有限元仿真技术在板材成形中的应用

有限元仿真技术具有很强的经济性和柔性，已广泛应用于汽车钢铁工业领域。文中论述了板材成形有限元仿真分析的关键技术及其研究进展，并采用动力显式有限元软件LS-DYNA对轻型车侧围后外板零件冲压成形过程进行了仿真计算，分析了变形过程的金属流动规律。     

Characteristics of volatile compounds removal in biogas slurry of pig manure by ozone oxidation and organic solvents extraction

Biogas slurry is not suitable for liquid fertilizer due to its high amounts of volatile materials being of complicated composition and peculiar smell. In order to remove volatiles from biogas slurry efficiently, the dynamic headspace and gas chromatography-mass spectrometry were used to clear the composition of volatiles. Nitrogen stripping and superfluous ozone were also used to remove volatiles from biogas slurry. The results showed that there were 21 kinds of volatile compounds in the biogas slurry, including sulfur compounds, organic amines, benzene, halogen generation of hydrocarbons and alkanes, some of which had strong peculiar smell. The volatile compounds in biogas slurry can be removed with the rate of 53.0% by nitrogen stripping and with rate of 81.7% by the oxidization and stripping of the superfluous ozone. On this basis, the removal rate of the volatile compounds reached 99.2% by chloroform and n-hexane extraction, and almost all of odor was eliminated. The contents of some dissolved organic compounds decreased obviously and however main plant nutrients had no significant change in the biogas slurry after being treated.     

自动顶空-气相色谱法测定水中甲醇的方法优化

从顶空进样器载气压力、顶空瓶压力、顶空瓶温度等方面对自动顶空-气相色谱法测定水中甲醇的方法进行了优化。该方法的灵敏度高于直接进样(水溶液)法、已有的顶空进样法,满足《空气和废气监测分析方法》(第4版)中吸收液中甲醇检出限0.4 mg/L的要求。     

用于气相色谱分析的样品导入技术及其应用

综述了几种用于气相色谱分析的绿色环保型样品导入技术,如静态顶空技术、吹扫捕集技术、固相微萃取技术和热脱附技术的原理及应用情况,并对这几种方法进行了比较。