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631.
深圳市公路建设对生态环境的影响、治理及对策 总被引:7,自引:0,他引:7
公路建设曾经给深圳的生态环境造成了较为严重的危害 ,主要有 :严重的水土流失及其派生影响 ,对一些具有观赏价值的自然景观产生破坏 ,影响了部分区域动植物生存环境等。主要对这些环境影响及已进行的治理及其成效进行综述 ,对治理工作的不足及未来对策也进行了探讨。 相似文献
632.
633.
A serious forest decline of Betula ermanii Cham. has been observed at Mt. Mae-Shirane, Oku-Nikko, Japan, where high ozone (O3) concentration and severe water deficiency have been measured. In order to consider the possibility whether O3 and/or water stresses could have been the causes of the forest decline of B. ermanii, plant growth experiments were conducted in environment-controlled growth cabinets. Two-year-old seedlings of B. ermanii were exposed to either charcoal-filtered air (O3 concentration <5 ppb) or 50 ppb O3 (daily average, ranging between 20–100 ppb) for 123 days at 20.0/12.5 ± 1.0°C (day/night) and 70/80 ± 7% relative humidity
(day/night). Simultaneously, seedlings were treated with three watering regime: 1.0 < pF < 1.8 (no water stress), 1.8 < pF < 2.5
(mild water stress) or 2.5 < pF < 3.0 (severe water stress). O3 exposure significantly reduced the dry weights of leaf, root and the whole plant, while water stress significantly reduced
the dry weights of each organ and the whole plant. Significant reductions of net photosynthesis, transpiration and stomatal
conductance were also observed under O3 and/or water deficiency treatments, while contents of RuBP carboxylase/oxygenase (Rubisco), chlorophyll
a+b
and some essential nutrient elements (N, P, K, Mg and Ca) were not markedly changed. It was suggested that the decrease in
net photosynthetic rate induced mainly by stomatal closure was the major cause of the growth reduction under O3 and/or water stresses. No significant interactions between O3 and water stresses were observed in terms of the depression of dry matter production, which suggested that simultaneous stress
treatments of O3 exposure and water deficiency could affect the tree growth of B. ermanii additively. 相似文献
634.
Phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate) dissolved in aqueous solution was almost completely decomposed by ozonation to form various species within 10 minutes of reaction time for the experimental conditions examined in this research. The generation rate of sulfate was found to be fairly independent of solution pH value. However, the formation of phosphate and carbonate was more favorable for alkaline solutions where hydroxyl free radical is the primary oxidative species. The reaction rates increased with initial gaseous ozone concentrations, indicating the reaction was mass transfer-controlled within the experimental range of this research. Combining the analytical results by various instruments, including gas chromatograph equipped with an electron ionization detector (GC-EID), high performance liquid chromatography (HPLC), ion chromatography (IC), and total organic carbon (TOC), the temporal sequence of phorate ozonation was proposed in this study. The oxidation of sulfur atoms on the phosphorus-sulfur double bond or carbon-sulfur-carbon bond by ozonation was found to occur at first to form sulfate and various intermediates. 相似文献
635.
Atmospheric aerosol particles and metallic concentrations, ionic species were monitored at the Experimental harbor of Taichung
sampling site in this study. This work attempted to characterize metallic elements and ionic species associated with meteorological
conditions variation on atmospheric particulate matter in TSP, PM2.5, PM2.5–10. The concentration distribution trend between TSP, PM2.5, PM2.5–10 particle concentration at the TH (Taichung harbor) sampling site were also displayed in this study. Besides, the meteorological
conditions variation of metallic elements (Fe, Mg, Cr, Cu, Zn, Mn and Pb) and ions species (Cl−, NO3
−, SO4
2−, NH4
+, Mg2+, Ca2+ and Na+) concentrations attached with those particulate were also analyzed in this study. On non-parametric (Spearman) correlation
analysis, the results indicated that the meteorological conditions have high correlation at largest particulate concentrations
for TSP at TH sampling site in this study. In addition, the temperature and relative humidity of meteorological conditions
that played a key role to affect particulate matter (PM) and have higher correlations then other meteorological conditions
such as wind speed and atmospheric pressure. The parameter temperature and relative humidity also have high correlations with
atmospheric pollutants compared with those of the other meteorological variables (wind speed, atmospheric pressure and prevalent
wind direction). In addition, relative statistical equations between pollutants and meteorological variables were also characterized
in this study. 相似文献
636.
