电感耦合等离子体-发射光谱法测定海洋沉积物中的常、微量元素

采用电感耦合等离子体-发射光谱法(ICP-OES)测定了海洋沉积物中18种常、微量元素。选择了适宜的标准溶液、溶样方法和分析谱线。该方法检出限低,精密度高,准确度好。采用国家一级标准物质GSMS-1、GSD-9、GSD-11进行测试,分析结果与标准值相吻合,相对误差均小于2.0%。用于黄河口沉积物测试,研究区内沉积物以SiO2和Al2O3为主,两者含量之和在70%左右。     

Stochastic motion of the untrapped particle in electrostatic mode

The stochastic energy diffusion of the untrapped particle in the electrostatic mode is investigated analytically. We find that the equilibrium electrostatic field of periodical structure plays the same role as the usual focusing magnetic field to lead the test particle to stochastic motion. The resonance overlapping criterion for the random state is given, and also the Fokker-Planek-Kohnogorov approach to diffusion is considered for our system.     

The stability, frontier orbitals, bond character, and static linear polarizability of the fluorinated fullerene H20@C80F60

This paper uses the density functional theory under generalised gradient approximation to analyse the stability,frontier orbitals,bond character,and static linear polarizability of H20@C80F60,which has not been isolated,as well as those of the synthesised H 20 @C 80 H 60.The H20@C80F60 should be considerably stable by analysing its energy and aromaticity.The inside H and outside X will play different role in the chemical reaction involving H 20 @C 80 X 60(X=H and F).The covalence of C-H bond is in the order that the inside C-H bond of H20@C80F60 > the inside C-H bond of H 20 @C 80 H 60 > the outside C-H bond of H 20 @C 80 H 60,whereas the C-F bond of H20@C80F60 have both the covalent and ionic characters.The static linear polarizabilities of C 80 and H 20 @C 80 X 60(X=H and F) are all isotropic.     

The density functional study of the stabilities,bond characters,static linear polarisabilities,and aromaticities of the ’in-out’ isomerism Hn-60@CnH60（n=70,72,74）

This paper uses the density functional theory to analyse the stabilities,bond characters,static linear polarisabilities,and aromaticities of the ’in-out’ isomerism H n-60 @C n H 60 (n=70,72,74).The binding energies,C-H bond energies,and energy gaps explore that the ’in-out’ isometric perhydrogenation of C n (n=70,72,74) can remarkably improve the stabilities.The static linear polarisabilies of H n-60 @C n H 60 (n=70,72,74) are indeed relative to their shapes,while they show almost nonaromatic character.This study can suggest that the ’in-out’ isometric perhydrogenation of fullerenes could lead to the invention of entirely novel potential hydrogen storage nanomaterials.     

超声辅助提取高效液相色谱法检测小麦籽粒中杀雄嗪酸的残留

建立了高效液相色谱法(HPLC)检测小麦籽粒中化学杂交剂SQ-1主成分杀雄嗪酸残留的方法。以75%乙醇为提取剂,正反萃取净化;采用Diamonsil C18不锈钢柱,以甲醇-0.5%(NH4)2HPO4溶液(60∶40,V/V,pH 2.5)为流动相,检测波长283 nm,流速1.0 mL/min。结果表明:化学杂交剂SQ-1主成分杀雄嗪酸在0.75～25.0 mg/L范围内线性关系良好,相关系数r=0.9999,在3个添加水平(1.0,5.0和10.0 mg/kg)范围内,平均加标回收率在84.2%～95.0%之间,相对标准偏差为1.0%～3.3%,检出限为0.075 mg/L。     

ZnO/ZnMgO异质结场效应管的制备与性能研究

利用等离子体增强化学气相沉积(PECVD)技术,在ZnO/ZnMgO异质结构上制备SiO₂作为栅绝缘层,采用光刻与腐蚀工艺制备ZnO/ZnMgO异质结场效应管。电学性能测试及计算结果表明器件栅压调控作用明显。发现栅端漏电流对器件性能造成一定影响。在低温条件下,栅绝缘层产生钝化,从而能够改善器件的性能。     

无阻尼单摆运动微分方程的反正切分式变换精确解

无阻尼单摆运动微分方程是一种具有物理背景的非线性常微分方程,研究其精确解和解法是非线性科学中的一个重要内容.在F展开法的基础上,应用反正切分式变换正弦函数方法,并引入Riccati辅助方程,得到了4种无阻尼单摆方程精确解的结果.达到了丰富此类方程求解技巧和精确解的目的.总结得出此类方程应用反正切分式变换方法具有一定普适性的结论.     

YBCO高温超导磁体临界电流密度快速确定方法

基于绘图法基本原理,以及YBCO高温超导带材的临界电流特性,采用有限元电磁场分析软件AnsoftMaxwell建立了空心圆柱磁体模型.根据磁场分布、并考虑到带材的临界电流密度随磁场大小和方向的变化关系,给出了影响磁体工作电流特性的磁场的分布.基于以上工作提出了一种利用Ansoft电磁场分析软件快速确定YB-CO高温超导带材临界电流密度的方法.     

介观薄圆环中的间隙性超导

本文运用了唯象的Ginzburg-Landau 理论研究了介观薄圆环的间隙性超导, 给出了在外磁场作用下超导圆环出现间隙性超导现象的尺寸相图. 这种间隙性超导现象只出现在尺寸小圆环中, 而且是超导圆环区别于超导圆盘的一个特征.     

浊点萃取-火焰原子吸收光谱法测定微量铜

本文研究了浊点萃取 -火焰原子吸收光谱法测定微量铜。利用表面活性剂浊点特性实现胶束相分离 /富集微量待测离子。探讨了影响浊点萃取的因素。该方法用于自来水、河水及标准土壤中痕量铜的测定 ,具有低毒、高效、安全、简便等特点。