全文获取类型
收费全文 | 894篇 |
免费 | 43篇 |
国内免费 | 98篇 |
专业分类
安全科学 | 197篇 |
废物处理 | 11篇 |
环保管理 | 152篇 |
综合类 | 375篇 |
基础理论 | 72篇 |
污染及防治 | 69篇 |
评价与监测 | 36篇 |
社会与环境 | 65篇 |
灾害及防治 | 58篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 18篇 |
2020年 | 19篇 |
2019年 | 12篇 |
2018年 | 18篇 |
2017年 | 22篇 |
2016年 | 25篇 |
2015年 | 39篇 |
2014年 | 40篇 |
2013年 | 86篇 |
2012年 | 57篇 |
2011年 | 69篇 |
2010年 | 51篇 |
2009年 | 51篇 |
2008年 | 39篇 |
2007年 | 97篇 |
2006年 | 61篇 |
2005年 | 52篇 |
2004年 | 35篇 |
2003年 | 38篇 |
2002年 | 42篇 |
2001年 | 27篇 |
2000年 | 29篇 |
1999年 | 16篇 |
1998年 | 20篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 8篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有1035条查询结果,搜索用时 31 毫秒
721.
排污权交易制度是一种通过市场机制实现对环境容量资源的基础性配置,以达到控制污染、保护环境的方法。我国借鉴发达国家的成功经验,于1988年开始尝试引入排污权交易制度进行环境治理工作,并取得了一定的成效。但综合看来,我国排污权交易制度体系的构建仍处于起步阶段,在总量控制的科学确定、排污权初始的公平分配、培育交易市场等问题上仍有待于进一步探索和研究。 相似文献
722.
液化天然气气化站风险评价实例分析 总被引:1,自引:0,他引:1
以某拟建液化天然气气化站项目为例,对环境风险评价的要点进行了分析.根据风险导则要求及重大危险源辨识标准,对液化天然气气化站的重大风险源进行了识别,给出了最大可信事故及源强的确定方法,采用多烟团模式及蒸气云爆炸模式对确定的最大可信事故后果进行预测,并阐述了风险计算和评价结论及风险管理等内容. 相似文献
723.
Francesco Ciliberti Pierpaolo Pontrandolfo Barbara Scozzi 《Journal of Cleaner Production》2008,16(15):1579-1588
This paper analyzes the practices adopted and difficulties experienced by Small and Medium-sized Enterprises (SMEs) to transfer socially responsible behaviors to suppliers that operate in developing countries. In particular, a multiple case study was conducted on five Italian socially responsible SMEs. It was found that companies use different strategies as well as diverse management systems and tools to address Corporate Social Responsibility (CSR) issues along their supply chains (SCs). The paper is innovative mainly since few are the existing studies that investigate the CSR practices adopted by SMEs in the SC. Furthermore, it is argued that our research can be helpful to SME managers willing to deal with CSR issues along their SCs, especially when developing countries are involved. 相似文献
724.
The present work deals with the As(Ⅴ) removal from an aqueous medium by calcined refractory grade bauxite (CRB) as a function of solution pH, time, As(Ⅴ) concentration and temperature. The residual As(Ⅴ) was lowered from 2 mg/L to below 0.01 mg/L in the optimum pH range 4.0-7.0 using a 5 g/L CRB within 3 h contact time. The adsorption data fits well with Langmuir isotherm and yielded Langmuir monolayer capacity of 1.78 mg As(Ⅴ)/g of CRB at pH 7.0. Presence of anions such as silicate and phosphate decreased As(Ⅴ) adsorption efficiency. An increase temperature resulted a decrease in the amount of As(Ⅴ) adsorbed by 6%. The continuous fixed bed column study showed that at the adsorbent bed depth of 30 cm and residence time of 168 min, the CRB was capable of treating 340 bed volumes of As(V) spiked water (C0 = 2 mg/L) before breakthrough (Ce = 0.01 mg/L). This solid adsorbent, although not reusable, can be considered for design of adsorption columns as an efficiency arsenic adsorption media. 相似文献
725.
