电磁辐射固定点监测布点方案

简要介绍了电磁辐射固定点监测的内容、作用、特点和发展趋势，分析讨论了电磁辐射固定点监测不同布点方案的适用场合及使用方法。     

双动态显示方式的软硬件设计

本文通过一个实例，介绍了利用并行口和串行口实现双动态显示的软硬件设计方法，并重点介绍了汉字显示方法。     

改性二胺扩链剂对合成聚脲性质的影响

为解决聚脲反应高活性方面存在的问题,对二胺扩链剂进行了改性。以己二胺为原料,在冰乙酸和磷酸条件下一步合成得到白色针状晶体产品即新型位阻型扩链剂二乙酰己二胺。并用红外光谱、凯氏定氮法和1H-NMR对其结构进行了表征,确定了合成产物的化学结构。将它和端氨基聚醚和4,4’-二苯甲烷二异氰酸酯(MDI)通过二步溶液法合成新型聚脲,考察二胺扩链剂改性对聚脲性能的影响。当用二乙酰己二胺代替己二胺合成聚脲时,其凝胶时间由原来的11s增加到52s,且拉伸强度大大提高。     

Influence of carbon on the synthesis of AlN powder from combustion synthesis precursors

AlN powders were synthesized by carbothermal reduction of combustion synthesis precursors. Water-soluble organics and carbon black were used as carbon sources. The effects of carbon on the synthesis of AlN powders were studied. Results showed that AlN powders were synthesized directly from γ-Al₂O₃ without γ-Al₂O₃ to α-Al₂O₃ phase transition when water-soluble organics were used as carbon sources, and the nitridation of the precursors could be completed at 1400 °C. However, AlN powders were synthesized from the nitridation of α-Al₂O₃ when carbon black was used as carbon source, and the reaction temperature for a complete conversion increased to 1500 °C. The particles of AlN powders synthesized with water-soluble organics was smaller than the particles of AlN powders synthesized with carbon black and their particle size distribution was sharper. The specific surface area of synthesized AlN powders increased with the increase of carbon content in the precursors.     

Effects of rare earth elements on properties of AB5-type electrode materials at different temperature

Discharge property is an important factor to evaluate electrode materials. The discharge capacity of the hydrogen-storing alloys are not only influenced by its thermodynamic property but also closely related to its dynamic property. When the temperature changes, the degrees of influence of the above-mentioned two factors on the discharge performance vary accordingly. As a consequence, adjusting compositions of the alloys to make them have good discharge performance under a relatively wide range of temperature is of great significance. On the basis of great deal of experimental investigation, the optimum combination of rare earth elements in hydrogen-storing electrode materials using at-30-55℃ is determined and the relationships between the cell parameters and discharge performance of alloys at -30℃ are discussed. Additionally, the DFEC calculation method has been improved to predict the discharge capacities, which is in good agreement with the experimental ones. This is of theoretical significance in investigating new hydrogen-storing alloys of the AB5 type.     

EXCEL在能力验证样品均匀性和稳定性评价中的应用

样品均匀性和稳定性评价是能力验证活动的重要组成部分。依据CNAS—GL03《能力验证样品均匀性和稳定性评价指南》,介绍了能力验证样品均匀性和稳定性评价的基本原理。以食用油中丁基羟茴香醚(BHA)的均匀性检验和茶叶中铜稳定性检验为例,简述了EXCEL“数据分析 ”工具应用于能力验证中样品均匀性和稳定性评价的使用方法,实现了实验数据的输入,得到数理统计的F值和t值。从结果可以看出:EXCEL数据处理结果与实例的计算结果是相一致的,即通过EXCEL的“数据分析”可以完成能力验证中样品均匀性和稳定性检验的工作,从而提高工作效率和统计结果的准确性。     

Study of nitrogen doping behavior in diamond film

Nitrogen-doped diamond films have been synthesized by EA-CVD （electron assisted chemical vapor deposition） technique. The quality and nitrogen impurity states of the diamond films are characterized by SEM, raman spectroscopy, XPS and EPR speclroscopy, respectively. The results show that the morphology changes from well-defined facets to cauliflower-like structures, the content of amorphous carbon increases and the quality drops with increasing the nitrogen flow rate. Furthermore, in the films, it can be observed that nitrogen impurity exists in the forms ofNs^0, [N-V]^0 and [N-V]^1. The contents of [N-V]^0 and [N-V]^-1 are lower when the nitrogen flow rate is relatively high, and the concentration of Ns^0 varies from 15 ppm to 483 ppm.     

离子液体催化制备生物柴油研究进展

生物柴油由于具有环保、可再生、良好的润滑性与稳定性等优良特征,已逐渐成为汽油、柴油等传统石化燃料的替代品。目前,生物柴油的制备过程中所采用的催化剂多为固体酸碱、液体酸碱等传统非均相与均相催化剂,虽然可以得到较高收率的生物柴油,但此类传统催化剂在使用过程中会造成设备腐蚀、废水处理等与环境、经济相关的问题。离子液体因具有结构可设计性、不易挥发、良好的化学稳定性、无污染以及易回收等优点,可作为一种应用于生物柴油制备的新型高效绿色环保催化剂。结合近几年离子液体在生物柴油合成领域的最新研究,综述了不同种类离子液体催化制备生物柴油的应用进展。     

环介导等温扩增技术在转基因成分检测中的应用

随着全球转基因作物商业化种植面积持续增长,转基因成分检测作为转基因作物安全管理的重要技术支撑受到越来越多的关注,世界各国与地区不断致力于转基因成分检测技术的开发。环介导等温扩增（loop-mediatedisothermal amplification,LAMP）技术由于简单快速等特点,近年来在转基因检测领域备受青睐。本文对LAMP技术在转基因成分检测中的最新研究与应用及其发展前景加以综述。