查询词典 turbulent current

In this thesis the process of constructing the non-perturbative Hamiltonian theory is de-scribed and is applied to estimate the vacuum condensate. It contains the following contents:At the very beginning, by using the path integral method and eliminating the gluon freedom, aGCM action 〓 of current quarks including lower order current-current coupling was derivedfrom the QCD Lagrangian and the effective Hamiltonian operator that could hardly be doneby the normal methods was derived. After doing this, the broken vacuum is introduced whichincludes quark-antiquark condensate through the generalized Bogoliubov-Valatin transformation,the effective Hamiltonian of constituent quark was derived. The detailed formulas containingthe spatial current-current coupling term for the effective Hamiltonian and gap equations wasworked out by parameterizing the correlation kernel as a quadratic potential. And then, the gapequation was solved and the quark-antiquark condensate of vacuum was studied both in the casesof instantaneous interaction and retarded interaction. In the end, the effective Hamiltionian withtwo-body quark-quark interaction was derived with one-body approximation, and with the helpof the functional integral method the coupling non-linear dynamic equations for systems withnuclear matter was derived. Finally, these equations were solved by selfconsistent method andthe effect of nuclear matter on vacuum condensate was studied. The spatial current-current coupling term is too difficult to handle, hence the correlationkernel is assumed to be not important and usually omitted in the pure vacuum condensate, andthe instantaneous interaction generally is adopted. Retaining the spatial current-current termand partial retardation effect, the quark pairs condensate in pure vacuum was studied, and theeffect of quark mass was also studied. At present, little study is focused in the case with nuclearmatter and spatial current-current term also omitted. Under the approximation with partialspatial current-current term, the effect of nuclear matter on vacuum condensate was studied.

本论文描述了量子色动力学整体色对称模型哈密顿量方法的构建过程，得到了反映正反夸克对凝聚真空结构的关于组分夸克的有效哈密顿量算符，它隐含了胶子作用，并且准确至流-流耦合项；接着，通过参数化哈密顿量中的夸克作用关联核，导出平方禁闭势参数化选择的哈密顿量的具体公式和能隙方程；随后，应用公式，编程求解，考察了瞬时作用下和部分延迟作用下真空的正反夸克对凝聚，在计算中保留了空间流-流耦合作用；之后，导出瞬时势和延迟势下包含二体作用项的哈密顿量公式，并采用单体化近似，通过泛函变分方法得到核物质存在时耦合的非线性动力学方程；在保留部分空间双流耦合作用的近似下，求解核物质的动力学方程，考察核物质密度对真空凝聚的影响，以往考察真空凝聚，对关联核的选用，由于空间流-流耦合项不易处理，也认为作用不大，常忽略该项，并且常采用瞬时作用；本文保留空间双流项和部分延迟作用，考察了真空情形的夸克对凝聚，还考察了夸克质量对纯真空凝聚的影响，以往对核物质存在情形的真空凝聚考察很少，也都忽略空间流-流项，本文在考虑部分空间流-流项近似下，考察了核物质存在对真空凝聚的影响。

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。

Therelationship between the turbulent kinetic energy and its dissipation rate,whichis widely used to parameterize the dissipation rate in turbulence closure models,is found to hold well for both reversing and rotating flows,but with differentcoefficients.Microstructure profiling measurements at two comparative stations (a deepercentral basin and a local shelf break) in the stratified Yellow Sea are analyzed,with emphasis on tidal and internal-wave induced turbulence near the bottomand in the pyenocline.The water column has a distinct three-layer thermohaline structure,consisting of weakly stratified surface and bottom boundary layers anda narrow sharp pycnocline.Turbulence in the surface layer is controlled by thediurnal cycle of buoyancy flux and wind forcing at the sea surface.while thebottom stress induced by barotropic tidal eurrents dominates turbulence in thebottom boundary layer.The maximum level at which the tidally enhanced mixingcan affect generally depends on the magnitude of the tidal current,and it canbe up to 10-15 m in the Yellow Sea.This suggests that,in the deeper regionsof the shelf seas,turbulent dissipation and mixing are very weak at the levelsbetween the near-bottom tidally enhanced layer and the pycnocline.Therefore,these levels provide a significant bottle neck for the vertical exchanges.In theshallow regions,however,the tidally-induced turbulence can occupy the wholewater colum below the pycnocline.A quarter-diurnal periodicities of the turbulentdissipation rate and eddy diffusivity are found at different heights with evidenttime lag.In the relatively flat central basin,the pycnocline is essentially non-turbulent and internal-wave activity is very weak.Therefore,vertical fluxes acrossthe pycnocline decreased to molecular levels.In contrast,internal waves of variousperiods can be always found near the local shelf break.

