全文获取类型
收费全文 | 978篇 |
免费 | 49篇 |
国内免费 | 276篇 |
专业分类
安全科学 | 52篇 |
废物处理 | 79篇 |
环保管理 | 60篇 |
综合类 | 475篇 |
基础理论 | 185篇 |
污染及防治 | 336篇 |
评价与监测 | 55篇 |
社会与环境 | 33篇 |
灾害及防治 | 28篇 |
出版年
2023年 | 10篇 |
2022年 | 57篇 |
2021年 | 43篇 |
2020年 | 32篇 |
2019年 | 21篇 |
2018年 | 44篇 |
2017年 | 29篇 |
2016年 | 52篇 |
2015年 | 68篇 |
2014年 | 61篇 |
2013年 | 104篇 |
2012年 | 92篇 |
2011年 | 79篇 |
2010年 | 70篇 |
2009年 | 65篇 |
2008年 | 76篇 |
2007年 | 44篇 |
2006年 | 59篇 |
2005年 | 39篇 |
2004年 | 28篇 |
2003年 | 29篇 |
2002年 | 19篇 |
2001年 | 31篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 26篇 |
1997年 | 22篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 14篇 |
1992年 | 11篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1983年 | 1篇 |
排序方式: 共有1303条查询结果,搜索用时 109 毫秒
991.
Qian SUI Jun HUANG Shuguang LU Shubo DENG Bin WANG Wentao ZHAO Zhaofu QIU Gang YU 《Frontiers of Environmental Science & Engineering》2014,8(1):62-68
The application of appropriate advanced treat- ment process in the municipal wastewater treatment plants (WWTPs) has become an important issue considering the elimination of emerging contaminants, such as pharma- ceutical and personal care products (PPCPs). In the present study, the removal of 13 PPCPs belonging to different therapeutic classes by the sequential ultraviolet (UV) and ozonation process in a full-scale WWTP in Beijing was investigated over the course of ten months. Most of the target PPCPs were effectively removed, and the median removal efficiencies of individual PPCPs, ranging from -13% to 89%, were dependent on their reaction rate constants with molecular ozone. Noticeable fluctuation in the removal efficiencies of the same PPCPs was observed in different sampling campaigns. Nevertheless, the sequential UV and ozonation process still made a significant contribution to the total elimination of most PPCPs in the full-scale WWTP, by compensating for the poor or fluctuant removal performance of PPCPs by biologic treatment process. 相似文献
992.
Di CUI Ang LI Tian QIU Rui CAI Changlong PANG Jihua WANG Jixian YANG Fang MA Nanqi REN 《Frontiers of Environmental Science & Engineering》2014,8(6):937-944
Bioaugmentation is an effective method of treating municipal wastewater with high ammonia concentration in sequencing batch reactors (SBRs) at low temperature (10℃). The cold-adapted ammonia- and nitrite- oxidizing bacteria were enriched and inoculated, respectively, in the bioaugmentation systems. In synthetic wastewater treatment systems, the average NH4+-N removal efficiency in the bioaugmented system (85%) was much higher than that in the unbioaugmented system. The effluent NH4+ -N concentration of the bioaugmented system was stably below 8 mg. L1 after 20 d operation. In municipal wastewater systems with bioaugmentation, the effluent NH4+- -N concentration was below 8 mg·L^-1 after 15 d operation. The average NH4+ -N removal efficiency in unbioaugmentation system (about 82%) was lower compared with that in the bioaugmentation system. By inoculating the cold-adapted nitrite-oxidizing bacteria (NOB) into the SBRs after 10 d operation, the nitrite concentration decreased rapidly, reducing the NO2 -N accumulation effectively at low temperature. The func- tional microorganisms were identified by PCR-DGGE, including uncultured Dechloromonas sp., uncultured Nitrospira sp., Clostridium sp. and uncultured Thauera sp. The results suggested that the cold-adapted microbial agent of ammonia-oxidizing bacteria (AOB) and NOB could accelerate the start-up and promote achieving the stable operation of the low-temperature SBRs for nitrification. 相似文献
993.
堆积型尾矿坝坝体颗粒级配情况因尾砂排放和堆积的形式而千变万化,因此仅仅采用海森经验公式估算其毛细水上升情况会造成很大的偏差。为此,以湖南某尾矿坝坝体尾砂为原料,采用均匀设计方案设计并配比了8种尾矿砂,随后对该8种尾矿砂中的毛细水上升情况进行了长达10个月的监测,系统地研究了颗粒级配的差异对毛细水上升过程的影响。研究表明,毛细水初期阶段上升速度与尾矿砂中粗粒颗粒含量成正比,其最终上升高度则由细粒含量所决定。进一步地,还得出了由颗粒级配估算毛细水上升高度的方法,为毛细水上升高度计算理论提供了一种新思路和新方法。 相似文献
994.
