全文获取类型
收费全文 | 2892篇 |
免费 | 202篇 |
国内免费 | 1169篇 |
专业分类
安全科学 | 238篇 |
废物处理 | 173篇 |
环保管理 | 240篇 |
综合类 | 1829篇 |
基础理论 | 447篇 |
污染及防治 | 1021篇 |
评价与监测 | 125篇 |
社会与环境 | 104篇 |
灾害及防治 | 86篇 |
出版年
2024年 | 6篇 |
2023年 | 83篇 |
2022年 | 182篇 |
2021年 | 189篇 |
2020年 | 134篇 |
2019年 | 115篇 |
2018年 | 124篇 |
2017年 | 156篇 |
2016年 | 144篇 |
2015年 | 166篇 |
2014年 | 248篇 |
2013年 | 301篇 |
2012年 | 226篇 |
2011年 | 278篇 |
2010年 | 202篇 |
2009年 | 190篇 |
2008年 | 195篇 |
2007年 | 177篇 |
2006年 | 145篇 |
2005年 | 107篇 |
2004年 | 89篇 |
2003年 | 84篇 |
2002年 | 70篇 |
2001年 | 79篇 |
2000年 | 87篇 |
1999年 | 79篇 |
1998年 | 72篇 |
1997年 | 51篇 |
1996年 | 58篇 |
1995年 | 50篇 |
1994年 | 33篇 |
1993年 | 29篇 |
1992年 | 25篇 |
1991年 | 21篇 |
1990年 | 22篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1974年 | 1篇 |
1973年 | 5篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有4263条查询结果,搜索用时 906 毫秒
991.
在经典的DEA模型的基础上进行了修正,采用四阶段DEA模型,旨在剔除环境控制变量对效率测度结果的影响.同时,在DEA模型的基础上引入Malmquist指数分析法,以弥补DEA模型无法测度面板数据的缺陷.选取了2012年-2014年A股节能环保上市公司的面板数据,测度了样本的融资效率及三年的融资效率变化情况,结果表明:资源循环利用行业的融资效率最高,其次是环保行业,融资效率最低的是节能行业.样本企业总体的融资效率每年都在增长,但增长速度开始放缓. 相似文献
992.
993.
994.
995.
Lan-Cui Liu Qi Li Jiu-Tian Zhang Dong Cao 《Mitigation and Adaptation Strategies for Global Change》2016,21(2):191-207
China encourages the demonstration of carbon capture and storage (CCS) projects. In an effort to identify gaps and provide suggestions for environmental risk management of carbon dioxide (CO2) geological storage in China, this article presents a concise overview of potential health, safety and environmental (HSE) risks and environmental management regulations for CO2 geological storage in Australia, Japan, the United States (USA), the European Union (EU), and the United Kingdom (UK). The environmental impact assessment (EIA) experience of Shenhua Ordos Coal-to-Liquid (CTL) Project and PetroChina Jilin Oil Field enhanced oil recovery (EOR) is subsequently analyzed in light of our field investigation, and gaps in current EIA guidelines that are applicable to CO2 geological storage projects are identified. It is found that there are no specific environmental risk regulations suitable for CO2 storage in China, and environmental risk management lags behind the development of CCS technology, which presents a challenge to demonstration enterprises in terms of assessing environmental risk. One major challenge is the overestimation or underestimation of this risk on the part of the enterprise, and another is a lack of applicable regulations for government sectors to supervise the risk throughout CCS projects. Therefore, there is a pressing need for China to formulate environmental management regulations that include environmental risk assessment, mandatory monitoring schemes, environmental emergency plans, and related issues. 相似文献
996.
运用富集系数等多种评价方法和多变量分析方法对海州湾潮滩HZ02岩芯沉积物的7种重金属(Cr、Mn、Ni、Cu、Zn、As、Pb)进行了污染生态风险评估和金属来源识别。结果表明,海州湾潮滩岩芯沉积物重金属平均浓度分别为Cr(92.56×10-6)、Mn(1492.02×10-6)、Ni(48.01×10-6)、Cu(40.24×10-6)、Zn(116.23×10-6)、As(17.98×10-6)和Pb(44.98×10-6),其平均浓度由大到小的顺序为:Mn > Zn > Cr > Ni > Cu > Pb > As。7种重金属浓度在1980年后开始逐渐上升,1985~1990年为低峰值,1990年后呈快速上升趋势。海州湾潮滩沉积物7种重金属在5种评价方法评估中均表现为轻度至中度污染。多变量分析结果表明重金属分三类:第一类为重金属Cr、Ni、Cu和Zn,可能来自工业和城市污染的排放,第二类为重金属Mn和As,可能来自农业污染,第三类为Pb,可能来源于海港交通。 相似文献
997.
Alberto Rovetta Fan Xiumin Federico Vicentini Zhu Minghua Alessandro Giusti He Qichang 《Waste management (New York, N.Y.)》2009,29(12):2939-2949
The present study describes a novel application for use in the monitoring of municipal solid waste, based on distributed sensor technology and geographical information systems. Original field testing and evaluation of the application were carried out in Pudong, Shanghai (PR China).The local waste management system in Pudong features particular requirements related to the rapidly increasing rate of waste production. In view of the fact that collected waste is currently deployed to landfills or to incineration plants within the context investigated, the key aspects to be taken into account in waste collection procedures include monitoring of the overall amount of waste produced, quantitative measurement of the waste present at each collection point and identification of classes of material present in the collected waste. The case study described herein focuses particularly on the above mentioned aspects, proposing the implementation of a network of sensorized waste containers linked to a data management system.Containers used were equipped with a set of sensors mounted onto standard waste bins. The design, implementation and validation procedures applied are subsequently described. The main aim to be achieved by data collection and evaluation was to provide for feasibility analysis of the final device. Data pertaining to the content of waste containers, sampled and processed by means of devices validated on two purpose-designed prototypes, were therefore uploaded to a central monitoring server using GPRS connection. The data monitoring and management modules are integrated into an existing application used by local municipal authorities.A field test campaign was performed in the Pudong area. The system was evaluated in terms of real data flow from the network nodes (containers) as well as in terms of optimization functions, such as collection vehicle routing and scheduling. The most important outcomes obtained were related to calculations of waste weight and volume. The latter data were subsequently used as parameters for the routing optimization of collection trucks and material density evaluation. 相似文献
998.
999.
1000.
The development of low-cost and efficient new mineral adsorbents has been a hot topic in recent years.In this study,Friedel's salt (FS:3CaO·Al2O3·CaCl2·10H2O),a hexagonal layered inorganic absorbent,wa... 相似文献