全文获取类型
收费全文 | 227篇 |
免费 | 13篇 |
国内免费 | 177篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 8篇 |
环保管理 | 26篇 |
综合类 | 219篇 |
基础理论 | 77篇 |
污染及防治 | 58篇 |
评价与监测 | 5篇 |
社会与环境 | 12篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 14篇 |
2020年 | 6篇 |
2019年 | 22篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 8篇 |
2015年 | 18篇 |
2014年 | 13篇 |
2013年 | 32篇 |
2012年 | 19篇 |
2011年 | 24篇 |
2010年 | 14篇 |
2009年 | 18篇 |
2008年 | 16篇 |
2007年 | 29篇 |
2006年 | 15篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 24篇 |
2002年 | 16篇 |
2001年 | 14篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
排序方式: 共有417条查询结果,搜索用时 15 毫秒
121.
122.
应用PCR-DGGE方法,追踪了汉沽工业废水处理中好氧工艺的活性污泥系统中微生物群落结构动态变化过程及其微生物群落结构组成。研究结果表明:系统中的微生物群落结构随水质变化而变化,随着培养时间的延长,微生物群落结构趋于稳定,分别属于5大类群,与γ、δ、α、ε变形杆菌(Proteobacterias)、芽孢杆菌(Bacilli)的亲缘关系较近。其中γ变形杆菌是该废水处理过程中的主要菌群,包括Pseudomonas sp.、Rheinheimera sp.、Citrobacter sp.、Klebsiella sp.、Enterbacte-riaceae、Stenotrophomonas maltophilia、Acinetobacter。在整个系统中uncultured Pseudomonas sp.、Halobacillus sp.、Pseudomonassp.、Pseudomonas stutzeri、Acinetobacter sp.可稳定存在于系统中,为该污水处理系统中的优势微生物。因此,提高Halobacillussp.、Pseudomonas sp.、Pseudomonas stutzeri、Acinetobacter sp.菌属在系统中的数量和质量,有利于提高废水生化处理的效果。 相似文献
123.
124.
Biodegradation of keratin waste: Theory and practical aspects 总被引:1,自引:0,他引:1
Keratin-rich by-products, i.e. bristles, horns and hooves, chicken feathers and similar, are a source of nutrients for animals (amino acids) and plants (N, S). Contemporary developments in the management of keratin waste in feeds and fertilizers comply with human and animal health protection regulations and respect the principles of ecological development. Biotechnological methods employing keratinolytic bacteria and microscopic fungi play a key role in processing keratin waste.This study reviews the current knowledge on the ecology and physiology of keratinolytic microorganisms and presents the biodegradation mechanism of native keratin. The structure and chemical composition of keratin proteins are described, and methods of keratin waste biotransformation into products of practical industrial and natural value, especially composts, are discussed. 相似文献
125.
126.
Yann Devos Pieter Maeseele Dirk Reheul Linda Van Speybroeck Danny De Waele 《Journal of Agricultural and Environmental Ethics》2008,21(1):29-61
Via a historical reconstruction, this paper primarily demonstrates how the societal debate on genetically modified organisms
(GMOs) gradually extended in terms of actors involved and concerns reflected. It is argued that the implementation of recombinant
DNA technology out of the laboratory and into civil society entailed a “complex of concerns.” In this complex, distinctions
between environmental, agricultural, socio-economic, and ethical issues proved to be blurred. This fueled the confusion between
the wider debate on genetic modification and the risk assessment of transgenic crops in the European Union. In this paper,
the lasting skeptical and/or ambivalent attitude of Europeans towards agro-food biotechnology is interpreted as signaling
an ongoing social request – and even a quest – for an evaluation of biotechnology with Sense and Sensibility. In this (re)quest, a broader-than-scientific dimension is sought for that allows addressing the GMO debate in a more “sensible”
way, whilst making “sense” of the different stances taken in it. Here, the restyling of the European regulatory frame on transgenic
agro-food products and of science communication models are discussed and taken to be indicative of the (re)quest to move from
a merely scientific evaluation and risk-based policy towards a socially more robust evaluation that takes the “non-scientific”
concerns at stake in the GMO debate seriously. 相似文献
127.
Celina Ramjoué 《Journal of Agricultural and Environmental Ethics》2007,20(5):419-436
The regulatory structures underlying United States and European Union policies regarding genetically modified (GM) food and crops are fundamentally different. The US regulates GM foods and crops as end products, applying roughly the same regulatory framework that it does to non GM foods or crops. The EU, on the other hand, regulates products of agricultural biotechnology as the result of a specific production process. Accordingly, it has developed a network of rules that regulate GM foods and crops specifically. As a result, US regulation of GM foods and crops is relatively permissive, whereas EU regulation is relatively restrictive. Why are genetically modified food policies in the United States and the European Union so strikingly different? In the light of the recent World Trade Organization dispute on agricultural biotechnology, it may seem that economic interests are the driving force behind policies. While they are certainly part of the picture, the issue is far more complex. This paper argues that three different elements help explain differences between US and EU GM food policies. First, an investigation of US and European policies of the 1970s and 1980s on recombinant DNA research and of events leading up to early GM food and crop regulation allows a deeper understanding of current policy. Second, scrutinizing underlying values and norms can uncover the beliefs that condition current GM food and crop policy. Third, an analysis of involved actors’ views and levels of success in influencing policy is essential to understanding US and EU policies. 相似文献
128.
Robert?StreifferEmail author Thomas?Hedemann 《Journal of Agricultural and Environmental Ethics》2005,18(2):191-210
Many people object to genetically engineerehd (GE) food because they believe that it is unnatural or that its creation amounts to playing God. These objections are often referred to as intrinsic objections, and they have been widely criticized in the agricultural bioethics literature as being unsound, incompatible with modern science, religious, inchoate, and based on emotion instead of reason. Many of their critics also argue that even if these objections did have some merit as ethicalobjections, their quasi-religious nature means that they are entirely irrelevant when interpreted aspolitical objections regarding what public policy ought to be. In this paper, we argue that this widespread view is false. Intrinsic objections have much more political import than has previously been recognized, and indeed the requirements of political liberalism and its associated idea of liberal neutrality, once properly understood, protect intrinsic objections from many of the most common objections. That is, policy-makers may not legitimately base public policy on grounds that are inconsistent with intrinsic objections, even when they believe those objections to be flawed in the ways mentioned above. This means that in the context of a political debate about GE food, the discussion should not center on the substantive merits of the intrinsic objections themselves but rather on the appropriate political norms for achieving democratically legitimate policy on issues that touch people’s deepest religious and moral beliefs. 相似文献
129.
Biodegradation of polymeric materials affect a wide range of industries, information on degradability can provide fundamental information facilitating design and life-time analysis of materials. Among the methods currently used in testing, traditional gravimetric and respirometric techniques are tailored to readily degradable polymeric materials mostly and polymer blends with biodegradable components, but they are not applicable to the new generation of engineering polymers which are relatively resistant to biodegradation. However, electrochemical impedance spectroscopy (EIS) has been tested for monitoring biodeterioration of high strength materials and the technique has very high sensitivity. A wide range of materials including electronic insulation polyimides, fiber-reinforced polymeric composites (FRPCs) and corrosion protective polyurethane coatings have been successfully measured under inoculation of degradative microorganisms using EIS. In addition, the mechanism of degradation of high strength polymers is mainly due to the presence of plasticizers in the polymer matrices. The information on various methods discussed in this review is intended to illustrate a suite of methods for those who are interested in testing biodeterioration of polymeric materials under different environmental conditions and in selecting appropriate techniques for specific applications. 相似文献
130.