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621.
秸秆黑碳的制备及吸附特性 总被引:1,自引:0,他引:1
基于前期实验确定在氮气保护3种温度(550、650和750℃)制备秸秆黑碳,并用XRD、SEM对其结构、形貌进行了表征,研究它对吡唑酮废水中铵盐吸附去除效果.结果表明,650℃秸秆黑碳改变了晶体的有序度和结晶度,断面微孔道分布疏松均匀规则,具有较大的比表面积,而且有一定数量的纳米级黑碳颗粒;它的吸附特性优于750℃和550℃的秸秆黑碳,吸附率最高为95.31%;650℃秸秆黑碳最佳吸附工艺:吸附温度和饱和时间分别为35℃和4h,吸附振荡频率为100r/min.秸秆黑碳的吸附速率快、适用条件宽是处理铵盐废水的良好材料. 相似文献
622.
分别采用4种纳滤膜处理某炼化公司的反渗透浓水。在初始COD为57.8 mg/L、TOC为23.94 mg/L、ρ(Ca2+)为289.0 mg/L、ρ(Mg2+)为54.6 mg/L、ρ(SO42-)为327.7 mg/L、ρ(Cl-)为1 106.8 mg/L的条件下,经纳滤处理后COD去除率达60%以上,污水COD降至30 mg/L以下,TOC去除率为31.9%~85.5%,阳离子的去除率为33.9%~97.0%,SO42-的去除率为63.3%~97.6%,Cl-的去除率较低。膜A的膜孔分布密集,具有很高的通量,对有机物和无机盐的截留效果较差;膜B和膜C对有机物和二价离子的截留效果较好;膜D的膜孔分布稀松,膜通量最低,对有机物和无机盐的截留能力均较强,但随出水体积的增加,对无机盐的截留能力下降较为明显。4种纳滤膜的性能各异,可满足不同企业的需求,具有良好的应用前景。 相似文献
623.
Cintia C. Santiago Mariela. A. Fernández 《Journal of environmental science and health. Part. B》2016,51(4):245-253
The 4-chloro-2-methylphenoxy acid (MCPA) is an herbicide widely used in agriculture, which generates a great concern about contamination of surface water and serious consequences for human health and the environment. In this work, the adsorption of MCPA on an Argentine montmorillonite (MMT) and its organo-montmorillonite product (OMMT) with different dodecyl trimethyl ammonium loading was investigated. MCPA adsorption on OMMT increases at least 3 times, with respect to the amount determined for MMT. X-ray diffraction and zeta potential analyses indicated the inner (interlayer) and outer surface participate as adsorption sites. Changes in surface electric charge and also interlayer expansion suggest that dimethyl amine (MCPA counterion) was also surface-adsorbed. The larger aggregates of OMMT, without and with MCPA, obtained compared to those of MMT samples, generate an improvement in the coagulation efficiency. This property, particularly after MCPA retention, allows an easier separation of the solids from the solution and enables a simple technological process application. 相似文献
624.
625.
研究聚丙烯酸钠(PAAS)溶液的超滤行为,考察各操作参数对膜通量(J)和截留系数(R)的影响,结果表明,J随运行时间延长衰减不明显,随压差增大呈线性递增,随温度升高而增大,pH高于5时J基本不变;R随压差增大或温度升高均下降,随pH增大而增大。建立膜阻力(rf)模型,研究影响rf的主要因素,发现,rf随压差增大而增大,随温度升高而减少,pH低于5时rf随pH增大而迅速下降。研究PAAS溶液浓缩过程,当体积浓缩因子为16时,J衰减明显,截留液PAAS浓度(Cr)呈线性递增,渗透液PAAS浓度(Cp)在较长时期内基本不变,至浓缩后期,Cp轻微下降。以去离子水对浓缩液予以洗涤,随着洗涤液体积增大,Cr轻微下降,Cp逐渐趋于零。 相似文献
626.
627.
Gillis PL 《Environmental pollution (Barking, Essex : 1987)》2011,159(6):1702-1708
Chloride concentrations in surface waters have increased significantly, a rise attributed to road salt use. In Canada, this may be a concern for endangered freshwater mussels, many with ranges limited to southern Ontario, Canada’s most road-dense region. The acute toxicity of NaCl was determined for glochidia, the mussel’s larval stage. The 24 h EC50s of four (including two Canadian endangered) species ranged from 113-1430 mg Cl L−1 (reconstituted water, 100 mg CaCO3 L−1). To determine how mussels would respond to a chloride pulse, natural river water (hardness 278-322 mg CaCO3 L−1) was augmented with salt. Lampsilis fasciola glochidia were significantly less sensitive to salt in natural water (EC50s 1265-1559 mg Cl L−1) than in reconstituted water (EC50 285 mg L−1). Chloride data from mussel habitats revealed chloride reaches levels acutely toxic to glochidia (1300 mg L−1). The increased salinization of freshwater could negatively impact freshwater mussels, including numerous species at risk. 相似文献
628.
629.
ABSTRACTThis study investigated the potential influence of three organic ameliorators (peat, biochar and leonardite) on salts and nutrients in salt-affected soils during intermittent leaching. Results showed that nearly 90% of salt was removed from columns in the leaching process and sodium adsorption ratio (SAR) of the soil after leaching was reduced by 67.3% (control, CK), 62.9% (peat), 70.1% (biochar) and 55.0% (leonardite). Total N loss declined by 26.2% (peat), 11.7% (biochar) and 55.5% (leonardite) compared with CK in the process of leaching. The maintaining N (NH4+ and NO3?) of soil after leaching was 8.25, 7.31, 11.31 and 14.48?mg/kg for CK, peat, biochar and leonardite treatments. Final P loss was 0.47, 0.31, 0.54, 0.27?mg/column in leaching for CK, peat, biochar and leonardite treatments. Soluble P of soil after leaching was measured as 6.95 (CK), 5.62 (peat), 8.52 (biochar) and 3.33 (leonardite) mg/kg. Leaching could remove the salt effectively but with nutrient loss in the process. The findings of this study suggest that organic ameliorators (biochar, peat or leonardite) play an important role in retaining nutrients during leaching as well as supplying nutrients after leaching to offer practical assistance for the amendment of salt-affected soil in the Yellow River Delta. 相似文献
630.
控制星湖内源性营养物质磷负荷的有效性研究 总被引:5,自引:0,他引:5
本文研究了天然沸石与石灰,铝盐,铁盐对湖水-沉积物系统中的湖水脱磷的可能性,以期在对星湖内源性营养物质磷负荷的控制方面提供科学依据。 相似文献