全文获取类型
收费全文 | 792篇 |
免费 | 79篇 |
国内免费 | 353篇 |
专业分类
安全科学 | 72篇 |
废物处理 | 29篇 |
环保管理 | 57篇 |
综合类 | 631篇 |
基础理论 | 131篇 |
污染及防治 | 199篇 |
评价与监测 | 37篇 |
社会与环境 | 40篇 |
灾害及防治 | 28篇 |
出版年
2024年 | 10篇 |
2023年 | 18篇 |
2022年 | 55篇 |
2021年 | 49篇 |
2020年 | 63篇 |
2019年 | 57篇 |
2018年 | 51篇 |
2017年 | 53篇 |
2016年 | 47篇 |
2015年 | 64篇 |
2014年 | 62篇 |
2013年 | 63篇 |
2012年 | 82篇 |
2011年 | 81篇 |
2010年 | 54篇 |
2009年 | 53篇 |
2008年 | 53篇 |
2007年 | 41篇 |
2006年 | 38篇 |
2005年 | 28篇 |
2004年 | 34篇 |
2003年 | 22篇 |
2002年 | 23篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 21篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有1224条查询结果,搜索用时 984 毫秒
131.
132.
利用UV/Fenton工艺对模拟间-甲苯酚废水进行了处理,研究了H2O2加入量、FeSO4加入量、pH、原水初始COD值、环境温度、反应时间等因素对COD去除率的影响.实验表明:间-甲苯酚浓度为100mg/L、初始COD值251 mg/L的废水,在30℃下,pH为4.Q,[H2O2]/[Fe2 ]=15(质量浓度比),紫外灯照射3 h后,COD去除率达86.3%,若再经Ca(OH)2絮凝沉降,则COD去除率提高到92.6%.同时,对Fenton及UV/Fenton的处理效果进行了比较,实验表明:UV/Fenton的处理效果明显优于Fenton法. 相似文献
133.
Comparison between fractionation and bioavailability of trace elements in rhizosphere and bulk soils 总被引:16,自引:0,他引:16
Rhizosphere is a microbiosphere and has quite different chemical, physical and biological properties from bulk soils. A greenhouse experiment was performed to compare the difference of fractionation and bioavailability of trace elements Cr, Ni, Zn, Cu, Pb and Cd between rhizosphere soil and bulk soil. In the meantime, the influence of air-drying on the fractionation and bioavailability was also investigated by using wet soil sample as a control. Soils in a homemade rhizobox were divided into four zones: rhizosphere, near rhizosphere, near bulk soil and bulk soil zones, which was designated as S1, S2, S3 and S4. Elemental speciations were fractionated to water soluble, exchangeable and carbonate bound (B1), Fe-Mn oxide bound (B2), and organic and sulfide bound (B3) by a sequential extraction procedure. Speciation differences were observed for elements Cr, Ni, Zn, Cu, Pb and Cd between the rhizosphere and bulk soils, and between the air-dried and wet soils as well. The concentrations of all six heavy metals in fraction B1 followed the order of S2 > S3 > S1 > S4 and for B2, the order was S2 > S3 S4 > S1. For B3, the order was S1 > S3 S4 > S2, while for Cd the order was S2 > S3 approximately/= S4 > S1. The air-drying increased elemental concentration in fractions B1 and B2 by 20-50% and decreased in fraction B3 by about 20-100%. Correlation analysis also indicated that the bioavailability correlation coefficient of fraction B1 in rhizosphere wet soil to plants was better than that between either air-dried or nonrhizosphere soils. Therefore, application of rhizosphere wet soils should be recommended in the future study on the speciation analysis of trace elements in soils and bioavailability. 相似文献
134.
135.
136.
