预蒸馏-气相色谱法测定水和废水中的N′N-二甲基甲酰胺

用蒸馏法对水样进行预处理，以气相色谱FFAP毛细管柱分离，FID检测，测定水和废水中的N′N-二甲基甲酰胺，在0．5～1000mg／L范围内有转好的线性关系，检出下限为0．2mg／L，相对标准差为6．1％～8．5％，加标回收率在78．3％～98．6％之间。本方法适用于地表水和工业废水中DMF的测定。     

高温液晶N,N′-双[对苯基苄叉]α,α′-双对甲苯胺(简称BPhBT)的合成和测定多环芳烃某些色谱性能评价

1890年,O.Lehmannt为了描述固态晶体和流动体的介晶态而首先提出了“液晶”这一概念。目前,已知有几千种有机物当加热其晶态超过熔点时会形成液晶。液晶就是指这样一类物质:它在一定温度范围内既具有液体的流动性和连续性又具有晶体的各向异性,它是一类有序流体。     

Radiometric studies of clear air attenuation and atmospheric water vapour at 22.235 GHz over calcutta (lat. 22°32′N,long. 88°20′E)

22.235 GHz is the thermal emission line of water vapour in the atmosphere. An estimate of attenuation and hence the water vapour content in the atmosphere has been made by using a 22.235 GHz radiometer installed at the Institute of Radiophysics and Electronics, Calcutta. The experimental results are compared with the results obtained by another 22.235 GHz radiometer over Delhi. The results are discussed and compared in the light of radiosonde observations over Calcutta. The results show a good resemblance between the radiosonde and radiometric observations.