电热蒸发ICP-AES法直接测定人血清中微量元素

建立了悬浮体制样电热蒸发电感耦合等离子体原子发射光谱法(ETVICPAES)直接测定人血清中微量元素(Cu,Cr,Fe)的方法。采用聚四氟乙烯(PTFE)悬浮体为化学改进剂,以促进待测物的蒸发,改善方法的分析性能。研究了影响待测元素信号强度的主要因素。在优化实验条件下,方法的检出限为14ng·mL-1(Cu)和29ng·mL-1(Fe),相对标准偏差小于60%。     

电感耦合等离子体原子发射光谱测定生脉散中多种微量元素

采用ICP-AES法测定生脉散中多种微量元素,考查不同品种人参的煎煮液中多种微量元素的溶出情况。实验表明人参、麦冬、五味子生药材及水煎液经硝酸-高氯酸体系消化,样品消解完全,可以满足ICP-AES检测的要求。结果的相对标准偏差为0.70%～5.9%,加标回收率为95.2%～112.4%,各种微量元素的溶出率以西洋参、麦冬、五味子为复方药的共煎液中溶出率较高,从而进一步证实了生脉散该复方药的合理性。文章为药剂学研究提出了一个简便、准确和可行的研究方法的同时,也对中药复方的合理性进行了考察,为其临床疗效研究提供了有效依据。     

Determination of 25 elements in the complex oxide mineral zirconolite by analytical electron microscopy

In this paper we describe a technique for the determination of 25 elements in natural zirconolite using energy-dispersive analytical electron microscopy (AEM). The method presented here allows one to quantitatively investigate the chemistry of submicron-scale zones in complex oxide minerals. The effects of electron channeling, thickness variability and variations in detector resolution were minimized by using a controlled set of operating procedures and instrument parameters. To provide a high level of accurayy, k_ATI-factors were determined from standards for most of the 25 elements of interest, including all of the major elements. Each analytical spectrum is reduced to a set of raw peak counts (and errors) using a digital top-hat filter to suppress background followed by multiple least squares fitting of reference spectra. Counting times of 12–15 min per analysis were required to provide suitable counting statistics. Results are presented for zirconolite samples from the contact metamorphic aureole of the Bergell granodiorite intrusion, Switzerland-Italy. A comparison of 43 AEM analyses with 15 analyses obtained by wavelength-dispersive electron probe microanalysis (EPMA) shows that there is excellent agreement between the two data sets in the amounts of individual elements present, chemical trends and overall stoichiometry. An assessment of the combined data set shows that the major substitution mechanisms in the Bergell samples are coupled substitutions involving the M5,6- and M8-sites of the zirconolite structure: ^M8Ca²⁺ + ^M5,6Ti⁴⁺→^M8REE³⁺ + ^M5,6(Al,Fe)³⁺ and ^M8Ca²⁺ + ^M5,6Ti⁴⁺→^M8(Th,U)⁴⁺ + ^M5,6 (Mg,Fe)²⁺.     

两种土壤中五种有毒元素的研究

本文通过对五种有毒金属（Pb,Hg,As,Cd,Cr)被土壤吸附后分配系数及形态变化的测定,对它们在土壤中的量变和质变规律进行了探讨,从而为推论其吸附机理和防止地下水及农作物污染等方面提供了科学依据。     

摆臂式三点光学镜面支撑系统的研究

提出了一种摆臂式三点光学镜面支撑系统,分析了其结构原理和工作性能,给出了实现的方法和制造工艺。该支撑系统具有结构简单、刚度恒定以及无附加温度应力等特点,可用于中小型光学镜面和光学元件的支撑,特别适用于空间仪器的光学加工领域。     

Uniform Convergence of Multigrid V-Cycle on Adaptively Refined Finite Element Meshes for Elliptic Problems with Discontinuous Coefficients

The multigrid V-cycle methods for adaptive finite element discretizations of two-dimensional elliptic problems with discontinuous coefficients are considered. Under the conditions that the coefficient is quasi-monotone up to a constant and the meshes are locally refined by using the newest vertex bisection algorithm, some uniform convergence results are proved for the standard multigrid V-cycle algorithm with Gauss-Seidel relaxations performed only on new nodes and their immediate neighbours. The multigrid V-cycle algorithm uses $\mathcal{O}(N)$ operations per iteration and is optimal.     

半线性抛物最优控制问题全离散插值系数有限元方法的收敛性分析

本文考虑全离散插值系数有限元方法求解半线性抛物最优控制问题,其中控制变量用分片常数函数逼近,状态变量和对偶状态变量用分片线性函数逼近.对于方程中的半线性项,先用插值系数技巧处理,再用牛顿迭代法求解.通过引入一些辅助变量和投影算子,并利用有限元空间的逼近性质,得到半线性抛物最优控制问题插值系数有限元方法的收敛性结果;数值算例结果验证了理论结果的正确性.     

A nonlinear model for marble sulphation including surface rugosity and mechanical damage

Here we propose and analyze a mathematical model that aims to describe the marble sulphation process occurring in a given material. The model accounts for rugosity as well as for damaging effects. This model is characterized by some technical difficulties that seem hard to overcome from a theoretical viewpoint. Therefore, we introduce some physically reasonable modifications in order to establish the existence of a suitable notion of solution on a given time interval. Numerical simulations are presented and discussed, also in view of further research.     

直接酸提取电感耦合等离子体发射光谱法测定煤中主要成灰 …

本文提出了一种全新的以酸直接提取煤中的矿物元素、ＩＣＰ－ＡＥＳ测定其含量的方法。考察了最佳酸配比、酸用量、最佳提取时间、仪器最佳操作参数以及元素间的干扰等诸多因素。与其灰分含量相比,煤中矿物质的提取率在９５％以上,各元素加标回收率为９６％～１０４％,九次测定相对标准偏差小于４％。方法准确、快速、适合于不同煤样中矿物元素的分析测定。     

Recovery of low temperature electron irradiation-induced damage in n-type gaas

Undoped n-type GaAa was irradiated near 5 and 77 °K with electrons having incident energies between 0.46 and 1.30 MeV. The recovery of the electrical resistivity and the Hall coefficient upon annealing from 4 to 520 °K was monitored. Changes which occurred upon annealing below 200 °K could be reversed by ionizing radiation. A small amount of irreversible ionization-induced recovery was observed after irradiation near 5 °K. Major irreversible recovery stages were centered near 235 (stage I), 280 (stage II) and 520 °K (stage III). Recovery in stage I and II obeyed first order kinetics. The activation energies of stages I and II were determined as 0.72 and 0.83 eV, respectively. The carrier concentration changes per unit irradiation dose corresponding to the three recovery stages differed in their energy dependence indicating that the defects which are removed in stage III have the lowest threshold energy. The carrier concentration changes per unit irradiation dose corresponding to stages I and III were higher for irradiation near 5 °K than for irradiation near 77 °K.