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991.
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993.
Ammonia-oxidising bacteria (AOB) are a major contributor to nitrous oxide (N2O) emissions during nitrogen transformation. N2O production was observed under both anoxic and aerobic conditions in a lab-scale partial nitritation system operated as a sequencing batch reactor (SBR). The system achieved 55 ± 5% conversion of the 1 g NH4+-N/L contained in a synthetic anaerobic digester liquor to nitrite. The N2O emission factor was 1.0 ± 0.1% of the ammonium converted. pH was shown to have a major impact on the N2O production rate of the AOB enriched culture. In the investigated pH range of 6.0-8.5, the specific N2O production was the lowest between pH 6.0 and 7.0 at a rate of 0.15 ± 0.01 mg N2O-N/h/g VSS, but increased with pH to a maximum of 0.53 ± 0.04 mg N2O-N/h/g VSS at pH 8.0. The same trend was also observed for the specific ammonium oxidation rate (AOR) with the maximum AOR reached at pH 8.0. A linear relationship between the N2O production rate and AOR was observed suggesting that increased ammonium oxidation activity may have promoted N2O production. The N2O production rate was constant across free ammonia (FA) and free nitrous acid (FNA) concentrations of 5-78 mg NH3-N/L and 0.15-4.6 mg HNO2-N/L, respectively, indicating that the observed pH effect was not due to changes in FA or FNA concentrations. 相似文献
994.
对半化学浆黑液进行磺化改性制备水泥减水剂,并对改性工艺进行优化。适宜的工艺条件为:Na_2SO_3用量20%,时间4h,温度160℃。反应改性物在掺量0. 4%、水灰此0.4条件下,水泥净浆流动度由基准的105mm提高到151mm。当改性物掺量在0.3%时,减水率为5.5%,而掺量达到0.6%时,减水率升高到9.0%。改性物的减水性能达到普通减水剂的标准。 相似文献
995.
996.
在盐品生产中,原料卤水杂质组分较高对盐产品质量影响严重,此方法论述了如何从源头上去除原料卤水的杂质离子,达到既经济又能产出高质量盐产品的卤水净化方案。 相似文献
997.
湘泉兼香型白酒与浓香型白酒以恰当的比例进行组合勾兑,对改善浓香型白酒酒质效果显著,可使组合后的酒体窖香优雅、醇甜、柔和、爽净,兼有清爽型、浓香型白酒的独特风格,更加迎合消费者的需求,赢得市场,对白酒酒体设计、勾兑具有指导意义;为白酒向多元化发展拓展了空间。(孙悟) 相似文献
998.
Song YB An YR Kim SJ Park HW Jung JW Kyung JS Hwang SY Kim YS 《Journal of the science of food and agriculture》2012,92(2):388-396
BACKGROUND: Ginseng saponin and ginsenosides exert anti‐obesity effects via the modulation of physiological lipid metabolism in vivo or intracellular signalling in cell culture systems. However, the complicated relationship between the anti‐obesity effects of ginseng and gene expression has yet to be defined under in vivo conditions. Therefore, we evaluated the relationship between the anti‐obesity effects of Korean red ginseng extract (KRGE) and hepatic gene expression profiles in mice fed long‐term on a high‐fat diet (HFD) in this study. RESULTS: KRGE reduces the levels of cholesterol, low‐density lipoprotein‐cholesterol (LDL‐C), serum triglycerides, and atherogenic indices. Levels of leptin, adiponectin and insulin, which regulate glucose and lipid metabolism, were impaired profoundly by HFD. However, KRGE treatment brought these levels back to normal. KRGE was found to down‐regulate genes associated with lipid metabolism or cholesterol metabolism (Lipa, Cyp7a1, Il1rn, Acot2, Mogat1, Osbpl3, Asah3l, Insig1, Anxa2, Vldlr, Hmgcs1, Sytl4, Plscr4, Pla2g4e, Slc27a3, Enpp6), all of which were up‐regulated by HFD. CONCLUSION: KRGE regulated the expression of genes associated with abnormal physiology via HFD. Leptin, insulin, and adiponectin, which carry out critical functions in energy and lipid metabolism, were shown to be modulated by KRGE. These results show that KRGE is effective in preventing obesity. Copyright © 2011 Society of Chemical Industry 相似文献
999.
1000.
从优质白酒窖泥中分离筛选出8 株高产蛋白酶的兼性厌氧细菌,通过测定内肽酶、氨肽酶、羧肽酶酶活力,最终筛选出3 株3 种蛋白酶活力相对较高的菌株HDS4、HDS6、HDS8,并对其进行形态观察、生理生化和16S rDNA鉴定,确定3 株菌分别为枯草芽孢杆菌(Baci l lus subt i l i s)、解淀粉芽孢杆菌(Baci l lusamyloliquefaciens)、苏云金芽孢杆菌(Bacillus thuringiensis)。以接种量为基础,对3 株目的菌株进行复配,得到的复配菌系3 种蛋白酶活力均比单一菌株高,3 种酶活力分别提高了8.907%、6.181%、8.781%。 相似文献