全文获取类型
收费全文 | 1206篇 |
免费 | 76篇 |
国内免费 | 490篇 |
专业分类
安全科学 | 88篇 |
废物处理 | 57篇 |
环保管理 | 126篇 |
综合类 | 693篇 |
基础理论 | 226篇 |
污染及防治 | 402篇 |
评价与监测 | 69篇 |
社会与环境 | 50篇 |
灾害及防治 | 61篇 |
出版年
2024年 | 2篇 |
2023年 | 29篇 |
2022年 | 85篇 |
2021年 | 59篇 |
2020年 | 60篇 |
2019年 | 48篇 |
2018年 | 55篇 |
2017年 | 73篇 |
2016年 | 53篇 |
2015年 | 60篇 |
2014年 | 90篇 |
2013年 | 118篇 |
2012年 | 100篇 |
2011年 | 127篇 |
2010年 | 83篇 |
2009年 | 82篇 |
2008年 | 76篇 |
2007年 | 67篇 |
2006年 | 78篇 |
2005年 | 56篇 |
2004年 | 38篇 |
2003年 | 27篇 |
2002年 | 47篇 |
2001年 | 36篇 |
2000年 | 43篇 |
1999年 | 35篇 |
1998年 | 18篇 |
1997年 | 25篇 |
1996年 | 15篇 |
1995年 | 17篇 |
1994年 | 11篇 |
1993年 | 20篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有1772条查询结果,搜索用时 31 毫秒
941.
超声波处理剩余活性污泥促进厌氧消化 总被引:9,自引:1,他引:8
用超声波处理剩余活性污泥(简称污泥),考察了污泥絮体结构、污泥中溶解性化学需氧量(SCOD)的变化规律及超声波处理对污泥厌氧消化的影响。实验结果表明,声强大于1 040W/m2时,用超声波处理污泥30m in以上,污泥絮体被打碎,污泥絮体结构遭到严重破坏,污泥中SCOD迅速增加,加速了污泥中有机质的水解反应;声强为2 000W/m2时,用超声波处理污泥60m in,中温((37±1)℃)厌氧消化10d,COD去除率为41%;厌氧消化25d的总产气量比未经超声波处理的污泥总产气量提高了53%;将发酵罐容积放大10倍,经超声波处理的污泥25d累积的总产气量比未经超声波处理的污泥总产气量提高了约25%。 相似文献
942.
Ceburnis D Yin J Allen AG Jennings SG Harrison RM Wright E Fitzpatrick M Healy T Barry E 《Journal of environmental monitoring : JEM》2006,8(4):479-487
An intensive two month measurement campaign has been performed during a two year study of major component composition of urban PM10 and PM2.5 in Ireland (J. Yin, A. G. Allen, R. M. Harrison, S. G. Jennings, E. Wright, M. Fitzpatrick, T. Healy, E. Barry, D. Ceburnis and D. McCusker, Atmos. Res., 2005, 78(3-4), 149-165). Measurements included size-segregated mass, soluble ions, elemental carbon (EC) distributions, fine and coarse fraction organic carbon (OC) and major gases along with standard meteorological measurements. The study revealed that urban emissions in Ireland had mainly a local character and therefore were confined within a limited area of 20-30 km radius, without significantly affecting regional air quality. Gaseous measurements have shown that urban emissions in Ireland had clear, but fairly limited influence on the regional air quality due to favorable mixing conditions at higher wind speeds, in particular from the western sector. Size-segregated mass and chemical measurements revealed a clear demarcation size between accumulation and coarse modes at about 0.8 microm which was constant at all sites. Carbonaceous compounds at the urban site accounted for up to 90% of the particle mass in a size range of 0.066-0.61 microm. Nss SO4(2-) concentrations in PM2.5 were only slightly higher at the urban site compared to the rural or coastal sites, while NO3- and NH4+ concentrations were similar at the urban and coastal sites, but were a factor of 2 to 3 higher than at the rural site. OC was highly variable between the sites and revealed clear seasonal differences. Natural or biogenic OC component accounted for <10% in winter and up to 30% in summer of the PM2.5 OC at urban sites. A contribution of biogenic OC component to PM2.5 OC mass at rural site was dominant. 相似文献
943.
944.
射阳河底泥重金属沿程变化分析及污染评价 总被引:2,自引:0,他引:2
分析了射阳河流域沿程20个底泥样品中6种重金属(Cr、Pb、Ni、Zn、Cu、As)的含量,并应用地累积指数法对其进行了污染评价。研究结果表明:除As在近一半的采样点没有污染,其他重金属污染均普遍存在,但多数属于轻度污染。Zn污染最为严重,几乎全程都是偏中等或中等以上的污染。纵观射阳河全程样品FN04,SY07污染最为严重,前者与其支流西塘河的污染有关,后者可能与河闸上侧的死水状态有关;黄沙河污染最轻,与河流沉积物粒径比较粗而导致的对重金属吸附能力减弱有关。 相似文献
945.
946.
947.
从含油废水中筛选分离到1株原油降解菌XD-1,鉴定为假单胞菌(Pseuomonas sp.).初步实验表明菌XD-1具有较强的产表面活性剂乳化原油的作用,对该菌的产表面活性剂性能进行了研究.实验证明,菌XD-1所产表面活性剂为脂肽类物质,菌在生长对数期产表面活性剂,表面活性剂的产生为生长相关型;充足的碳源是产表面活性剂的必需条件,菌利用原油为碳源时能持续大量地产表面活性剂;原油和尿素为产表面活性剂的最适碳源和氮源,菌XD-1产表面活性剂的最佳营养培养基组成为葡萄糖10 g,尿素4 g,磷酸二氢钾1 g,微量元素液4 mL,水1 L,pH 8.0. 相似文献
948.
949.
采用离子交换和溶剂萃取相结合的分离;富集技术,事等离子体发射光谱仪(ICP-AES)测定,对昆明滇池7个取样点的砷形态进行了分离和必滇池环境对池中砷形态的迁移转化进行了探讨,为滇池砷污染的研究和治理提供了一定依据。 相似文献
950.
Xiaoming Zou Xianghong Zhou Zhifen Lin Ziqing Deng Daqiang Yin 《Environmental monitoring and assessment》2013,185(6):4513-4527
As organisms are typically exposed to chemical mixtures over long periods of time, chronic mixture toxicity is the best way to perform an environmental risk assessment (ERA). However, it is difficult to obtain the chronic mixture toxicity data due to the high expense and the complexity of the data acquisition method. Therefore, an approach was proposed in this study to predict chronic mixture toxicity. The acute (15 min exposure) and chronic (24 h exposure) toxicity of eight antibiotics and trimethoprim to Vibrio fischeri were determined in both single and binary mixtures. The results indicated that the risk quotients (RQs) of antibiotics should be based on the chronic mixture toxicity. To predict the chronic mixture toxicity, a docking-based receptor library of antibiotics and the receptor-library-based quantitative structure–activity relationship (QSAR) model were developed. Application of the developed QSAR model to the ERA of antibiotic mixtures demonstrated that there was a close affinity between RQs based on the observed chronic toxicity and the corresponding RQs based on the predicted data. The average coefficients of variations were 46.26 and 34.93 % and the determination coefficients (R 2) were 0.999 and 0.998 for the low concentration group and the high concentration group, respectively. This result convinced us that the receptor library would be a promising tool for predicting the chronic mixture toxicity of antibiotics and that it can be further applied in ERA. 相似文献