污泥资源化是污泥处置的发展趋势,以脱水污泥为主料,添加适量粉煤灰和粘土,制备生物膜载体填料是实验研究的主要内容。实验表明,污泥使用量为70%、粉煤灰和粘土各15%时,烧成温度为1000±25℃、保温时间为40min,烧制的填料抗压强度能达到25mpa、吸水率17%;用于药厂废水处理测试,在常温下的化学需氧量(CODCr)的平均去除率为74.0%、悬浮物(SS)的去除率为54.1%。使用扫描电镜、显微镜像检测,分析了填料烧制中孔隙形成机理、填料外貌、表面微孔结构等。实验表明,以污泥代替天然原料,在一定条件下可以烧制成填料,并能用作污水处理中生物膜载体。 相似文献
137.
138.
Guobin Shan Rao Y. Surampalli Rajeshwar D. Tyagi Tian C. Zhang 《Frontiers of Environmental Science & Engineering in China》2009,3(3):249-264
Nanomaterials are applicable in the areas of reduction of environmental burden, reduction/treatment of industrial and agricultural
wastes, and nonpoint source (NPS) pollution control. First, environmental burden reduction involves green process and engineering,
emissions control, desulfurization/denitrification of nonrenewable energy sources, and improvement of agriculture and food
systems. Second, reduction/treatment of industrial and agricultural wastes involves converting wastes into products, groundwater
remediation, adsorption, delaying photocatalysis, and nanomembranes. Third, NPS pollution control involves controlling water
pollution. Nanomaterials alter physical properties on a nanoscale due to their high specific surface area to volume ratio.
They are used as catalysts, adsorbents, membranes, and additives to increase activity and capability due to their high specific
surface areas and nano-sized effects. Thus, nanomaterials are more effective at treating environmental wastes because they
reduce the amount of material needed. 相似文献
139.
QIN Xiaofei XIA Xijuan LI Yan ZHAO Yaxian YANG Zhongzhi FU Shan TIAN Mi ZHAO Xingru QIN Zhanfen XU Xiaobai YANG Yongjian 《环境科学学报(英文版)》2009,21(12)
To understand potential ecotoxicological effects of electrical and electronic equipment waste (e-waste) recycling and polybrominated diphenyl ethers (PBDEs) bioaccumulation in loaches, a semi-field experiment using Chinese loach (Misgurnus anguillicaudatus) as experimental fish was performed. Larval loaches were kept into net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site (27%, 19/70) and from reference site (70%, 49/70). Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers (PBDEs), the main pollutants in e-waste, in loaches was also studied in this e-wastes recycling site, the mean concentrations of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L (dissolved phase). BDE209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE209 (less than 0.01% of total PBDEs) and high concentration of BDE47 (up to 39.34% of total PBDEs) were detected in loaches. 相似文献
140.
以采集自云南滇池的水华束丝藻(Aphanizomenon flos-aquae)为研究对象,分别用壳聚糖和聚合氯化铝对云南省常见的硅藻土进行改性,在实验室条件下研究两种改性黏土对水华束丝藻的去除效果。通过去除率的比较,得出两种改性黏土去除水华束丝藻的线性拟合方程。每毫升藻液壳聚糖改性硅藻土投加量(m L)与藻细胞光密度OD_(680)、叶绿素a质量浓度(mg/L)的关系分别为y=0.0377x-0.0014和y=0.009x+0.0002;每毫升藻液聚合氯化铝改性硅藻土投加量(m L)与藻细胞光密度OD_(680)、叶绿素a质量浓度(mg/L)的关系分别为y=0.0135x+0.002和y=0.0039x+0.002。壳聚糖改性硅藻土和聚合氯化铝改性硅藻土去除水华束丝藻的最适pH值范围分别为5~8、5~9,总氮(TN)去除率分别为39.77%、45.44%,总磷(TP)去除率分别为64.92%、78.01%。聚合氯化铝改性硅藻土去除水华束丝藻的最适pH值范围较宽,且其除藻过程中对TN、TP的去除率均较高。用透明溞(Daphnia magna)对其进行生态安全性试验,得出壳聚糖改性硅藻土和聚合氯化铝改性硅藻土除藻至48 h死亡率分别为30.77%、0。 相似文献