全文获取类型
收费全文 | 2509篇 |
免费 | 86篇 |
国内免费 | 700篇 |
专业分类
安全科学 | 136篇 |
废物处理 | 167篇 |
环保管理 | 194篇 |
综合类 | 1128篇 |
基础理论 | 431篇 |
环境理论 | 1篇 |
污染及防治 | 961篇 |
评价与监测 | 111篇 |
社会与环境 | 58篇 |
灾害及防治 | 108篇 |
出版年
2023年 | 36篇 |
2022年 | 110篇 |
2021年 | 104篇 |
2020年 | 64篇 |
2019年 | 68篇 |
2018年 | 73篇 |
2017年 | 111篇 |
2016年 | 131篇 |
2015年 | 120篇 |
2014年 | 208篇 |
2013年 | 254篇 |
2012年 | 229篇 |
2011年 | 231篇 |
2010年 | 171篇 |
2009年 | 162篇 |
2008年 | 164篇 |
2007年 | 144篇 |
2006年 | 142篇 |
2005年 | 99篇 |
2004年 | 68篇 |
2003年 | 80篇 |
2002年 | 69篇 |
2001年 | 52篇 |
2000年 | 49篇 |
1999年 | 57篇 |
1998年 | 50篇 |
1997年 | 52篇 |
1996年 | 31篇 |
1995年 | 32篇 |
1994年 | 27篇 |
1993年 | 19篇 |
1992年 | 23篇 |
1991年 | 12篇 |
1990年 | 18篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1958年 | 2篇 |
排序方式: 共有3295条查询结果,搜索用时 62 毫秒
751.
752.
753.
Juan Qin Chuanmeng Yang Chong Cui Jiantao Huang Ahmad Hussain Hailong Ma 《环境科学学报(英文版)》2016,28(9):91-99
Lime mud is a kind of solid waste in the papermaking industry, which has been a source of serious environmental pollution. Ceramsites containing anorthite and gehlenite were prepared from lime mud and fly ash through the solid state reaction method at 1050°C. The objective of this study was to explore the efficiency of Ca2 + and OH− release and assess the phosphorus and copper ion removal performance of the ceramsites via batch experiments, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that Ca2 + and OH− were released from the ceramsites due to the dissolution of anorthite, gehlenite and available lime. It is also concluded that gehlenite had stronger capacity for Ca2 + and OH− release compared with anorthite. The Ca2 + release could be fit well by the Avrami kinetic model. Increases of porosity, dosage and temperature were associated with increases in the concentrations of Ca2 + and OH− released. Under different conditions, the ceramsites could maintain aqueous solutions in alkaline conditions (pH = 9.3–10.9) and the release of Ca2 + was not affected. The removal rates of phosphorus and copper ions were as high as 96.88% and 96.81%, respectively. The final pH values of both phosphorus and copper ions solutions changed slightly. The reuse of lime mud in the form of ceramsites is an effective strategy. 相似文献
754.
Changzhou Xu Rongjun Qu Shasha Li Changmei Sun Ying Zhang Jingjing Gao Yuzhong Niu Qianli Ma Xiquan Song Shuangcheng Wang Chunxia Li 《Journal of Polymers and the Environment》2016,24(3):206-220
A series of nanaoscale aramid-based adsorbents were prepared by the functionalization of poly (p-phenylene terephthalamide) (PPTA) with different content of ethylenediamine (EDA). Their structures were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. Metal ions, including Hg2+, Pb2+, Ag+, Cu2+, Cd2+, and Ni2+ were chosen as the models to explore the binding behaviors of PPTA–ECH–EDA in aqueous medium. Results showed that PPTA–ECH–EDA exhibited higher adsorption capacity for Hg2+ due to their nanoscale structures. In particular, the adsorption rate was so high that equilibrium was achieved within 15 min for Hg2+. The adsorption of Hg2+ on PPTA–ECH–EDA followed the pseudo second-order model well. Langmuir and Freundlich models were employed to fit the isothermal adsorption, and the results revealed that Freundlich isotherm was a better model to predict the experimental data. The adsorption mechanism was revealed by X-ray photoelectron spectroscopy. It is preconceived that PPTA–ECH–EDA could be used as an effective adsorbent for fast removal of heavy ions from wastewater. 相似文献
755.
采用水热法制备了BiPO_4-BiVO_4复合光催化剂,运用XRD,SEM,UV-Vis DRS技术对其进行了表征,并以亚甲基蓝为目标降解物考察了复合光催化剂在模拟太阳光下的光催化性能。实验结果表明:当BiPO_4与BiVO_4的摩尔比(磷钒比)为2∶8时BiPO_4-BiVO_4的光催化性能最优,光照180 min时对亚甲基蓝(初始质量浓度5mg/L)的降解率达96.20%,反应速率常数为0.018 1 min-1,明显优于单纯BiPO_4和BiVO_4。表征结果显示:单斜相的BiPO_4与BiVO_4晶粒实现了复合生长,BiPO_4-BiVO_4(磷钒比2∶8)的晶粒粒径比单纯BiPO_4和BiVO_4小;复合光催化剂在紫外光和可见光区均具有较好的光响应,且其禁带宽度较BiPO_4明显减小。 相似文献
756.
开封市公园灰尘重金属含量及潜在生态风险 总被引:3,自引:0,他引:3
采集河南省开封市区4个典型公园(清明上河园、龙亭公园、铁塔公园、相国寺)52个地表灰尘样品,采用原子荧光(AFS)法、电感耦合等离子体发射光谱法(ICP)和电感耦合等离子体质谱(ICP-MS)法测定灰尘重金属含量,并用调整后的Hkanson潜在生态危害分级标准对重金属潜在生态危害进行评价。结果表明:灰尘Cd、Hg、Pb、Zn、Cu富集显著。重金属单项生态风险指数(E)顺序为HgCdPbCuNiZnCoCrMnTi,除Hg和Cd出现强烈以上生态风险外,其他重金属风险轻微。所有公园灰尘重金属潜在生态总风险(RI)均在很强等级以上,其大小依次为RI相国寺RI龙亭公园RI铁塔公园RI清明上河园。灰尘Hg和Cd对RI的平均贡献率分别为45.28%和46.77%,是最主要的风险因子。 相似文献
757.
758.
759.
760.
运用探地雷达进行加油站埋地罐区油品泄漏检测,先后对8座加油站进行了埋地罐区泄漏测试,发现某加油站埋地罐区的疑似泄漏区域,并对疑似泄漏区域进行了验证确认。 相似文献