宜产葛根中微量元素含量的测定

原子吸收分光光度法测定了宜昌地区产葛根中的Cu．Fe．Zn、Mn、Mo．Mg、Se等6种微量元素。为葛根的药效进一步研究和综合开发利用提供了新的科学依据。     

成人血清元素相关性及比值分析

用ＩＣＰ－ＭＳ法测定了７９例成人血清１４种元素水平,并进行了相关分析。结果提示,多种元素间存在显著正相关;分析了部分元素的比值,为相关研究提供了参考范围,且对元素比值的离散程度进行分析,为多元素关系研究提供了新的线索与依据。     

微波消解-电感耦合等离子体质谱法测定丙烯腈-丁二烯-苯乙烯共聚物塑料中的铅、镉、汞、铬、砷

建立了微波消解技术-电感耦合等离子体质谱(ICP-MS)法同时测定丙烯腈-丁二烯-苯乙烯共聚物(ABS)塑料中的铅、镉、汞、铬、砷五种元素的方法。对仪器的参数设置、进样系统进行了优化,并对此类塑料样品中上述元素分析的前处理条件,如消解体系、消解温度、恒温时间以及酸用量等进行了优化。方法检出限为0.7～6.5 ng·g-1;用加标回收的方法评价了该方法的准确性,加标回收率为89.8%～110.8%;样品测定相对标准偏差为2.8%～11.3%。该方法检出限低、精确度好、准确度高、简单快速、无需基体匹配。     

电感耦合等离子体发射光谱法检测獭兔肉中的微量元素

研究了用电感耦合等离子体光谱法检测獭兔肉中多种微量元素的实验方法。实验表明,獭兔肉中多种微量元素在选定的最佳条件下能够可靠、准确测得,且精密度在0.59%—8.85%之间,回收率为96.5%—103.5%。该方法具有灵敏度高、干扰少、线性范围宽和多元素同时测定等优点,是科学工作者研究微量元素可行的方法之一;同时该方法准确、快速、简便,适用于同类样品的测定,结果令人满意。     

碲材料中钠,钾杂质成份的测定

本文揭示了钠、钾受基体元素碲干扰的现象和分析系统中酸度对钠、钾吸光度的影响,在理论上探讨了碲对钠、钾干扰的原因,利用加入盐酸和铝元素的方法分别排除碲对钾、钠的干扰,提出一个方便,实用的测定方法,回收率和RSD分别为95-102%和7.4%。     

Navier－Stokes方程的变网格非协调有限元法

本文通过所谓的速度－压力型公式讨论了Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程的变网格非协调有限元逼近，得到了在确定模意义下的速度、压力误差估计，且在一定条件下，某些误差估计能达到最优。     

VISCOUS FORCES BETWEEN TWO SPHERES COLLIDING THROUGH INTERSTITIAL POWER-LAW FLUID

Interaction between two spheres with an interstitial fluid is essential in Discrete Element modeling for simulating the behaviors of ‘wet‘ particulate materials. In this paper the interaction between two spheres with an interstitial Power-law fluid was approximately resolved as normal and tangential interactive models respectively, for which the governing equations were simplified on the basis of Reynolds approximation. These equations were then solved analytically together with the boundary conditions to obtain the pressure distributions for each individual model, and event ually solutions of the viscous squeeze force and the tangential viscous resistance were obtained, which provide a set of solutions for implementing into DEM code or other purposes.     

求解stokes问题的一个新的非协调混合元格式

构造一个新的非协调混合元格式求解stokes问题,证明了该元满足B-B条件,并且有2阶收敛速度.     

Development and application of an adaptive finite element method to reaction-diffusion equations

An adaptive finite element method is developed and applied to study the ozone decomposition laminar flame. The method uses a semidiscrete, linear Galerkin approximation in which the size of the elements is controlled by an integral which minimizes the changes in mesh spacing. The sizes and locations of the elements are controlled by the location and magnitude of the largest temperature gradient. The numerical results obtained with this adaptive finite element method are compared with those obtained using fixed-node finite-difference schemes and an adaptive finite-difference method. It is shown that the adaptive finite element method developed here using 36 elements can yield as accurate flame speeds as fourth-order accurate, fixed-node, finite-difference methods when 272 collocation points are employed in the calculations.