GJ—341小型遥控光电经纬仪垂直轴系结构可靠性研究

本文讨论了“GJ-341”垂直轴系的结构可靠性模型;并分析了“GJ-341”垂直轴系的结构可靠性。     

Synthesis of a slow‐release and superabsorbent nitrogen fertilizer and its properties

A slow‐release and superabsorbent nitrogen fertilizer (SSNF) was synthesized by aqueous solution copolymerization of acrylic acid and maleic anhydride using N,N′‐methylene bisacrylamide as a crosslinker, ammonium persulfate and sodium sulfite as an initiator in the presence of urea. The effects on water absorbency such as amount of crosslinker, initiator, urea and maleic acid, degree of neutralization, etc. were investigated. To improve slow release and water retention properties, the product was surface‐crosslinked with trihydroxymethyl propane glycidol ether (6360). The nitrogen content of the SSNF synthesized under optimal conditions was 28.5%, and the water absorbencies were about 900 (g/g) in distilled water and 180 (g/g) in tap water. The nitrogen slow release behavior of the SSNF in water and water retention capacity of the soil with SSNF were also investigated. The results showed that the surface‐crosslinked product not only had good slow release property but also excellent soil moisture preservation capacity, which could effectively improve the utilization of fertilizer and water resources simultaneously. The results of the present work indicated that the SSNF could be found an application in agriculture and horticulture, especially in drought‐prone areas where the availability of water is insufficient. Copyright © 2006 John Wiley & Sons, Ltd.     

Applications of scanning probe microscopy in intrinsically conducting polymer research

The applications of scanning probe microscopy (SPM) in intrinsically conducting polymer research is briefly reviewed, including morphology observation, nanofabrication, microcosmic electrical property measurements, electrochemistry researches, in-situ measurements of film thickness change, and so on. At the same time, some important variations of SPM and the related techniques are briefly introduced. Finally, the future development of SPM in the study of intrinsically conducting polymers is prospected. Translated from Chinese Journal of Applied Chemistry, 2006, 23 (2) (in Chinese)     

饮料中总砷的测定及其价态形态分析

本文采用新银盐光度法,通过对样品的全消解、改变氢化物发生的介质和酸度等方法,成功地对同一样品中砷总量、砷的价态和砷的形态进行了分析。三价砷和无机砷总量的检出限分别为0.1和0.2ppb(3S),相关系数r_1=0.9995、r_2=0.9998。样品中砷总量(无机砷和有机砷)和无机砷总量(As(Ⅲ)和As(Ⅴ))的回收率分别为95～105%和100%,适用于饮料中超痕量砷的全分析。     

GdFeO3纳米晶的制备及其光催化活性

以Gd2O3, Fe(NO3)3·9H2O, 硝酸(1∶1)为原料, 在柠檬酸体系中用溶胶凝胶法制备了具有钙钛矿结构的稀土复合氧化物GdFeO3; 用XRD, TEM对产物的组成、颗粒大小、形貌进行了表征. 结果表明, 产物为纳米颗粒, 平均粒径为21 nm左右, 且颗粒均匀,并呈现一定的晶格畸变. 另外以GdFeO3为光催化剂, 对多种水溶性染料进行了光催化降解实验; 研究了光照时间、催化剂投加量对光催化活性的影响. 发现 GdFeO3有较好的光催化效果, 光照和增加催化剂用量均可提高GdFeO3对染料的降解率.     

以临床案例为导向的检验班分析化学教学实践

The clinical case-guided teaching, to combine analytical chemistry contents with medical practice, could excite students' interest in learning, deepen concept understanding and improve the abilities of analysis, induction and synthesis, and then of applying professional knowledge to solve medical practical problems. Meanwhile, it helps students enhance their sense of responsibility, accept the idea of dialectics and the concept of self-access learning, and gradually develop the habit of lifelong learning.     

稀土与甘氨酰－L－亮氨酸的配位作用

用ｐＨ电位法测定了生理条件下（３７℃，Ｉ＝０．１５ｍｏｌ／Ｌ）和２５℃，Ｉ＝０．１０ｍｏｌ／Ｌ时甘氨酰－Ｌ－亮氨酸的质子化常数及其稀土配合物稳定常数，结果表明稀土可与该配体形成１：１配合物，并且配合物稳定性呈现明显“四分组效应”。讨论了钇的位置以及肽键对配合物稳定性的影响。     

用于筛膜反应器的γ-MnO_2纳米粉的合成

醋酸锰与柠檬酸发生沉淀反应生成锰配合物,经热分解和酸处理手段最终制备出γ-MnO2纳米材料,用X射线衍射、差热/热重分析、透射电镜及原子力显微镜等手段对合成的样品进行了表征.同时考察了反应条件对反应速度、最终产品粒度的影响.结果表明,通过对反应条件的控制可以在一定程度上控制产品的粒度,得到了均粒度和超细粒度的γ-MnO2纳米材料.对于异丙醇和环己烷等氧化脱氢反应,γ-MnO2纳米筛膜反应器与传统的固定床反应器相比反应物的转化率提高了20%.     

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。