首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   52篇
  免费   0篇
安全科学   1篇
废物处理   3篇
环保管理   10篇
综合类   12篇
基础理论   10篇
污染及防治   8篇
评价与监测   3篇
社会与环境   4篇
灾害及防治   1篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   2篇
  2019年   4篇
  2018年   3篇
  2016年   5篇
  2015年   1篇
  2014年   1篇
  2013年   6篇
  2012年   2篇
  2011年   3篇
  2010年   2篇
  2009年   2篇
  2007年   1篇
  2006年   2篇
  2005年   1篇
  2004年   3篇
  2002年   3篇
  1995年   1篇
  1994年   1篇
  1990年   1篇
  1982年   3篇
  1971年   1篇
  1961年   1篇
排序方式: 共有52条查询结果,搜索用时 31 毫秒
1.
Production facilities serve to transform raw materials into products, usually with the goal of achieving a designated output, in terms of quantity and quality, with the minimum of cost and labour. With the aid of production planning and controlling (PPC) systems, raw material inputs, and labour can be planned to achieve a determined output of products. In general, the role of environmental and social aspects is neglected in production planning processes. Because of the growing pressure from politics and customers, sustainable production of products is becoming more important. One possibility for supporting sustainable manufacturing is, to integrate sustainable aspects in the production planning process. This paper presents input and output information for current PPC systems and discusses the need for additional information necessary for sustainable PPC. For this approach, a text review of cooperate social responsibility (CSR) reporting indicators provided by the GRI was performed. Based on the text review, an input-output model has been developed for conventional and another one for sustainable PPC systems. Through the comparison of the two input-output models, challenges and requirements for sustainable PPC systems have been defined as a basis for future work and analyses.  相似文献   
2.
Smallholder farmers play an important part in the dairy value chain in Sub-Saharan Africa. Three technological approaches have been used to improve productivity. These are through, applying agricultural ecological processes (ecological intensification), utilising modern livestock breeding (genetic intensification), and socio-economic intensification. Ecological intensification includes continuous housing of cows applying a cut-and-carry feeding system, introduction of purpose-bred forages and pastures, and the introduction of agro-forestry within the dairy systems. Genetic intensification strategies include: importation of dairy breeds such as Holstein–Friesian (HF) and cross-breeding of the indigenous breeds with HF. Training and capacity-building activities to create sustainable livelihoods have been initiated for farming and technological practices of animal husbandry, but also to enhance appropriate leadership and corporative-building skills that would create and support an enabling environment for sustainability. These improvements and initiatives in the service delivery have been championed by national governments, development partner institutions, or non-governmental organisations through different programmes. Challenges of intensification include matching management to genetic potential of imported and cross-bred improved dairy breeds, ensuring low post-harvest losses, proper utilisation, and reducing environmental impact. Using examples from Kenya, Malawi, Mozambique, Tanzania, and Zambia, this paper reviews the management and assessment approaches used in fostering smallholder dairy development strategies and dairy’s contribution to sustainable livelihoods in the face of intensification.  相似文献   
3.
Rainwater harvesting, consisting in collecting runoff from precipitation, has been widely developed to stop groundwater declines and even raise water tables. However, this expected environmental effect is not self-evident. We show in a simple setting that the success of this conjunctive use depends on whether the runoff rate is above a threshold value. Moreover, the bigger the storage capacity, the higher the runoff rate must be to obtain an environmentally efficient system. We also extend the model to include other hydrological parameters and ecological damages, which respectively increase and decrease the environmental efficiency of rainwater harvesting.  相似文献   
4.
The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 required the federal government to establish criteria for setting priorities among releases of hazardous substances, pollutants, and contaminants. The U.S. Environmental Protection Agency responded by developing the Hazard Ranking System (HRS), which is a scoring system used to establish the National Priorities List (NPL). The Superfund Amendments and Reauthorization Act of 1986 required EPA to amend the HRS so it will more accurately assess relative risks and take into account certain specific elements of risk. On December 23,1988, EPA published in the Federal Register the proposed rule to revise the HRS.1 EPA expects to issue the final rule in 1990 after reviewing public comments. This paper describes the proposed revisions and summarizes major technical findings that support the revisions. As a result of the HRS revisions, there may be some changes in the types of sites that score high enough to be placed on the NPL. A projection of those changes is discussed.  相似文献   
5.
Abstract

Cholinesterase activity in the brain, RBC and plasma of Swiss mice was determined following different routes of administration of methamidophos. Continuous feeding with the insecticide caused a progressive inhibition of both plasma‐ and erythrocyte enzymes. The effect of methamidophos was more pronounced when applied in diet than when administered dermally or intraperitoneally. Following a single injection (i.p.) of methamidophos, the brain enzyme showed maximum inhibition 24 hr following treatment. At the appearance of tremors, the plasma and RBC‐enzymes showed considerable inhibition, the former being more inhibited. The plasma enzyme appears to be the most sensitive enzyme and may be taken as a suitable index for exposure to methamidophos.  相似文献   
6.
7.
In the context of the desire to steer urban transformation towards sustainability transition, the development of proposals for alternative futures assists policy-makers and practitioners in focusing on impact by organising the various drivers, particularly spatial ones that cause an interactive urban system to transit. This paper presents the methodology that has been developed by the Chair for Urban Development, Munich University of Technology (TUM) as it was working within an inter-disciplinary research team on a project commissioned by the municipality of Nuremberg. The objective of this project was to develop ideas for regenerating the formerly industrial area of Nuremberg West (NW) under the guiding theme of sustainable urban development. This methodology focuses on the development of proposals of positive and possible transformations of NW in the year 2050 based on the analysis of economy, housing and space at various scales and a systematic assessment of trends. These alternative futures became framing and guiding narratives to internalise and anchor the debate in-between the various disciplines involved in this project.  相似文献   
8.
