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排序方式: 共有1188条查询结果,搜索用时 46 毫秒
371.
372.
文中对灾害医学的诞生和发展,灾害医学的特点以及灾害医学的任务进行了论述,并对军队在灾后救援中的作用作出客观的评价。 相似文献
373.
The objective of this paper is to compare the following four methods of measuring oxygen transfer in wastewater treatment plants under process conditions: the offgas, hydrogen peroxide (H2O2), reaeration, and in situ oxygen uptake rate (OUR) methods. Comparative tests were performed under controlled conditions in a pilot column and in six full-scale oxidation ditches equipped with fine-bubble diffusers and slow-speed mixers. The offgas and H2O2 methods give similar results (differences between the oxygen-transfer coefficients under field conditions [k(L)a(f)] from each method lower than 10%). The reaeration procedure gives more random results (differences from -5 to -43% compared with values obtained using the offgas method). The in situ OUR method, in the presence of a horizontal flow of mixed liquor, leads to an estimate of k(L)a(f) to within 15% of the offgas value. 相似文献
374.
Brigitte Simon-Bouy Agnès Taillandier Delphine Fauvert Isabelle Brun-Heath Jean-Louis Serre Carmen G. Armengod Martin G. Bialer Michèle Mathieu Jacques Cousin David Chitayat Jan Liebelt Barbara Feldman Marion Gérard-Blanluet Stefani Körtge-Jung Cath King Hannele Laivuori Martine Le Merrer Sarju Mehta Christina Jern Saba Sharif Fabienne Prieur Gabriele Gillessen-Kaesbach Andreas Zankl Etienne Mornet 《黑龙江环境通报》2008,28(11):993-998
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376.
Adsorption/thermal desorption-GC/MS for the analysis of pesticides in the atmosphere 总被引:2,自引:0,他引:2
An analytical methodology using Automatic Thermal Desorption (ATD) and GC/MS was developed for the determination of the pesticides alachlor, atrazine, captan, formothion, lindane and phosalone in atmospheric samples. This methodology was developed to evaluate the atmospheric contamination by pesticides during treatments and by post-application. Atmospheric samples were collected by using (4 i.d. x 89 mm) stainless steel sampling tubes containing 125 mg of adsorbents at a flow rate of 80 ml min-1. Different types of adsorbents were tested for their ability to efficiently trap pesticides under study: Tenax TA, Carbopack Y, Carbopack B, Carbotrap, Carboxen, Chromosorb 106 and XAD-4. Results of experiment show that Tenax gives the better results for all the pesticides used but the use of the thermal-desorption method, especially for pesticides with low volatility and/or poor thermal stability presents some difficulties. This method was validated by the analysis of the contamination of atmosphere, through volatilization by post-application processes, of atrazine in a parcel of 1 ha. 相似文献
377.
Energy planners in developing countries have traditionally sought to meet their nations' growing electricity demands by adding more generation and transmission capacity. But as the foreign investment situation became critical in the 1980s, private investment and system efficiency improvement programmes began to garner interest. One of the most promising system efficiency improvement options is load management, which uses a variety of techniques to utilize the electricity system's existing capacity more efficiently. However, to date, only three countries have seriously considered implementing large load management programmes: Pakistan, Peru and Costa Rica. This paper describes a 1987-89 load control demonstration programme in Costa Rica, sponsored by the US Agency for International Development (AID), in which participating industries were able to reduce their peak demand by 14%. 相似文献
378.
Following the grounding and subsequent explosion, in October 2003, of a nuclear submarine in the waters of the La Maddalena National Marine Park, fears arose of possible radioactive leakages. However, isotopic analyses on algae showed that the gamma-ray emitting artificial radionuclides that one might expect to leak from a damaged nuclear reactor (such as U-235, I-131, Cs-137) were absent, and that U-238/U-234 activities were in equilibrium with values typical of sea water; this excluded any direct anthropogenic contamination as a result of the accident. We used alpha autoradiographic techniques to detect possible traces of transuranium radionuclides; 160 samples of algae, granites, sea urchins, gastropods, limpets, cuttlefish and jellyfish were collected from the area, as well as from other Mediterranean coastlines and the Baltic Sea. All samples were autoradiographed, and selected samples further analysed by alpha spectrometry. There were no alpha track concentrations above background levels in our control Mediterranean specimens. In the samples from the La Maddalena and Baltic areas two different track distributions were observed: --those homogeneously distributed over the surfaces examined; --groups (10 to over 500) of radially distributed alpha tracks (forming "star" bursts, or "hot spots") emanating from point sources. By comparing radionuclide activities measured by alpha spectroscopy with alpha track densities, we extrapolated Pu activities for all samples. About 74% of algae had Pu activities of less than 1 Bq/kg and 0.25 Bq/kg, 16% had accumulated Pu to levels between 1 and 2 Bq/kg, and a very few specimens had concentrations between 2 and 6 Bq/kg. Plots showed that alpha tracks and stars concentrate around the northern and eastern margins of the Rada (Basin) di Santo Stefano, sites facing the nuclear submarine base on the eastern shore of the island of Santo Stefano. What is the source of these nuclides: last century's atmospheric nuclear testing, Chernobyl or a local source? Their concentrated, extremely localised occurrence seems difficult to explain in terms of left-over worldwide nuclear pollution. A local source seems more plausible. 相似文献
379.
Le Billon P 《Disasters》2005,29(1):1-25
This paper examines advocacy initiatives by humanitarian and human rights organisations to address problems of governance in resource-rich and conflict-affected countries, focussing on the case of Angola. Humanitarian principles preclude the use of indiscriminate conditionality and point towards a cautious approach to advocacy aimed at assisting vulnerable populations. Furthermore, the relatively insignificant amount of aid supplied to resource-rich local authorities means that individual agencies have precious little leverage, especially when commercial interests rather than humanitarian or 'good governance' principles influence the priorities of bilateral donors. A context of resource wealth calls for: high levels of coordination and cooperation between human rights groups, aid agencies and donors; balanced use of conditionality, based on the drawing, by donors, of a clear distinction between emergency and development-oriented assistance; and a sustained effort to highlight the responsibilities of local authorities, foreign governments and businesses in meeting humanitarian and development objectives. 相似文献
380.