1) conditional symmetric instability
条件对称不稳定
1.
Based on FY-2 infrared images and the reanalysis data for six hours of NCEP(1°×1°),the heavy dust storm process occurred on 13 April 2007 in the middle west part of Hexi corridor is analyzed,particularly the cloud head of the descending jet was tracked and the gravitational instability,conditional symmetric instability and conditional instability are diagnosed in detail.
用风云2号卫星红外云图对下沉急流云头进行跟踪,并用NCEP(1°×1°)6h再分析数据对高速下沉急流到达冷锋云带前后的静力不稳定、条件不稳定、条件对称不稳定等进行了诊断分析。
2) conditional symmetric instability
条件性对称不稳定
1.
The analysis shows that conditional symmetric instability might be the unstable mechanism responsible for the heavy rain event.
分析表明:条件性对称不稳定是这次强降水发生的不稳定机制之一。
2.
From the conditional symmetric instability (CSI) numerical experiment we draw main conclusions as follows: A typical slantwise roll of CSI appears in the meridional plane.
模式采用非静力平衡条件、非常值湍流扩散系数，并具有最优协调分辨率，弥补了以往条件性对称不稳定数值研究中的诸多缺陷。
3) CSI(conditional symmetric instability)
条件性对称不稳定(CSL)
4) conditional symmetric instability(CSI)
条件性对称不稳定(CSI)
5) Symmetry instability
对称不稳定
1.
In this paper, a modified symmetry instability criterion for thermal wind non equilibrium basic flow is deduced by using two dimensional liner equations with Boussinesq approximation of moist air.
从湿大气的绝热、无粘、包辛内斯克近似的二维线性化方程组出发 ,考虑基本气流热成风不平衡 ,在经典的对称不稳定理论基础上推导出修正了的对称不稳定判据 ,发现基流热成风不平衡在一定条件下有利于对称不稳定发展。
6) Symmetric instability
对称不稳定
1.
Advances in synoptic analysis and application of symmetric instability theory
对称不稳定理论的天气分析与预报应用研究进展
2.
The results show that the existence of the maximum of inertial stability in the left front of the low level jet is favorable to the accumulation of moist thermal energy and that the conditional symmetric instability or convective instability can be expected in this region.
通过对低空西南急流左前方和高空偏北大风轴右后方的惯性稳定性和对称稳定性的理论分析和实例计算 ,表明 :低空急流左前方惯性稳定度大值区的存在 ,有利于低层湿热能量的积累 ,使低层倾斜对流的不稳定发展更多期望于条件性对称不稳定或对流不稳定 ;高空偏北大风轴 (西风急流 )的存在 ,是其右后方 (右侧 )出现对称不稳定的有利条件 ,高空相对容易出现干对称不稳定 ;惯性稳定性的作用 ,使低层的倾斜对流更偏向于垂直方向 ,有利于对流发展 ,使高层的倾斜对流更偏向于水平方向 ,有利于高层辐散。
3.
The dynamic stability of meso-scale symmetric perturbation is discussed in terms of two-dimensional fluid-dynamics equations under anelastic approximation,which obtains the criterion of symmetric instability in an adiabatic case.
采用滞弹性近似下的二维流体动力学方程组 ,讨论了中尺度对称扰动的动力稳定性 ,得到其绝热情况下对称不稳定的判据条件。
补充资料：条件稳定系统
以开环传递函数的增益值在某个范围内为条件才能保证稳定性的闭环控制系统。下图为条件稳定系统开环频率响应的奈奎斯特图的典型形状。图中ω为参变量频率。根据奈奎斯特稳定判据,当(-1,j0)点位于奈奎斯特曲线的A点和B点之间时，闭环系统是稳定的。通过减小增益值改变奈奎斯特曲线,使(-1,j0)点位于C点和B点之间，或加大增益值使(-1,j0)点位于A点和O点之间,都会导致闭环系统的不稳定。在工程实际中应尽可能避免采用条件稳定系统。系统元件特性的老化和输入信号过大引起的系统元部件的饱和，都会减小条件稳定系统开环增益值，从而使系统变为不稳定。
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