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Fresh TiO2 was found to possess a strong germicidal activity even without UV irradiation. Live Yeast (Saccharomyces cerevisiae) cells in contact with fresh TiO2 were found deformed and dead after 15 min contact. The cause of germicidal activity was discussed from the observed cell deformation, lysis and increased absorption at 1680 cm-1 in FT-IR spectra of the affected cells, which proved the oxidizing effect of fresh TiO2 to cells. The deformation caused by the stretching of cell wall and pressure built-up inside the cell, led to cell burst and release of intracellular materials. The degree of cell deformation was found positively related with the wetting property of TiO2. Cells are negatively charged, for Gram-negative cell (thinner cell wall), a higher germicidal effect was observed than Gram-positive cells. The germicidal effect of TiO2 gradually decreases after exposure to air at room temperature, as the wetting property decreases. This kind of germicidal activity was more effective compared to other germicidal process such as UVA/TiO2 or Ag+. This shed light on designing new germicidal material either maintained by visible light irradiation, or by oxidation effect generated by reactive oxygen species. 相似文献
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<正>1、首先要迅速了解或判明事故的性质、地点、范围和事故区域的巷道情况,通风系统、风流及火灾烟气蔓延的速度、方向以及自己所处巷道位置之间的关系,并根据实际情况,确定撤退路线和避灾自救的方法。2、撤退时不要惊慌,不能狂奔乱跑,应在现场负责人及有经验的老工人带领下有组织地撤离。 相似文献
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《资源节约与环保》2016,(7)
实验目的是调查分析杭州下沙地区市售新鲜香菇中重金属的污染状况。随机采购杭州下沙地区市售的新鲜香菇,用湿式消解法处理后以火焰原子吸收光谱法对样本中镉和铜的含量进行了定量分析。20个新鲜香菇品经检验,结果测得镉和铜含量范围分别为0.0535 mg/kg~0.4245 mg/kg,0.008 mg/kg~0.4055 mg/kg。依据该实验结果得出,选用湿式消解—火焰原子吸收法测定新鲜香菇中镉和铜的含量方法简单、准确、效率高。所采购的新鲜香菇14个样本镉含量超过了国家标准(GB2762—2005食品中污染物的限量),全部样本的铜含量都没有超过国家标准(GB2721—2003食品中铜的测定)。 相似文献
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Transformation of organic matters in fresh leachate during anaerobic
degradation under long hydraulic retention time 总被引:1,自引:0,他引:1
This study investigated the biodegradability of fresh leachate from a young municipal solid waste landfill at the inoculum to substrate
ratios (V/V) of 10/100, 25/100, 50/100 and 100/100, as well as the transformation of organic matters in leachate under prolonged
hydraulic retention time (HRT) of 50 d. Fresh leachate showed a good biodegradability, with chemical oxygen demand (COD) removal
e ciency as high as 87%–92% and cumulative methane yield close to theoretical value (0.35 L CH4/g CODdeg). Methane production
and COD depletion presented biphasic characteristics associated with the successive utilization of two major intermediates, acetate and
propionate. The biphasic degradation of fresh leachate was resulted from the di erent hydrolysis rates of diverse substrates and the
changes in microorganism community structure. After 50 d, the e uents were dominated by high-MW organic compounds (MW > 10
kDa) at each inoculum ratio, which might be refractory compounds released from cell lyses. 相似文献
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英国天空电视台一直在业界享有盛誉,几乎三分之一的英国家庭订购了sky电视节目,拥有约850万客户。此次中国“欧洲环保之窗”采访团详细了解了作为强势电视媒体的天空电视台是如何利用其有效的交流平台,加强节能减排宣传。 相似文献
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实验结果表明,用新鲜蒸馏水代替无氨水测定总氮,技术指标符合要求,方法可靠,有推广价值。 相似文献