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491.
温度对吸油毡吸油性影响试验研究 总被引:1,自引:1,他引:0
分别利用低温和高温环境试验箱严格模拟环境温度,在不同温度环境下测试四种常用吸油毡对三种渤海原油的吸油性。试验同时测定三种原油的凝点,用于探索油品凝点对吸油毡吸油性的影响。试验结果表明:被测试的十二组吸油过程均属于物理过程,提出的关于吸油毡表面黏附和渗透作用的数学模式能较好描述这些过程;对于这三种原油而言,渗透吸油作用在冬季只适合于绥中原油;另外,吸油毡对三种原油,即使在夏秋季也无法达到最大吸油性;黏附和渗透吸油倍数同原油凝点以及吸油毡类型有关。四种吸油毡中,MXU1000系列的吸油性最好,羊毛毡的吸油性最低。 相似文献
492.
Ren M Peng P Cai Y Chen D Zhou L Chen P Hu J 《Environmental pollution (Barking, Essex : 1987)》2011,159(5):1375-1380
The study presented the concentrations and distributions of polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans (PBDD/Fs) as impurities in some commercial decabromodiphenyl ether (DBDE) mixtures that were produced by several manufacturers. The total concentrations of 12 2,3,7,8-substituted tetra- to octa-BDD/F congeners were found to be in the range of 3.4-13.6 (mean 7.8) μg/g, averagely accounting for 99% of total PBDD/Fs. OBDF was the prevailing congener, followed by 1,2,3,4,6,7,8-HpBDF. In addition, OBDD and 1,2,3,4,7,8-HxBDF were also obviously detectable. The total concentrations of PBDD/Fs varied both between the manufacturers and between the lots. On the basis of the global demand for the commercial DBDE in 2001, the annual potential emissions of PBDD/Fs were calculated coarsely to be 0.43 (range: 0.21-0.78) tons. The major dioxin congeners, OBDF and 1,2,3,4,6,7,8-HpBDF, presenting in DBDE, were estimated to be formed from BDE-209, BDE-206, and/or BDE-207 via an intra-molecular elimination of Br2/HBr. 相似文献
493.
494.
With their widespread application in agriculture, industry, culture, medicine, and daily life, lanthanide compounds are being brought into the ecological environment and human body through food chains. It is important to know the acute and chronic effects of lanthanides on the environment, nature balance, and the human body after their entry into bodies and the environment. Lanthanides have been demonstrated to cause spleen apoptosis and decreased immunity of mice, but very little is known about the molecular aspects of these mechanism. In order to understand the spleen apoptotic mechanism induced by intragastric administration of 2, 10 and 20 mg kg(-1) body weight CeCl(3) for consecutive 60 d, we investigated the cerium accumulation, apoptosis, the expression levels of the apoptosis-related cytokines into apoptosis-related genes and proteins. The results demonstrated that cerium had obvious accumulation in the mouse spleen, leading to the significant increase of the spleen indices and splenocyte apoptosis. Furthermore, CeCl(3) could effectively activate caspase-3 and -9, decrease the Bcl-2 the levels of gene and protein, and increase the levels of Bax, and cytochrome c genes and their protein expressions, and promote reactive oxygen species production. It implied CeCl(3)-induced apoptosis in the mouse spleen via intrinsic pathway. Our findings suggest the need for great caution to handle the lanthanides for workers and consumers. 相似文献
495.
Accumulation levels and characteristics of some pesticides in human adipose tissue samples from Southeast China 总被引:1,自引:0,他引:1
This paper presents a comprehensive study of pesticide levels and bio-accumulation characteristics in human adipose tissues among residents of Southeast China. A large number of adipose samples (n = 633) were selected for 58 pesticides and were analyzed by high sensitive Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). The results showed that POPs pesticides were frequently detected, including 2,4′-DDD, 2,4′-DDE, 2,4′-DDT, 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, α-HCH, β-HCH, γ-HCH, δ-HCH, hexachlorobenzene (HCB), and mirex. Other detected pesticide species were dicofol, methamidophos and chlordimeform, which have rarely been reported. Comparing to different countries, the concentrations of total DDT and HCH in these three Chinese southeastern sites were in the middle range, whereas the HCB and mirex were in the lower end. A significant correlation was observed between region as well as age and POPs pesticide levels. Some pesticide residue levels were also found significantly correlated to occupation. However, there was no significant correlation between gender and pesticides. Meanwhile, it is interesting to find that mortality of malignant tumors tends to associate with the pesticides levels in human adipose tissue. More importantly, the measured data presented in this study provide realistic information which is useful for assessing human exposure to pesticides in the general population of Southeast China. 相似文献
496.
497.
超声强化Fe0去除阳离子红GTL的研究 总被引:1,自引:1,他引:0
采用US/Fe0系统去除阳离子红GTL,考察了pH值、Fe0用量、超声功率及活性炭、H2O2、盐分添加对阳离子红GTL去除率的影响,利用紫外-可见吸收光谱变化查明阳离子红GTL在不同条件下的去除差异性,利用SEM解析铁的形态与染料去除的相关性。结果表明: pH≥5.0时超声和Fe0具有协同效应,Fe0用量2 g/L,pH=7.0,超声功率135 W,阳离子红GTL去除率达到96.07%;一定量的活性炭、H2O2、盐分添加会加速染料去除,US加速Fe0反应速度,但不改变染料降解机理,添加活性炭能够彻底降解阳离子红GTL,添加H2O2提供的氧化环境抑制苯胺类化合物生成;铁的形态及与染料的接触是影响染料去除效果的重要原因。 相似文献
498.
灭菌预处理污泥及其滤液产氢发酵的比较研究 总被引:1,自引:0,他引:1
剩余污泥中的固态物质包含大量的蛋白质和多聚糖等有机质,一直被认为是一种具有潜力的生物制氢原料。灭菌预处理的剩余污泥会释放出大量的有机质,真空抽滤后去除掉污泥中固态物质得到滤液。将预处理污泥与滤液分别作为底物,接种产氢菌Pseudomonas sp. GZ1后产氢发酵。测定2种不同底物发酵反应过程中氢气的产量,以及底物的变化(SCOD、可溶性蛋白质、总糖、pH值)。实验结果表明,利用预处理后的污泥滤液作为底物能够有效提高氢气产量。滤液发酵的产氢量达到了4.44 mg H2/g COD,比预处理污泥直接发酵提高了近3.3倍。本实验证明污泥中的固态物质在发酵过程中能释放出更多的营养物质,但实际上并不能被产氢菌有效地利用产生更多的氢气,并对其原因进行了探讨。 相似文献
499.
在大量试验研究获得数据基础上,结合机理分析,考虑ACF同时脱除多种污染物的主要影响因素,运用气固催化反应动力学方法进行分析,采用"混合模型法"建立ACF反应器数学模型,并用MATLAB软件与实验数据相结合迭代求取了模型参数,求出了宏观反应速率方程,并将计算模拟值与实验值进行比对,发现模拟结果与实验结果基本吻合,证实了模型的可靠性.为ACF反应器从试验研究的成果放大到工业规模的应用奠定了基础. 相似文献
500.