全文获取类型
收费全文 | 2431篇 |
免费 | 151篇 |
国内免费 | 745篇 |
专业分类
安全科学 | 226篇 |
废物处理 | 142篇 |
环保管理 | 185篇 |
综合类 | 1399篇 |
基础理论 | 342篇 |
污染及防治 | 542篇 |
评价与监测 | 167篇 |
社会与环境 | 177篇 |
灾害及防治 | 147篇 |
出版年
2024年 | 13篇 |
2023年 | 48篇 |
2022年 | 152篇 |
2021年 | 112篇 |
2020年 | 111篇 |
2019年 | 98篇 |
2018年 | 137篇 |
2017年 | 124篇 |
2016年 | 105篇 |
2015年 | 140篇 |
2014年 | 203篇 |
2013年 | 193篇 |
2012年 | 177篇 |
2011年 | 173篇 |
2010年 | 161篇 |
2009年 | 156篇 |
2008年 | 136篇 |
2007年 | 141篇 |
2006年 | 120篇 |
2005年 | 67篇 |
2004年 | 102篇 |
2003年 | 98篇 |
2002年 | 114篇 |
2001年 | 115篇 |
2000年 | 84篇 |
1999年 | 72篇 |
1998年 | 41篇 |
1997年 | 28篇 |
1996年 | 31篇 |
1995年 | 22篇 |
1994年 | 16篇 |
1993年 | 11篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有3327条查询结果,搜索用时 0 毫秒
141.
Ji-Feng Yang Shi-Biao Zhou An-Guo Xiao Wen-Jun Li Guang-Guo Ying 《Journal of environmental science and health. Part. B》2013,48(12):909-916
This paper investigated sulfadiazine oxidation by the Fenton process under various reaction conditions. The reaction conditions tested in the experiments included the initial pH value of reaction solutions, and the dosages of ferrous ions and hydrogen peroxide. Under the reaction conditions with pH 3, 0.25 mM of ferrous ion and 2 mM of hydrogen peroxide, a removal efficiency of nearly 100% was achieved for sulfadiazine. A series of intermediate products including 4-OH-sulfadiazine/or 5-OH-sulfadiazine, 2-aminopyrimidine, sulfanilamide, formic acid, and oxalic acid were identified. Based on these products, the possible oxidation pathway of sulfadiazine by Fenton's reagent was proposed. The toxicity evaluation of reaction solutions showed increased antimicrobial effects following the Fenton oxidation process. The results from this study suggest that the Fenton oxidation process could remove sulfadiazine, but also increase solution toxicity due to the presence of more toxic products. 相似文献
142.
143.
Distribution and bioavailability of ceria nanoparticles in an aquatic ecosystem model 总被引:1,自引:0,他引:1
Along with the increasing utilization of engineered nanoparticles, there is a growing concern for the potential environmental and health effects of exposure to these newly designed materials. Understanding the behavior of nanoparticles in the environment is a basic need. The present study aims to investigate the distribution and fate of ceria nanoparticles in an aquatic system model which consists of sediments, water, hornworts, fish and snails, using a radiotracer technique. Concentrations of ceria in the samples at regular time intervals were measured. Ceria nanoparticles were readily removed from the water column and partitioned between different organisms. Both snail and fish have fast absorption and clearance abilities. Hornwort has the highest bioaccumulation factors. At the end of the experiment, sediments accumulated most of the nanoparticles with a recovery of 75.7 ± 27.3% of total ceria nanoparticles, suggesting that sediments are major sinks of ceria nanoparticles. 相似文献
144.
Huang C Chen X Liu T Yang Z Xiao Y Zeng G Sun X 《Environmental science and pollution research international》2012,19(5):1416-1421
Introduction
The suitability of the application of ultrafiltration (UF) to harvest Chlorella sp. from the culture medium was examined. We investigated the effects of two improved UF system, forward air?Cwater flushing and backwash with permeate, on the concentration process.Materials and methods
Backwash with permeate was selected as an optimization of the improved UF system, which was more effective for permeate flux recovery. Moreover, the hollow fiber UF system by adding periodical backwash with permeate was examined for Chlorella sp. harvesting.Results and discussion
It was found that Chlorella sp. could be concentrated with high recovery in a lab-scale experiment. An overall algal biomass recovery of above 90% was achieved when the volume concentration factor was 10. For an original biomass of 1.3?±?0.05?g/L, 1?min backwash followed by 20?min forward concentrating was more effective, which resulted in a recovery of 94% and a high average flux of 30.3?L/m2/h. In addition, the algal recovery was highly correlated to the volume concentration factor and the initial biomass. A high concentration factor or a high initial biomass resulted in a low biomass recovery. 相似文献145.
