数一数

A novel direction of arrival and polarization estimation of electromagnetic vector sensors mounted on the airframe is proposed based on biquaternion. The signal processing model for EM-sensor mounted on the airframe is made by biquaternion and then the eigenvalue decomposition of spectral matrix is obtained by means of the EVD of its quaternion adjoint matrix. The memory requirement for data is reduced, and more accurate estimation result is gotten by deducing the stronger orthogonality constraint between the sin- gal and noise subspaces on the field of biquaternion. The performance of the new algorithm is confirmed through numerical examples.

针对机载电磁矢量传感器阵列DOA和极化参数估计问题，提出了一种基于复四元数估计方法，该算法利用四元数建立机载电磁矢量传感器阵列信号处理模型，然后利用四元数联合矩阵的特征分解得到阵列数据相关矩阵的特征分解，一方面使得计算过程中数据的贮存量大大减少，另一方面通过推导得到信号子空间和噪声子空间在四元数域上的正交性从而使DOA和极化参数佑计的精度更高，仿真证实了本算法的有效性。

The numerical results indicate that the operator splitting method effectively suppresses numerical oscillations in the cases of high air bearing number. The numerical results show that both air lift force and pitch moment increase with the ratio of the slider's rail height to the air film characteristic height and the air bearing number, and finally reaches to stable value.

比较在不同轴承数下的气浮力和纵倾力矩发现：同一轴承数下，气浮力随气膜特征厚度减小而增加；当磁头槽台高度与气膜特征厚度的比值相同时，气浮力随轴承数增大而逐渐增加直到达到某一值后保持不变；纵倾力矩随轴承数增加而增大到某个最大值后减小。

The analytical method is always used due to the large amount of the objects and not very high accuracy of forecasting. A method based on the position and velocity derived from the mean orbit elements directly is given, which is to avoid the problem of singularity in calculating the periodic terms of orbit elements variation, thus the process and software can be simplified.

在已有分析法得到t时刻平均根数的基础上给出一种轨道预报方法，由t时刻的平均根数给出该时刻卫星的位置和速度，在此基础上将地球非球形引力摄动的周期项直接用卫星直角坐标的位置和速度分量表示，这样可以避免在计算轨道根数变化的周期项时出现的奇点问题，从而对根数的选择无特殊要求，可适用于各种轨道，简化预报程序和相应的软件，提高预报效率。

With the help of the notation of the skew-symmetric tensor, the expression for the 1st order absolute and relative derivatives of a tensor was presented, and the expression for the 2nd order absolute and relative derivatives of a tensor was offered further.

由此，并借助于反对称张量，给出了张量的一阶绝对导数和相对导数之间的关系式，并又进一步给出了张量的二阶绝对导数和相对导数之间的关系。

Based on the introduction of quantum numbers and bonding parameters,a novel molecular topological index ~A~was suggested.

通过引入量子数、键参数，认为分子的性质与其中各原子的电负性、价电子数、成键电子数、价层主量子数及各化学键的键长有关，提出了一种新的分子拓扑指数mAY。

Result of thermogravity analysis showed that the thermal stability of polyvinylamine chloride lowers with increasing in amination degree. Moreover, properties of dilute aqueous solutions of three types of poly chloride with different amination degree were compared by use of viscosimetric, conductometric, and potentiometric measurements. Results showed that both the electrostatic interaction of neighboring groups on the chain and the reduced viscosity of poly chloride are increased with increasing the degree of amination of poly . The equivalent conductivity is decreased with the increasing the concentration of poly chloride and increased with the increasing the amination degree of poly .

研究了聚乙烯胺盐酸盐的热稳定性和水溶液性质，发现：随着胺化度的提高，聚乙烯胺盐酸盐的对热稳定性逐步降低；聚乙烯胺盐酸盐是一种典型的聚电解质，其水溶液的pH值随平均分子量的变化并不明显，而随着聚乙烯胺胺化度的升高，pH值降低；随着聚乙烯胺盐酸盐的平均聚合度由82.3增加到201.8，它的m值（用于表征聚电解质侧链基团之间相互作用大小的常数）从5.13升高到5.58，而当聚乙烯胺盐酸盐的平均聚合度增加到311.4时，它的m值反而降低到了5.48；随着胺化度由55.65%升高到82.36%，m值由3.65提高到5.50；随着聚乙烯胺盐酸盐的平均聚合度的提高，聚乙烯胺盐酸盐的平均解离常数由7.48降低到7.26，同时随着胺化度的提高，聚乙烯胺盐酸盐的平均解离常数也由8.33降低到7.37；随着聚乙烯胺盐酸盐浓度的提高，溶液的摩尔电导率逐步降低，随着聚乙烯胺胺化度和聚合度的提高，溶液的摩尔电导率有所升高；在pH值为4左右时，聚乙烯胺盐酸盐的比浓粘度分别达到极值，而与聚合度的大小关系不大；聚乙烯胺盐酸盐的特性粘数明显高于其原料聚丙烯酰胺的特性粘数，分子量对特性粘数的影响十分明显，胺化度对特性粘数的影响并不显著。

In model experiments, we find that the deviation of the first derivative calculated by Fourier transform is very large to comparing with the theoretical derivative, but the fitting effect of the derivative of anomalies calculated by cosine transform is very good. The calculation accuracy of data are all very high except that errors of several data on the boundary are large because of the residual Gibbus effect induced by finite truncation of gravity anomalies. Errors are -009%～5%.

模型实验中发现，用Fourier变换计算的一阶导数与理论导数偏差很大，而余弦变换计算的导数与理论异常导数拟合效果非常好，除边界几个数据因重力异常的有限截断产生的吉布斯效应残留使误差较大外，数据的计算精度均很高，误差为-009%～5%。

Finally, the influence of permanent tide is recalculated using the same precise development of TGP. This work can be taken as a theoretical reference for the research of highprecision space geodesy and astrogeodynamics. tide-generating potential ; station displacements ; spectrum method ; Love/Shida number

最初的Love数和Shida数是由静态球形地球的潮汐模拟理论推求的，由于地球是旋转椭球形的天体，地球形变对引潮力位的响应存在着不同调和函数的微小混合，这样Love数和Shida数就与测站纬度和TGP的调和级次有关，纬度特性可通过引入一组常数来表示，最初的结果由Wahr

The object of the game is to move the boxes to the mad paved with cobblestones.

炮打笑面人，是一利用物理引擎来虚拟大炮的游戏，很真实的模仿了大炮，发射炮弹去轰炸那些躲起来的笑面人，游戏总共为12关，能记录用户已经玩过的关数，而不必重玩前面的关数，直接进入想玩的关数，箭头为炮弹发射的角度，触摸屏幕调整，下面有一进度条显示力度，按住不放聚力，从而可以让炮弹发射的更远。

A special kind of mean which is determined by calculating the mean of the reciprocals of the values concerned and then calculating the reciprocal of this quantity.

调和平均数，倒数平均数一种特殊的均数，求得方法是先求出有关倒数的均数，再求出这一均数的倒数。

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。