89 research outputs found
Effect of Flue-gas Cleaning Devices on Mercury Emission From Coal-fired Boiler
为研究燃煤锅炉烟气净化设施对汞排放特性的影响,采用Ontario-Hydro方法,对设有催化脱硝、静电除尘、海水脱硫的300MW燃煤锅炉排放烟气中汞的含量与形态进行分析,同时测定锅炉的煤、底渣、飞灰等固体样品以及脱硫塔前后、曝气之后海水样品中的汞含量。实验结果为:烟气中的气态汞占总汞的79.1%以上,脱硝催化剂对汞的价态具有强烈的转化作用,烟气中83.4%的气态Hg0被氧化成气态Hg2+;静电除尘对颗粒态汞的去除率几乎达到100%;在脱硫塔中,海水对烟气中汞的洗脱率高达73.6%,曝气后排放前的海水中含汞量是新鲜海水的5.5倍。研究表明锅炉烟气净化设施对汞的排放特性有着重要的影响。In order to study the effect of flue-gas cleaning devices on mercury emission from coal-fired boiler, Ontario-Hydro method had been applied to determine the mercury concentration and speciation in the flue-gas emitted from a 300MW coal-fired boiler, which was equipped with various pollution control devices, including selective catalyst reduction (SCR) De-NOx system, electrostatic precipitator (ESP), and flue-gas seawater De-SO2 system (FGD). Mercury concentration in raw coal, bottom ash and fly ash of the boiler, seawater at the inlet and outlet of SO2 absorption reactor and the drainage of aeration sink, were also analyzed. The results indicate that the percentage of gaseous mercury in total mercury discharged is more than 79.1%. De-NOx catalyst strongly affects the mercury speciation transformation, showing a conversion rate of 83.4% for Hg0 to Hg2+. The removal efficiency of particulate mercury by ESP is close to 100%. With seawater FGD, the removal efficiency of mercury is as high as 73.6%. The mercury concentration in the seawater of drainage from aeration sink is 5.5 times higher than that in fresh seawater. The study shows that the flue-gas cleaning devices in coal-fired power plant play an important role on mercury emission characterization
基于MIMO电力线信道的定时同步算法
针对多输入多输出(MIMO)电力线通信(PLC)系统中的脉冲噪声造成定时同步不准确的问题,文章提出了一种基于MIMO PLC系统的正交频分复用(OFDM)符号定时同步算法,利用差分相关和最大比合并(MRC)提高同步性能。在2×2 MIMO PLC信道模型下,两个发送端口发送自相关性和互相关性良好的前导序列,在接收端通过设置阈值过滤电力线中的脉冲噪声,采用改进的延时自相关算法实现定时粗同步。利用窗口求和方法减小精同步的估计范围后,通过差分相关和MRC联合算法完成定时精同步。相比互相关算法,所提算法有2 dB的提升。仿真结果表明,该方法同步性能明显优于传统互相关算法
用于酯化反应的亲水性渗透汽化膜研究进展
渗透汽化是分离其沸混合物或者某一物质含量较低混合液的方法.在酯化反应中,耦合渗透汽化可以提高反应转化率.本文根据膜的制备材料,对有机膜、无机膜、有机无机杂化膜在该方面的应用进行了较详细的报道.且分析了各种膜在酯化反应中的催化效果
普通小球藻细胞色素b559α亚基编码基因的克隆及序列分析
细胞色素b559是由α和β两个亚基组成的一种血红蛋白,是光系统Ⅱ的必需组分,可以保护光系统Ⅱ免受光抑制的危害。为了从分子水平深入了解细胞色素b559的功能,从普通小球藻(Chlorella vugaris)中克隆了编码细胞色素b559α亚基的基因序列及其5′-侧翼序列。结果表明,DNA全长包括1个252 bp的开放读码框,442 bp的5′-侧翼序列和195 bp的3′-侧翼序列,5′-侧翼序列区域存在一系列预测的顺式作用元件
氮胁迫下小球藻淀粉与脂肪的合成关系
绿藻特别是小球藻细胞存在两大储碳代谢物,脂肪(TAG)和淀粉,且二者的合成享有共同的前体物质。本实验以小球藻Chlorella sp.为研究对象,在氮胁迫的条件下,抑制淀粉合成途径的关键酶和脂肪合成途径的关键酶,通过对比淀粉及脂肪的积累情况来探究两条代谢途径之间的关系。实验结果显示:加入5 mmol·L-1 Pi明显抑制了淀粉合成途径,导致淀粉含量降低,脂肪酸浓度有所增加,单位细胞脂肪酸无显著影响。加入40μmol·L-1稀禾定在第6 d表现出对脂肪的抑制,淀粉浓度降低,单位细胞淀粉含量并无显著影响
Synthesis pathway relationship between starch and fat in Chlorella sp. under nitrogen starvation
Triacylglycerol(TAG) and starch, as the two main energy storage products in green microalgae, especially the Chlorella sp., share the same synthesis precursor in its metabolisim system. This research aimed at the key enzymes in inhibiting starch and TAG
巴夫杜氏藻β-肌动蛋白基因的克隆和分析
目的获得巴夫杜氏藻β-肌动蛋白基因cDNA全长序列。方法以巴夫杜氏藻cDNA为模板,采用简并引物进行PCR扩增,获得533bp特异cDNA片段。在此基础上,设计特异引物,采用5’-Genome Walking和3’-RACE的方法,获得基因的5’-端DNA序列和3’-端cDNA序列,进而获得β-肌动蛋白基因cDNA全长序列。结果获得了巴夫杜氏藻β-肌动蛋白基因的特异cDNA片段、5’-端DNA和3’-端cDNA片段。经拼接后,扩增出全长cDNA。β-肌动蛋白基因cDNA全长1754bp,包括1137bp的开放读码框和617bp的3’-非翻译区序列。氨基酸序列相似性分析发现,巴夫杜氏藻β-肌动蛋白氨基酸序列与杜氏盐藻、莱茵衣藻等的同源性较高。系统发育分析表明,巴夫杜氏藻β-肌动蛋白与杜氏盐藻的相似性最高。结论首次获得了巴夫杜氏藻β-肌动蛋白基因cDNA全长序列,并发现巴夫杜氏藻β-肌动蛋白基因非常保守
- …