全文获取类型
收费全文 | 1696篇 |
免费 | 13篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 44篇 |
废物处理 | 81篇 |
环保管理 | 171篇 |
综合类 | 159篇 |
基础理论 | 324篇 |
环境理论 | 3篇 |
污染及防治 | 640篇 |
评价与监测 | 166篇 |
社会与环境 | 126篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 16篇 |
2022年 | 44篇 |
2021年 | 53篇 |
2020年 | 22篇 |
2019年 | 23篇 |
2018年 | 33篇 |
2017年 | 50篇 |
2016年 | 79篇 |
2015年 | 54篇 |
2014年 | 90篇 |
2013年 | 154篇 |
2012年 | 117篇 |
2011年 | 137篇 |
2010年 | 73篇 |
2009年 | 81篇 |
2008年 | 114篇 |
2007年 | 101篇 |
2006年 | 94篇 |
2005年 | 62篇 |
2004年 | 60篇 |
2003年 | 49篇 |
2002年 | 63篇 |
2001年 | 27篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1986年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1964年 | 1篇 |
1958年 | 2篇 |
1956年 | 1篇 |
排序方式: 共有1720条查询结果,搜索用时 62 毫秒
981.
Current brief aims to introduce the concept of safety in European industrial sectors, particularly in mechanics and machinery industry. It also highlights the importance to ensure an even level of machinery safety along the European Union, setting up the appropriate frame and procedures to keep it under control. An overview over market surveillance activities for machinery (regulations, main actors and their roles) first at Community level, and secondly an approach to one of the Member States is also introduced. 相似文献
982.
Effectiveness of three bulking agents for food waste composting 总被引:3,自引:0,他引:3
Rather than landfilling, composting the organic fraction of municipal solid wastes recycles the waste as a safe and nutrient enriched soil amendment, reduces emissions of greenhouse gases and generates less leachate. The objective of this project was to investigate the composting effectiveness of three bulking agents, namely chopped wheat (Triticum) straw, chopped mature hay consisting of 80% timothy (milium) and 20% clover (triphullum) and pine (pinus) wood shavings. These bulking agents were each mixed in duplicates at three different ratios with food waste (FW) and composted for 10 days using prototype in-vessel composters to observe their temperature and pH trends. Then, each mixture was matured in vertical barrels for 56 days to measure their mass loss and final nutrient content and to visually evaluate their level of decomposition. Chopped wheat straw (CWS) and chopped hay (CH) were the only two formulas that reached thermophilic temperatures during the 10 days of active composting when mixed with FW at a wet mass ratio of 8.9 and 8.6:1 (FW:CWS and FW:CH), respectively. After 56 days of maturation, these two formulas were well decomposed with no or very few recognizable substrate particles, and offered a final TN exceeding the original. Wood shavings (WS) produced the least decomposed compost at maturation, with wood particles still visible in the final product, and with a TN lower than the initial. Nevertheless, all bulking agents produced compost with an organic matter, TN, TP and TK content suitable for use as soil amendment. 相似文献
983.
984.
Mariken H.C. Everdij Henk A.P. Blom Jelmer J. Scholte Jos W. Nollet Bert Kraan 《Safety Science》2009,47(3):405-420
The high volume of air traffic over Europe is expected to double within the next 15 years. This requires changes in the airspace structure and in the organisation of air transport operations that involve multiple stakeholders. Changes, by regulation, require a sufficient safety validation, in order to show that the changed situation is safe and will remain safe during an applicable period. Many methods and techniques exist that can be used to support such safety validation process. However, for air transport operations, the stakeholders involved are numerous and diverse, and there are no guidelines on how to address their roles, responsibilities and goals during development and validation.This paper develops a safety validation framework that emphasises the active roles and collaboration of multiple stakeholders during the development phases of air transport operations. The framework is developed in three steps: First, established validation views from literature are identified and analysed to reveal open issues when it comes to their use for multi-stakeholder changes in air transport operations. Next, validation views emerging beyond the established ones are identified, and evaluated on whether they address the open issues. Finally, the strong points of established and emerging views are combined into a novel framework. 相似文献
985.
