四元

We investigate mixed totally umbilical QR-submanifolds in a quaternionic space form and also study the pseudo-umbilical QR-submanifolds of a quaterninoic space form with some additional conditions.

考查四元数空间形式中混合型全拟脐QR子流形并研究了四元数空间形式中具有某种条件下的混合型伪脐QR子流形。

Specifying a rotation directly as a quaternion is completely unintuitive, so what you\'ll want to do is convert quaternions to and from other representations.

四元数并不天生就具有旋转的特性，因此你还要做一些转换四元数或其它的一些必要工作。

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 metastable phase diagram of the quaternary system Li+,K+,Mg~(2+)//SO_4~2-_-H_2O at 15℃, there are three invariant points of four co-existed phases, seven univariant metastable solubility curves and five crystallizing zones.

四元体系Li+，K+，Mg~(2+)//SO_4~2-_-H_2O在15℃介稳相图存在3个四元无变量点、7条单变量介稳溶解度曲线和5个介稳结晶区。

In the metastable phase diagram of the quaternary system Li+,K+,Mg~(2+)//SO_4~2-_-H_2O at 15℃, there are three invariant points of four co-existed phases, seven univariant metastable solubility curves and five crystallizing zones.

四元体系Li+，K+，Mg~2+(来源：bcAB77C论文网www.abclunwen.com//SO_4~2-_-H_2O在15℃介稳相图存在3个四元无变量点、7条单变量介稳溶解度曲线和5个介稳结晶区。

The metal element powders were mixed proportionally with ZrB2/ZrC/SiC ceramic powders in the cylinder mill, then the quaternary ZrB2/ZrC/SiC+Me ceramics were prepared by hot-pressing mixed powders.

将金属元素粉按一定配比与ZrB2、ZrC和SiC陶瓷粉末混合后热压制备了ZrB2/ZrC/SiC+Me 四元陶瓷，重点研究了四元陶瓷的密度、弯曲强度、断裂韧性、烧蚀性能以及烧蚀前、后的微观组织。

From the potential energy profile, it can be predicted that, the dominant channel of this reaction consists of three steps: the two reactants first form a three-membered ring intermediate (INT1) through a barrier-free exothermic reaction of 19.2 kJ/mol; three-membered ring intermediate (INT1) isomerizes to a four-membered ring silylene(P2) via the transition state (TS2) with an energy barrier of 22.8 kJ/mol; four-membered ring silylene(P2) further reacts with ethene(R2) to form a silicic bis-heterocyclic compound (P3), which is also a barrier-free exothermic reaction of 132.2 kJ/mol.

用CCSD//MP2/6-31G*方法研究了单重态二甲基亚烷基硅烯与乙烯生成硅杂双环化合物环加成反应的机理，根据该反应的势能面可以预言，该反应的主反应通道有三步组成：第一步是两反应物（R1， R2）首先生成了一三元环中间体（INT1），它是一无势垒的放热反应，放出的能量为19.2 kJ/mol；第二步是三元环中间体(INT1)经过渡态TS2异构化为了四元环硅烯（P2），其势垒为22.8 kJ/mol；第三步是四元环硅烯（P2）进一步与乙烯(R2)反应生成了硅杂双环化合物（P3），该反应也是一无势垒的放热反应，放出的能量为132.2 kJ/mol。

The conjugation by a unit quaternion (a quaternion of absolute value 1) with real part cos is a rotation by an angle 2''t'', the axis of the rotation being the direction of the imaginary part.

单位四元数（绝对值为1的四元数）若实部为 cos，它的共轭作用是一个角度为2''t''的转动，转轴为虚部的方向。

As it is expected, the main obstacle in the study of quaternion matrices is the non-commutation in multiplication of quaternions.

实四元数矩阵研究的主要难点是四元数乘法的不可交换性。

INS with single axis stablization is analyzed using quaternions, and system quaternions error model is worked out.

应用四元数方法分析了单轴稳定惯导系统，建立了系统的四元数误差模型。

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。