COD测定仪使用中的几个问题

HACH COD测定仪具有测量范围宽、试剂用量少、能耗低、操作方便和二次污染小等特点,现已广泛应用于环境监测及相关行业,但在使用HACH COD测定仪时,仍存在若干问题。     

Effect of bio-column composed of aged refuse on methane abatement – A novel configuration of biological oxidation in refuse landfill

An experimental bio-column composed of aged refuse was installed around the exhaust pipe as a new way to mitigate methane in refuse landfill.One of the objectives of this work was to assess the effect of aged refuse thickness in bio-column on reducing CH 4 emissions.Over the study period,methane oxidation was observed at various thicknesses,5 cm (small size),10 cm (middle size) and 15 cm (large size),representing one to three times of pipeline diameters.The middle and large size both showed over 90% methane conversion,and the highest methane conversion rate of above 95% occurred in the middle-size column cell.Michaelis-Menten equation addressed the methanotrophs diffusion in different layers of the bio-columns.Maximum methanotrophic activity (V max) measured at the three thicknesses ranged from 6.4 × 10 3 to 15.6 × 10 3 units,and the half-saturation value (K M) ranged from 0.85% to 1.67%.Both the highest V max and K M were observed at the middle-size of the bio-column,as well as the largest methanotrophs population,suggesting a significant efficiency of methane mitigation happened in the optimum zone with greatest affinity and methanotrophic bacteria activities.Therefore,bio-column is a potential style for methane abatement in landfill,and the aged refuse both naturally formed and artificially placed in the column plays a critical role in CH 4 emission.     

航天科工二院成功研制国内第一套智能型低失真度标准源

日前,中国航天科工二院203所研制成功了国内第一套智能型低失真度标准源。该系统具有测量范围宽和准确度高等特点,被授予了一项国家发明专利和一项国家实用新型专利。其主要技术指标国内领先,同时国际市场上未见同类水平的低失真度标准源。     

时代集团推出新型的TH180里氏硬度计

时代TH180里氏硬度测量系统测试精度高、体积小、操作容易、携带方便，测量范围宽，适用于测试金属材料的硬度。在第六届中国国际科学仪器及实验室装备展览会获自主创新银奖，并且投放生产，于2009年1月11日正式上市。