全文获取类型
收费全文 | 23800篇 |
免费 | 2662篇 |
国内免费 | 2704篇 |
专业分类
安全科学 | 3117篇 |
废物处理 | 573篇 |
环保管理 | 4730篇 |
综合类 | 12181篇 |
基础理论 | 2463篇 |
环境理论 | 9篇 |
污染及防治 | 1731篇 |
评价与监测 | 929篇 |
社会与环境 | 2390篇 |
灾害及防治 | 1043篇 |
出版年
2024年 | 424篇 |
2023年 | 689篇 |
2022年 | 747篇 |
2021年 | 947篇 |
2020年 | 924篇 |
2019年 | 670篇 |
2018年 | 591篇 |
2017年 | 834篇 |
2016年 | 880篇 |
2015年 | 847篇 |
2014年 | 981篇 |
2013年 | 1380篇 |
2012年 | 1526篇 |
2011年 | 1657篇 |
2010年 | 1123篇 |
2009年 | 1215篇 |
2008年 | 967篇 |
2007年 | 1506篇 |
2006年 | 1533篇 |
2005年 | 1326篇 |
2004年 | 1198篇 |
2003年 | 1136篇 |
2002年 | 1018篇 |
2001年 | 868篇 |
2000年 | 833篇 |
1999年 | 754篇 |
1998年 | 529篇 |
1997年 | 426篇 |
1996年 | 295篇 |
1995年 | 280篇 |
1994年 | 226篇 |
1993年 | 217篇 |
1992年 | 130篇 |
1991年 | 75篇 |
1990年 | 62篇 |
1989年 | 29篇 |
1988年 | 35篇 |
1987年 | 30篇 |
1986年 | 26篇 |
1985年 | 17篇 |
1984年 | 24篇 |
1983年 | 19篇 |
1982年 | 24篇 |
1981年 | 16篇 |
1980年 | 23篇 |
1979年 | 25篇 |
1978年 | 13篇 |
1977年 | 11篇 |
1973年 | 11篇 |
1971年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
A model is presented for evaluating waste management systems for their contribution to a sustainable development, including environmental, economic and social aspects. The model was tested in a case-study, where groups of long-term unemployed people were offered both education on environmental issues and practical work with the recovery and recycling of building and demolition waste as a form of vocational development. Application of the suggested model revealed the overall effects on sustainability of different methods of waste management. In addition, negative aspects of the systems analysed were identified, which led to discussions about possible improved practices within the waste management systems. Two of the waste management systems investigated (the recycling of steel and re-use of sanitary porcelain) showed a potential contribution to sustainable development in all of the aspects studied. Preparing bricks for re-use showed the largest potential for eco-efficiency, but had negative effects on sustainability from the social perspective of health and the working environment. The possibility of further use of the model and the remaining obstacles to such analyses are discussed. One observation is that the data collection needed to perform this kind of sustainability analysis is resource-demanding, and that it would therefore be better to identify a smaller number of key indicators. 相似文献
152.
K. A. Rosentrater T. L. Richard C. J. Bern R. A. Flores 《Resources, Conservation and Recycling》2003,39(4):341-367
Increasing production of corn masa for tortillas, chips, and related snack foods is resulting in large quantities of organic residuals requiring environmentally sound management. These byproduct streams appear suitable for use as livestock feed material, thus eliminating landfilling costs. Possibilities for developing livestock feed include direct shipping to livestock feeding facilities, blending prior to shipping, extrusion processing, pellet mill processing, and dehydration. To assess the viability of these options for reprocessing masa byproducts as livestock feed materials, an economic model was developed and applied to each of these alternatives. Through a series of simulation runs with this model, it was determined that direct shipping was by far the most inexpensive means of recycling masa processing residuals (10–57 $/Mg). Other alternatives examined in increasing order of costs included blending prior to shipping, extrusion, pellet mill processing (3–15, 5–18, and 4–18 times greater than direct shipping, respectively), while dehydration was clearly cost-prohibitive (33–81 times greater). Bagged feed was slightly more expensive to produce than bulk feed (1.1 times greater), and reprocessing costs increased as delivery distance increased, due to increased labor, equipment, and fuel costs, but decreased as byproduct generation rate increased, due to the development of the economies of scale. Alternately, based on a tipping fee of 50 $/Mg, the total estimated cost to landfill ranged from 65 to 112 $/Mg. Based on this cost analysis, direct shipping and feeding to livestock is the recycling option of choice for masa processing byproducts. Although specific details of process configurations and associated costs will vary, similar results are likely for other high moisture food processing residuals destined for utilization as livestock feed or components thereof. 相似文献
153.
