全文获取类型
收费全文 | 1693篇 |
免费 | 20篇 |
国内免费 | 139篇 |
专业分类
安全科学 | 66篇 |
废物处理 | 196篇 |
环保管理 | 276篇 |
综合类 | 933篇 |
基础理论 | 76篇 |
污染及防治 | 148篇 |
评价与监测 | 127篇 |
社会与环境 | 22篇 |
灾害及防治 | 8篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 42篇 |
2021年 | 28篇 |
2020年 | 48篇 |
2019年 | 23篇 |
2018年 | 14篇 |
2017年 | 43篇 |
2016年 | 35篇 |
2015年 | 44篇 |
2014年 | 134篇 |
2013年 | 101篇 |
2012年 | 58篇 |
2011年 | 106篇 |
2010年 | 40篇 |
2009年 | 93篇 |
2008年 | 74篇 |
2007年 | 100篇 |
2006年 | 79篇 |
2005年 | 71篇 |
2004年 | 64篇 |
2003年 | 83篇 |
2002年 | 85篇 |
2001年 | 69篇 |
2000年 | 81篇 |
1999年 | 62篇 |
1998年 | 56篇 |
1997年 | 53篇 |
1996年 | 34篇 |
1995年 | 26篇 |
1994年 | 44篇 |
1993年 | 19篇 |
1992年 | 12篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有1852条查询结果,搜索用时 234 毫秒
991.
Jan M. Kooijman 《Environmental management》1993,17(5):575-586
The functions of packaging are derived from product requirements, thus for insight into the environmental effects of packaging
the actual combination of product and package has to be evaluated along the production and distribution system. This extension
to all related environmental aspects adds realism to the environmental analysis and provides guidance for design while preventing
a too detailed investigation of parts of the production system. This approach is contrary to current environmental studies
where packaging is always treated as an independent object, neglecting the more important environmental effects of the product
that are influenced by packaging.
The general analysis and quantification stages for this approach are described, and the currently available methods for the
assessment of environmental effects are reviewed. To limit the workload involved in an environmental assessment, a step-by-step
analysis and the use of feedback is recommended. First the dominant environmental effects of a particular product and its
production and distribution are estimated. Then, on the basis of these preliminary results, the appropriate system boundaries
are chosen and the need for further or more detailed environmental analysis is determined. For typical food and drink applications,
the effect of different system boundaries on the outcome of environmental assessments and the advantage of the step-by-step
analysis of the food supply system is shown. It appears that, depending on the consumer group, different advice for reduction
of environmental effects has to be given. Furthermore, because of interrelated environmental effects of the food supply system,
the continuing quest for more detailed and accurate analysis of the package components is not necessary for improved management
of the environmental effects of packaging. 相似文献
992.
The recycling sector in India, which consists of a comprehensive trade and production sector, is rather complex. Nevertheless, it creates important benefits for both the economy and the environment. In order to comprehend the system, a case study has been performed on the recycling sector (paper, plastic, glass and non-ferrous metal) in Bangalore (India), focussing on the market structure, the scale of operation, employment effects, constraints, and recent developments. It was found that this highly competitive and labour-intensive industry is largely dependent on cheap labour and the supply of solid waste from the local trade system. Its mostly informal nature results from the ‘unregisteredness’ of the materials. Consequently, government involvement is avoided as much as possible. With present growth rates, prospects of recycling in Bangalore are advancing. Yet, problems such as lack of supply and loss of quality emerge. Therefore, quality control and market conditions should be improved. 相似文献
993.
994.
用硝酸银滴定法测定水中氯离子时,存在S~2-、SO_3~2-、S_2_O_3~2-的干扰,原用H_2O_2消除干扰,但滴定到达终点后,颜色不太稳定,为此,我们采用过硫酸钾氧化法进行消除干扰的试验。实践证明,该方法对消除上述干扰物是可行的,对测定石油勘探开发废水中氯离子时消除干扰是适用的。 相似文献
995.
Martin B. Hocking 《Environmental management》1986,10(2):179-187
Here are assembled representative excerpts from a new text in applied chemistry. They illustrate the well-referenced treatment of industrial processes that are here considered with their related emission control problems and solutions. A brief account of general aspects of the industry is followed by surveys of the significance and technical aspects of air and water pollution chemistry. Consideration is given to emission avoidance or containment, waste treatment, and waste disposal options as they relate to both of these environmental areas. Details of salt recovery and the products of brine electrolysis plus environmental aspects of these operations are treated as examples of some of the processes discussed. Also covered are fertilizer constituent preparation, formulation, and use with consideration of the large-scale effects of each of these activities. Detailed reference is made to the chemical technology and emission control aspects of the pulp and paper industry and refinery operations. Throughout, integral process changes and waste recycling practices are directly related to emission control aspects of each process in a way to be useful to the student and professional alike. These excerpts are extracted from one of the first, single volume accounts to take this unified approach to the subject.Extract from the bookModern Chemical Technology and Emission Control by M. B. Hocking, published by Springer-Verlag, Berlin, Heidelberg, New York, Tokyo (1985). 相似文献
996.
根据冶金,煤炭及无机化工工业类废渣的物理化学性质,通过M^n+ e-H2O系和M^n+e-F^-H2O系热力学平衡图,对废渣中硅,铝,铁及钙镁等主要矿物的溶出热力学行为进行了分析。 相似文献
997.
998.
The use of recycled waste glasses in Portland cement and concrete has attracted a lot of interest worldwide due to the increased disposal costs and environmental concerns. Being amorphous and containing relatively large quantities of silicon and calcium, glass is, in theory, pozzolanic or even cementitious in nature when it is finely ground. Thus, it can be used as a cement replacement in Portland cement concrete. The use of crushed glasses as aggregates for Portland cement concrete does have some negative effect on properties of the concrete; however, practicle applicability can still be produced even using 100% crushed glass as aggregates. The main concerns for the use of crushed glasses as aggregates for Portland cement concrete is the expansion and cracking caused by the glass aggregates. This paper summarizes the progresses and points out the directions for the proper uses of waste glasses in Portland cement and concrete. 相似文献
999.
高功率微波武器对C^4ISR系统毁伤效应研究 总被引:1,自引:0,他引:1
复杂电磁环境下电子设备易感性问题已引起广泛的关注,特别是军用C4ISR.系统对电子设备的依赖性,使得电磁脉冲的威胁进一步增大。对电磁脉冲的毁伤机理进行了阐述,概叙了电子器件毁伤的特征阈值,并从电磁脉冲对C^4ISR系统信息源的威胁、对计算机系统网络的威胁以及对C4ISR通信网络的威胁等方面分析了高功率微波武器对作战系统的影响,最后提出了防御电磁脉冲的具体防护措施。 相似文献
1000.
针对沈阳市环保系统实行会计集中核算制的背景、意义及会计核算中心运行状况进行详细地分析,总结了当前实行会计集中核算制的积极作用和存在问题,同时提出了完善会计集中核算制的相关措施。 相似文献