The effectiveness of market-based conservation in the tropics: forest certification in Ecuador and Bolivia 总被引:1,自引:0,他引:1
During the last decade, forest certification has gained momentum as a market-based conservation strategy in tropical forest countries. Certification has been promoted to enhance forest management in countries where governance capacities are insufficient to adequately manage natural resources and enforce pertinent regulations, given that certification relies largely on non-governmental organisations and private businesses. However, at present there are few tropical countries with large areas of certified forests. In this study, we conducted semi-structured stakeholder interviews in Ecuador and Bolivia to identify key framework conditions that influence the costs and benefits for companies to switch from conventional to certified forestry operations. Bolivia has a much greater relative area under certified forest management than Ecuador and also significantly more certified producers. The difference in the success of certification between both countries is particularly notable because Bolivia is a poorer country with more widespread corruption, and is landlocked with less access to export routes. Despite these factors, several characteristics of the Bolivian forest industry contribute to lower additional costs of certified forest management compared to Ecuador. Bolivia has stronger government enforcement of forestry regulations a fact that increases the cost of illegal logging, management units are larger, and vertical integration in the process chain from timber extraction to markets is higher. Moreover, forestry laws in Bolivia are highly compatible with certification requirements, and the government provides significant tax benefits to certified producers. Results from this study suggest that certification can be successful in countries where governments have limited governance capacity. However, the economic incentives for certification do not only arise from favourable market conditions. Certification is likely to be more successful where governments enforce forestry laws, provide financial incentives for certified forestry, and provide land tenure security, and where large-scale and vertically integrated forestry operations are commercially feasible. For this reason, at present, there are few developing countries where forest certification is likely to achieve widespread success. 相似文献
986.
José Pereira Tom H. Misselbrook David R. Chadwick João Coutinho Henrique Trindade 《Atmospheric environment (Oxford, England : 1994)》2010,44(28):3413-3421
There is a lack of information on ammonia (NH3) emissions from cattle housing systems in Mediterranean countries, with most published data deriving from NW Europe. An investigation was carried out in NW Portugal to quantify NH3 emissions for the main types of dairy cattle buildings in Portugal, i.e. naturally ventilated buildings and outdoor concrete yards, and to derive robust emission factors (EFs) for these conditions and compare with EFs used elsewhere in Europe. Measurements were made throughout a 12-month period using the passive flux sampling method in the livestock buildings and the equilibrium concentration technique in outdoor yards.The mean NH3 emission factor for the whole housing system (buildings + outdoor yards) was 43.7 g NH3–N LU?1 day?1 and for outdoor concrete yards used by dairy cattle was 26.6 g NH3–N LU?1 day?1. Expressing NH3 emission in terms of the quantity of liquid milk produced gave similar values across the three dairy farms studied (with a mean of 2.3 kg N ton-milk?1 produced) and may have advantages when comparing different farming systems. In dairy houses with outdoor yards, NH3 emissions from the yard area contributed to 69–92% of total emissions from this housing system. Emissions were particularly important during spring and summer seasons from outdoor yards with NH3 emitted in this period accounting for about 72% of annual emissions from outdoor yards. Mean NH3 emission factors derived for this freestall housing system and outdoor concrete yards used by dairy cattle in Portugal were higher than those measured in northern Europe. In addition, values of animal N excretion estimated in this study were greater than official National standard values. If these emissions are typical for Portuguese dairy systems, then the current National inventory underestimates emissions from this source in NW of Portugal, because of the use of lower standard values of N excretion by dairy cattle. 相似文献
987.
José M. Baldasano María Gonçalves Albert Soret Pedro Jiménez-Guerrero 《Atmospheric environment (Oxford, England : 1994)》2010,44(25):2997-3006
Assessing the effects of air quality management strategies in urban areas is a major concern worldwide because of the large impacts on health caused by the exposure to air pollution. In this sense, this work analyses the changes in urban air quality due to the introduction of a maximum speed limit to 80 km h?1 on motorways in a large city by using a novel methodology combining traffic assimilation data and modelling systems implemented in a supercomputing facility. Albeit the methodology has been non-specifically developed and can be extrapolated to any large city or megacity, the case study of Barcelona is presented here. Hourly simulations take into account the entire year 2008 (when the 80 km h?1 limit has been introduced) vs. the traffic conditions for the year 2007. The data has been assimilated in an emission model, which considers hourly variable speeds and hourly traffic intensity in the affected area, taken from long-term measurement campaigns for the aforementioned years; it also permits to take into account the traffic congestion effect. Overall, the emissions are reduced up to 4%; however the local effects of this reduction achieve an important impact for the adjacent area to the roadways, reaching 11%. In this sense, the speed limitation effects assessed represent enhancements in air quality levels (5–7%) of primary pollutants over the area, directly improving the welfare of 1.35 million inhabitants (over 41% of the population of the Metropolitan Area) and affecting 3.29 million dwellers who are potentially benefited from this strategy for air quality management (reducing 0.6% the mortality rates in the area). 相似文献
988.