Comparative equilibrium studies of sorption of Pb(II) ions by sodium and
calcium alginate 总被引:1,自引:0,他引:1
The absorption of Pb(II) ions from aqueous solution by di erent alginate compounds was studied in a batch sorption system. Water
soluble sodium alginate and insoluble calcium alginate beads were investigated. The lead-binding capacity of both alginate compounds
was highest within the pH range 6–8. The binding capacities and rates of Pb(II) ions by alginate compounds were evaluated. The
Langmuir, Freundlich, and Bruneaur, Emmet and Teller (BET) sorption models were applied to describe the isotherms and isotherm
constants. Sorption isothermal data could be well interpreted by the Langmuir model. The results obtained through the study suggest that
alginate compounds are favorable sorbents. The largest amount of Pb(II) ions were bound by sodium alginate although the di erence
between two compounds was slight. Therefore, alginate substances may be considered as an alternative for sorption and removal of
Pb(II) ions from wastewaters. 相似文献
726.
在实验室及生产性试验考察基础上,对某能源公司高浓度焦化污水进行深度处理后排放并回用。处理工程选择气浮-两相厌氧-A/O-混凝砂滤处理工艺,最大限度的去除掉水中高浓度焦油、酚、氰、氨氮、有机物等物质,使出水达到生产回用标准,为焦化废水的治理提供新经验,也为解决水资源供需矛盾探讨一条新的途径。 相似文献
727.
A fuzzy expert system for soil characterization 总被引:1,自引:0,他引:1
As soil is a natural resource not always renewable, the risk characterization of contaminated soils is an issue of great interest. Artificial Intelligence (AI), based on Decision Support Systems (DSSs), has been developed for a wide range of applications in contaminated soil management. Decision trees have already shown to be easy to interpret and able to treat large scale applications. Fuzzy logic gives an improvement in the perturbations and the variance of the training data, due to the elasticity of fuzzy set formalism. In this study, we have developed a classificatory tool applied to characterize contaminated soil in function of human and environmental risks. Knowledge engineering for constructing the Soil Risk Characterization Decision Support System (SRC-DSS) involves three stages: knowledge acquisition, conceptual design and system implementation. A total of 26 parameters were divided into three groups to facilitate the configuration of the expert system: source attributes, transfer vector attributes, and local properties. Sixteen case studies were evaluated with the SRC-DSS. In comparison with other techniques, the results of the current study have shown that SRC-DDS is an excellent tool to classify and characterize soils according to the associated risk. 相似文献
728.
729.
山地旅游研究进展与启示 总被引:10,自引:1,他引:9
为探讨山地旅游研究中存在的问题及发展方向,在参阅相关研究文献的基础上,分析了国内外山地旅游研究进展。从研究内容、研究结果等方面论述了国外山地旅游研究进展,按时间进展将国内山地旅游研究划分为三个阶段:起步阶段、发展阶段和深化阶段,每一阶段的研究方法、研究内容以及表现特征都有较大差异。从研究内容和研究方法两个方面分析了国内外山地旅游研究差异。从山地旅游发展及研究现状来看,今后山地旅游研究应创新和改进研究方法以及技术路线,加强旅游发展条件下的山地人地关系地域系统研究,研究新的要素在山地旅游发展中的作用过程和作用机制,加强不同时空尺度条件下的山地旅游发展特征、演化过程和演化规律研究。 相似文献
730.
以富源县“十一五”工业发展规划环评为例,就西部欠发达地区如何采用简单、实用的评价手段,克服西部欠发达地区社会、经济落后、观念意识淡薄、环境污染严重、生态环境恶化、评价方法不成熟等困难,使规划环评真正做到评价与决策有机结合进行了研究和探讨。 相似文献