查询词典 velocity

Under a fixed model of chromospheric flare, we investigate the influences of Hα and CaIIK line profilles on various velocity distributions from semiempirical view. The results show that: Hα line is very sensitive to the velocity in upper chromosphere; the profile of CaIIK line have responses to velocity in any layer of chromosphere, but the degree of CaIIK line asymmetry is much weaker than that of Hα and can be ignored if velocity is as small as 10km/s; chromospheric condensation in lower part of transition region have strong influence on Hα line but contrary to CaIIK line, the typical characteristic of H line effected by chromospheric condensation in transition region is reversed blue asymmetry, i.e. the intensity of blue peak is stronger than that of red peak; the stronger the chromosphoric condensation is, the more obvious the Hα line asymmetry appears; and so on.

在确定的大气模型下，从半经验角度系统地研究了大气各个层次的速度场和运动结构对Hα和CaⅡK谱线轮廓的影响，得到；Hα线对色球上部速度场敏感，而对色球下部和温度极小区附近速度场不敏感；CaⅡK对整个色球速度场均有反应，但不对称性较Hα弱，且速度小于10km/s时不对称性很不明显；CaⅡK受过渡区色球凝聚的影响较弱，而Hα对色球凝聚十分敏感；色球凝聚影响Hα轮廓的典型特征是呈反转结构的兰不对称性，即兰峰强于红峰；色球凝聚越强，Hα不对称性也越显著：等。

The main characteristics include: the quiet Sun corona has a rapid response to the flare heating, within 2 second the corona temperature increases nearly one order of magnitude, but later such increase becomes very slowly; the downward velocity at early stage of impulsive phase is too small to be negnected; chromospheric evaporation made by conduction shows some intensely, the maximum evaporated velocity may be as large as 1000 km/s; the chromospheric condensation appears just when the chromospheric evaporation takes place and its place always coincide with that of transition region in the early stage; the maximum of chromospheric condensation occurs also in the early stage of impulsive phase, at which the density in condensation may be larger two order of magnitude than that of surround and the downward velocity may be as large as 100 km/s; after the maximum of chromospheric condensation, its strongth decreases gradually but its width becomes greater with time and have a tendency to transport into deep chromosphere; the front of chromospheric condensation heats atmosphere obviously and the temperature in the chromospheric condensation is higher than the original case; the downware velocity of transition region may be greater than 100 km/s at the early stage; when the evaporated material collide at the top of loop, the densityand the presure there increase rapidly, which result in the formation of a shock wave; and so on.

在改善色球辐射损失和精确分辨过渡区的基础上，通过联立求解连续性方程、动量方程和能量方程，构造了一维磁限制性耀斑环在热沉积作用下的大气动力学模型，获得了耀斑热模型下脉冲相早期较为细致的大气演化理论图象，其主要特征是：耀斑对宁静日冕的加热相当迅速，仅2秒钟日冕温度增加即达一个量级，之后日冕温度增加缓慢；脉冲相早期日冕向下速度很小，几乎可以忽略，热传导驱动色球蒸发，其过程较为激烈，蒸发极大速度可达到1000km/s；色球压缩区与色球蒸发几乎同时形成，且在早期其位置总是与过渡区位置重合；色球压缩极大发生在脉冲相早期，其时密度可高于周围约2个量级，向下速度可超过100km/s；色球压缩极大后，其强度逐渐减弱，但宽度明显增大，且渐渐脱离过渡区往色球传播；压缩区内物质温度要高于原先的大气温度；过渡区下降在脉冲相早期相当迅速，可超过100km/s；当蒸发物质在环顶高速相碰时，环顶的密度、压力迅速增大，且温度也有所增加，导致形成激波，其波面以每秒上百公里的速度自环顶向下传播；在脉冲相前期，日冕软x辐射对色球的加热作用可以忽略；等。

In the upper bound approach, the velocity of each node are seen as unknown quantity, with the conditions of flow rule, velocity discontinuity, velocity boundary, the energy work equation considered, then the strength safety coefficient of slope, and the corresponding kinematically admissible velocity field are obtained.

在上限法中，以结点速度为未知量，根据单元塑性流动约束条件、速度不连续约束条件、速度边界约束条件，以及由外功功率与内功功率相等条件得到的目标函数，求得了强度储备系数的上限值及相应的机动容许位移场。

The study covers the vertical displacement distribution character of each mode of Rayleigh wave, theoretical dispersion curve character of multi-modes Rayleigh wave and the characters of the max-mode Rayleigh wave dispersion curve in different layers structure, which are velocity increasing with deep, high velocity layer within underground, low velocity layers within undergroan and high velocity surface layer, within the depth of 15 meters.

