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991.
用水热法合成δ-MnO2,研究其对重金属Pb2 的吸附性能,以及溶液的pH值、盐浓度对吸附效果的影响,并与无定型二氧化锰对比.研究结果表明水热法可以成功合成δ-MnO2,且具有颗粒微小,无杂质等优点.δ-MnO2对Pb2 的等温吸附结果用多种等温吸附式拟合,结果显示Temkin方程的拟合效果最好.相同条件下,δ-MnO2对Pb2 的吸附量远大于无定型二氧化锰.同一种吸附剂,对Pb2 吸附率随着溶液pH值的增大而增大,随着盐浓度的增加先增加后稳定再减少. 相似文献
992.
化学洗脱法去除生物过滤塔中菌体的研究 总被引:1,自引:1,他引:0
研究生物量控制技术对于提高生物过滤法处理VOCs气体的长期运行性能具有重要意义.用4套平行的生物过滤塔处理甲苯气体,考察了NaOH溶液对生物过滤塔中菌体的去除效果及其对过滤塔去除甲苯性能的影响.NaOH循环洗脱的试验结果表明,在0.2%~0.8%的NaOH浓度范围内,适宜的循环洗脱持续时间为2~3 h.在4个试验浓度下,浓度为0.4%的NaOH溶液对菌体的去除效果最佳,此时菌体洗脱以脱附作用为主.对不同化学洗脱方式进行综合比较发现,循环洗脱是较为适宜的化学洗脱方式.对过滤塔甲苯去除性能的监测表明,洗脱后过滤塔的去除性能可在3~4 d内恢复,不同浓度NaOH对去除性能的影响差别不大. 相似文献
993.
我国城镇化进程持续加快,1996年以来年均增长1.4个百分点,同时,居民生活直接能源消费快速增长。区域发展不平衡使各区域城镇化水平与居民生活直接用能存在差异。本文探讨2000-2011年间城镇化进程对各区域居民生活直接用能的影响规律。根据Divisia指数分解法,将居民生活直接用能变化分解为人口增长效应、城镇化率增加效应、城镇居民人均生活用能变化效应和农村居民人均生活用能变化效应。着重分析了东、中、西部区域城镇化率增加对区域生活直接用能总量变化、各类型能源品种变化的贡献及边际贡献。结果发现:12000-2011年间,城镇化进程对东、中、西部和东北区域居民生活直接用能的贡献分别为4.2%,20.6%,4.1%,-0.01%,人口结构的变动对中部居民直接用能的拉动作用明显;2城镇化率每提高一个百分点,对各区域间生活直接用能贡献差别不大,其中,对东部区域增量贡献最小;3与其他区域不同,中部区域城镇化进程对煤炭消费有增量贡献;东、中部区域城镇化进程对油品消费增量的贡献是西部区域的3-4倍;东部区域城镇化进程对电力消费增量的贡献接近0;4城镇化率每增加一个百分点,对东部地区油品消费增量贡献分别是中西部区域的1.9和2.3倍;对天然气和热力消费增量贡献的情况类似,均是西部区域最高,是东部和中部1.4-2.6倍。研究结论对城镇化进程下开展区域能源管理、节能减排具有指导意义。 相似文献
994.
以ABR反应器为基础,采用笼状填料,增加了缺氧与好氧段,设计了新型的ABR;以啤酒废水为处理对象,考察了新型反应器的启动过程,研究了新型反应器对废水COD的去除效果,分析了HRT、有机容积负荷对COD去除的影响,探讨了新型反应器处理过程中的pH变化及其原因,阐述了笼状填料截留和微生物的附着生长是出水SS较低的原因,出水氨氮浓度较低是增设的缺氧段和好氧段共同作用的结果。实验结果表明,其COD去除效率达96%,有机容积负荷约0.647~1.745 kg/(m3.d);当进水量为50 L/d时,其出水水质达到啤酒废水排放标准。 相似文献
995.
996.
Candis S. Claiborn Dennis Finn Timothy V. Larson Jane Q. Koenig 《Journal of the Air & Waste Management Association (1995)》2013,63(8):1440-1445
ABSTRACT The revised National Ambient Air Quality Standards for PM include fine particulate standards based upon mass measurements of PM25. It is possible in arid and semi-arid regions to observe significant coarse mode intrusion in the PM2.5 measurement. In this work, continuous PM10, PM2.5, and PM1.0 were measured during several windblown dust events in Spokane, WA. PM2 5 constituted ~30% of the PM10 during the dust event days, compared with ~48% on the non-dusty days preceding the dust events. Both PM10 and PM2.5 were enhanced during the dust events. However, PM1.0 was not enhanced during dust storms that originated within the state of Washington. During a dust storm that originated in Asia and impacted Spokane, PM1.0 was also enhanced, although the Asian dust reached Washington during a period of stagnation and poor dispersion, so that local sources were also contributing to high particulate levels. The “intermodal” region of PM, defined as particles ranging in aerodynamic size from 1.0 to 2.5 um, was found to represent a significant fraction of PM25 (~51%) during windblown dust events, compared with 28% during the non-dusty days before the dust events. 相似文献
997.
Photocatalytic mineralization of glyphosate in a small-scale plug flow simulation reactor by UV/TiO2
Jian Q. Chen Zhi J. Hu Nan X. Wang 《Journal of environmental science and health. Part. B》2013,48(6):579-588
The present work involves the photocatalytic mineralization of glyphosate on a plug flow reactor by UV/TiO2. The effect of catalyst loading shows an optimal value (0.4 g L?1) which is necessary to mineralize glyphosate. The kinetic rate of glyphosate mineralization decreases with the increasing initial concentration of glyphosate, and the data can be described using the first-order model. An alkaline environment is conducive to glyphosate mineralization. The mineralization efficiency increases with elevated flow rate to 114 mL min?1, which is followed by a decrease with a further increase in flow rate due to the reduction of the residence time. The presence of external oxidants (K2S2O8, H2O2 and KBrO3) and photosencitizer (humic acid) can significantly enhance glyphosate mineralization. Photocatalysis oxidation ability of the three studied oxidants decrease in the order of: S2O8 2? > BrO3 ? > H2O2. Finally, the Langmuir–Hinshelwood (L-H) model was used to rationalize the mechanisms of reactions occurring on TiO2 surfaces and L-H model constants were also determined. 相似文献
998.
999.
1000.
The European Union directive for electric and electronic waste, published in 2003, enforced all European countries to meet some targets concerning the recycling and recovery of these products. This directive was transposed to the Portuguese legislation in 2004. Following this, a group of EEE producers set up an organization (Amb3e) whose mission was to design and manage a nationwide recovery network for WEEE, which will be the subject matter of this work. A generic MILP model is proposed to represent this network, which is applied to its design and planning, where the best locations for collection and sorting centres are chosen simultaneously with the definition of a tactical network planning. Several analyses are performed to provide further insights regarding the selection of these alternative locations. The results gave support to the company strategic expansion plans for a high number of centres to be opened and to their location near the major WEEE sources. 相似文献