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741.
复合式渗流试验装置对微污染河道水的脱氮除磷研究 总被引:1,自引:1,他引:0
针对微污染河道水体的水质特点,考察了复合式渗流试验装置对此类河道水的处理效能。试验结果表明:在10 cm/d和20 cm/d水力负荷条件下,两个阶段TN的平均去除率分别为36.34%、28.53%;TN平均出水浓度分别为6.15,12.45 mg/L;TP的平均去除率分别为90.86%、64.15%;TP平均出水浓度分别为0.05,0.42 mg/L。氮的去除主要发生在前两个格室,前两个格室填充的腐木作为补充碳源,有利于微生物的反硝化脱氮作用;磷的去除主要发生在后两个格室,原因是后两个格室填充了水泥砖块,水泥砖块对磷具有较好的吸附性能,但随着时间的推移,系统的除磷能力会因填料对磷的吸附饱和而逐渐下降,故需要及时更换填料。 相似文献
742.
Xiaoliu HUANGFU Yaan WANG Yongze LIU Xixin LU Xiang ZHANG Haijun CHENG Jin JIANG Jun MA 《Frontiers of Environmental Science & Engineering》2015,9(1):105
The aggregation of common manganese dioxide (MnO2) colloids has great impact on their surface reactivity and therefore on their fates as well as associated natural and synthetic contaminants in engineered (e.g. water treatment) and natural aquatic environments. Nevertheless, little is known about the aggregation kinetics of MnO2 colloids and the effect of humic acid (HA) and surfactants on these. In this study, the early stage aggregation kinetics of MnO2 nanoparticles in NaNO3 and Ca(NO3)2 solutions in the presence of HA and surfactants (i.e., sodium dodecyl sulfate (SDS), and polyvinylpyrrolidone (PVP)) were modeled through time-resolved dynamic light scattering. In the presence of HA, MnO2 colloids were significantly stabilized with a critical coagulation concentration (CCC) of ~300 mmol·L-1 NaNO3 and 4 mmol·L-1 Ca(NO3)2. Electrophoretic mobility (EPM) measurements confirmed that steric hindrance may be primarily responsible for increasing colloidal stability in the presence of HA. Moreover, the molecular and/or chemical properties of HA might impact its stabilizing efficiency. In the case of PVP, only a slight increase of aggregation kinetics was observed, due to steric reactions originating from adsorbed layers of PVP on the MnO2 surface. Consequently, higher CCC values were obtained in the presence of PVP. However, there was a negligible reduction in MnO2 colloidal stability in the presence of 20 mg·L-1SDS. 相似文献
743.
Cathode ray tube (CRT) recycling: current capabilities in China and research progress 总被引:1,自引:0,他引:1
It is estimated that approximately 6,000,000 scrap TVs and 10,000,000 personal computers are generated each year in China. Cathode ray tubes (CRTs) from these machines consist of 85% glass (65% panel, 30% funnel and 5% neck glass). The leaded glass (funnel-24%, neck-30%) may seriously pollute the environment if it is not properly disposed of. In this paper, the past, current and future status of CRT dismantling technologies as well as the CRT glass recycling situation in China are presented and discussed. Recycling technology for waste CRTs in China is still immature. While the conventional CRT dismantling technologies have disadvantages from both economic and environmental viewpoints, some of the new and emerging treatments such as automatic optical sorting facilities that have been applied in developed countries offer advantages, and therefore should be transferred to China in the next few years to solve the CRT pre-processing problem. Meanwhile, because the demand for CRT glass closed-loop recycling is extremely limited, the authorities should take effective measures to improve CRT glass recycling rates and to facilitate a match to local conditions. Moreover, we also provide a broad review of the research developments in recycling techniques for CRT cullet. The challenge for the future is to transfer these environmentally friendly and energy-saving technologies into practice. 相似文献
744.
铁炭微电解法降解1-丁基-3-甲基咪唑六氟磷酸盐 总被引:2,自引:0,他引:2
使用铁炭微电解法降解1-丁基-3-甲基咪唑六氟磷酸盐([BMIM]PF6),并探讨了铁炭微电解法降解[BMIM]PF6的影响因素、工艺条件及其反应动力学.结果表明,影响铁炭微电解降解[BMIM]PF6的因素按从大到小的顺序为:炭铁比、pH、反应时间;铁炭微电解降解[BMIM]PF6的最佳工艺条件是:铁粉用量3g.l-1、水样pH2.5、炭铁比2、反应时间为60—90min;在此条件下,[BMIM]PF6的去除效率可以达到90%以上且该降解反应为三级反应. 相似文献
745.
Here, we report anticipatory behaviors of sea snakes and provide the first evidence for a sensory mechanism by which they
survive a catastrophic cyclone. Sea kraits (Laticauda spp.) are normally abundant in littoral habitats at Lanyu (Orchid Island), Taiwan but disappeared coincident with falling
barometric pressure prior to typhoon Morakot, which impacted the island severely during 7–9 August 2009. The abundance of
sea kraits that are visible within the littoral zone correlates with barometric pressure, but not with precipitation or wind
speed, which drives the surf. We found very little evidence of direct mortality caused by the storm, and the visible abundance
of sea kraits following the storm returned to pre-storm levels. Data suggest that survival of sea kraits depends on the sensory
perception of low pressures preceding a tropical cyclone, followed by behaviors which avoid the lethal storm energies potentially
affecting this coastal population. Sea kraits likely find refuge in cavernous spaces beneath volcanic rocks of the seacoast. 相似文献
746.
747.
非离子表面活性剂溶液中多环芳烃的溶解特性 总被引:15,自引:1,他引:14
采用3种典型非离子表面活性剂(Tween80、Tween20和Triton X-100),对4种典型多环芳烃萘(naphtha-lene)、菲(phenanthrene)、芴(fluorene)和芘(pyrene)进行了溶解特性研究.结果表明,非离子表面活性剂对多环芳烃具有较好的增溶效果,在浓度大于临界胶束浓度(CMC)时,多环芳烃的溶解度与表面活性剂浓度成正比例线性相关通过质量溶解率(WSR)的比较,确定3种非离子表面活性剂对多环芳烃的增溶效果为Triton X-100>Tween80>Tween20,与其HLB值呈负相关.在非离子表面活性剂溶液中,多环芳烃的正辛醇-水分配系数(Kow)与其胶束-水分配系数(Km)呈现良好的线性相关关系. 相似文献
748.
水污染控制规划与GIS 总被引:3,自引:0,他引:3
在水污染控制规划中,总量控制是新手段,概率模型是新方法,GIS是新工具。利用上述新手段,新方法和新工具,系统地介绍了水污染控制规划,初步探索了基于GIS的水污染控制规划的实施途径。 相似文献
749.
750.
不同类型城市人工湿地底栖动物多样性的比较研究 总被引:1,自引:0,他引:1
在常州市范围内选取具有代表性的三大人工湿地,对其底栖动物多样性情况进行春秋两季的调查研究。结果显示:软件园秋季底栖动物各项生物多样性指标均高于春季,荆川公园和五星公园则呈现春季生物多样性状况优于秋季的状况。从总体上看,底栖动物的Shannon—Wiener多样性指数软件园〉荆川公园〉五星公园;Pielou均匀度指数荆川公园〉软件园〉五星公园;BI指数表现为五星公园〉荆川公园〉软件园。此外从调查结果来看,软体动物种类数、分布密度与水体的污染程度呈反向趋势,由此推断软体动物种类丰富程度可作为评价城市人工湿地水体受污染程度的重要指标。 相似文献