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251.
化学气相沉积法可对13X分子筛进行孔径修饰,并用于含重金属离子废水的净化处理。研究结果表明,随13X分子筛外表面SiO2沉积量的增加,孔径收缩。 相似文献
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This study compared three forecasting models based on the mean absolute percentage errors (MAPE) of their accuracy in forecasting
air pollution in a traffic tunnel: the Grey model (GM), the combination model used four sample point and five sample point
prediction with GM (1,1)(GM(1,1)4 + 5), and the modified grey model (MGM). An MGM was combined using the four points of the original sequence using the original
grey prediction GM (1,1) for short-term forecasting. The proposed method cannot only enhance the prediction accuracy of the
original grey model, but can also solve the jump data forecasting problem something for which the original grey model is inappropriate.
The MAPE was applied to the models, and the MGM found the proposed method to be simple and efficient. The MAPE of MGM, calculated
over 3 h of forecasts, were as follows: 10.12 (Upwind), 10.07 (Middle) and 7.68 (Downwind) for CO; 10.79 (Upwind), 6.05 (Middle)
and 5.98 (Downwind) for NO
x
, and 11.67 (Upwind), 7.32 (Middle) and 4.56 (Downwind) for NMHC. The MGM model results reveal that the combined forecasts
can significantly decrease the overall forecasting error. Results of this demonstrate that MGM can accurately forecast air
pollution in the Kaohsiung Chung–Cheng Tunnel. 相似文献
254.
D.B. Prelusky 《Journal of environmental science and health. Part. B》2013,48(5):1103-1117
Abstract Central serotoninergic (5‐hydroxytryptamine, 5HT) pathways are believed to be involved in the mechanisms of anorexia and/or emesis evoked by the trichothecene mycotoxin deoxynivalenol (DON). Using an in vitro membrane receptor binding assay, the competitive potency of DON was investigated against several radioactive ligands that have a high affinity for selective 5HT‐receptor subgroups. Receptor site densities and displacement profiles in twelve selected regions of pig brain were investigated. Overall, DON possessed only minimal efficacy to competently block any of the 5HT‐ligands tested. IC50 values (50% inhibitory concentration) of at least 5 mM DON were required to inhibit binding, and in certain regions concentrations of 100 mM were ineffective. In comparison, several standard 5HT‐antagonists showed 103‐105 times greater capability than DON to displace binding of these ligands. Because these results indicated DON possesses only weak affinity for the 5HT‐receptor subtypes investigated here, this suggested that in vivo, unless relatively high concentrations of the toxin are present, its pharmacological effects may be mediated by mechanisms other than a functional interaction with serotoninergic receptors at the central level. 相似文献
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通过在不同pH值,温度等条件下Ca5(AsO4)3OH的溶解,确定其稳定存在的pH值范围,得出它的溶度积和生成的自由能(ΔG0f)。结果表明,Ca5(AsO4)3OH在水中的溶解度和稳定范围与pH和温度有关,在酸性条件下(初始pH=2)它的溶解度较大,而且在水中的溶解度随着温度的升高而降低。利用PHREEQC程序计算确定Ca5(AsO4)3OH的溶度积为10-40.86,生成自由能ΔG0f为-5 063.53 kJ/mol。利用JADE5软件计算得到其晶格参数a=b=9.696,c=6.967和晶胞体积为567.304 3。 相似文献
257.
zer nar Semra Yaar Metin Kertmen Kevser Demirz Nevzat
zgü Yigit Mehmet Kitis 《Process Safety and Environmental Protection》2008,86(6):455-460
The effects of cycle time on the biodegradation of the azo dye remazol brilliant violet 5R (RBV-5R) were investigated in an anaerobic–aerobic sequencing batch reactor (SBR). System performance was determined by monitoring chemical oxygen demand (COD), color, anaerobic enzyme (azo reductase) and aerobic enzyme (catechol 2,3-dioxygenase), and aromatic amine concentration. SBR was operated in three different total cycle times (48 h, 24 h and 12 h), fed with a synthetic textile wastewater. In this study, the anaerobic period of SBR was found to allow the reductive decolorization of azo dye and the aerobic period was found to be effective on further COD removal after the anaerobic period. The percentage reductions in color by the anaerobic stage of the SBR were at 72%, 89% and 86% for the 24-h, 12-h and 6-h cycle times, respectively. Total COD removal efficiencies were over 75% for all operational conditions and about 70% of the COD removal was achieved in the first 3 h of anaerobic stages. During the decolorization of RBV-5R, two sulfonated aromatic amines (benzene-based and naphthalene-based) were formed and detected by HPLC. Aerobic phases of SBR with total cycle times of 48 h, 24 h and 12 h were able to remove benzene-based aromatic amines with removal efficiency of 64%, 92% and 89%, respectively. The results indicated that the best SBR performance in terms of color removal and aromatic amine degradation was achieved from total cycle time of 24 h. 相似文献
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Ken Inoue Makoto Kanai Yuzo Tanabe Takeo Kubota Catherine D. Kashork Keiko Wakui Yoshimitsu Fukushima James R. Lupski Lisa G. Shaffer 《黑龙江环境通报》2001,21(13):1133-1136
A submicroscopic genomic duplication in Xq22.2 that contains the entire proteolipid protein 1 gene (PLP1) is responsible for the majority of Pelizaeus–Merzbacher disease (PMD) patients. We previously developed an interphase FISH assay to screen for PLP1 duplications in PMD patients using peripheral blood and lymphoblastoid cell lines. This assay has been utilized as a clinical diagnostic test in our cytogenetics laboratory. To expand usage of the interphase FISH assay to prenatal diagnosis of PLP1 duplications, we examined three PMD families with PLP1 duplications utilizing aminiotic fluid samples. In two families the FISH assay revealed fetuses with PLP1 duplications, whereas the other fetus showed a normal copy number of PLP1. Haplotype analyses, as well as an additional FISH analysis using postnatal blood samples, confirmed the results of the prenatal analyses. Our study demonstrates utility of the interphase FISH assay in the prenatal diagnosis of PLP1 duplications in PMD. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献