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通过分析现有OFA系列石油定量分析仪的使用对操作人员的职业危害,从试剂对人体的危害程度、对油气发出荧光的干扰程度、油气萃取灵敏度与萃取荧光效率、钻井液添加剂选择性进行对比实验提出了采用异丙醇代替正已烷作为萃取剂的可能性,并对工作台进行改造,将有害气体迅速排除,降低室内有害气体浓度,从而实现“绿色”操作的方法。 相似文献
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萃取膜生物反应器处理苯酚废水的试验研究 总被引:2,自引:0,他引:2
从经过驯化的活性污泥中筛选出苯酚降解菌.制备成菌悬液,对比活性污泥体系和菌悬液体系的萃取膜生物反应器(EMB)对苯酚废水的处理效果,考察了料液苯酚浓度、反应器温度等因素对膜萃取速率及生物降解效果的影响.结果表明,通过以苯酚为唯一碳源,逐渐提高苯酚浓度的方法对活性污泥进行驯化.当进水苯酚浓度为700 mg·L-1时,苯酚去除率达99%以上;适当提高反应器温度和料液初始浓度有利于提高膜萃取速率;当初始料液苯酚浓度为2000 mg·L-1时,膜萃取速率高于生物降解速率,生物相中产生苯酚积累;菌悬液体系EMB的生物膜厚度明显小于活性污泥体系,且水力反冲洗可有效控制生物膜厚度.对苯酚生物降解产物的GC-MS分析结果表明,苯酚的生物降解较彻底,基本无苯酚中间产物的残留. 相似文献
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A. Begossi R.A.M. Silvano B.D. do Amaral O.T. Oyakawa 《Environment, Development and Sustainability》1999,1(1):73-93
The fishing and hunting performed by inhabitants of the Extractive Reserve of the Upper Juruá, Acre, Brazil was studied, and an ecological analysis on the use of fish and game, including preferences, taboos and medicinal uses, and of fish abundance was made. Research was carried out at the Upper Juruá Extractive Reserve in three visits (1993 and 1994). A total of 143 individuals (101 families) living along the banks of the rivers Juruá, Tejo, Bagé, S. João and Breu were interviewed, and 115 species of fish with set gillnets were collected. Local economic activities included rubber-tapping and small-scale agriculture. Fishing was especially important in the dry season, when cast net and hook and line were used. Hunting and game consumption were intensive in the wet season. Some local rules may be useful as starting points for local management, such as the use of fish diversity through lake management, the use of water level seasonality, hunting periods or quotas, and food taboos. The integration of academic research with indigenous knowledge and demands is important to develop management plans which protect both biological and cultural diversity. 相似文献
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为了研究自来水有机提取物与藻毒素在大鼠肝癌诱导过程中的协同作用.以自来水有机提取物为启动剂,藻毒素为促进剂,构建大鼠肿瘤促进模型(Solt-farber模型),观察肝脏病理形态改变,并检测肝细胞中c-fos、c-jun、GSTPi表达情况.结果表明,实验组动物肝脏产生结节性增生灶,自来水有机提取物能诱导肝细胞GSTPi表达,藻毒素单独作用不能诱导GSTPi表达,但能够促进自来水有机提取物诱导产生的GSTPi表达;同时,藻毒素还能诱导肝细胞中c-fos、c-jun表达增加,并具有一定的剂量反应关系.自来水有机提取物具有启动活性,藻毒素具有促癌活性,影响细胞MAPK信号旁路而诱导具有增殖潜能的启动细胞克隆增殖异常是藻毒素可能的促癌机制. 相似文献
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萃取精馏法分离醋酸-水的研究 总被引:1,自引:0,他引:1
采用萃取精馏法从醋酸水溶液中分离回收醋酸是一新的研究方向,而适宜溶剂的筛选是研究关键.本实验以高沸点含氮类有机化合物作为醋酸-水萃取精馏的候选溶剂,采用平衡组分分析法对溶剂进行了实验筛选.结果表明,溶剂的引入使体系的相对挥发度有较大程度的提高,其中N-甲基乙酰胺(NMA)使水对醋酸的相对挥发度提高最多,为4.75.因此实验确定NMA为最优溶剂,并进行了醋酸-水萃取精馏的工艺实验.与普通精馏结果对比表明,以NMA为溶剂的萃取精馏法分离醋酸-水的效果非常显著,研究结果对开发环保型的醋酸-水分离新工艺具有重要意义. 相似文献
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ABSTRACT Agricultural and extractive frontiers experiment rapid landscape transformation. Land-Use Sciences and Political Ecology are complementary approaches for analysing how landscape transformations are related to biophysical conditions, and socioeconomic, cultural and political processes developed at global, national and local scales. This study examines such relationships in a long-standing agrarian and resource frontier in southern Mexico for the 1986–2015 period. We combine insights from: (1) a quantitative land use/land cover change pattern-based model, involving a weights of evidence and cellular automata simulations, and (2) a qualitative content analysis of literature and of local actors’ perspectives. Two grand frontier processes have developed in this region: NAFTA-related agrarian transition toward intensification and the establishment of wind farms. Both were triggered by global forces and new forms of land and resources use, but mediated by national-to-local ecological, socioeconomic and political processes, producing particular landscape transformations. 相似文献
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Transfer rate of pesticide residues from medicinal plants in different types of extractive solutions
Alexandru Mihai Florea Veronica Drumea Roxana Andreea Nita Adelina Bicu Laura Olariu Ligia Elena Dutu 《毒物与环境化学》2020,102(1-4):37-61
AbstractStarting from the suspicion that the medicinal herbs may contain traces of pesticides and taking into account the risks of patients being exposed to contaminated products, the aim of this research was to evaluate the pesticide residues and the degree of their transfer (%) in three types of preparations (infusion, decoctionand cold maceration), for four medicinal plant species very often used in phytotherapy (Rosmarini folium, Menthae folium, Saturejae herba and Basilica herba). For each type of plant product, four samples were purchased from different manufacturers and they have been analyzed using gas chromatography- tandem mass spectrometry. One out of four samples of the same plant species contain at least one pesticide residue above the maximum level and shows a significant transfer of these residues in aqueous extractive solutions during extraction. The highest rate of pesticide transfer from medicinal plants was identified in infusions, recommended by many manufacturers. 相似文献