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341.
封闭垃圾填埋场通过地表向大气释放汞的测定 总被引:2,自引:0,他引:2
利用动力学通量箱及自动测汞仪联用技术,于2004年3月中旬对贵阳市的一座封闭生活垃圾填埋场汞通过地表向大气释放的过程进行了研究。3个采样点的汞释放通量日均值分别为559.1、88.2、53.6ng·m-2·h-1,汞释放通量强度与表层基质中的汞含量密切相关,该测定值高于世界背景地区通量的1~2个数量级,说明封闭垃圾填埋场也是大气汞的潜在来源。汞释放通量呈现明显的昼夜变化规律,白天较高并在午间前后达到最大,而夜间降至最低。气相因子中光照强度与汞的释放过程相关性最高,其次分别是气温、相对湿度、地温和风速。氧化态汞的光致还原作用是可能垃圾填埋场Hg0生成的主要途径,降雨初期能促进地表汞的释放。 相似文献
342.
F. Benoit-Marquié C. de Montety V. Gilard R. Martino M. T. Maurette M. Malet-Martino 《Environmental Chemistry Letters》2004,2(2):93-97
We studied the hydrolysis and TiO2 photocatalysis of the pesticide dichlorvos at pH 2.6–9 using phosphorus-31 nuclear magnetic resonance (31P NMR). We found that the hydrolysis of dichlorvos led to the formation of dimethyl phosphate at pH 5.6–9. On the other hand, TiO2 photocatalysis decomposed dichlorvos into dimethyl phosphate, which further reacted to form monomethyl phosphate at pH 2.6 and 9. Monomethylphosphate was hydrolysed into phosphate at pH 2.6. 31P NMR is therefore a promising tool to study the degradation of organophosphorus pesticides. 相似文献
343.
为了研究平行双样对天然气中硫化物采样质量控制措施的可靠性,对现场采集的8对硫化物平行样用对氨基二甲基苯胺光度法进行测定。对测定结果及相对偏差进行W(Shapiro-Wilk)检验,检验结果说明平行双样相对偏差服从正态分布,数据的一致性较好,说明用平行双样对采样进行质量控制是可行的。文中还用Grubbs检验法计算出在该实验条件下测定天然气中硫化物平行双样的相对偏差质量控制范围为1.93%±12.5%。 相似文献
344.
利用大气污染源和环境质量监测等资料,计算分析了锦州市区大气污染现状。结果表明:在锦州市区空气污染以煤烟类为主,汽车尾气成为大气污染源之一。PM10和SO2超过二级标准的天数将近95%出现在采暖期。提出了可行的具体措施,指出采用以集中供热、推广使用天然气、小型锅炉改造工程和控制汽车尾气为主要措施,廉顾绿化,制定市区大气污染治理方案比较合理。 相似文献
345.
Fearnside Philip M. Lashof Daniel A. Moura-Costa Pedro 《Mitigation and Adaptation Strategies for Global Change》2000,5(3):239-270
Many proposed activities formitigating global warming in the land-use change and forestry(LUCF) sector differ from measures to avoid fossilfuel emissions because carbon (C) may be held out ofthe atmosphere only temporarily. In addition, thetiming of the effects is usually different. Many LUCFactivities alter C fluxes to and from the atmosphereseveral decades into the future, whereas fossil fuelemissions avoidance has immediate effects. Non-CO2 greenhouse gases (GHGs), which are animportant part of emissions from deforestation inlow-latitude regions, also pose complications forcomparisons between fossil fuel and LUCF, since themechanism generally used to compare these gases(global warming potentials) assumes simultaneousemissions. A common numeraire is needed to expressglobal warming mitigation benefits of different kindsof projects, such as fossil fuel emissions reduction,C sequestration in forest plantations, avoideddeforestation by creating protected areas and throughpolicy changes to slow rates of land-use changes suchas clearing. Megagram (Mg)-year (also known as`ton-year') accounting provides a mechanism forexpressing the benefits of activities such as these ona consistent basis. One can calculate the atmosphericload of each GHG that will be present in each year,expressed as C in the form of CO2 and itsinstantaneous impact equivalent contributed by othergases. The atmospheric load of CO2-equivalent Cpresent over a time horizon is a possible indicator ofthe climatic impact of the emission that placed thisload in the atmosphere. Conversely, this index alsoprovides a measure of the benefit of notproducing the emission. One accounting methodcompares sequestered CO2 in trees with theCO2 that would be in the atmosphere had thesequestration project not been undertaken, whileanother method (used in this paper) compares theatmospheric load of C (or equivalent in non-CO2GHGs) in both project and no-project scenarios.Time preference, expressed by means of a discount rateon C, can be applied to Mg-year equivalencecalculations to allow societal decisions regarding thevalue of time to be integrated into the system forcalculating global warming impacts and benefits. Giving a high value to time, either by raising thediscount rate or by shortening the time horizon,increases the value attributed to temporarysequestration (such as many forest plantationprojects). A high value for time also favorsmitigation measures that have rapid effects (such asslowing deforestation rates) as compared to measuresthat only affect emissions years in the future (suchas creating protected areas in countries with largeareas of remaining forest). Decisions on temporalissues will guide mitigation efforts towards optionsthat may or may not be desirable on the basis ofsocial and environmental effects in spheres other thanglobal warming. How sustainable development criteriaare incorporated into the approval and creditingsystems for activities under the Kyoto Protocol willdetermine the overall environmental and social impactsof pending decisions on temporal issues. 相似文献
346.
