地球环境中的放射性污染

地球环境中的放射性污染有天然辐射来源和人为放射性来源,通过消化道、呼吸道和皮肤、粘膜或伤口进入人体内,对人体形成直接损伤、间接损伤和远期辐射效应,应从内照射和外照射防护两个方面来防止环境中的放射性污染.     

化学教学中应重视绿色化学教育

在高职的化学教学中渗透绿色化学教育，既让学生在潜移默化中增强了环保意识，又使其书本知识与实际得到了很好的结合，有助于学生素质的提高，值得进一步完善和推广。     

农业生态环境中的锰元素

论述了锰元素的地球化学特征和分布，农作物与锰元素的关系以及锰元素有效态含量的制约因素：土壤的含量、土壤的酸碱度、土壤的氧化还原环境、土壤的有机质含量。     

广西南部三叠纪强过铝质火成岩岩石化学特征的动力学意义

为深化对广西南部地区印支期造山运动深部动力学机制的理解,采用该地区三叠纪强过铝质火成岩的岩石化学数据提取其源区熔融温度以及成分特征方面的信息。结果显示:广西南部三叠纪强过铝质火成岩属于高钾钙碱性系列,形成于印支期后碰撞构造背景中。它们的Al2O3/TiO2小于100,CaO/Na2O多数大于0 3、少数小于0 3。同时,这些强过铝质火成岩的Al2O3/TiO2与其SiO2含量有正相关趋势,而CaO/Na2O与SiO2含量呈明显的负相关关系。这些岩石化学特征表明,强过铝质火成岩部分源于泥质岩的部分熔融,部分源于砂岩或正变质岩的部分熔融,但不排除后者可能是泥质岩部分熔融产物和玄武质岩浆相混合的结果;同时这些强过铝质火成岩形成源区的温度高(>=875℃)。因此,广西南部三叠纪时期的深部能量来自以底侵玄武岩浆加热作用所体现出来的软流圈地幔的平流热传递过程。     

Photodegradation of acetochlor in water and UV photoproducts identified by mass spectrometry

The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous solution was rapidly degraded. The half-lives were7.1, 10.1, and 11.5 min in de-ionized water, river water and paddy water, respectively. Photopreduets of acetochlor were identified by gas chromatography/mass spectrometry(GC/MS) and found at least twelve photoproducts resulted from dechlorination with subsequent hydrtrxylation and cyclization processes. The chemical structures of ten photoproducts were presumed on the basis of mass spectrum interpretation and literature data. Photoproducts are identified as 2-ethyl-6-methylaniline; N, N-diethylaniline ; 4, 8-dimethyl-2-oxo- 1,2,3,4- tetrahydroquino-line; 2-oxo-N-(2-ethyl-6-methylphenyl)-N-(ethoxymethyl) acetamide; N-(ethoxymethyl)-2‘-ethyl-6‘-methylformanilide; 1-hydroxyaeetyl-2-ethoxyl-7-ethylind ole; 8-ethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 4, 8-dimethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 2-hydroxy-2‘-ethyl-6‘-methyl-N-(ethoxymethyl) acetanilide and a compound related to acetochlor. The other two photoproducts were detected by GC/MS although their chemical structure was unknown.     

绿色化学与化工

本简述了绿色化学与化工产生的背景、发展绿色化学和化工的意义以及绿色化学与化工领域现状和发展趋势。