9.
Within the context of biogas R & D and demonstration project undertaken by the Egyptian National Resarch Centre, village demonstrations are of paramount importance. In this paper, a case study of a pioneering village demonstration is presented. Based on a preliminary sociological survey, “Al Manawat” - a traditional Egyptian village was selected for the first demonstration. After a short orientation phase through which the biogas technology was introduced to a group of village representatives, a family was selected to conduct the demonstration experiment. Concomitant with the family energy requirements, availability of digester feed materials, site characteristics and other relevant factors, a family-size unit of a modified Indian type was designed and erected by the side of the farmer's house. The digester effective volume is 9 cu.m. and is connected to both a latrine and animal shed. The unit has been successfully operated since May 1981. The highlights of the construction stage as well as the unit performance characteristics are discussed. A preliminary techno-economic appraisal is also outlined. Finally, social impacts are assessed. Initial results indicate that under the Egyptian village conditions, and particularly with the heavily subsidized fuel prices, the high saving in manure transport attained through the introduction of the biogas unit, appears to be the main benefit from the farmer's point of view. Dans le cadre de la recherche et du développement du gaz de fermentation et d'un projet pilote entrepris par le Centre national de recherche égyptien, les démonstrations faites dans les villages occupent une place prépondérante. Dans cet article, l'auteur présente le cas-type d'une démonstration pilote faite dans un village. En se basant sur une enquêue sociologique préliminaire, “Al Manawat”, qui est un village égyptien traditionnel, a été choisi comme lieu de la première démonstration. Après une courte phase d'orientation au cours de laquelle le technologie du gaz de fermentation a été présentée à un groupe de notables du village, on a choisi une famille pour effectuer la démonstration expérimentale. En même temps que l'on étudiait les besoins énergétiques de cette famille, la disponibilité de matières de base de fermentation, les caractéristiques de l'emplacement et tous autres facteurs pertinents, une unité familiale de type indien modifié a été con?ue et érigée à côté de la ferme. Le composteur, d'un volume utile de matières premières de 9 m3, est relié à la fois aux latrines et à l‘étable. Cette unité fonctionne avec satisfaction depuis le mois de mai 1981. L'article met en avant les points essentiels des étapes de la construction et les caractéristiques de rendement de l'unité de fermentation. Il esquisse une évaluation technico-économique préliminaire et fait l'estimation des retombées sociales. Les premiers résultats montrent que, dans le cadre du village égyptien et particulièrement du fait que les prix du fuel sont largement subventionnés, les économies importantes réalisées dans le transport du fumier grâce á l'introduction de l'unité de fermentation semblent étre, du point de vue du fermier, le bénéfice principal. Dentro del contexto del proyecto de I & D y demostración realizado por el Centro de Investigación Nacional de Egipto, la demostración en los villorrios es de suma importancia. Este artículo presenta un caso pionero de este tipo. Basado en encuestas sociológicas, un villorrio tradicional de Egipto, “Al Manawat” fue selectiondo para la primera demostración. Después de una fase corta de orientación en la que se introdujo la tecnologia del biogás a los representantes del villorrio, se seleccionó una familia con cuya colaboración se Ilevaria a cabo el experimento. Teniendo en cuenta las necesidades de energia de la familia, la disponibilidad de materia prima para el digestor, las caracter ísticas del lugar y otros factores importantes, se diseñó y construyó un digestor de tamaño familiar, usando un modelo Indio, al lado de la casa de la familia. El volumen efectivo del digestor es 9 metros cúbicos y está conectado a la letrina y al corral de animales. La unidad está funcionando con éxito desde Mayo de 1981. Se discuten aspectos de la etapa de construcción y las características de operación. Se hace también una evaluación técnico-económica preliminar. Finalmente se evalúa el impacto social de la experiencia. Los resultados indican que en las condiciones de los villorrios Egipcios, especialmente en condiciones de precios de combustibles altamente sub-sidiados, los grandes ahorros en el transporte de abono debido a la introducción del digestor de biogas parece ser el mayor beneficio desde el punto de vista de la familia.  相似文献   
10.
Mercury (Hg) is a ubiquitous and a major environmental metal pollutant in the aquatic ecosystem. The present study was performed to evaluate the effect of mercury graded doses exposure on oxidative stress, redox status, metallothionein levels and genotoxicity in the intestine of sea cucumber Holothuria forskali. Specimens were exposed for 96?h to three concentrations of Hg (40, 80 and 160?µg/L). Exposure of H. forskali to Hg promoted oxidative stress with an increase in malondialdehyde (MDA), protein carbonyl (PCO) and advanced oxidation protein products (AOPP) levels. An increase of glutathione (GSH), vitamin C (ViteC) and non-protein thiols (NPSH) contents was also observed. Additionally, antioxidant activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) increased especially with the highest doses of Hg indicating a great defense of the antioxidant system. Our investigation revealed an increase in total Metallothionein (MT) content which was more pronounced at the sharpest concentrations of Hg. A significant decline of AChE activity was also observed. In the intestine of Hg-treated H. forskali genotoxicity was confirmed by DNA degradation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号