萃取色谱法富集原子吸收法测定环境水中超痕量金属元素──两种萃取剂的比较

本文研究并比较了分别以８－羟基喹啉和巯基苯骈噻唑为萃取剂，以活性硅胶为载体的柱式萃取色谱法对环境水中Ｚｎ、Ｃｕ、Ｐｂ、Ｃｄ、Ｆｅ、Ｃｏ、Ｎｉ和Ｍｎ的最佳富集和洗脱条件。实验证明，后者明显优于前者。以巯基苯骈噻唑为萃取剂的色谱柱对金属元素的吸附具有快速、完全、寿命长和重现性好等特点。在ｐＨ＝７～８之间回收率可达９８％以上，富集倍数为２００倍。     

侧析我国的学术环境——对诺贝尔奖困惑的反思

诺贝尔自然科学奖是比较公正的,但政治对科学发展的影响又是现实的。我国之所以未曾问津诺贝尔自然科学奖,在很大程度上是由于政治环境影响了基础研究的学术自由和学术交流。     

Environment-induced decoherence II. Effect of decoherence on Bell''s inequality for an EPR pair

According to Bell's theorem, the degree of correlation between spatially separated measurements on a quantum system is limited by certain inequalities if one assumes the condition of locality. Quantum mechanics predicts that this limit can be exceeded, making it nonlocal. We analyse the effect of an environment modelled by a fluctuating magnetic field on the quantum correlations in an EPR singlet as seen in the Bell inequality. We show that in an EPR setup, the system goes from the usual ‘violation’ of Bell's inequality to a ‘non-violation’ for times larger than a characteristic time scale which is related to the parameters of the fluctuating field. We also look at these inequalities as a function of the spatial separation between the EPR pair.     

A study of methylation of inorganic tin by iodomethane in an aquatic environment with 13C carbon isotope tracer technique

The methylation of tin(II) [Sn(II)] by iodomethane (CH₃I) under environmental conditions has been further demonstrated by a ¹³C carbon isotope tracer method. Methylation products are mainly monomethyltin, and very small amounts of dimethyltin. The reaction of Sn(II) and CH₃I was investigated at pH 2, 4, 6, 8, 10 and salinity (S) 8, 15, 22, 28, 35%; it has been found the reaction was affected by pH and salinity, the tin methylation activity being highest at about pH 6 and S = 28% . The methylation reaction is first-order for both CH₃I and Sn(II), and the rate equation has been obtained as follows: .     

Gold nanoparticles as dehydrogenase mimicking nanozymes for estradiol degradation

Small gold nanoparticles can mimic dehydrogenase activity to catalyze estradiol (E2) oxidation to estrone (E1), extending the range of nanozyme catalysis to environmentally and biologically important substrates.     

Determination of low levels of free fibres of chrysotile in contaminated soils by X-ray diffraction and FTIR spectroscopy

A new analytical method for the determination of low levels (0.01–1 wt%) of free fibres of chrysotile in contaminated clayey, sandy and sandy-organic soils is described. The detection limit of 0.01 wt% is reached with an enrichment of free fibres of chrysotile in the sample using a standard laboratory elutriator for sedimentation analysis. The chrysotile quantitative determination is performed both by X-ray powder diffraction, using the internal standard and reference intensity ratio methods, and by Fourier-transform infrared absorption spectroscopy. The procedure can be successfully applied to different soils after removal, by a thermal treatment, of the matrix components which can interfere. This straightforward method fulfils the request of public institutions and private companies for an appropriate quantitative determination of chrysotile-free fibres in contaminated soils.     

土壤环境中铅的化学

论述了环境中铅的背景值、来源、污染、质量标准、化学循环以及环境中铅的烷基化，为铅污染治理提供理论依据。     

Hydroxyl radical formation upon dark oxidation of reduced iron minerals: Effects of iron species and environmental factors

Dark formation of hydroxyl radical upon oxidation of reduced iron minerals plays an important role in the degradation and transformation of organic and inorganic pollutants. Herein, we compared the hydroxyl radical formation from various reduced iron minerals at different redox conditions. OH production was generally observed from the oxidation of reduced iron minerals, following the order: mackinawite (FeS) > reduced nontronite (iron-bearing smectite clay) > pyrite (FeS₂) > siderite (FeCO₃). Structural Fe²⁺ and dissolved O₂ play critical roles in OH production from reduced iron minerals. OH production increases with decreasing pH, and Cl^? has little effect on this process. More importantly, dissolved organic matter significantly enhances OH production, especially under O₂ purging, highlighting the importance of this process in ambient environments. This sunlight-independent pathway in which OH forms during oxidation of reduced iron minerals is helpful for understanding the degradation and transformation of various inorganic and organic pollutants in the redox-fluctuation environments.     

环境元素与健康

通过一些分析数据，说明了环境元素与健康的关系。     

包头市中小学教师基于信息技术环境的专业研修情况调查

“包头地区校本培训中信息技术资源的开发与利用”课题组于2005年4月在包头市124所中小学的350名教师中进行了“基于信息技术环境下的专业研修情况”调查，结果显示：包头市中小学的现代信息技术条件已具备一定基础。绝大多数学校和教师比较重视信息技术对于教育教学及教师专业发展的作用，初步形成了使用信息技术的环境;具备了使用信息技术的一定能力，教育信息技术与教学、与教师专业研修的联系日趋紧密。存在的主要问题是：薄弱学校的信息技术条件差距较大;相当数量的教师接触的信息资源有限；好多教师对电脑的更多功能不了解、不熟悉；网络利用率偏低，而且不同学段、不同条件、不同性别、不同学科教师的使用情况存在较大差异。