全文获取类型
收费全文 | 748篇 |
免费 | 33篇 |
国内免费 | 334篇 |
专业分类
安全科学 | 51篇 |
废物处理 | 61篇 |
环保管理 | 48篇 |
综合类 | 430篇 |
基础理论 | 166篇 |
污染及防治 | 269篇 |
评价与监测 | 31篇 |
社会与环境 | 25篇 |
灾害及防治 | 34篇 |
出版年
2023年 | 10篇 |
2022年 | 34篇 |
2021年 | 27篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 27篇 |
2017年 | 34篇 |
2016年 | 33篇 |
2015年 | 56篇 |
2014年 | 62篇 |
2013年 | 82篇 |
2012年 | 59篇 |
2011年 | 79篇 |
2010年 | 57篇 |
2009年 | 48篇 |
2008年 | 52篇 |
2007年 | 61篇 |
2006年 | 44篇 |
2005年 | 32篇 |
2004年 | 20篇 |
2003年 | 37篇 |
2002年 | 24篇 |
2001年 | 18篇 |
2000年 | 24篇 |
1999年 | 30篇 |
1998年 | 17篇 |
1997年 | 19篇 |
1996年 | 17篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有1115条查询结果,搜索用时 456 毫秒
601.
602.
DX—100型离子色谱仪用于冰雪样品中阴,阳离子的测定 总被引:9,自引:0,他引:9
本文介绍了DX-100型离子色谱仪用于冰雪样品中阴,阳离子的测定,以东北五大连池地区白龙洞和水晶宫为例,介绍了阴,阳离子测定在分析化学物质来源和成冰过程中的重要作用。 相似文献
603.
Polybrominated biphenyls have been widely used as flameretardants in textile and electronic industries, and additives in plastics. Over the past few decades, much attention has been given to polybrominated biphenyls in the environment and their effects on humans. In this paper, we studied on the degradation of 4,4′-dibromobiphenyl, a typical one of polybrominated biphenyls, through photoelectrocatalytic process with TiO2, Zr/TiO2 and Zr, N/TiO2 nanotube arrays. The results showed that the photoelectrocatalytic process was more efficient than photocatalytic and electrolytic process alone. The results exhibited that the photoelectrocatalytic efficiency was significantly affected by the properties of the catalysts and bias potential, and the highest photoelectrocatalytic degradation rate was achieved with Zr, N/TiO2 at 1 V and the order was Zr, N/TiO2 > Zr/TiO2 > TiO2. The mechanism was also discussed by detecting the changes of pH value, bromine anion, total organic carbon and intermediates during the process. 相似文献
604.
Degradation of rhodamine B by Fe(0)-based Fenton process with H2O2 was investigated. The effects of H2O2 dose, Fe(0) dose, initial concentration of rhodamine B and initial pH value on the degradation of rhodamine B were examined. The results showed that the degradation and mineralization of rhodamine B occurred with low dose of H2O2 and Fe(0). The intermediates of rhodamine B were analyzed with UV-Vis spectrophotometry and ion chromatography and the mechanism of oxidative degradation of rhodamine B was also discussed. The reactive oxygen species (·OH) produced in Fe(0)-based Fenton process with H2O2 is the key to the degradation of rhodamine B by ways of N-de-ethylation, chromophore cleavage, ring-opening and mineralization. 相似文献
605.
606.
607.
608.
为了在酸性条件下实现剩余污泥中磷的高效回收,对pH=3时剩余污泥水解酸化过程中氨氮、正磷酸盐和钙镁离子的溶出现象以及磷回收进行了研究分析。结果表明:当pH=3时,所溶出的氨氮、镁离子和钙离子与磷酸盐的摩尔比均大于1,能满足采用鸟粪石沉淀法或者羟磷灰石沉淀法回收磷的要求;但所溶出的钙镁离子的摩尔比大于1,会对鸟粪石沉淀法回收磷的顺利进行有较大影响;有无外加镁剂对磷回收率影响不大。采用改型后的镁型强酸性阳离子交换树脂进行离子交换可以得到较高纯度的鸟粪石沉淀产品,通过XRD检测其纯度为95%以上。 相似文献
609.
采用酸浸法处理高硅铁尾矿,制备工业原料Fe2O3和SiO2微粉.最佳工艺条件为:反应温度100℃,反应时间90 min,铁尾矿中位粒径6.19 μm,盐酸体积分数60%.在上述最佳条件下,制备的SiO2产率(所得产品中SiO2的质量占原铁尾矿中SiO2质量的比例,下同)达98.2%,品质达到YB/T 115-2004《... 相似文献
610.
An experimental study on using rare earth elements to trace phosphorous losses from nonpoint sources
Controlling phosphorous (P) inputs through management of its sources and transport is critical for limiting freshwater eutrophication. In this study, characteristics of exogenous rare earth elements (REEs) and P and their losses with surface runoff (both in the water and sediments) during simulated rainfall experiments (83 mm h−1) were investigated. The results revealed that on average most REEs (La, 94%; Nd, 93%; Sm, 96%) and P (96%) transported with sediments in the runoff. The total amounts of losses of REEs and P in the runoff were significantly correlated, suggesting the possibility of using REEs to trace the fate of agricultural nonpoint P losses. 相似文献