院士风采 高小霞

化学家。女。浙江萧山人。1944年毕业于上海交通大学化学系。1951年获美国纽约大学硕士学位。北京大学教授。长期致力于分析化学的教学和研究。专长点分析化学和极谱催化波以及环保大气污染检测仪的研制。在极谱催化波的理论与应用方面从事了大量工作，在国内起了积极促进作用，形成了极谱分析的某些特色。后又开创了稀土极谱络合吸附波分析方法，总结在专著《极谱催化波》一书中。方法应用于稀土农用的植物生理功能研究中，获得可喜成果。     

Experimental parameters during optical floating zone crystal growth of rare earth silicides

Optical floating zone（FZ） crystal growth involving growth stability and as-grown crystal perfection is affected by experimental conditions and the specific material. Referring to rare earth silicides, high purity of raw rare earth elements and ambient argon atmosphere are crucial to grow high-quality crystals; the maximum zone height is determined by equating the capillary forces of the surface tension; and asymmetric counter rotation of crystal and feed rod with convex（toward the melt） interfaces are favored to reach single crystals. Influences of several other growth parameters were also discussed in detail in this paper.     

美国环境保护署确定阻燃剂安全替代品 丁二烯苯乙烯溴化共聚物替代六溴环十二烷

<正>本刊讯美国环境保护署(EPA)日前发布报告,确定了聚苯乙烯建筑物保温材料和软质聚氨酯(PU)泡沫内常用阻燃剂的安全替代品。EPA建议用丁二烯苯乙烯溴化共聚物替代六溴环十二烷(HBCD),因为该物质比六溴环十二烷的安全性高,并且已在美国实现了商业化生产。而五溴联苯醚的     

混合稀土及半固态等温热处理对原位Mg_2Si/Al复合材料组织与性能的影响

在原位Mg2Si/Al复合材料中,通过混合稀土变质及半固态等温热处理,分析变质及等温热处理后材料组织与力学性能的变化。结果表明:添加0.8%的混合稀土对Mg2Si起到很好的变质效果,初生Mg2Si的形貌由变质前的粗大十字状变为均匀分布的不规则块状,平均尺寸由变质前的74μm减小至24μm左右;同时,材料的力学性能也显著提升,抗拉强度由变质前的134 MPa提高至187.5 MPa,布氏硬度由HB 74.5提升至HB 89.5左右。最佳的等温热处理工艺为600℃保温90 min,此时,材料中初生Mg2Si转变为近球形,其形状因子为0.93左右,平均尺寸29μm左右。     

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Synthesis of lanthanum ricinoleate and its effect on thermal stability and mechanical properties in PVC

The lanthanum ricinoleate（abbreviated as Lari3） of rare earth heat stabilizer was synthesized by the reaction of ricinoleic acid, lanthanum nitrate and sodium hydroxide. The IR and fluorescence spectra methods confirmed the structure of the product. The thermal stability of PVC in the presence of Lari3 was studied by the Congo method and using TG analysis. The results showed that Lari3 could be used as a thermal stabilizer for PVC. When the ratio of Lari3/pentaerythritol was 3：1, the complex exhibited better synergistic effect. Incorporation of Lari3 to PVC resulted in a marked increase of maximum and onset degradation temperature as well as elongation and impact strength of PVC. Lari3 might replace the labile chlorine atoms to interrupt the formation of conjugated double bonds in PVC chains and act as HCl scavenger to restrain the self-catalyticdehydrochlorination.     

稀土永磁同步电机及变频调速技术在城市自来水厂的应用

城市自来水厂是耗能大户,节能潜力很大。通过分析水厂水泵机组耗能现状及高耗能原因,在国内首次将稀土永磁同步电机及变频调速技术成功用于自来水厂拖动水泵运行,节能效果非常好,用电量减少20%以上,降低了自来水的生产成本,并减少了碳排放,取得了良好的经济效益和社会效益。     

Ganzhou Qiandong Rare Earth Group Go.,Ltd.

Ganzhou Qiandong Rare Earth Group Co.,Ltd .is located in Qiandong Road.Shuidong Town.Zhanggong District of Ganzhou City .The predecessor is Ganzhou Qiandong Industrial（Group）Co.,Ltd.