Li X Wang C Zhang G Xiao L Dixon J 《Environmental science and pollution research international》2012,19(5):1375-1384
Background, aims and scope
Current studies have paid little attention to the dynamism in urban spatial expansion and its possible environmental and health effects or to the health effects of rapid urban environmental change at different points along the urbanisation gradient. This study adopts a public health ecology approach to systematically understand the relationship between urbanisation, urban environmental change and human health in China.Method
Remote sensing image analysis, based on night light data at five different time periods in recent decades, was used to determine changes to the overall urban area. Through a review of the evidence on the relationships between environmental health, urbanisation and health, we advance a pathway framework for explaining urban human health ecology. The Spearman rank correlation coefficient was used to measure the correlation between disease prevalence and urbanisation level, adding a further dimension to a systemic understanding of urban health.Results and conclusions
Urban areas have been increasing spatially, but unevenly, in recent decades, with medium and small cities also expanding rapidly in the past decade. Urbanisation and urban expansion result in changes to land use/coverage change, the urban environment and the residents?? lifestyle, which result in human health problems. Regions with the highest urbanisation level were more inclined to have a high prevalence of chronic disease in recent decades. An ecological public health approach provides insights into the multiple types of data which need to be routinely collected if human disease is not to become a barrier to social and economic development. 相似文献146.
147.
利用自行设计的生物膜培养装置,通过对4种不同填料载体进行连续曝气循环培养生物膜,对湖水中的溶解态微囊藻毒素(MCs)的去除作用进行了研究。结果表明,填料载体上生物膜从形成到稳定大约需要3周;生物膜形成后对MCs的去除效率由高到低的顺序是:颗粒活性炭柱>多密孔球型滤料柱>塑料悬浮填料柱>陶瓷滤球柱。在实验水质条件下,当水力停留时间(HRT)=5 h,进水MCs浓度为21.5~47.25μg/L时,颗粒活性炭、多密孔球型滤料柱对MCs的去除率最高可达100%,塑料悬浮填料柱对MC-LR和MC-RR的去除率分别为70%和88%。当HRT=2.5 h时,塑料悬浮填料柱对MC-RR的去除率为MC-LR的2倍。生物膜对MCs的降解效果随温度(5~20℃)和溶解氧的升高而增加。塑料悬浮填料作为合适的生物膜挂膜填料载体对水源水的生物预处理具有良好的应用前景。 相似文献
148.
针对某水厂以超滤为核心的短流程水处理工艺,在通过聚氯乙烯(PVC)超滤膜之前选择不同投加量(5、10、15和20 mg/L)的高效聚合氯化铝(HPAC)对长江下游原水进行混凝处理。通过跨膜压差(TMP)增长趋势、CODMn的去除率以及混凝后的水质,可知HPAC的最优投加量为15 mg/L。在此投加量下,运用体积排阻色谱法分析原水、膜前水、膜后水中各相对分子质量有机物的变化,可以发现混凝去除有机物的效果要优于超滤截留的。继而将HPAC与另外4种常用混凝剂:硫酸铝(分析纯)、氯化铁(化学纯)、聚合氯化铝(PAC)、聚合硫酸铁进行对比,结果表明,在它们各自最优投加量下,HPAC能够更有效地减缓超滤膜TMP的增长率,从而降低膜污染。因此,认为HPAC是与PVC超滤合金膜契合效果最佳的混凝剂。 相似文献
149.
针对维生素C生产工艺中产生的凝结水产量大、处理成本高、存储运输困难和营养物质含量偏低等问题,采用反渗透技术对VC凝结水进行处理。实验建立小试规模反渗透膜处理装置,采用无量纲化多元回归分析方法,分析了操作条件指标与渗透水评价指标两套指标体系之间的关系,定量评价了各个操作条件指标对渗透水评价指标的整体影响程度,并在此基础上研究了最佳操作条件的工艺参数。结果表明:建立的无量纲化多元回归分析方法切实有效,在正交实验设计水平范围内,压力、pH和回流比均是多目标系统的影响因子,操作条件指标对渗透水评价指标的整体影响程度大小顺序为:压力〉pH〉回流比〉温度,且各自影响程度所占比例分别为43.02%、29.01%、25.07%和2.89%。各个操作因子对多指标系统的影响是独立的。在只考虑系统收益而不考虑膜污染的情况下,最佳操作条件分别为:温度r=30.65,压力P=1.5MPa,回流比r=0.78,pH=7.475。 相似文献
150.
植物配置对表层流湿地净化效果的影响研究 总被引:2,自引:0,他引:2
以郑州市贾鲁河河水为处理对象,研究了不同植物配置表层流湿地的水质净化效果及影响因素。研究表明,单纯挺水植物湿地对TN、TP、NH4+-N和COD的平均去除率分别为28%、58%、49%和26%;采用沉水植物+浮叶植物+挺水植物组合的湿地对TN、TP、NH4+-N和COD的平均去除率分别为37%、64%、63%和32%,在对NH4+-N和TN的处理效果上表现出明显的优势,DO含量变化是导致处理效果差异的主要原因。研究结果表明,在湿地植物配置上,可从氮循环的角度,通过合理搭配湿地植物,强化硝化反硝化作用,以提高对氮素的去除效果。 相似文献