Shengliang Zhou Hui Qiu Chengcheng Feng Yanhua Guo Xiaoning Wang 《Chemistry and Ecology》2016,32(3):259-269
Endophytic fungi, being closely associated with their host plants, are an important part of the ecosystem and food web. In modern agriculture, pesticides are widely used. The impact of pesticides on the endophytic fungal community of crops remains poorly understood. In this paper, Chinese cabbage Brassica chinensis, a popular leafy vegetable consumed worldwide, was selected for evaluating the potential effects of a pesticide, deltamethrin, on the endophytic fungal community. By culture method, 195 endophytic fungal strains classified into 39 taxa and 186 strains classified into 30 taxa, respectively, were isolated from the pesticide-treated and untreated B. chinensis samples. Sirodesmium spp. were the predominant endophytic fungi from both samples. The colonisation rates of endophytic fungi of the treated and the untreated samples were not significantly different, as determined by one-way analysis of variance (p?>?.05). The Shannon diversity indexes (H′) were close, being 2.216 and 2.152, respectively. However, the endophyte compositions of the treated and the untreated samples were significantly different (p?.01) by the canonical correspondence analysis. The similarity coefficient of the endophyte assembles was only 29.0%. Our results indicate that the application of deltamethrin lead to the change of the endophytic fungal assemble in B. chinensis. 相似文献
995.
利用含砷氧化锌尘制备活性氧化锌 总被引:3,自引:0,他引:3
用NH3-(NH4)2SO4溶液浸取处理含砷氧化锌尘,可彻底清除砷,制备出合格的活性氧化锌。对于含砷质量分类为1%-2%的原料,产品中所含砷质量分数可降至0.0005%以下。该方法具有除砷彻底,不易产生二次污染的优点,为含砷氧化锌尘的综合利用提供了一种新方法。 相似文献
996.
997.
998.
不同生境条件下苦槠丛枝菌根对根际土壤磷酸酶活性的影响 总被引:4,自引:1,他引:3
以浙江千岛湖和宁波天童两个不同区域内的苦储(Castanopsis sclerophytta)为材料,对处于不同生境条件下的苦槠丛枝菌根(AM)进行了研究.结果表明:两地区土壤pH均处于苦储丛枝菌根生长发育的最适范围内,丛枝菌根的侵染率无明显差异;酸性磷酸酶为两区域内的主导磷酸酶,各种磷酸酶活性均是天童地区高于千岛湖地区;AM侵染率与根际土壤磷酸酶活性之间均呈现正相关,其中天童地区为显著相关,说明AM侵染率对根际土壤磷酸酶活性在某种程度上存在有一定的影响. 相似文献
999.
1000.
石灰与磷肥对籽粒苋吸收镉的影响 总被引:9,自引:0,他引:9
籽粒苋(Amaranthus hypochondriacus L.)是我国广泛栽种的牧草,但具有富集重金属Cd的特性,探讨减少其吸收镉的方法技术,可以降低人畜受害风险.研究利用温室盆栽方法,比较了施用磷肥和石灰对降低籽粒苋Cd吸收量的影响.于含镉5 mg·kg-1的污染菜园土中,以粉末形式加入3 g·kg-1 Ca(OH)2,或以液态形式加入磷肥(0.326 g·kg-1 Ca(H2PO4)2)至P浓度80 mg·kg-1,该施用量为农业应用常规水平.播种籽粒苋,于60 d后收获,测定相关参数.结果表明,施用石灰使土壤pH上升1.7单位,土壤有效Cd下降至极低水平,从而大幅降低籽粒苋Cd吸收量,较对照下降约56%,但施石灰也使土壤供磷量下降,使籽粒苋的生物量也减少了约一半.施用石灰后,土壤的Ca与K供应量以及籽粒苋体内Ca与K含量均明显增加,Ca、K与Cd形成的竞争吸收也是施用石灰后籽粒苋Cd含量下降的一个原因.本地菜同土含有较高的有效磷,以常规农业磷肥施用量施用磷肥对籽粒苋吸收Cd没有明显影响,对生物量也没有明显影响,但适当提高施用量预期会有一定的效果.因而,对广州地区菜园土,使用合理的石灰施用量,可有效降低籽粒苋Cd吸收量. 相似文献