基于MP3的汽车报站器

要介绍一种基于AT89C51SND1C单片机和闪存实现的MP3公交车报站器,可通过键盘和播放列表文件实现高品质语音信息的播放,同时使用LED点阵显示播放的内容。报站器可作为优盘方便地更换语音文件,便于车载广告信息的更换。     

Targeting of Proteins for Translocation at the Endoplasmic Reticulum

The endoplasmic reticulum represents the gateway to the secretory pathway. Here, proteins destined for secretion, as well as soluble and membrane proteins that reside in the endomembrane system and plasma membrane, are triaged from proteins that will remain in the cytosol or be targeted to other cellular organelles. This process requires the faithful recognition of specific targeting signals and subsequent delivery mechanisms to then target them to the translocases present at the ER membrane, which can either translocate them into the ER lumen or insert them into the lipid bilayer. This review focuses on the current understanding of the first step in this process representing the targeting phase. Targeting is typically mediated by cleavable N-terminal hydrophobic signal sequences or internal membrane anchor sequences; these can either be captured co-translationally at the ribosome or recognised post-translationally and then delivered to the ER translocases. Location and features of the targeting sequence dictate which of several overlapping targeting pathway substrates will be used. Mutations in the targeting machinery or targeting signals can be linked to diseases.     

钙离子浓度对活性污泥处理系统脱氮效果的影响

考察了钙离子浓度对活性污泥系统脱氮效果的影响。在单级序批式反应器(SBR)中,对于化学需氧量(COD)为680 mg/L、氨氮(NH⁺₄-N)质量浓度为20 mg/L的自配废水,逐步增加钙离子浓度,测定了在不同钙离子浓度下的总氮(TN)去除率、NH⁺₄-N去除率、亚硝酸氮(NO^-₂-N)和硝酸氮(NO^-₃-N)累积量及污泥体积指数(SVI),并采用最大或然数(MPN)法测得亚硝酸菌、硝酸菌和反硝化菌数量的变化规律。结果表明,在钙离子质量浓度为480~1000 mg/L时,SVI为25 mL/g,污泥颗粒密实度较大,系统中硝酸菌与反硝化菌的数量均维持在10⁴~10⁵数量级,TN和NH⁺₄-N去除率均在90%以上,NO^-₃-N累积量小于0.25 mg/L,实现了同步硝化反硝化(SND)作用,这是实现较高脱氮效果的主要原因。     

含氨氮废水生物脱氮新工艺

综述了传统生物脱氮的理论与工艺，以及基于微生物过程的氨氮废水生物脱氮新工艺的基：本概况、处理能力和运行条件，并对氨氮废水脱氮新工艺的应用前景进行了展望．     

免曝气混合填料反应器处理生活污水的性能

采用沸石-塑料混合填料为载体构建固定床生物膜反应器,周期性进水（厌氧）-排水（好氧）富集培养聚糖菌（GAOs）,结合沸石颗粒吸附作用实现厌氧条件下COD和氨氮的去除。在进水COD和氨氮浓度分别为（508±19）mg/L和（40±3）mg/L、HRT为12 h（厌氧6 h、好氧6 h）的运行条件下,单级反应器COD、氨氮和总氮去除率分别为89.2%、57.5%、57.5%。双级反应器条件下,COD、氨氮和总氮的平均去除率分别为93.1%、84.9%、70.8%。缩短50% HRT（厌氧/缺氧3 h+好氧3 h）后,双级反应器总氮去除率提升到81.7%。16S rRNA高通量测序结果显示,聚糖菌Candidatus Competibacter的相对丰度在塑料填料表面上升了30.43倍（0.46%→14%）,而在沸石颗粒表面上升了14.35倍（0.46%→6.60%）,表明塑料填料表面更有利于聚糖菌的富集。     

采用同时硝化-反硝化工艺处理含氨废水

采用同时硝化-反硝化工艺处理石化工业含氨废水,实现了投资少、流程短、设备少、操作简便和脱氮效果稳定的目标。运行结果表明,采用同时硝化-反硝化工艺具有同步高效降解有机污染物和总氮的功能,CODC r平均去除率为89.3%、NH3-N去除率达99%以上。     

气水比对曝气生物滤池SND的影响

采用两段BAF处理城市污水,探讨了气水比对反应器处理效果的影响.在A段水力负荷为0.81 m/h、气水比为3∶1时,分析了B段气水比分别为3∶1、2∶1和1∶1时反应器的运行情况.结果表明:A段反应器对TN基本上没有去除效果,因NH4+ -N的部分氧化使得出水中NO2--N质量浓度介于0.45～0.70 mg/L之间,...     

溶解氧和污泥粒径分布对城市污水SND影响

为了进一步探讨同步硝化反硝化的反应机理,采用SBR工艺,考察溶解氧和污泥粒径分布对城市污水同步硝化反硝化的影响。结果表明：低溶解氧（平均DO-0．5～0．8mg／L）条件下,氮平衡计算证实SBR工艺发生了明显的SND现象,总氮中大约23．11％的氮是通过SND现象去除的。当DO浓度为0．5mg／L时,硝态氮生成量与氨氮的减少量之比为0．454,硝化速率与反硝化速率基本相当。当DO浓度为4．296mg／L时,硝化反应产生的氨氮的减少量与硝态氮的生成量相等,此时基本不发生SND现象。当SND发生时,污泥菌胶团颗粒的平均颗粒粒径仅为5．02μm～6μm,说明SND不是单纯的“微环境作用”的结果。     

NOx monitoring of a simultaneous nitrifying-denitrifying (SND) activated sludge plant at different oxidation reduction potentials

Simultaneous nitrification-denitrification (SND) allows biological nitrogen removal in a single reactor without separation of the two processes in time or space but requires adapted control strategies (anoxic/aerobic conditions). In this study, the formation of gaseous nitric oxide (NO(G)) and nitrogen dioxide (NO(2G)) was monitored for SND in relation to the oxidation-reduction potential (ORP) and nitrogen removal in a lab batch reactor and a pilot membrane bio-reactor (MBR). In addition hospital wastewater (COD/N(tot)>6:1) was treated on site for 1 year. The highest total nitrogen removal rates of max 90% were reached at 220-240mV ORP (given as E(h)) with corresponding maximal NO(G) emissions rates of 0.9microgg(-1)VSSh(-1). The maximal emission rates of NO(2G) (0.2microgg(-1)VSSh(-1)) were reached at the same ORP level and the NO(2G) emissions correlated to the nitrite accumulation in the activated sludge up to 5mgl(-1)NO(2L)-N. It was shown that this correlation was due to biological production and not due to pH-dependent chemical conversion. Therefore, NO(2G) can be used as additional control loop for ORP-controlled SND systems to avoid the inhibition of denitrification and high nitrite concentrations in the plant effluent.