Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine

A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions, the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10⁻⁷ to 1.0 × 10⁻⁴ M with a detection limit of 4.0 × 10⁻⁷ M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation of 3.2% for nine successive measurements of 1.0 × 10⁻⁵ M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed a good agreement with the data obtained by atomic emission spectrometry. The text was submitted by the authors in English.     

气提法富集气相色谱／质谱法测定水中痕量挥发有机物

作者改进了气提法富集水中痕量挥发性有机物装置。研究了实验条件对水中痕量有机物富集的影响，并确定了最佳富集条件。以气提法富集气相色谱／质谱法（ＧＣ／ＭＳ）测定了水样中痕量挥发性有机物，取得了满意的结果。     

钴(Ⅱ)(C_(2v))配合物电子光谱的强场处理及AOM参量计算

应用强场近似拟合了10个假四面体Co(Ⅱ)(C_(2γ))配合物的配体独场光谱,由拟合得到的单电子矩阵元得到了各个配体的AOM参量。结果说明各配体的AOM参量同该配体与金属离子之间的配键强度相关。     

Fabrication of Cu/rGO/MoS2 nanohybrid with energetic visible-light response for degradation of rhodamine B

A novel visible-light-driven Cu/rGO/MoS₂ ternary nanostructure as a photocatalyst with high catalytic activity towards degradation of rhodamine B was successfully synthesized through a facile solvothermal method.     

丙炔醇对奥氏体不锈钢应力腐蚀的缓蚀作用

丙炔醇对奥氏体不锈钢应力腐蚀的缓蚀作用牛林＊林海潮曹楚南宋光铃（中国科学院金属腐蚀与防护研究所，金属腐蚀与防护国家重点实验室沈阳１１００１５）关键词丙炔醇，奥氏体不锈钢，应力腐蚀，缓蚀作用１９９７－０５－１３收稿，１９９７－０９－０２修回国家自然科学...     

具避难所的次线性型食饵-捕食收获模型

讨论了一类具避难所的次线性型食饵-捕食收获模型.应用Hurwize判据和Dulac判据分析了系统平衡点的局部和全局性态,通过Pioncare-Bendixson环域定理证明了极限环的存在唯一性,利用Pontyagin最大值原理得到了两种群的最优收获策略.最终发现避难所对此系统具有稳定化作用,且最优收获策略对生物资源的可持续利用具有一定实用价值.     

龟甲及其伪品随机扩增DNA多态性(RAPD)鉴定方法研究

目的建立一种快速、准确的龟甲及其伪品随机扩增DNA多态性(RAPD)鉴定方法,为龟甲的鉴别提供可靠依据.方法采用盐析法从龟甲及其伪品中提取mt DNA,并进行随机DNA多态性扩增.结果通过电泳图谱明显看出正品龟甲与其常见伪品mt DNA随机扩增产物条带数量和位置均不同,说明本文建立的方法可以有效区分正品龟甲与其常见伪品.结论 RAPD技术为龟甲及其伪品的鉴别提供一种简单、有效、可信度高的方法.     

An efficient one-pot synthesis of 1,2,4-triazoloquinoxalines

A transition metal-free tandem process for the synthesis of 1,2,4-triazoloquinoxalines was described. The construction of this tricyclic system went through a one-pot condensation/nucleophilic aromatic substitution approach. This methodology applied to a broad range of substrates, which included 2-halogenated or 2-nitro aryl aldehydes and ketones.