磷酸铵镁法综合处理磷酸盐工业废水和垃圾渗滤液研究

探讨了磷酸铵镁法综合处理磷酸盐工业废水和垃圾渗滤液的可行性.探讨了pH、物质摩尔配比、搅拌速度、反应时间、陈化时间等因素对氨氮和磷酸盐去除效果的影响.实验得出只加MgSO4·7H2O)处理氨氮质量浓度为2 677.34 mg/L的垃圾渗滤液和磷酸盐质量浓度为l 804.48 mg/L的磷酸盐工业废水时的较佳实验条件为:搅拌速度200 r/min左右,反应时间20 rain,pH=9.5,n(Mg):n(P):n(N)=1.5:1.187:1.0.在陈化时间为30 min以及上述实验条件下,磷酸盐的去除率为99.53%,处理液中的残磷质量浓度为6.79 mg/L,氨氮的去除率为87.56%,残氮质量浓度为76.12 mg/L.并对所得磷酸铵镁沉淀进行了X-衍射光谱和扫描电镜分析.     

可充镁电池电解质研究现状

综述了可充镁电池电解质材料的研究进展;介绍了有机格氏试剂盐系列电解质和可传导镁离子的聚合物电解质(GPE);简述了相应的制备工艺和存在的主要问题;最后提出可充镁电池电解质的发展趋势.     

高镁边缘磷矿制取阻燃剂氢氧化镁的工艺

为解决大量的高镁低磷边缘磷矿废渣堆存对环境的影响,开发了以其为原料制取阻燃剂氢氧化镁工艺.该工艺主要包括酸解磷矿和镁沉淀过程,重点讨论了沉淀氢氧化镁过程中时间、温度、氨镁摩尔比n(NH3/MgO)等多种因素的影响,得到的最佳工艺条件是:反应温度65℃,反应时间80min,n(NH3/MgO)为5∶ 1,镁的沉淀效率为80%.     

Effect of cerium on ignition point of AZ91D magnesium alloy

The surface and interior temperature-time curves of blocky cerium modified AZ91D magnesium alloy were measured during a non-protective heating and melting process. Two inflection points with rapid increase in temperature were found on both curves, which corresponded to the formation of ＂aulifiower＂ oxide on the surface and the occurrence of flame during melting. These two temperatures are therefore defined as oxidation point and ignition point, respectively. The interior temperature-time curve is similar to that measured on the surface except for a comparable time delay. The oxidation and ignition temperatures increase with Ce content, an average increase of 33℃ and 61℃ was found when Ce addition was about 1.0 wt %. However, the increasing rate of the oxidation and ignition temperature decreases with increasing Ce content. An addition of 0.6wt% Ce is recommended for ignition-resistant AZ91 magnesium alloy.     

AZ系镁合金化学镀镍的初始沉积机理研究

采用金相观察、XRD、SEM、EDS等实验方法,研究了铸态和固溶态AZ系镁合金化学镀Ni—P合金的初始沉积特点。结果表明,镀层初始沉积最先是电化学机制占主导地位,然后是次磷酸盐的还原作用机制和电化学机制并存,最后逐步过渡到以次磷酸盐的还原作用机制占主导地位。同时基体成分和组织影响着镀层的初始沉积机制和沉积速度。     

氢氧化镁改性硅藻土对阴离子染料的吸附性能研究

对硅藻土进行氢氧化镁改性以提高它对印染废水中染料的吸附性能.采用原位沉淀法由MgCl2及NaOH在硅藻土上制备了氢氧化镁,并用SEM、XRD对改性材料进行了表征;用分光光度法研究了它对阴离子染料的吸附性能.结果显示:改性硅藻土的染料吸附能力比原硅藻土及氢氧化镁都高;染料的吸附等温线采用Langmuir及Freundlich模型拟合,结果表明改性硅藻土对染料的吸附更符合Freundlich模型.     

