四元法

A ratio spectra derivative spectrophotometry for simultaneous determination of quaternary mixture of aminopyrine, phenobarbital, caffeine and phenacetin was studied.

提出了可应用于四元混合体系同时测定的比光谱-导数分光光度法，阐述了该方法的基本原理，并将其应用于氨基比林、苯巴比妥、咖啡因和非那西丁四元混合体系中各组分的同时测定。

Seven kinds of antijamming methods,such as time correlated choice and field-of-view shrinkage, inertial track,real-time memory criterion,amplitude discrimination, pulse-width discrimination, pulse-amplitude time sequence discrimination and pulse-width amplitude discrimination for Counter-Infrared-Interference-Missile with the cross-shaped detector array are given.

介绍了四元正交探测器以及红外干扰弹的工作原理，对四元正交探测器导引系统抗红外干扰的7种方法(即时间相关选择和视场收缩技术、惯性跟踪机制、实时记忆准则、幅值鉴别法、脉冲宽度鉴别法、脉冲幅值序列鉴别法和脉冲宽度幅值鉴别法)等进行了讨论。

According to the experimental data,the equilibrium phase diagram and the physico-chem.

采用等温蒸发法研究了四元体系K+、Na+∥CO32-、HCO3--H2O 35℃相平衡及平衡液相的密度、电导率、折光率和pH值，测定了该四元体系在35℃条件下平衡溶液的浓度及物化性质。

To mitigate this, this sample uses a quadratic normal interpolation.

为了解决这个问题，sample里使用了四元法向插值。

In this paper, phase equilibria of quinary reciprocal system Li+, Na% KV/ C032. B4O72~-H2O and its subsystems (nine ternary systems and five quaternary systems) at 288K were studied by isothermal method; An experimental study on metastable equilibria at 288K in the quinary system was done by isothermal evaporation method, also.

采用等温溶解平衡法研究了五元体系Li~+，Na~+，K~+∥CO_3~(2-)，B_4O_7~(2-)—H_2O及其九个三元子体系、五个四元子体系288K相平衡关系；采用等温蒸发的方法研究了该五元体系288K介稳相平衡关系。

In order to investigate the relationship of solubility between vanadium and the other co-existing ion in soil. The phase equilibria of the quinary systemNaVO_3 + KVO_3 + NaH_2PO_4 + KH_2PO_4 +(NH_2)_2CO + H_2O and its five quaternary sub-systems were studied at 298K with isothermal dissoluble method. According to the reference, all these systems are not reported yet. The solubilities and the physico-chemical properties such as density, conductivity, pH value and refractive index of the equilibrium solutions were determined. Based on the determined values, the solubility stereo-diagram and projected-diagram( saturated with KVO3), projected-diagramsaturated with (NH_2_2CO, and water content diagram of the quinary system, isothermal solubility diagrams of the quaternary sub-systems, and the physico-chemical properties-composition diagrams of the equilibrium solutions were plotted.

为探明土壤中钒的溶解性同土壤中主要共存离子间的关系，本论文采用等温溶解平衡法研究了文献中还未见报道的五元体系NaVO_3+KVO_3+NaH_2PO_4+KH_2PO_4+(NH_2)_2CO+H_2O及其五个四元子体系298K相平衡关系，测定了这些体系298K时各组分的溶解度及平衡液相的密度、电导率、pH值和折光率等物化性质，并绘制了五元体系溶解度空间立体图，以KVO_3为饱和的投影图，以(NH_2)_2CO为饱和的投影图、水图及四元子体系的溶解度等温图、水图和平衡液相物化性质一组成图。

The examples given have proved the advantage of the Boundary Element Method. In the analysis of the fracture mechanics using Boundary Element Method, the calculation model of one-quarter singular element has been established, and has been proved its validity.

把边界元法应用于线弹性结构断裂分析中，建立了裂尖奇异区分析的四分之一奇异元计算模型，算例表明，用四分之一奇异元分析断裂力学问题是一种有效的逼近裂尖场的数值方法。

This paper first elaborated the principle of SINS, some interrelated information,and the affect of renewed arithmetic to the system"s precision. Then, we studied thequaternion in traditional renewed attitude arithmetic. The quaternion is simple, andwhen run it into computer, it"s time saving. So, this arithmetic is often adopted byengineering. However, the quaternion brought unexchangeable error inevitably. Whenthe carrying body moves in highly dynamic situation, the error would become larger.So we should take effective measure to get over it.

本文首先论述了捷联式惯性导航系统的工作原理及相关知识，捷联惯导系统姿态更新算法对系统精度的影响；其次研究了传统的姿态更新算法中四元数法，该算法简单，计算量小，因而在工程中经常被采用，但是在四元数法中不可避免的引入了不可交换性误差，特别是在载体处于高动态环境时，这种误差就会很大，必须采取有效措施加以克服。

The metastable phase equilibrium of the quaternary system Na(superscript +)∥Cl(superscript -), CO3(superscript 2-), B4O7(superscript 2-)-H2O was studied at 273 K by isothermal evaporation method, the solubility and density of the equilibrium solution of this system were determined and the metastable equilibrium phase diagram was plotted in line with the experimental data. The phase diagram of the system consists of three univariant curves, three crystallization fields and one invariant point.

采用等温蒸发法研究简单四元体系Na∥Cl，CO3(上标 2-)，B4O7(上标 2-)-H2O273K时的介稳相平衡，并测定该体系273K平衡液相中各组分的溶解度及密度，该体系的介稳相图和密度组成图显示：该四元体系在273K时的相图由3条溶解度单变量线、3个结晶区及1个共饱和点组成。

In the last part, analysis of the sound field around the shell of the fan is done with combining finite element method and boundary element method by using software ANSYS and SYSNOISE.

第四部分分析风机外壳周围声场，结合有限元法和边界元法，应用ANSYS和SYSNOISE软件，建立声场边界元模型。

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。