1) second-order moment
二阶矩
1.
A second-order moment two-phase turbulence model for dense gas-particle flows (USM-θ) model), combining the unified second-order moment two-phase turbulence model for dilute gas-particle flows with the kinetic theory of particle collision, is proposed.
本文将统一二阶矩两相湍流模型和颗粒动力学理论结合,推导并封闭了稠密两相流考虑颗粒间碰撞的统一二阶矩两相湍流模型。
2.
A mass-weighed averaged second-order moment (MUSM) two-phase turbulence model is proposed.
本文用视密度加权平均代替时平均，建立了视密度加权平均的统一二阶矩两相湍流模型方程组（ＭＵＳＭ），其中用体积分数代替了数密度，用颗粒驰豫时间作为封闭两相脉动速度关联方程耗散项的时间尺度，并引入了颗粒视在的气体速度脉动的输运方程。
3.
According to ISO 11146 standard,laser beam width is calculated in second-order moment arithmetic.
为了获取激光束的准确束宽值,模拟了基模和高阶模的高斯光束以及CCD噪声,并根据国际标准ISO 11146规定的二阶矩算法计算激光束宽。
2) second order moment
二阶矩
1.
To investigate the automatic modulation recognition of Phase Shift Keying(PSK) signals widely used in TTC(Tracking,Telemetry and Control) of satellite links,such as BPSK,QPSK,OQPSK(Offset QPSK),and UQPSK(Unbalanced QPSK),an algorithm based on second order moment and statistic of phase differences is proposed.
针对卫星测控链路中常用的数字调相信号BPSK、QPSK、OQPSK(偏移QPSK)和UQPSK(非平衡QPSK)的调制识别问题,提出了基于二阶矩和相位差统计特性的分类算法。
2.
Based on the second order moment method recommended in ISO11146 international standard,the facular of the sender after focused by using CCD can be measured and divided into several parts to get the factor M2 of the sender of laser fuse.
以ISO11146标准中的二阶矩法为基础,使用CCD采集聚焦后的光斑图像,并对光斑图像进行分块处理,从而得到激光引信发射组件的M2因子。
3.
Based on the second order moment method,the power density across of the beam section is measured.
根据激光引信中激光器的脉冲功率高、发散角大的特殊测量要求,比较了ISO 11146标准文件对激光束的3种测量方法,以二阶矩法为基础,运用机械扫描法测量光束截面的功率密度,进而再现出光斑图形。
3) second moment
二阶矩
1.
Based on calculating minimal path sets,using Boolean manipulation and disjoint method, quick calculation method of first moment and second moment of reliability evaluation is proposed for large-scale complicated system.
基于大型复杂系统最小路集计算基础,根据最小路集不交化方法,提出了系统可靠性一阶矩、二阶矩的快速计算方法;提出了根据一阶矩、二阶矩,拟合贝塔函数和对数伽马函数,进行大型复杂系统可靠性快速评定方法;并且编制了相应C++计算程序,解决了大型复杂系统可靠性评定问题。
2.
Based on logic expression calculation of normal working state of system,and disjointed calculation of logic expression of normal working state of systdm,calculation method of first moment and second moment of system reliability is presented.
根据系统正常工作状态的逻辑表达式计算,及其不交化计算,提出了系统可靠度一阶矩和二阶矩计算方法,利用系统可靠度的一阶矩和二阶矩相等原理,进行了k/N系统的Bayes方法可靠度评定。
3.
Owing to complexity of reliability diagram of complicated system,approximate method of reliability evaluation is needed by fitting β-function or logarithmic Γ-function,which equal-principle of first moment and second moment of reliability is employed,therefore calculating method of first moment and second moment of reliability is key technology for complicated system.
复杂系统可靠度评定,由于其可靠性框图结构复杂,只能采用计算系统可靠度的一阶矩、二阶矩,然后根据一阶矩、二阶矩相等原则,拟合贝塔函数和对数伽马函数,评定出系统可靠度的近似下限。
4) second-order moments
二阶矩
1.
Our numerical calculation show that the entropy and its differentiation with respect to the propagation direction can describe the compression and broadening of light pulse(or the focusing and diffussion of light beam), which is better than pulse(beam) width and second-order moments.
用熵表征非线性光传输优于用脉 (束 )宽、二阶矩表征。
5) second order moments
二阶矩
1.
Relations between beam parameters and second order moments of astigmatic beams;
像散光束的光束参数与光强二阶矩的关系
6) second-order moments matrix
二阶矩矩阵
1.
Based on the propagation law of the second-order moments matrix,the focusing of twisted anisotropic Gaussian-Schell model (AGSM) beams through a lens is studied.
基于有扭曲的各向异性高斯 谢尔模型 (AGSM)光束二阶矩矩阵的传输公式 ,研究了AGSM光束通过透镜的聚焦。
补充资料：矩矩吒
【矩矩吒】
（动物）又作鸠鸠吒。鸡也。见求法高僧传等。
（动物）又作鸠鸠吒。鸡也。见求法高僧传等。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条