Effect of component substitution on the microstructure and mechanical properties of MCoCrFeNiTix （M = Cu, Al） solid-solution alloys

MCoCrFeNiTix (M = Cu, Al; x: molar ratio, x = 0, 0.5) alloys were prepared using the new alloy-design strategy of equal-atomic ratio and high entropy. By the component substitution of Al for Cu, the microstructure changes from the face-centered cubic solid solution of original CuCoCrFeNiTix alloys to the body-centered cubic solid solution of AlCoCrFeNiTix alloys. Compared with original CuCoCrFeNiTix alloys, AlCoCrFeNiTix alloys keep the similar good ductility and simultaneously possess a much higher compressive strength, which are even supe- rior to most of the reported high-strength alloys like bulk metallic glasses.     

铁基超微晶软磁合金的热处理特性研究

研究了Ｆｅ７４Ｃｕ１Ｎｂ（３Ｘ）ＭｏＸＳｉ１２５Ｂ９５（Ｘ＝０,１,２,３）系列合金的退火温度与软磁性能的关系。实验结果表明,最佳退火温度随Ｎｂ含量减少、Ｍｏ含量增加而降低;取得最佳直流磁性能和最佳交流磁性能的退火温度不同;无磁场退火和磁场退火取得最佳磁性能的退火温度不同。最佳温度退火得到的是晶态和非晶态复合结构,晶态组分是具有ＤＯ３超点阵结构的ｂｃＦｅ（Ｓｉ）相,平均晶粒直径１０～２０ｎｍ。     

MEASUREMENT OF THERMODYNAMIC PROPERTIES OF LIQUID Al-Mg ALLOYS

ＭＥＡＳＵＲＥＭＥＮＴＯＦＴＨＥＲＭＯＤＹＮＡＭＩＣＰＲＯＰＥＲＴＩＥＳＯＦＬＩＱＵＩＤＡｌＭｇＡＬＬＯＹＳ①ＬｕＧｕｉｍｉｎａｎｄＱｉｕＺｈｕｘｉａｎＰ．Ｏ．Ｂｏｘ３１７,ＳｃｈｏｌｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＭｅｔａｌｕｒｇｙ,Ｎ...     

Influence of epitaxial stress on spinodal decomposition in binary alloys with large size effects: application to the Au–Ni system

Within the framework of Cahn’s pioneering theory of spinodal decomposition, the effect of the epitaxial stress on the stability of a binary alloy solid solution against infinitesimal compositional fluctuations is revisited. It is shown that the elastic energy term due to a coherent lattice mismatch with a substrate modifies the linearised diffusion equation. This term is particularly high when size effects between the two constituents are strong. It is then necessary to take into account anharmonic terms in the expression of the elastic energy. From the modified diffusion equation, a new spinodal curve, called the epitaxial coherent spinodal, may be calculated for different substrate lattice parameters. The results of the model are compared with recent experiments on coherently grown (001) Au–Ni alloys. A modulated structure has been evidenced upon annealing which is in good agreement with our calculations.

Résumé

Dans le cadre de la théorie de la décomposition spinodale développèe par Cahn, nous présentons l’effet des contraintes épitaxiales sur la stabilitéd’une solution solide d’alliage binaire soumise ádes fluctuations de compostion infinitésimales. Les contraintes induites par l’épitaxie cohérente sur un substrat ayant un paramètre de maille différent de celui de la solution solide considérée sont àl’origine d’un terme d’énergie élastique dont il faut tenir compte dans l’équation de diffusion. Ce terme devient particulièrement important lorsque les effets de taille entre les deux constituants sont grands. Nous montrons qu’il est alors nécessaire de considérer dans l’expression de l’énergie élastique les termes anharmoniques. Une nouvelle spinodale, appelée spinodale cohérente épitaxiale, peut être calculée pour différentes valeurs du paramètre de maille du substrat. Les calculs sont comparés avec les résulats expérimentaux obtenus sur des alliages Au–Ni (001) élaborés de manière cohérente. Une structure modulée a étémise en evidence au cours de recuits, ce qui est en accord avec les résultats du modèle.