Experimental observations of ferroelectricity in double pyrochlore Dy2Ru2O7

Double pyrochlore Dy2Ru207 is synthesized and its magnetism and ferroelectricity below the Ru4＋ spin ordering temperature （NI00 K） are investigated. The ferroelectric transition appears at -18 K, much higher than the Dy3＋ spin ordering point at -1.8 K and lower than the Ru4＋ spin ordering point at -100 K. The measured electric polarization at ,-2 K is as big as 145℃/m2 in the polycrystalline samples. It is argued that the ferroelectricity is possibly ascribed to the electric dipole ordering arising from the collective monopole excitations in the Dy3＋ tetrahedrons in prior to the Dy3＋ spin ordering into spin-ice like state below -1.8 K.     

富马酸比索洛尔与茜素的荷移反应研究

研究了富马酸比索洛尔与茜素的电荷转移反应条件,建立了快速测定富马酸比索洛尔的可见分光光度法。富马酸比索洛尔与茜素反应生成的电荷转移络合物的最大吸收波长是542nm,表观摩尔吸光系数为4.67×103L·mol-1·cm-1。富马酸比索洛尔质量浓度在12～160mg·L-1范围内服从比耳定律,相关系数为0.9993。当富马酸比索洛尔浓度为80mg·L-1时,六次测定结果的相对标准偏差为1.42%。测得荷移络合物的组成比和稳定常数分别为1∶1和1.53×104。本方法用于测定胶囊中富马酸比索洛尔的含量结果与文献方法相符,平均回收率在99.0%以上。     

人造岩石固wx 包容锕系核素废物

研究了富钙钛锆石型和富烧绿石型两种人造岩石固化体包容锕系核素的配方设计和固化产品的鉴定评价,包括物理性能、抗浸出性能和耐辐照性能。采用了X射线衍射(XRD)、扫描电镜/能谱分析(SEM/EDS)和透射电镜/能谱分析(TEM/EDS)研究了矿相组合、元素分布和矿相化学组成等。研究表明,富钙钛锆石和富烧绿石型人造岩石都能很好地固化包容锕系核素废物。     

钪-钙-茜素S异多核络合物的极谱吸附波

报道了钪－钙－茜素Ｓ（ＡＲＳ）异多核络合物极谱吸附波的形成及利用它测定钪的最佳实验条件。用此方法测定了矿石中的微量钪,并初步探讨了该极地的性质和电极反应机理。在单扫描极谱上用等魔鬼洋连续变化法和单纯形法测得络合物组成的摩尔比为ｎｓｃ＾３＋,ｎｃａ＾２＋;ｎＡＲＳ＝２：１：２。     

L-Prolinamide Catalyzed Aqueous Direct Aldol Reaction： an Environment-friendly Method for the Synthesis of β- Hydroxyl keto nes

An environment-friendly L-prolinamide catalyzed aldol reaction has been developed. The reaction exhibited broad substrate generality, and high yields with good diastereoselectivity were obtained for cyclic ketones.The simplicity of product isolation, usage of water as environmentally benign reaction medium, and the usage of cheap, readily available and recyclable catalyst make this process promising to be developed for large-scale preparation of β-hydroxyl ketones.     

次甲基绿—溴酸钾体系催化光度法测痕量钒（V）的研究

本文基于在抗坏血酸存在下，痕量钒（Ｖ）对溴酸钾氧化次甲基绿褪色的新指示反应，建立了一个催化动力学光度法测痕量钒（Ｖ）的新方法。线性范围为０－０．１２μｇ／２５ｍＬ和０．１２－０．２０μｇ／２５ｍＬ，方法检出限为３．４×１０＾－１０ｇ／ｍＬ。用于人发、水样中痕量钒（Ｖ）的测定，结果满意。     

二极管泵浦被动调QNd∶YAG/KTP绿光激光器（英文）

报道了LD泵浦的Nd∶YAG/KTP/Cr∶YAG结构被动调Q绿光激光器.当注入泵浦功率为750mW时,获得了平均功率38mW,脉冲宽度14.7ns,重复频率20.4kHz,峰值功率126.6W的调Q绿激光输出.