对强层化季节黄海两对比性站位(分别位于中央海盆区与局地陆坡区)处层化、内波以及湍流混合特征的研究结果表明：1、强层化季节的陆架海水体一般呈现显著的三层热盐结构，在水体近乎混合均匀的上混合层与潮流底边界层之间为强跃层；2、近表层水体的湍流混合强度主要由海表浮力通量的日变化与海表风强迫控制，而在潮流底边界层内，潮混合是水体热量、物质、动量与能量垂直交换的主要机制；3、潮混合影响的深度由潮流大小决定，在黄海，一般可达10-15 m，因此，在水深较深的区域，在跃层与潮混合所至深度范围的上界之间存在湍流混合非常弱的区域，这显著抑制水体内物质的垂直通量，为物质垂直交换的瓶颈，而在水深较浅的区域，潮混合影响范围可至跃层底部，因此物质在跃层以下整个水体中混合非常均匀，当跃层内间歇性强混合发生时，可以产生显著的跨跃层物质输运；4、近底潮致强湍流耗散缓慢地向上传播，底上不同深度处垂直湍扩散系数也具有显著的位相差异，且二者均随时间呈现四分之一周日周期的变化；5、在地形较为平坦的中央海盆区，内波活动非常微弱，因此跃层内湍流混合非常弱，垂直扩散系数为分子扩散水平，跨跃层物质通量受到显著抑制，而在地形变化较为显著的局地陆坡区，内波活动非常活跃，除内潮的影响外，高频内波与内孤立波的影响也很显著，因此跃层内存在很强的间歇性强混合，内孤立波存在的区域，水体湍流混合显著增强。

Whole-cellpatch-clamp technology demonstrated that VDPG (1g/L) had notsignificant effects on the delayed-rectified K~+ current, TTX-sensitive Na~+ current and high-voltage-activated Ca~(2+) current of rat dorsalroot ganglion cells. The fast transiet K~+ current of cottonbollworm dorsal DUM cells, the fast transiet K~+ current, Na~+ current andhigh-voltage-activated Ca~(2+) current of Periplaneta Americana dorsalunpaired median cells were also not significantly affected byVDPG at the same concentration. However, VDPG had significant effecton the fast transiet K~+ current of Pieris rapae. The VES had not significanteffects on the high-voltage-activated and low-voltage-activated Ca~(2+)current of rat DRG cells.

膜片钳电生理实验显示1g／L毒囊粗毒对蜚蠊DUM神经元的快瞬时钾电流、钠电流、高电压激活的钙电流，对棉铃虫快瞬时钾电流和大鼠DRG细胞延迟整流钾电流、TTX-S型钠电流、高电压激活的钙电流均无明显作用，却对菜青虫快瞬时钾电流有明显作用；电刺激粗毒对大鼠DRG细胞低电压和高电压激活的钙通道无明显作用。

Firstly, the two parts are solved separately, and the results are then coupled together. Because the thickness of the combustion reaction zone at high Re and Da numbers is less than the turbulent diffusion scale in diesel engines, the flame is extremely thin, its micro-structure keeps the laminar structure, so the turbulent flame can be regard as the ensemble of locally one dimensional, thin laminar flamelet embedded within the turbulent flow field.