María N. Murga Salvador Vega José J. Pérez Rutilio Ortiz Beatriz Schettino 《Journal of environmental science and health. Part. B》2016,51(9):589-593
The objective of this study was to evaluate the presence of organochlorine pesticides in samples of forage, soil, water, and milk in four units of an organic production system for cow´s milk (samples of forage, milk, soil, and water) in Tecpatan, Chiapas, Mexico. The organochlorine pesticides were extracted from forage, soil and water based on the USEPA (2005) guideline and from milk based on the IDF 1991 guideline. The pesticides were identified and quantified by gas chromatography with electron capture detector (CG-ECD). In general, the highest average concentration of total pesticides was found in the samples of milk and forage (311 ± 328 and 116.5 ±77 ng g?1 respectively). Although, the production systems analyzed are organic, organochlorine pesticides were detected in all environmental samples (forage, soil, water, and organic milk). Although no values surpassed the defined limits of Mexican and International regulation it is advisable that a monitoring program of contaminants in these production systems is continued. 相似文献
989.
A Systematic Framework for the Design and Implementation of a Quality Management Practice: The Case of a Consulting Engineering Company
下载免费PDF全文
![点击此处可从《环境质量管理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Herlander Mata‐Lima Fernando Morgado‐Dias Marina Carrato Galuzzi da Silva Kelly Alcântara José António Almeida 《环境质量管理》2016,25(4):49-61
Company productivity and competitiveness in today's marketplace requires creative design, innovation, and the reduction of nonconformances, which require costly rework and can damage a firm's reputation with its customers and potential customers. Using the International Organisation of Standardization's (ISO) 9000 and 14000 series of standards, the authors of this article walk readers through the rigorous process of obtaining upper management buy‐in and sponsorship and engaging workers in a bottom‐up approach to establish the procedures necessary to perform world‐class engineering services. 相似文献
990.
Valéria R. F. da Silva Sylvia F. Mitraud Maria L. C. P. Ferraz Eduardo H. S. M. Lima Maria Thereza D. Melo Armando J. B. Santos Augusto César C. D. da Silva Jaqueline C. de Castilhos Jamyle A. F. Batista Gustave G. Lopez Frederico Tognin João Carlos Thomé Cecília Baptistotte Berenice M. Gomes da Silva José Henrique Becker Juçara Wanderline Fernanda de Vasconcellos Pegas Gonzalo Róstan Guy Guagni dei Marcovaldi Maria Ângela G. dei Marcovaldi 《Environment, Development and Sustainability》2016,18(6):1541-1558
In the 35 years since its inception, the Brazilian National Program for the Conservation of Marine Turtles (TAMAR) has had great success in protecting the five species of sea turtles that occur in Brazil. It has also contributed significantly to worldwide scientific data and knowledge about these species’ biology, such as life cycles and migration patterns. TAMAR’s conservation strategies have always relied on a variety of environmental education and social inclusion (EESI) activities highly adapted to the socio-environmental evolving contexts of its 25 locations distributed across nine states. Diversity and flexibility are critical to enable timely and effective local responses to existing or potential threats to sea turtles. The intuitive, locally adapted, decentralized, and independent way EESI activities have been carried out have generated positive results in the resolution of specific and evolving local problems through the course of the project. This article brings EESI under the same conceptual framework that underlies its conservation approach by adopting an adaptive threat management framework to organize and qualify its educational and social inclusion interventions according to the main categories of threat addressed by TAMAR. 相似文献