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981.
为解决快速测量生化需氧量,生化需氧量智能生物检测仪对多种废水的实际测定表明,操作简单,测量周期为30min,精密度为±10%左右,特别适用于污水处理中控制分析及批量样品的分析测定。 相似文献
982.
This paper presents a case study of the Abanico Medicinal Plant and Organic Agriculture Microenterprise Project in the Arenal Conservation Area, Costa Rica. Microenterprise is the Sustainable Development and the Women in Development model for gender equity and environment of the World Bank, International Monetary Fund and large non-government organizations, like the World Wildlife Fund-Canada. The authors of this paper argue that debt-for-nature investment in microenterprise and ecological economic models are not distinct from neoclassical economic and development models that created the environmental, social and cultural crises in the first place. This case study shows that the world market accommodates only one model of development: unsustainable export-oriented production based on flexible labour markets, low wages, indebtedness and low cost production. Working standards in those micro-enterprises are eroded due to many factors,including indebtedness. What happened at a national level in non-industrial countries with the international debt crisis is now mirrored in individual indebtedness through microenterprise. Is current development policy creating a new form of indentured servitude? Medicinal plants, prior to commodification, were a source of women's power and upon commodification in international development projects, are the source of their exploitation. 相似文献
983.
984.
This study aims to develop an integrated model - NFPA-68-BRANN model, which can be used to calculate the vent areas of cubic enclosures with obstacles. Seven experiments regarding vented explosion inside the obstructed enclosure are reviewed and applied to check the accuracy of two existing standards, i.e. the NFPA-68 2018 and the BS EN 14994:2007. Accordingly, the parameters to describe the flame development in the NFPA-68 2018 are amended by adopting the Bauwens model. Bayesian Regularization Artificial Neuron Network (BRANN) model presenting the non-linear relationship between the turbulent flame enhancement factor X and its affecting factors is subsequently developed. Eventually, the NFPA-68-BRANN model is generated by incorporating the BRANN model into the modified NFAP-68 2018. The accuracy of the NFPA-68-BRANN model is validated by using a series of the New Baker Test data. 相似文献
985.
Recent Changes of Sediment Yield in the Upper Yangtze, China 总被引:2,自引:0,他引:2
/ Reservoir sedimentation is one of the many environmental problems associated with the Three Gorges Project in China. The rate and characteristics of sedimentation that directly affect the operating life of the reservoir are closely related to soil erosion and sediment transport dynamics in the upstream catchment and to the ability to manage the throughput of sediment-laden waters. The recent changes in sediment yield were examined using gauging data from 187 stations of varying sizes from less than 100 km2 to larger than 1,000,000 km2 in the Upper Yangtze basin between 1956 and 1987. Whereas many previous studies have concentrated on the trends in the main channel of the Yangtze, the distributed pattern of changes across the whole catchment is complex. Results from time series analysis indicate ten stations, mainly located in the Dadu and Wu tributaries (with a total incremental catchment area of 78,963 km2) have shown increasing trajectories of sediment yield, and six stations, located in the upper Jialing and Tuo tributaries (with a total incremental area of 27,816 km2) have experienced decreasing trajectories. By dividing the time series into three components, it is possible to map significant decadal changes in sediment yields that can be related to phases of deforestation and the construction of water conservancy projects. Most of the observed decreases in sediment yield are associated with large reservoir schemes on tributary rivers. The lack of evidence for increasing sediment input to the Three Gorges area masks a considerable variation in sediment conveyance and storage within the Upper Yangtze catchment.KEY WORDS: Sediment yield; Reservoir sedimentation; Three Gorges Project; Time series analysis; China 相似文献
986.
B.A. Wrenn A. Virkus A.D. Venosa 《Environmental pollution (Barking, Essex : 1987)》2009,157(6):1807-1814
The effects of surfactant composition on the ability of chemical dispersants to disperse crude oil in fresh water were investigated. The objective of this research was to determine whether effective fresh water dispersants can be designed in case this technology is ever considered for use in fresh water environments. Previous studies on the chemical dispersion of crude oil in fresh water neither identified the dispersants that were investigated nor described the chemistry of the surfactants used. This information is necessary for developing a more fundamental understanding of chemical dispersion of crude oil at low salinity. Therefore, we evaluated the relationship between surfactant chemistry and dispersion effectiveness. We found that dispersants can be designed to drive an oil slick into the freshwater column with the same efficiency as in salt water as long as the hydrophilic-lipophilic balance is optimum. 相似文献
987.
Low-temperature VOCs oxidation performance of Pt/zeolites catalysts with hierarchical pore structure
Different zeolites supported Pt catalysts with micro-mesoporous structure were prepared by organic base tetrapropylammonium hydroxide (TPAOH) treatment and their catalytic oxidation activity for various volatile organic compounds (VOCs) were evaluated. The results reveal that the synergistic effect between Pt nanoparticles and surface acid sites plays an important role in VOCs low-temperature removal. The small size and high dispersion of Pt nanoparticles on the surface of the zeolites would promote the catalytic oxidation of aromatics and alkanes over the Pt/zeolite catalysts, while strong acidity and abundant acid sites of catalysts are in favour of the oxidation of the VOCs containing N and O heteroatoms. In addition, it was found that Pt/ZSM-5 catalyst exhibits the highest oxidation activity for various VOCs low-temperature removal amongst all the catalysts due to the balance of both Pt dispersion and abundant acid sites in the catalyst. This comprehensive consideration should be very helpful when designing and preparing novel catalysts for the low-temperature removal of VOCs. 相似文献
988.
Allan Curtis 《Environmental management》1998,22(4):563-574
/ With over 2500 Australian Landcare groups, 65,000 volunteer members, and considerable evidence of program impact, Landcare is an important example of state-sponsored rural development in a developed nation. The agency-community partnership is a fundamental element of Landcare and getting the partnership right is vital to long-term program success. After reviewing the emergence of Landcare in the state of Victoria, the author reports research from a 1995 survey of Victorian Landcare groups. Survey information highlighted the extent of agency-group contact, the important roles agency staff played in many Landcare groups, and the positive impact of agency contact and government funding upon group activity. Large majorities of groups reported they were satisfied with their relationship with agency staff. However, a majority of groups reported money or materials provided to manage land and water degradation was inadequate. Recently proposed changes to the Landcare program will provide government funding of work on private property and may address this concern. A majority of groups also reported support for leadership and management training was inadequate and respondents emphasized the need to revise program guidelines that limit funding for group coordinators. This information highlighted the importance of articulating a practical model of community participation in Australia and adopting a systematic approach to providing agency support for Landcare groups. Reflecting upon the Landcare experience, the author suggests some of the key elements of a practical model of state-sponsored citizen resource management contributing to rural development.KEY WORDS: Landcare; Australia; Community participation; Rural development; Citizen resource management; Sustainable agriculture 相似文献
989.
利用枣庄电磁信息台DPJ Ⅲ、ULF Ⅲ及JD 03型电磁辐射仪观测到的资料,分析了山东苍山5.2级地震前多数台站记录到的异常信息及其特征。 相似文献
990.
D. Jones A.G. Scarlett C.E. West R.A. Frank R. Gieleciak D. Hager J. Pureveen E. Tegelaar S.J. Rowland 《Chemosphere》2013
‘Naphthenic acids’ (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted. 相似文献