由于柴油机中在高雷诺数和高Damkoeler数的情况下，燃烧反应区厚度小于湍流耗散尺度，火焰极薄，其微元保持层流结构，因此，湍流火焰可视为嵌入湍流流场内局部具有一维结构的薄的层流小火焰的系综，这便构成了层流小火焰模型主导思想，同时也使层流小火焰模型模拟柴油机湍流燃烧过程成为可能。

Main creative points of the thesis are as following:1. It is the first time to apply 2-D and 3-D turbulent model of the air-water two phases flow to the study on hydraulic properties of groyne. It makes description of the turbulent flow field to be possible precisely. This offers a more accurate method to determine the water surface in channel improvement.2. Based on the results of experiment and simulation for 3-D turbulent model of air-water two phases flow, a new formula to compute the height of damming is built.3. Based on the 2-D mode and the formula to compute the height of damming, the subdivision method of 2-D computation for water surface at upstream and downstream.

本文的创新工作主要是：首次将三维水气两相流紊流数学模型应用于丁坝水动力学特性研究，使丁坝附近流场和紊动场的精细描述成为可能，为航道整治中水面线确定提供了一个更为准确的方法；(2)基于水槽实验和三维水气两相流紊流数学模型数值模拟结果，建立了新的丁坝前奎水高度计算公式；(3)基于上述奎水高度计算公式和本文二维水面计算数学模型，首次提出了丁坝上下游二维水面分段计算方法。

Three turbulent models used recently have been analyzed. On the basis of turbulent random theory, the k-εtwo equations turbulent model has been modified by nonisotropic hypothesis, to accommodate the nonisotropic property of flow field.

重新推导了雷诺应力表达式，将湍动粘性系数用一个二阶张量形式表示，以适应流场的各向异性性质，并对ε输运方程的生成项做了修正。

The mean velocity distributions in turbulent boundary layers of smooth surface and two different riblet surfaces are measured with IFA300 constant-temperature anemometer in low-speed wind tunnel to validate the full development of turbulent boundary laye. Friction velocity and wall friction stress of turbulent boundary layer are obtained with the least-squares fitted curve of the sublayer velocity distribution based on Spalding formula, and virtual origin position of riblet surface can be acquired accurately.

在低速风洞中来流速度一定的情况下使用IFA300恒温热线风速仪测量了光滑表面和两种不同尺寸的脊状表面湍流边界层平均速度分布剖面，并验证了试验段湍流发展的充分性；通过应用Spalding壁面公式使用最小二乘法精准拟合了实验测量的边界层内层速度分布曲线，得到了湍流边界层壁面摩擦速度并进一步求得湍流壁面摩擦应力，较准确地计算出脊状表面的虚拟原点位置，并通过与对数律公式拟合结果比较分析，证实了该方法更加准确有效。

In order to reduce the skin friction efficiently,more research works should be done on the characteristics of turbulent boundary layer,turbulent coherent structures and the mechanism of turbulent drag reduction for flow over riblets surfaces.

为更有效地减少表面摩阻，必须深入开展对沟槽面湍流边界层特性、湍流拟序结构及湍流减阻机理等方面的研究。

Results of simulation indicate that a series of "second-vortex" are produced in the riblets structure, turbulent kinetic energy and turbulent burst intensities are debased, which reveals reasonably turbulent drag reduction mechanism.

数值仿真结果则发现，在脊状结构内形成了稳定的&二次涡&，边界层内湍动能和湍流猝发强度降低，很好地揭示了减阻机理。

Anna: No, I've got a hangover.

不是，我昨晚宿醉了。

We head into the mountains in Su's new Land Cruiser, stop for lunch at a scenic restaurant and then hang around drinking beer and eating fruit as two of his employees attempt to lure the birds with a tape recording of the fowl's mating call.

我们坐上苏的巡逻车向山顶出发，在一家风景优美的餐馆吃了中饭。然后我们喝着啤酒吃着水果四处逛。