screened oxidized thiosulphate, and three-fourths of them oxidized elemental sulphur. Some strains were found to be very good acidifiers. in spite of such acidification by the ambient thiobacilli, the pH of the river water remained alkaline. the specific rates of thiosulphate (0.18 -0.51 μMmolh-1 mg-1 cell) and sulphur (1.3 - 6.2 Normality day-1 mg-1 biomass) oxidations under simulated natural condition were found to be higher in polluted areas when compared with the unpolluted one (sulphur: 0.8 - 1.0 Normality day-1 mg-1).
Further, addition of thiouslphate or elemental sulphur in the river water in simulated in vitro condition resulted in the increase of respective oxidation rates. the variations in the natae of pollutants discharged into the river water influenced the oxidation rate of thiosulphate or sulphur. 相似文献
Thiobacillus thioparus, T. thiooxidans and T. denitrificans were isolated from the river water. the former two occurred in both polluted and unpolluted sites, while T. denitrificans occurred in polluted areas only. the paper pulp mill effluent discharge area contained the highest population of T. thioparus. the sewage drainage area showed relatively higher populations of T. thiooxidans and T. denitrificans.
The present study revealed that only biological oxidation of either thiosulphate or elemental sulphur occurred in the river water. All the thiobacilli screened oxidized thiosulphate, and three-fourths of them oxidized elemental sulphur. Some strains were found to be very good acidifiers. in spite of such acidification by the ambient thiobacilli, the pH of the river water remained alkaline. the specific rates of thiosulphate (0.18 -0.51 μMmolh-1 mg-1 cell) and sulphur (1.3 - 6.2 Normality day-1 mg-1 biomass) oxidations under simulated natural condition were found to be higher in polluted areas when compared with the unpolluted one (sulphur: 0.8 - 1.0 Normality day-1 mg-1).
Further, addition of thiouslphate or elemental sulphur in the river water in simulated in vitro condition resulted in the increase of respective oxidation rates. the variations in the natae of pollutants discharged into the river water influenced the oxidation rate of thiosulphate or sulphur. 相似文献