Hydrothermal Synthesis and Characterization of a Novel Two-dimensional Framework Materials Constructed from Polyoxometalate and Coordination Groups: [H_2Mo_(5.5)V_(10.5)O_(40)(PO_4)][Cu(en)_2]_4·7H_2O

IntroductionPolyoxometalatesarewidelystudiedfortheirin terestingapplicationsincatalysis ,electronicconduc tivity ,magnetism ,nonlinearopticsandmedicine[1— 4 ] .Whilethemechanismofthesynthesisofpolyoxometalatesremainselusiveandisoftende scribedasself assembly ,thereseemstobeanincreas inguseofthecombinationofthehydrothermalmethodandthestructure directingtemplate .There searchwiththismethodhasdemonstratedthatanum beroftransitionmetaloxides ,typicallyreducedmolybdenumoxides ,mixedvalancevanadiumo…     

La_(0.7-x)Gd_xSr_(0.3)MnO_3(x=0.20,0.30,0.40,0.50)的TCR研究(英文)

研究了La位Gd掺杂对La0.7-xGdxSr0.3MnO3(x=0.20,0.30,0.40,0.50)体系的电阻温度系数(TCR)的影响.实验结果表明:Gd掺杂将引起电阻率曲线的急剧变化,导致出现大的TCR;而且随Gd掺杂的增加,TCR在x=0.30出现峰值,然后随掺杂量增加逐步降低.体系出现大的TCR,来源于Gd掺杂引起的额外磁性耦合.     

一种求循环码对偶码的新方法

本文应用离散傅里叶变换来分析有限域上时域多项式环和它的频域多项式环之间的同构,从另一角度提出了一种由循环码单位元生成它的对偶码的新方法。本文还建立了循环码单位元与它的频域单位元之间的联系,由此可以很方便地生成它的对偶码,理论和实例表明这种方法是行之有效的。     

ON SOLVING PERIODIC BOUNDARY PROBLEM OF SEMILINEAR SYSTEMS WITH A ONE-PARAMETER IMBEDDING

The paper is concerned with solving periodic boundary problem of semilinear systems, which will be differentiably embedded into an one-parameter family of operators. The solution of the systems is then found by continuing the solution curve of operator homotopy. When the Newton-Kantorovich's procedure is applied to the cor