研究了地层速度随深度递增型、地层中有硬层或软夹层型、表层为高速的公路型等4种地层结构在15m深度内，瑞利面波各阶模态的位移幅度分布特征、多阶模态面波的理论频散曲线特征以及不同地层结构上的&最大模&面波频散曲线的特征。

Finally, he air velocity, the velocity of the wood particle, the relative velocity between the air and the wood particle, the wood particle's residence time and the variations of the particle's velocity along radial and circle are measured. The ISD of particles is analyzed on dynamics.

最后，测量了气流速度、刨花速度、刨花与气流间的相对速度、刨花在半环内的停留时间及刨花在半环内沿径向和周向的速度分布，并地基础上进行了刨花对撞流干燥的动力学分析。

Finally, the air velocity, the velocity of the wood particle, the relative velocity between the air and the wood particle, the wood particle's residence time and the variations of the particle's velocity along radial and circle are measured.

最后，测量了气流速度、刨花速度、刨花与气流间的相对速度、刨花在半环内的停留时间及刨花在半环内沿径向和周向的速度分布，并在实验基础上进行了刨花对撞流干燥的动力学分析。

Finally,the air velocity,the velocity of the wood particle, the relative velocity between the air and the wood particle,the wood particle's residence time and the variations of the particle's velocity along radial and circle are measured. The ISD of particles is analyzed on dynamics.

最后，测量了气流速度、刨花速度、刨花与气流间的相对速度、刨花在半环内的停留时间及刨花在半环内沿径向和周向的速度分布，并地基础上进行了刨花对撞流干燥的动力学分析。

Therefore, the 'generalized velocity unit' was introduced on the assumption that the surface velocity in the direction perpendicular to the line is a steady velocity frame with the topographic relief. The 3-D tomostatics velocity inversion was improved to suit the crooked wide line geometry.

为此，在假设垂直测线方向上表层速度是随地形起伏的稳定速度结构的情况下，引入&广义速度单元&概念，对三维层析静校正速度反演过程加以改进，使其适合宽、弯线资料观测系统。

We firstly classified the existing velocity analysis methods into different categories from various kinds of criterions, and then made an analysis by comparison of each other. After that we discussed factors that affect velocity accuracy and the selection of parameters. Finally, we described the process of migration velocity analysis and velocity model construction such as construction of initial model, as well as update and verification of the model.

从不同出发点对各种求取速度的方法进行了分类和分析比较，讨论了影响速度精度的因素及处理参数的选择，最后从初始模型的建立、模型的更新修正及模型的优化等方面提出了进行速度分析与建模的思路。

Evidence suggests that 1 under more stable stratification, the basic flow, if moving faster at low and high levels (particularly in the presence of jets there), allows a resulting meso-β unsteady wave to propagate eastward with respect to basic flow and even at greater velocity compared with it; 2 vertical windspeed shear of basic flow causes instabilities of the TWT perturbation; 3 considering the second derivative of basic-flow wind with respect to z (denoted by zz≠ 0 which is simply given as β* hereafter) the expression for the phase velocity of vortex Rossby wave is obtained, which is unidirectional in propagation with respect to basic flow; 4 VRoW has its physical origin from β*, i.e., from z-varying heterogeneities of y-direction averaged vorticity of the basic flow field; 5 VRoW phase velocity is associated with zonal wave number k, its energy is dispersive and the group velocity exists in the x direction; 6 when windspeed meets the condition of β*, TWT disturbance instability may be that of mixed VRoW and gravity wave; 7 if basic flow is subject to linear shear but does not meet the condition of β*, the TWT instability is that of inertia-gravity wave.

在大气层结比较稳定的情况下，如果基本气流在低层和高层较大(有可能存在低空急流和高空急流)，此时产生的β中尺度不稳定扰动相对于基流向东传播，甚至于快速向东传播。基本气流在垂直方向上的风速切变对于中尺度横波型的扰动起着不稳定的作用。如果考虑基流的二次切变，可以得到涡旋Rossby波的相速度表达式，涡旋Rossby波相对于基本气流是单向传播的。涡旋Rossby波产生的物理根源是基本流场的风速二次切变，亦即基本流场y方向的平均涡度在空间z方向上的不均匀所致。涡旋Rossby波的相速度与纬向波数也有关，它的能量是频散的，其在纬向x方向也存在群速度。在基本流场的风速存在二次切变时，横波型不稳定可能是混合的涡旋Rossby重力波的不稳定；而在基本流场的风速仅仅存在线性切变，不存在二次切变时，横波型扰动的不稳定则是重力惯性波的不稳定。

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？