元素

Concentrations of 24 elements in the blood were determined by inductively coupled plasma mass spectrometry, and correlation analysis was done between Pb and other elements.

用电感耦合等离子体质谱法测定血中的24种元素含量，并对铅与其他元素做相关分析。

This is the third and last part in the series of articles about block and inline.

这是关于块级元素和内联元素的系列文章的第三篇也是最后一篇。

Combining the experimental results and theoretical analysis, the following work has been accomplished.(1) Reasons of the decrease of interelectrode capacitance and the increase of discharge gap caused by the powder suspended in dielectric fluid are explained. And the mechanism that surface quality of workpiece improved by powder-mixed EDM is analyzed from this viewpoint.(2) The variation regularity of the percentage of silicon on the machined surface of workpiece has been summarized according to the experiment results when silicon powder was added into the working fluid. The entropy is introduced to explain the reasons for this variation regularity by thermodynamics.(3) The dimensional accuracy is greatly influenced by the overcut resulting from discharge gap and electrode wear in practice application. Empirical formulas for the overcut in EDM and powder-mixed EDM are established based on the experimental results using the ternary linear regressive method in this paper.(4) The influence of main factors on the machined surface characteristics has been evaluated based on the orthogonal experimental design method.

通过一系列普通电火花加工与混粉电火花加工的对比实验，运用工艺实验和理论分析相结合的方法，重点做了以下工作：(1)探讨了粉末颗粒导致极间电容减小、放电间隙增大的原因，并从这个角度解释了混粉电火花加工可以改善工件表面质量的机理；(2)以混合硅粉的电火花加工为例，实验得出峰值电流和脉冲宽度对加工表面层成分中硅元素含量的影响规律，并引入熵的概念从热力学的角度对硅元素含量变化的原因寻找了理论依据；(3)在实际加工中，由于粉末的加入使放电间隙变大，这使得混粉电火花加工的尺寸精度难以控制，本文利用三元线性回归的方法，在实验数据的基础上，建立了两种电火花加工过切量的计算公式；(4)将正交试验法应用于混粉电火花加工实验研究，并通过对实验指标极差的直观分析，得出各电参数对加工指标影响的敏感程度。

The eigenvalues of circulant matrices compose of the discrete Fourier transform of the first line, on the contrary, the elements of the first line can recovered from the Fourier inversion formula, all circulant matrices have the same eigenvector that with the same order.

循环矩阵的特征值由其第一行元素的离散傅里叶变换组成，并且第一行元素是特征值的傅里叶变换的逆，而且所有同阶循环矩阵的特征向量相同。

This paper focuses on direct determination of anions in environmental water samples by reversed-phase ion-pair chromatography and effects of Se on the growth of vegetable seedling under Cr stress.

许多元素在环境中的分布、迁移规律以及对人体健康的影响与其价态有关，因而元素价态分析在环境监测中尤为重要。

Valence characterized by the transfer of electrons from atoms of one element to atoms of another during the formation of an ionic bond between the atoms.

电价在原子间形成离子键的过程中，由电子从一种元素的原子转移到另一种元素的原子所表示的价

Electro valence :Valence characterized by the transfer of electrons from atoms of one element to atoms of another during the formation of an ionic bond between the atoms.

电价：在原子间形成离子键的过程中，由电子从一种元素的原子转移到另一种元素的原子所表示的价。

The ionization potential of an element is a measure of its ability to enter into chemical reactions requiring ion formation or donation of electron s and is related to the nature of the chemical bonding in the compounds formed by elements

为元素参与取得离子形式或移出电子的化学反应能力的量度，也与元素形成化合物中的化学键的性质有关。

The ionization potential of an element is a measure of its ability to enter into chemical reactions requiring ion formation or donation of electrons and is related to the nature of the chemical bonding in the compounds formed by elements

为元素参与取得离子形式或移出电子的化学反应能力的量度，也与元素形成化合物中的化学键的性质有关。

It has been proved that the sensitivity of analytes can be significantly enhanced by adding small amounts of oxalic acid,especially for the elements with ionization potential between 9 and 11 eV.

结果表明，低浓度乙二酸对所分析元素的灵敏度具有显著的增敏效应，尤其是对电离电位在9～11eV的Be，Zn，Se，As，Sb，Hg等高电离电位元素。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。