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991.
随着油田的持续开发,油气开采总量逐年增加,导致生态环境恶化加剧。文章综述了油田开发对油田生态环境的影响,并针对油田开发对水环境、土壤环境的污染,重点介绍了国内外油田生态环境污染的修复技术。  相似文献   
992.
低温影响人工湿地污水的处理效果,限制了人工湿地在寒冷地区的推广应用。文章综合分析了影响寒冷地区人工湿地污水处理效果的因素,提出:潜流式的人工湿地具有一定的保温特点,在潜流湿地土壤上面铺盖一定厚度的覆盖物可以提高保温效果,再选择科学合理的工艺流程——复合垂直流等可提高人工湿地的污水处理效率。有关实例也证明:通过合理的设计,人工湿地可以在寒冷地区成功越冬。  相似文献   
993.
Premiere Pro 2.0 是用于编辑影视作品的专业软件,可以编辑和制作电影、DV、栏目包装、字幕、网络视频、电子相册等.本文介绍了其自带的制作倒计时片头效果模板的使用方法,提出了利用Premiere Pro 2.0视频转场特效结合专业制图软件制作艺术倒计时效果的具体方法.  相似文献   
994.
随着水污染物排放标准的日益严格,絮凝剂的市场需求逐步增大。本文通过对山东省絮凝剂市场的实际调查,分析了絮凝剂的需求、种类、价格等市场因素,对市场需求进行预测并提出了市场营销建议。  相似文献   
995.
高职数学教学必须加强数学思想方法的教学   总被引:1,自引:0,他引:1  
数学思想方法是数学知识的核心,是数学的精髓和灵魂,是研究数学理论和运用数学解决实际问题的指导思想。本文针对目前高职数学教学中存在的数学思想方法教学重视不够以及教法上随意性的现状,提出通过加强数学史和基本数学思想方法的介绍,以及倡导“问题解决”的教学模式来提高学生的数学素养。  相似文献   
996.
Antibiotic formulation effluents are well known for their difficult elimination by traditional bio-treatment methods and their important contribution to environmental pollution due to its fluctuating and recalcitrant nature. In the present study the effect of ozonation on the degradation of oxytetracycline (OTC) aqueous solution (100mgl(-1)) at different pH values (3, 7 and 11) was investigated. Ozone (11mgl(-1) corresponds the concentration of ozone in gas phase) was chosen considering its rapid reaction and decomposition rate. The concentration of oxytetracycline, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and BOD5/COD ratio were the parameters to evaluate the efficiency of the ozonation process. In addition, the toxic potential of the OTC degradation was investigated by the bioluminescence test using the LUMIStox 300 instrument and results were expressed as the percentage inhibition of the luminescence of the marine bacteria Vibrio fischeri. The results demonstrate that ozonation as a partial step of a combined treatment concept is a potential technique for biodegradability enhancement of effluents from pharmaceutical industries containing high concentration of oxytetracycline provided that the appropriate ozonation period is selected. At pH 11 and after 60min of ozonation of oxytetracycline aqueous solutions (100 and 200mgl(-1)) the BOD5/COD ratios were 0.69 and 0.52, respectively. It was also shown that COD removal rates increase with increasing pH as a consequence of enhanced ozone decomposition rates at elevated pH values. The results of bioluminescence data indicate that first by-products after partial ozonation (5-30min) of OTC were more toxic than the parent compound.  相似文献   
997.
次氯酸钠催化氧化法处理十二碳硫醇恶臭污水   总被引:7,自引:0,他引:7  
采用活性炭和次氯酸钠催化氧化处理含有十二碳硫醇的恶臭污水,进行了小试并取得了良好的效果。在活性炭作催化剂,反应温度为100℃,反映时间为2-3min的实验条件下,1mL1%(m/v)NaClO即可处理100mL污水,处理后的废水无色无臭,可直接排放。  相似文献   
998.
区域易损性分析、评估及易损度区划:—以重庆市为例   总被引:29,自引:4,他引:25  
根据重庆市建国50年来的灾害统计资料,选取灾害密度、灾害频数、经济(GDP)损失模数、生命易损模数等易损性评价指标,在详尽分析了重庆市各区县市易性的基础上,对重庆市各区县市的脆弱性和易损强度进行了综合评估,并且计算出了各区县市的易损度,结合GIS方法对重庆进行了易损度区划。并借此提出域易损性分析、评估的模式、为区域防灾、减灾规划提供科学依据。  相似文献   
999.
Phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate) dissolved in aqueous solution was almost completely decomposed by ozonation to form various species within 10 minutes of reaction time for the experimental conditions examined in this research. The generation rate of sulfate was found to be fairly independent of solution pH value. However, the formation of phosphate and carbonate was more favorable for alkaline solutions where hydroxyl free radical is the primary oxidative species. The reaction rates increased with initial gaseous ozone concentrations, indicating the reaction was mass transfer-controlled within the experimental range of this research. Combining the analytical results by various instruments, including gas chromatograph equipped with an electron ionization detector (GC-EID), high performance liquid chromatography (HPLC), ion chromatography (IC), and total organic carbon (TOC), the temporal sequence of phorate ozonation was proposed in this study. The oxidation of sulfur atoms on the phosphorus-sulfur double bond or carbon-sulfur-carbon bond by ozonation was found to occur at first to form sulfate and various intermediates.  相似文献   
1000.
Xu J  Yu Y  Wang P  Guo W  Dai S  Sun H 《Chemosphere》2007,67(7):1408-1414
Fourteen surface sediment samples were collected from Lanzhou Reach of Yellow River, China in July 2005. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector (GC-MS). Total concentrations of the PAHs ranged from 464 to 2621 ng/g dry weight. Sediment samples with the highest PAH concentrations appeared at the downstream of Lanzhou City, where there was the biggest wastewater discharge pipeline from Lanzhou Oil Refinery Factory and Lanzhou Chemical Industry Company. Municipal sewage also contributed to the PAH contamination in the sediments. A correlation existed between the sediment organic carbon content (f(oc)) and the total PAH concentrations (r(2)=0.57), suggesting that sediment organic carbon content played an important role in controlling the PAHs levels in the sediments. According to the observed molecular indices, PAHs contamination in Lanzhou Reach of Yellow River originated both from the high-temperature pyrolytic processes and from the petrogenic source, showing a mixed PAH input pattern, which was also confirmed by the results of a principal component analysis (PCA). According to the numerical effect-based sediment quality guidelines (SQGs) of the United States, the levels of PAHs at most studied sites in Lanzhou Reach of Yellow River should not exert adverse biological effects. Although at some sites (such as S10, S12, etc.) one PAH may exceed the effects range low (ERL), individual PAH did not exceed the effects range median (ERM). The results indicated that sediments in all sites should have potential biological impact, but should have no impairment.  相似文献   
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