涡

By means of the present model certain phenomena related to the nonlinear acoustic properties of an orifice, such as the roll-up of the shed vortex sheet and the forming of the Vena-Contracta are simulated. For a sinusoidal sound pressure, the time- history of the average velocity through the orifice is computed, and the nonlinear distortion of the velocity is examined by means of the Fourier decomposition.

依据此模型，对圆孔声学非线性效应的若干特征现象进行了数值模拟，如脱落涡层的卷曲，Vena收缩段的动态形成；在孔板前声压按余弦规律变化的情况下，计算了孔中平均速度的时间历程，并借助于Fourier分解分析了孔中平均速度的畸变情况。

The interactions between the shock wave and vortex ring are discussed.

在此基础上，考察了不同出口形状对爆轰波溢出后的外流场的动力学演变规律的影响，分析讨论了涡环与激波的相互作用过程。

Vortex ring generators have been invented that project stable doughnut-shaped clouds of smoke for long distances.

涡环发电机已发明了这一项目稳定的甜甜圈状云烟雾，为长途跋涉。

In the future, some issues need to be investigated further, which include: establish and study the low-dimensional dynamical system of turbulent jet, with the POD bases, the control of turbulent jet based on the low-dimensional dynamical system of turbulent jet, investigate the physics mechanism of intermittence shed-off of the vortex ring in turbulent jets in crossflow.

有待进一步研究的问题是：建立基于POD模的湍流射流低维动力系统，并对其进行分析；研究基于湍流射流低维动力系统的湍流射流控制；探讨湍流横向射流中涡环间歇脱落的物理机制。

Assuming fluid is and viscid and slightly compressible, bubble collapse near rigid boundary and free surface is simulated, displaying characteristics such as formation, penetration and impact of reentrant jet as well as vortex ring and bubble rebound.

采用粘性、微可压流体模型，数值模拟了空泡在刚性边界和自由面附近溃灭及空泡溃灭后流动的发展，显示了空泡溃灭过程中的凹陷射流形成、空泡贯穿、射流冲击、涡环的形成和空泡回弹等流动特征，提出空泡回弹的另一种机制是凹陷射流冲击形成的旋涡。

Production of various automotive motorcycle shaft parts, automobile ball, clubs, gear, bearing sets, screws, non-standard nuts, pipe joints, turbine vortex rod, ring, universal joints, fittings and other stampings.

企业生产各种汽车摩托车轴类零件、汽车球头、球杆、齿轮、轴承套、螺丝、非标螺帽、弯管接头、涡轮涡杆、挡圈、万向节、冲压件等配件。

Vortex Ring ; Temperature Inversion Layer ; Laser Induced Fluorescence ; Particle Image Velocimetry ; Comsol Multiphysics

指导教授朱锦洲；共同指导教授郭志禹；中文关键字涡环；逆温层；雷射萤光显影技术；质点显像测速仪；数值分析

Also,we found that the daily average value of WUEe always higher than that of leaf level WUE,one reason maybe lie in that they can not be compared directly for using two kinds of different measurement methods,the other reason may be associated with the energy fluxes underestimate by EC technology.4.Simulation of winter wheat canopy CO_2 fluxes by a multiplayer two-leaf model.

将生态系统水平与叶片水平的水分利用效率日均值进行比较，前者较后者高，原因可能与研究时对不同尺度采用了不能直接可比的不同的测定方法有关，也可能与涡度相关技术对能量通量的低估有关。4。

We analyzed and discussed the characteristics of cycle of carbon and water,and after having obtained important physiological parameters based on field experiment,a process-based, multilayer two-leaf model which calculates energy and material cycle separately for sunlit and shaded leaves was developed,then characteristic of CO_2 fluxes above the canopy was simulated.The main results are as follows:1.Characteristics of carbon and water cycle in the relationship of leaf photosynthesis -stomatal conductance-transpiration.

本研究以冬小麦为研究对象，利用LI-6400R光合—蒸腾测量系统、LI-6400-09土壤呼吸室和禹城生态试验站涡度相关系统等高精度仪器设备，对2007年和2008年小麦拔节至乳熟期间涉及碳、水循环过程的叶片光合—蒸腾作用、土壤呼吸作用及相关农田气象要素和植被特征进行了野外试验测定和分析，在试验观测基础上提取了重要生理参数，建立了基于过程的农田与大气间物质输送和能量交换的多层—双叶模型，并对2008年试验期间冠层上方碳通量特征进行了模拟，试验分析和模拟的主要结论如下：1。

Two-fluid large eddy turbulence model is applied to research the movement of the sand clouds in quiescent water.

本文采用双流体大涡紊流模型对静水中泥沙云团下落过程进行了研究。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。