科研成果 by Type: 期刊论文

Eight water-soluble organic anions were measured in 70 aerosol samples and 10 snow samples at Barrow, Alaska in March-April, 1989. The ranking of the ions in aerosols according to total (coarse+fine aerosol) median concentrations was acetate (44 ng m-3), oxalate (27), benzoate (23), formate (22), propionate (6), methanesulfonate (5), lactate (4), and pyruvate (4). When added up, the median organic anion mass was 156 ng m-3. The organic anions/nssSO4= mass ratio had a median of 0.18 and 0.07 in the coarse (>l mum) and fine (<1 mum) size fractions, respectively, but can be very high on occasions. On average, the organic anions made up more than 10% of the water-soluble aerosol mass. A similar ranking in concentration was also found for the organic ions in the snow pack samples. The organic anion/nssSO4= mass ratio in these samples was >0.5, substantially higher than in aerosols.

<正> “凯拉姆”是阿拉伯文“Kalam”的音译,意为语言、言论,后来成为伊斯兰教教义学的专名,指有关教义与信条的依据逻辑的或辩证的方式而表明的言论.研究教义的人则被称为“穆台凯里姆”(Mutakkalimun).传统的伊斯兰教史学家并不否认凯拉姆学与希腊哲学间的联

<正> 加拿大图书馆的发展,一般地讲,是与下列因素相关的:地理环境、人口、经济、政治和政府体制,以及历史的演变。除此以外,加拿大的图书馆形成还与美国的影响有着直接的

本文发现了货郎问题(TSP)能量函数的参数空间中的吸引域与全局性优化解之间存在着确定的对应关系,并找到了许多参数空间中的吸引域。在此基础上提出了一种新算法——参数正交选优神经网络算法求解TSP,30城市,31城市(中国)和300城市TSP的求解结果都十分满意,表明这种新算法的有效性。

<正> 1992年4月中旬,在郁金香花盛开的时节,我到圣佛朗西斯科参加学术会议,在朋友的安排下,有幸到慕名已久的斯坦福大学胡佛研究所东亚图书馆去参观。汽车一驶进校区,与喧闹的市区形成一鲜明的对比,这里除了从四周的绿树丛中。透过晨曦中的薄雾,偶尔传来一两声清脆的鸟鸣外,再也听不到其他声音。路旁整齐的棕榈树,轻轻摇动着巨大的枝叶,像是在向我们表示欢迎。