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441.
研究了大田栽培和自然光条件下,模拟紫外辐射(UB-B,280-315nm)增加对春小麦根际土壤微生物种群数量的影响。UV-B辐射能显著降低细菌总数以及放线菌和真菌数量;UV-B辐射对好氧性自生固氮菌、亚硝酸细菌、反硝化细菌、好氧性纤维素分解菌和解磷细菌数量也有显著的影响,但这种影响具有生育期之间的差异,春小麦根际土壤微生物种群数量与土壤营养成分有关。  相似文献   
442.
4-Nonylphenol, a compound with estrogenic activity, has been shown to occur in sewage sludges and effluents of sludge treatment. This, as well as its use in the formulation of pesticides, may result in the contamination of crop plants and may therefore have an impact on the quality of food or feedstuff. The toxicity, uptake and metabolism of 4-n-nonylphenol (4-n-NP) were investigated as14C-labeled 4-n-NP in root cultures under septical and aseptical conditions and with intact plants grown in containers with soil and aseptically grown in nutrient media. 4-n-NP was toxic to all plant systems tested. The presence of microorganisms and the developmental state of the plant material appeared to have an influence on the EC50 values. 4-n-NP was taken up by the roots and a metabolism to polar compounds was observed in the cases where sufficiently high uptake rates. With intact plants a transport from roots to the shoots was evident. Metabolism in roots changed quantitatively in the presence of microorganisms. The mineralization of 4-n-NP to14CO2 only occurred with microorganisms.  相似文献   
443.
固定化微生物处理含H2S气体的试验研究   总被引:54,自引:3,他引:54  
研究海藻酸钠包理固定化微生物颗粒填充床去除气相H2S的过程,活性微生物为经S^2-加富驯化的污水水污泥。填充滴滤塔运行实验表明,除H2S外适宜的PH值和喷淋率分别为1.8-4.0和〉0.17m^3(m^3.d);  相似文献   
444.
A strain saccharomycete STSM-I with high flocculanting activity was isolated from activated sludge with conventional methods.The high production rate and the low cost STSM-I medium was obtained by selecting different kinds of media, carbon source, nitrogen source and inorganic salt ion. The best flocculant-producing conditions were found by changing medium initial pH, culture temperature and ventilation flow. The best flocculating effect was obtained by changing positive ion types, density and concentration of flocculant.  相似文献   
445.
A growing awareness of the value of indigenous knowledge has prompted calls for its use within disaster risk reduction. The use of indigenous knowledge alongside scientific knowledge is increasingly advocated but there is as yet no clearly developed framework demonstrating how the two may be integrated to reduce community vulnerability to environmental hazards. This paper presents such a framework, using a participatory approach in which relevant indigenous and scientific knowledge may be integrated to reduce a community's vulnerability to environmental hazards. Focusing on small island developing states it presents an analysis of the need for such a framework alongside the difficulties of incorporating indigenous knowledge. This is followed by an explanation of the various processes within the framework, drawing on research completed in Papua New Guinea. This framework is an important first step in identifying how indigenous and scientific knowledge may be integrated to reduce community vulnerability to environmental hazards.  相似文献   
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