Is an adjusted rhizosphere-based method valid for field assessment of metal phytoavailability? Application to non-contaminated soils 总被引:1,自引:0,他引:1
Fang J Wen B Shan XQ Lin JM Owens G 《Environmental pollution (Barking, Essex : 1987)》2007,150(2):209-217
Previously recommended rhizosphere-based method (RHIZO) applied to moist rhizosphere soils was integrated with moist bulk soils, and termed adjusted-RHIZO method (A-RHIZO). The A-RHIZO and RHIZO methods were systematically compared with EDTA, DTPA, CaCl2 and the first step of the Community Bureau of Reference (BCR1) methods for assessing metal phytoavailability under field conditions. Results suggested that moist bulk soils are equally suited or even better than rhizosphere soils to estimate metal phytoavailability. The A-RHIZO method was preferred to other methods for predicting the phytoavailability of Ni, Cu, Zn, Cd, Pb and Mn to wheat roots with correlation coefficients of 0.730 (P<0.001), 0.854 (P<0.001), 0.887 (P<0.001), 0.739 (P<0.001), 0.725 (P<0.001) and 0.469 (P<0.05), respectively. When including soil properties, other extraction methods were also able to predict phytoavailability reasonably well for some metals. Soil pH, organic matter and Fe-Mn oxide contents, and cation-exchange capacity mostly influenced the extraction and phytoavailability of metals. 相似文献
637.
上海市环境监测质量管理规划探讨 总被引:8,自引:0,他引:8
针对上海市环境监测行业质量管理工作在宏观管理和微观控制两个方面存在的问题,制定了上海市环境监测质量管理近期和中期规划。建立质量管理信息共享平台和QC指标评定体系,组建质量与技术管理委员会,建立环境质量和污染源连续自动监测系统的QA/QC体系。在全市环境监测行业内建立质量管理考核评价体系和法制保障体系,推进LIMS建设并实现与上海市环境监测中心LIMS的无缝链接,探索构建"上海市水环境监测质量控制平台"。 相似文献
638.
Kerrylee Rogers Neil Saintilan Matthew J. Colloff Li Wen 《Environmental monitoring and assessment》2013,185(10):8583-8600
We propose a framework in which thresholds of potential concern (TPCs) and limits of acceptable change (LACs) are used in concert in the assessment of wetland condition and vulnerability and apply the framework in a case study. The lower Murrumbidgee River floodplain (the ‘Lowbidgee’) is one of the most ecologically important wetlands in Australia and the focus of intense management intervention by State and Federal government agencies. We used a targeted management stakeholder workshop to identify key values that contribute to the ecological significance of the Lowbidgee floodplain, and identified LACs that, if crossed, would signify the loss of significance. We then used conceptual models linking the condition of these values (wetland vegetation communities, waterbirds, fish species and the endangered southern bell frog) to measurable threat indicators, for which we defined a management goal and a TPC. We applied this framework to data collected across 70 wetland storages’, or eco-hydrological units, at the peak of a prolonged drought (2008) and following extensive re-flooding (2010). At the suggestion of water and wetland mangers, we neither aggregated nor integrated indices but reported separately in a series of chloropleth maps. The resulting assessment clearly identified the effect of rewetting in restoring indicators within TPC in most cases, for most storages. The scale of assessment was useful in informing the targeted and timely management intervention and provided a context for retaining and utilising monitoring information in an adaptive management context. 相似文献
639.
安徽省环境系统经济损失值及其分布特征 总被引:5,自引:0,他引:5
提出了环境系统经济损失概念,并在这一概念框架中建立了符合安徽省实际情况的指标体系,测算了以货币值表达的1990年的安徽省及该省分地市、分行业,以及各损体类型的环境系统经济损失值,分析了各损失分布特征。结果表明,安徽省为人口增长和经济发展所付出的环境损失代价是巨大的。 相似文献
640.
大气中痕量持久性有机污染物年均值的测定 总被引:7,自引:1,他引:6
采用以XAD-2树脂为吸附介质的大气被动采样器,在四川卧龙自然保护区设置6个采样点,进行了为期2年(2005年-2007年)的环境大气样品采集。用气相色谱-高分辨质谱方法对HCB,HCHs,DDTs和PCBs测定。结果表明,平行样品的重现性良好,平均相对偏差为9%。POPs检测下限的范围为1.0pg/m^3-5.9pg/m^3。2年的年均值数据表现出较好的一致性和规律性。以XAD-2树脂为吸附介质的大气被动采样器能够便利地采集进而测定半年或一年污染物的平均浓度,可以经济、有效地获得大气中痕量POPs的年均值。ρ(α—HCH)/ρ(γ-HCH)从成都到卧龙的上升的趋势反映的是传输过程中HCH的降解;而卧龙地区跨年度数据所反映出的ρ(α—HCH)/ρ(γ-HCH)下降趋势,可以归因于林丹的使用。 相似文献