水/油型微乳液中球形及棒状钛酸锶钡纳米粒子的控制合成

Barium strontium titanate nanoparticles with spherical and rod-like morphologies were synthesized in water/Triton X-100/n-hexanol/cyclohexane quaternary reverse microemulsion solution. The influences of the molar ratio of water to surfactant (ω₀) and the concentration of reactants on the morphology and size of barium strontium titanate nanoparticles were studied. The structure, compositions and morphology of the prepared products were characterized by XRD, SAED, ICP, EDS and TEM. The results show that the obtained Ba_0.7Sr_0.3TiO₃ spherical nanoparticles with diameters of 20～100 nm and the Ba_0.7Sr_0.3TiO₃ nanorods with diameters of 70～120 nm and lengths up to 600～800 nm are a single crystal, with a cubic phase. The molar ratio for barium, strontium and titanate in products is about 0.7:0.3:1.     

复方程f″+Af=0解的迭代级零点充满圆

研究了齐次线性微分方程f″+Af=0的迭代级零点充满圆问题:设f1,f2是复方程f″+A(z)f=0的两个线性无关解,其中A是整函数,令E=f1f2,文章证明了E的迭代级充满圆必是E的迭代级零点充满圆.所得结果精确了一些已有得结果。     

某类高阶整函数系数微分方程解的零点和超级

研究了非齐次线性微分方程f(k) Ak-1fk-1 … Asf(s) … A0f=F的增长性问题,其中A0,A1,…,Ak-1,F是整函数,当存在某个系数As(s∈{0,1,…,k-1})为缺项级数且比其它系数有较快增长的意义下时,得到了上述非齐次微分方程的一定条件下超越解的超级的精确估计.     

某类高阶线性微分方程解的增长性

研究了线性微分方程f^（k）＋ak-1（z）e^pk-1（z）f（k-1）＋…＋A0（z）e^Po（x）f=0及其相应的非齐次线性微分方程解的增长性．在一定条件下，得到了其解的级及零点收敛指数的精确估计。