全文获取类型
收费全文 | 361篇 |
免费 | 12篇 |
国内免费 | 88篇 |
专业分类
安全科学 | 21篇 |
废物处理 | 16篇 |
环保管理 | 28篇 |
综合类 | 182篇 |
基础理论 | 51篇 |
污染及防治 | 121篇 |
评价与监测 | 18篇 |
社会与环境 | 14篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 14篇 |
2020年 | 4篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2017年 | 18篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 21篇 |
2013年 | 51篇 |
2012年 | 25篇 |
2011年 | 30篇 |
2010年 | 32篇 |
2009年 | 21篇 |
2008年 | 29篇 |
2007年 | 23篇 |
2006年 | 23篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 11篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有461条查询结果,搜索用时 250 毫秒
61.
Dyestuffs and heavy metal ions in water are seriously harmful to the ecological environment and human health.Three-dimensional(3 D) flowerlike Fe(OH)_3 microspheres were synthesized through a green yet low-cost injection method,for the removal of organic dyes and heavy metal ions.The Fe(OH)_3 microspheres were characterized by thermal gravimetric analysis(TGA),Fourier transform infrared(FT-IR),and transmission electron microscopy(TEM) techniques.The adsorption kinetics of Congo Red(CR) on Fe(OH)_3 microspheres obeyed the pseudo-second-order model.Cr~(6+) and Pb~(2+) adsorption behaviors on Fe(OH)_3 microspheres followed the Langmuir isotherm model.The maximum adsorption capacities of the synthesized Fe(OH)_3 were 308,52.94,and 75.64 mg/g for CR,Cr~(6+),and Pb~(2+) respectively.The enhanced adsorption performance originated from its surface properties and large specific surface area of 250 m~2/g.The microspheres also have excellent adsorption stability and recyclability.Another merit of the Fe(OH)_3 material is that it also acts as a Fenton-like catalyst.These twin functionalities(both as adsorbent and Fenton-like catalyst) give the synthesized Fe(OH)_3 microspheres great potential in the field of water treatment. 相似文献
62.
Photovoltaic (PV) power generation has high investment costs and long payback periods. Therefore, during early deployment, subsidies are fundamental and necessary to accelerate its development. We consider the question of how to promote PV industry development and which supporting policy is more efficient in accelerating adoption. Based on real options method, we establish a subsidy efficiency model for electricity price subsidies and carbon-trading subsidies under two sources of uncertainty power demand for PV and the investment cost-reduction probability. This study aims to compare the two forms of subsidies from the perspective of promoting immediate investment and maximizing the subsidy policy efficiency for the government (minimizing the unit carbon-mitigation cost) and advance relevant policy proposals. An example of China is provided to test the effectiveness of the model and to illustrate the implications of the solutions. The results show that a carbon-trading subsidy is better than an electricity price subsidy and that it is essential to improve the demand for the power produced by the PV power-generation projects. Lower market risk and driving technology progress are both conducive to improving the subsidy efficiency. This study also provides a meaningful reference for governments worldwide to formulate subsidy programs to support PV power-generation projects. 相似文献
63.
64.
Bing Zhang Jun Bi Beibei Liu 《Frontiers of Environmental Science & Engineering in China》2009,3(2):210-220
Small- and medium-sized enterprises (SMEs) play an important role in sustainable development not only for their significant
contribution to China’s economy, but also for their large share of total discharged pollutants. Therefore, this research takes
the enterprises in Suzhou Industrial Park, China as the case study to investigate the environmental management practices of
SMEs, and identify drivers and barriers to engaging businesses in environmental management initiatives. It is shown that,
as in other countries, SMEs are less active in adopting environmental management initiatives than larger companies. Legislation
remains the key driver to engage SMEs in environmental management initiatives. Based on the analysis, policy recommendations
are also presented. 相似文献
65.
分析了苯乙烯装置的主要污染源及装置能耗高、物耗高和污染重的重点部位,介绍了主要的清洁生产方案,并对方案实施后产生的效果进行了分析。 相似文献
66.
移民与生态环境问题是丹江口水库水位抬高所面临的主要问题。移民问题是水位抬高首当其冲需要解决的难题,存在政策法规、移民资金、安置措施、脱贫致富等问题,需要以市场为导向,综合考虑诸多因素,制定可行的移民规划,确保移民的稳定和发展。生态环境问题是非常艰巨的问题,水土流失严重、污染源与污染总量日益增加、水质下降、支流库湾富营养化进程加剧等问题将困扰水库的运行与管理,后靠移民的生产生活也在一定程度上对生态环境产生影响;建议成立专门的监管机构,全方位开展水源地保护工作,确保水库水质安全和南水北调中线工程战略目标的实现。 相似文献
67.
采用超声萃取-高效液相色谱荧光检测法对土壤中苯并[a]芘含量进行定性、定量分析.土壤样品用正己烷/二氯甲烷(1+1)超声萃取,萃取液经硅胶柱或佛罗里硅土柱净化浓缩定容,乙腈-水为流动相,线性梯度洗脱,流速为1.0 mL/min,荧光检测器激发波长为280 nm,发射波长为420 nm,外标法峰面积定量.结果显示:该方法检出限低,苯并[a]芘的检出限为0.15μg/kg.这种方法具有很好的精密度,相对标准偏差为3.9%~8.4%.实际水样加标回收率范围在72.5%~85.8%.能够满足土壤的监测要求. 相似文献
68.
利用反渗透工艺对冷轧废水生化处理废水进行处理,获得了较好的脱盐效果。选取进水含盐量、回收率、pH值对系统脱盐率的影响。结果表明:当进水电导率为1 360μs/cm时,系统脱盐率可达94.7%;进水电导率为3 353μs/cm时,系统脱盐率为85.9%。当系统回收率低于77%时,除盐率受其影响较小在90%左右,但是若进一步增加系统回收率,则脱盐效果显著下降。当进水pH值越高脱盐效果越高,但为降低结垢风险,本系统进水pH值控制在7.1左右。 相似文献
69.
70.
In this paper we address the problem of estimation of the variance of a normal population based on a balanced as well as an unbalanced ranked set sample (RSS), which is a modification of the original RSS of McIntyre (1952).We have proposed several methods of estimation of variance by combining different unbiased between and within estimators, and compared their performances 相似文献