基于偏心光束法的离焦量探测装置及计算方法的改进

引入生物显微镜用于探测病理切片离焦量。针对反射光斑内部纹理缺陷、畸变严重的特殊情况,通过自适应中值滤波、基于Ostu算法的Canny边缘检测(去除非圆弧边缘部分)、畸变校正、最小二乘法拟合非完整圆等算法,直接计算光斑半径大小及离焦方向,建立光斑半径与离焦量的线性关系模型。实验结果表明,与传统的灰度重心法相比,离焦量计算方法抗噪性强、稳定性高,可大幅度地提高线性关系模型的范围及光斑半径、圆心位置的准确度。     

进一步优化关于素数无穷性的Euclid证法

令pi表示第I个素数.本文主要目的是用初等的方法构造性证明了,当r≥4时区间Ir中至少有2「log2(2r)」+1个素数,这一结果是Aldaz和Bravo对区间Ir中素数的个数的估值两倍.     

钾助催氧化铁催化剂上乙苯脱氢的活性中心和吸附过渡态模型及其催化作用机理

提出了催化剂的活性相组成、乙苯脱氢生成苯乙烯的活性中心模型和在此模型上催化作用的微观机理;同时提出了副反应的氧自由基机理,以及氧化钾助催剂对抑制副产物与稳定活性相的作用。EHMO近似量子化学计算的结果表明了所提出的乙苯脱氢机理,以及关于吸附能量、决定性步骤、活化能、电子迁移和铁离子价态的变化等是合理的。     

Enhancement of ferromagnetic resonance in Al_2O_3-doped Co_2FeAl Heusler alloy film prepared by oblique sputtering

Large and variable in-plane uniaxial magnetic anisotropy in a nanocrystalline(Co2FeAl)97.8(Al2O3)2.2soft magnetic thin film is obtained by an oblique sputtering method without being induced by magnetic field or post annealing. The in-plane uniaxial magnetic anisotropy varies from 50 Oe to 180 Oe(1 Oe = 79.5775 A·m-1) by adjusting the sample’s position. As a result, the ferromagnetic resonance frequency of the film increases from 1.9 GHz to 3.75 GHz.     

Ho and Ti co-doped BiFe03 multiferroic ceramics with enhanced magnetization and ultrahigh electrical resistivity

Bio.9HOo.lFeo.9503 and Bio.9HOo.lFeo.9Tio.0503 ceramics were prepared and compared to reveal the effects of Ho and Ti codoping in BiFeO3. X-ray diffraction indicated that both ceramics had a high rhombohedral perovskite phase content, and microstructural analyses showed that the grains of the Bio.9HOo.lFeo.9Tio.0503 ceramics were much smaller than those of Bio.9HOo.lFeo.9503. An electrical resistivity of more than 1 × 1014.cm at room temperature, and a magnetic hysteresis loop with a remnant magnetization 2Mr of 0.485 emu/g were obtained for Bi0.9HO0.1Fe0.9Ti0.0503; both were much higher than those of Bio.9Hoo.1Feo.9503. Changes in the defect subsystem of BiFeO3 induced by Fe-deficiency and （Ho,Ti） codoping are proposed as being responsible for the improvement in the properties.     

Ho and Ti co-doped BiFeO_3 multiferroic ceramics with enhanced magnetization and ultrahigh electrical resistivity

Bi0.9Ho0.1Fe0.95O3 and Bi0.9Ho0.1Fe0.9Ti0.05O3 ceramics were prepared and compared to reveal the effects of Ho and Ti codoping in BiFeO3. X-ray diffraction indicated that both ceramics had a high rhombohedral perovskite phase content, and microstructural analyses showed that the grains of the Bi0.9Ho0.1Fe0.9Ti0.05O3 ceramics were much smaller than those of Bi0.9Ho0.1Fe0.95O3. An electrical resistivity of more than 1 × 1014?·cm at room temperature, and a magnetic hysteresis loop with a remnant magnetization 2Mr of ～ 0.485 emu/g were obtained for Bi0.9Ho0.1Fe0.9Ti0.05O3; both were much higher than those of Bi0.9Ho0.1Fe0.95O3. Changes in the defect subsystem of BiFeO3 induced by Fe-deficiency and(Ho,Ti) codoping are proposed as being responsible for the improvement in the properties.     

β-NaYF4：Yb,Er纳米晶与四甲基异氰酸罗丹明染料分子间的发光共振能量转移研究

Yb^3＋和Er^3＋离子掺杂的NaYF4纳米晶在近红外光（980nm）激发下可产生中心位于539和655nm的上转换发光,其中位于539nm的发光与四甲基异氰酸罗丹明（tetrametrylrhodarnine isothiocyante,TRITC）染料分子的吸收光谱部分重叠.本文基于上述光谱重叠特性,构筑了以β-NaYF4：Yb,Er为能量给体、TRITC为能量受体的发光共振能量转移（LRET）体系.TRITC分子通过静电作用紧密吸附于纳米晶表面,其较近距离的相互作用利于提高LRET效率和体系的稳定性.在980nm近红外光激发下,LRET过程使NaYF4：Yb,Er位于539nm的上转换发光减弱,同时可观察到TRITC染料分子的发光.对发光寿命的研究也证实了β-NaYF4：Yb,Er到TRITC的能量传递.     

方沸石对Cd2+离子的交换性能研究

在静态条件下,研究了温度、浓度、pH值等条件对方沸石与Cd2 离子交换的影响;探讨了当溶液中有其它阳离子共存时对方沸石与cd2 的交换的影响;考察了方沸石时模拟废水中的重金属离子的去除效果.结果表明,方沸石能够有效去除废水中的cd2 ,去除率可达90.0%以上.     

范希尔理论指导下的数列教学

数列的相关知识是高中数学课程的重点之一,现实生活中的许多问题,例如增长率、银行信贷、环境绿化等都与数列问题有关,此外数列中还涉及到累加、累乘、错位相减等多种计算方法以及递归的思想、极限思想、函数思想、数形结合思想等,这些思想都是初等数学与高等数学重要的衔接点.在历年的高考中可以发现,对数列的考查要求也非常高,除了直接考查数列通项公式和计算数列前n项和之外,还会将数列与函数、不等式、算法程序等问题进行综合考查.因此,如何执教数列问题,值得思考.