Georgios E. Pavlikakis Vassilios A. Tsihrintzis 《Journal of the American Water Resources Association》2003,39(2):277-288
ABSTRACT: The Ecosystem Management (EM) process belongs to the category of Multi‐Criteria Decision Making (MCDM) problems. It requires appropriate decision support systems (DSS) where “all interested people” would be involved in the decision making process. Environmental values critical to EM, such as the biological diversity, health, productivity and sustainability, have to be studied, and play an important role in modeling the ecosystem functions; human values and preferences also influence decision making. Public participation in decision and policy making is one of the elements that differentiate EM from the traditional methods of management. Here, a methodology is presented on how to quantify human preferences in EM decision making. The case study of the National Park of River Nestos Delta and Lakes Vistonida and Ismarida in Greece, presented as an application of this methodology, shows that the direct involvement of the public, the quantification of its preferences and the decision maker's attitude provide a strong tool to the EM decision making process. Public preferences have been given certain weights and three MCDM methods, namely, the Expected Utility Method, Compromise Programming and the Analytic Hierarchy Process, have been used to select alternative management solutions that lead to the best configuration of the ecosystem and are also socially acceptable. 相似文献
154.
环境政策作用机制的分析框架 总被引:1,自引:0,他引:1
了解环境政策作用机制是环境政策有效调控的前提和核心,准确理解环境政策作用的背景、成因、过程、作用机制、效应动态、演变规律等;全面而深刻地环境政策副作用和变形的生成-演变规律,了解政策副作用形成机制、传导机制、积累发展机制、作用机制、研究政策变形对环境政策适应性和效率的影响才可能准确预测环境政策所引发的变化,这些变化对社会经济的影响,进而对环境政策的反馈影响和反馈作用,才可能准确有效地设计开发政策工具和调控机制,有铲地进行环境政策调控,提高环境政策的预见性、准确性、操作性和适应性。 相似文献
155.
中国湿地现状综述 总被引:9,自引:0,他引:9
刘军 《中国环境管理干部学院学报》2004,14(2):64-67
湿地是重要的自然资源,对人类生存起着重要作用。本文综述了湿地的含义、功能与 价值、中国湿地的特点与现状,以促进中国湿地的可持续发展与利用。 相似文献
156.
红外光度法测定石油类和动植物油常见问题探讨 总被引:2,自引:0,他引:2
根据石油类在波数为2930cm-1、2960 cm-1、3030 cm-1全部或部分谱带处有物征吸收的原理,采用红外光度测油仪和水样絮凝富集技术测定石油类、动植物油。 相似文献
157.
虚拟技术正从多方面改变着传统的建筑与环境设计方法。本文主要讨论在建筑与环 境设计领域引入虚拟技术的方法以及当前实践中的具体应用状况。 相似文献
158.
针对环境科学的特点,立足于长远发展,从生态哲学角度分析了生态道德观对环境科学技术的重要价值。分析认为应用生态的观点来学习和研究环境科学,才能达到最大程度防治的目的;合理融入生态观念的环境治理技术有利于经济发展;生态道德观是环境科技工作者必备的品质和环境科学发展的动力。通过这三个方面的分析得出环境科学技术的发展必须以生态道德观为指导的结论。另外本文从纵向和横向分析了生态道德观在指导环境科学技术发展过程中存在的问题并提出了相应的措施和建议。 相似文献
159.
青藏高原与东南沿海区域联合发展旅游的构想 总被引:2,自引:0,他引:2
由于历史条件和地理位置差异等原因,导致我国东西部区域间发展出现明显的差距,而经济发达的东部地区与资源丰富的西部地区要各抒所长、互助互补、共同发展才能达到双赢的目标.文章就青藏高原与东南沿海地区实现跨区域联合发展的背景、影响因素、对策与措施进行了探讨. 相似文献
160.
从区域可持续发展的角度出发,提出了区域资源环境经济(REE)系统的概念,初步对区域REE系统的研究对象、系统结构进行了探讨,建立了区域REE系统可持续运行的评价指标体系,并通过实例研究论证了它对区域可持续发展的基础性和指导作用,以及评价指标体系的可用性. 相似文献