微量Ge对大气下液态Sn抗氧化性能的影响

采用观察液态Sn表面氧化行为和刮取表面氧化渣的方法,研究了微量元素Ge对液态Sn在大气和250℃条件下表面抗氧化性能的影响,并与纯Sn的氧化行为进行对比;利用X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)研究了合金表面元素的含量、价态,及合金氧化后的表面形貌.结果表明:当微量元素Ge浓度达到0.01%时(质量分数),大气下液态Sn表面具有很好的抗氧化性能,同时微量元素在液态Sn表面高度富集.XPS分析表明:表面富集的Ge以4价氧化物形式存在.静态液面氧化时,Ge在液态Sn中迅速偏析,并形成一种保护性的致密氧化膜,是提高液态Sn抗氧化性能的原因.     

高压压铸铝合金

日本一公司(Ryobi Ltd．)研制的铝-镁-锰系高压压铸合金在美国取得了专利，专利号为US6649126B2。该合金的成分如下：ω(Mg)：3．6％～3．5％，ω(Un)=0．6％～1．2％，ω(Ni)=0．2％～0．5％，ω(Ti)=0．01％～0．3％，ω(B)：0．001％～0．05％，其余为Al及不可避免的微量杂质。     

Thermochemistry on coordination behavior of samaric chloride hydrate with diethylammonium diethyldithiocarbamate

The complex of samaric chloride lower hydrate-with diethylammonium diethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N2 atmosphere. The title complex was identified as Et2NH2[Sm(S2CNEt2)4] by chemical and elemental analyses, the bonding characteristics of which was characterized by IR.T he enthalpies of solution of samaric chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change of liquid-phase reaction of formation for Et2NH2[Sm(S2CNEt2)4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy, and the activation free energy), the rate constant, and three kinetic parameters (the apparent activation energy, the pre-exponential constant, and the reaction order) of liquid phase reaction of formation were obtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle.     

微量射出标签机数控系统的开发

提出了一种用于微量射出标签生产的自动加工设备,并重点介绍了其嵌入式控制器的研制.该嵌入式控制器硬件平台采用ARM7微处理器和AT89C52单片机,驱动芯片采用TA8435;软件平台采用ìC/OS-II实时操作系统,将控制软件划分成几个功能模块,并给出了各功能模块在系统中对应任务的优先级.该嵌入式控制器的软硬件划分及缓冲区的使用较好地满足了微量射出标签加工的实时性要求.实际应用表明该自动加工设备具有操作简单、稳定可靠、低成本、高性能的特点.     

原子吸收光谱法快速测定松香皂中几种金属元素

提出了用原子吸收光谱法快速测定松香皂中几种金属元素的方法。考察了元素干扰情况及灰化温度。该方法快速、简便、准确 ,RSD为 0 .95 %～ 2 .2 1% ,回收率为 95 .6 %～ 10 8.7%。     

库仑滴定法测定工业废水中微量砷

以库仑滴定法测定工业废水中微量砷，以死停终点法确定滴定终点，最后以EXCEL处理实验数据，本方法具有灵敏度高，准确，简便快速，仪器便宜，易于推广的特点，特别适用于工厂及县级以下环境监测站进行水中微量砷的检测，方法的回收率为99．3％。     

Trace amounts of impurities in electrolytic manganese metal by sector field inductively coupled plasma mass spectrometry

An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.     

稀土和微量元素玻璃肥料

玻璃肥料以玻璃态为基质,添加稀土和微量营养元素,具有合适的植物营养物释放速率。玻璃肥料有效地应用于水稻、水果、蔬菜、食用菌、花卉及其他植物,施用玻璃肥料可以促进植物生长,增加产量。综述了玻璃肥料成分与制备,并指出玻璃肥料存在的问题和发展方向。     

对增加铜塔入口气体中 CO_2分析之我见

《化工设计通讯》在1991年第3期上发表了一篇题为《增加铜塔入口气体中 CO_2分析的建议》的文章。该文系读者结合所在厂的生产实践所撰写的一篇读后文章,对增加铜塔入口气体中 CO_2分析提出了四条补充意见(①CO_2红外气体分析仪的位置选择;②增加 CO 含量自动分析的必要性和可行性;③改进压缩机直通阀;④增加精炼气中 CO+CO_2自动分析)。     

微量溶氧表在我厂的使用情况

目前我国高压以上机组的热力系统均为无氧运行，在热力系统中除氧器承担了除去大部分溶解氧的任务，另外化学和真空除氧，也为热力系统无氧运行提供了保证。由于热力系统的严密性、除氧设备以及人员操作等方面的原因，热力系统中仍或多或少有微量氧的存在。如何做到准确测量微量溶解氧，是火力发电厂考核化学监督水汽的重要指标。