347.
Schaeffer Roberto Logan Jeffrey Szklo Alexandre Salem Chandler William de Souza Marques João Carlos 《Mitigation and Adaptation Strategies for Global Change》2001,6(1):47-69
This study analyzes the options for meeting power demand in the Brazilianpower sector through the year 2015. Three policy cases are constructedto test economic and environmental policy measures against a baseline:advanced technologies scenario, environmental control scenario and carbon(C) elimination scenario. Least-cost modeling simulated these scenarios throughchanges in emissions fees and caps, costs for advanced technologies,demand side efficiency, and clean energy supplies. Results show that, in theabsence of alternative policies, new additions to Brazil's electric powersector will shift rapidly from hydroelectricity to combined-cycle natural gasplants. When the cost of environmental impacts are incorporated in theprice of power, the least-cost mix of electric power generation technologycould change in other ways. In all scenarios, energy efficiency andcogeneration play an important role in the least-cost power solution. Savingelectricity through increased efficiency offsets the needs for new supply andhas enormous potential in Brazil's industrial sector. Efficiency also reducesthe environmental burden associated with electricity production andtransmission, without compromising the quality of the services demandedby end users. Interesting enough, carbon dioxide (CO2) emissions will remainrelatively low under almost every conceivable scenario. 相似文献
348.
Will Simplified Modalities and Procedures Make More Small-Scale Forestry Projects Viable Under the Clean Development Mechanism? 总被引:2,自引:0,他引:2
Bruno Locatelli Lucio Pedroni 《Mitigation and Adaptation Strategies for Global Change》2006,11(3):621-643
Simplified modalities and procedures (M&P) are expected to increase the viability of small-scale project activities under
the Clean Development Mechanism (CDM). A small-scale afforestation or reforestation (AR) project is defined as a project removing
less than 8 kilotons of carbon dioxide equivalent (CO2e) per year. Depending on the project type and the method for measuring scale, 8 kilotons of CO2e per year correspond to highly diverse areas, possibly ranging from 200 to 6000 ha. Using a model to calculate the minimum
project scale above which the CDM is a positive financial incentive for eligible AR project activities, the paper analyzes
whether a reduction of transaction costs under simplified M&P will be a sufficient incentive to motivate small-scale participation
in the CDM. Model results show that, even under optimistic assumptions on carbon market conditions and transaction costs,
small-scale project activities will not benefit from simplified M&P. Results also show that project activities removing more
than 8 kilotons of CO2e per year and registered as small-scale would be the ones that could benefit the most from simplified M&P. It is concluded
that the participation of small-scale project activities to the CDM requires more than simplified M&P, the price of expiring
Certified Emission Reductions being one of the most critical parameters. 相似文献
349.
Based on hourly measurements of NOx NO2 and O3 and meteorological data, an ordinary least squares (OLS) model and a first-order autocorrelation (AR) model were developed to analyse the regression and prediction of NOx and NO2 concentrations in London. Primary emissions and wind speed are the most important factors influencing NOx concentrations; in addition to these two, reaction of NO with O3 is also a major factor influencing NO2 concentrations. The AR model resulted in high correlation coefficients (R > 0.95) for the NOx and NO2 regression based on a whole year's data, and is capable of predicting NO2 (R = 0.83) and NOx (R = 0.65) concentrations when the explanatory variables were available. The analysis of the structure of regression models by Principal Component Analysis (PCA) indicates that the regression models are stable. The results of the OLS model indicate that there was an exceptional NO2 source, other than primary emission and reaction of NO with O3, in the air pollution episode in London in December 1991. 相似文献
350.
Trace metal emissions from co-combustion of refuse derived and packaging derived fuels in a circulating fluidized bed boiler 总被引:3,自引:0,他引:3
Helena Manninen Annikki Perkiö Juha Palonena Karl Peltola Juhanl Ruuskanen 《Chemosphere》1996,32(12):2457-2469
Energy recovery from refuse derived fuels (RDF) and packaging derived fuels (PDF) is one option in integrated waste management. Nine RDF and PDF co-combustion tests with peat and coal in a circulating fluidized bed boiler were carried out in this work. Heavy metal emissions in flue gas and fly ash were measured. Multivariate data analyses were used to find out the most important parameters affecting metal emissions in the flue gas.
The results showed that total heavy metal emissions were low. Although RDF and PDF had more heavy metals than peat and coal, the multivariate data analysis showed that an increase of the RDF or PDF share in the fuel mixture up to 20% did not correlate directly with the metal emissions in the flue gas. Distribution of Cd, Cu, Zn and Sn between flue gas and fly ash correlated with each other. Injection of limestone to bind sulphur and chlorine did not have a significant effect on heavy metal emissions in the flue gas. Heavy metals concentrated on the fly ash, but all fly ashes passed the EPA-TCLP tests. 相似文献