Gd-Sn-Te体系稀磁半导体合金的合成

介绍了用合成法制备稀磁半导体Gd—Sn—Te体系合金试样的工艺，利用金相显微镜和X射线衍射仪分析了试样的成分和组织。结果表明，该方法制备的试样成分和组织均匀，达到了平衡，克服了合金成分偏离，满足相图和相结构研究的试验要求。     

Effect of rapid solidification treatment on structure and electrochemical performance of low-Co AB5-type hydrogen storage alloy

The effect of rapid solidification on structure and electrochemical performance of the LaNi4.5Co0.25Al0.25 hydrogen storage alloy was investigated by X-ray powder diffraction and a simulated battery test, including maximum capacity, cycling stability, self-discharge, and high-rate discharge ability （HRD）. All the melt-spun alloys were single-phase with the CaCu5-type structure （space groupP6/mmm）. In comparison to the as-cast alloy, the rapidly quenched alloys manifested an improved homogeneity of com-position and expanded lattice parameters. The electrochemical measurements showed that the activation property, cycling stability and self-discharge of the alloy electrodes were also improved for the rapid solidified alloys. The HRDof the as-cast alloy was better than those of all the rapidly solidified alloys. As the quenching rate increased, the HRD and exchange current density first decreased and then increased.     

Isothermal section of Gd-Sm-Co ternary system at 773 K

The isothermal section of the phase diagram of the Gd-Sm-Co ternary system at 773K was investigated by X-ray powder diffraction(XRD),differential thermal analysis(DTA),optical microscopy and scanning electron microscopy(SEM) techniques.The result shows that the isothermal section consists of 12 single-phase regions,16 two-phase regions and 5 three-phase regions.Five pairs of corresponding compounds of Gd-Co and Sm-Co systems,i.e.,Gd2Co17 and Sm2Co17,Gd2Co7 and Sm2Co7,GdCo3 and SmCo3,GdCo2 and SmCo2,Gd3Co and SmCo form continuous series of solid solutions.The maximum solid solubility of Sm in Gd 4Co3 and Gd12Co7 were about 7.2 at.% and 47.8 at.% Sm,respectively.The maximum solid solubility of Gd in Sm5Co19 and Sm5Co2 were about 4.7 at.% and 7.6 at.% Gd,respectively.The binary compounds Sm9Co4,GdCo5 and SmCo5 were not observed at 773K.No ternary compound was found.     

利用EXCEL工具插补展延降水量资料系列方法探讨

介绍了线性回归原理,归纳了利用EXCEL一元线性回归建模方法;利用实测资料以EXCEL[数据分析]工具分别建立一元、二元、三元回归模型插补展延年降水量并进行了误差统计分析,阐述了建模和插补年降水量资料应注意的问题。     

荧光法鉴定柑桔汁饮料掺假

用荧光光度计调查了35个品种柑桔原汁的荧光特性,结果表明,这些柑桔汁具有相同的荧光吸收,最大激发波长平均值为288.8nm,变化范围284.6～296.5nm,最大发射波长348nm。原汁用水稀释至1%时,荧光强度的平均值为65.94nm(25℃),该方法至少可检测出0.5%原汁。本文提出用检查柑桔汁饮料激发光谱在280～300nm有无最大吸收作为判定饮料中有无原汁的方法。模拟柑桔汁饮料在280～300nm无吸收,将此方法应用于实际工作中,效果很好。该法快速、灵敏、简单、准确。     

二极管阵列高效液相色谱法测定果冻制品中诱惑红

建立一种二极管阵列高效液相色谱法(DAD-HPLC)测定果冻制品中的诱惑红的方法。样品经聚酰胺粉净化,采用Agilent Eclipse XDB-C18色谱柱(5μm,4.6×250 mm),流动相为甲醇和0.02mol/L乙酸铵(35∶65),流速1.0 mL/min,进样量10μL,柱温25℃,其最大吸收波长为510 nm。结果显示浓度在1—20μg/mL范围内有良好的线性关系,相关系数为0.999。平均回收率在87.2%—93.8%之间,相对标准偏差1.24%—3.86%。本方法可应用于果冻制品中诱惑红的日常检测工作。     

Structure and Magnetocaloric Effect in Tb（ Co1-xSnx）2 Alloys

Recently,researchonmagnetocaloriceffect(MCE)hasattractedagreatdealofinterestinrare earth(RE)basedcompoundsbecauseoftheirenergy efficiencyandenvironmentalsafetyformagneticrefrig eration.Afirst ordermagneticphasetransitionwas foundintheintermetalliccompoundsRECo2(RE=Er,Ho,Dy)withMgCu2typestructure[1,2],leadingtoa largemagneticentropychangeforthesecompounds,whereasasecond ordertransitionwasfoundinTbCo2andGdCo2.IntheintermetalliccompoundsRECo2,theloweringofd electronconcentrationbythesubst…     

Zr-Sn-Nb-Fe合金金属间化合物及其α/β相变温度的研究

利用大功率X射线衍射仪研究了Zr-1.0Sn-1.0Nb-0.3Fe合金金属间化合物的晶体结构,结果表明,Zr-1.0Sn-1.0Nb-0.3Fe合金的金属间化合物是Ti2Ni结构的立方(ZrNb)2Fe和六方Zr(NbFe)2。在轧制状态下,六方Zr(NbFe)2是主要的析出相。400℃淬火时,立方(ZrNb)2Fe是主要的析出物。750℃时,不再观察到六方Zr(NbFe)2;850℃时,不再观察到立方(ZrNb)2Fe。综合DTA和X射线测试结果,确定合金-αZr→-βZr转变开始温度为633℃,这个温度也是Zr(NbFe)2开始熔入-βZr的温度,在785℃,立方(ZrNb)2Fe开始熔入-βZr,到1000℃时,-αZr→-βZr转变结束。     

东湖源水与自来水中致突变性物质比较

应用Ames试验与色质联机（GC／MS）分析相结合的方法，对武汉东湖源水及自来水中非挥发性有机物的致突变性及化学组分进行了比较。试验结果表明，无论投加体外代谢活化系统（S9）与否，自来水非挥发性有机物对TA98与TA100菌株均具明显的致突变性，而源水为阴性结果；GC／MS分析鉴定了源水及自来水的非挥发性有机物中含有邻苯二甲酸酯（酞酸酯）等20余种化合物。