四分之三

In the second chapter, We obtain some linear estimates, trilinear estimates .

在第二章中，我们得到线性估计和三线性估计，然后证明了四分之一平面上的modified Korteweg-de Vries方程的局部适定性。

The numerical results based on this algorithm show that it is possible to obtain a reasonable recovery of the shape of the three-dimensional obstacle from the incomplete far-field measurements for low wavenumbers even when the observation range is as small as the quarter of a unit sphere.

基于这个算法的数值模拟表明了，对较小的波数，即使只用测量范围为四分之一单位球面范围中少量测量方向上的信息，得到三维障碍物的一个合理的重构也是可能的。

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。

Model of "pavement surface-vehicle-human"vibration system is established,and the representative one-quarter automobile model with three degree of freedom is introduced to carry out dynamic analyses of the vertical vibration system.

建立&路面—车辆—人&振动系统模型，选择有代表性的三自由度四分之一车辆模型对其进行竖直方向振动系统的动力分析。

That love affair translates to big consumption: The U.S. slurps up to a quarter of the world's oil—about three gallons (11 liters) a person every day—even though it has just 5 percent of the world's population.

这种酷爱也随之带来了巨大的消耗量：尽管美国人口只占世界人口总数的百分之五，但却消耗了世界上四分之一的原油--大约每人每天消耗三加仑(11升)。

Others, representing the safer, more conventional wisdom, will insist that all the constitutional compromise on slavery—the omission of abolitionist sentiments from the original draft of the Declaration, the Three-fifths Clause and the Fugitive Slave Clause and the Importation Clause, the self-imposed gag rule that the Twenty-fourth Congress would place on all debate regarding the issue of slavery, the very structure of federalism and the Senate—was a necessary, if unfortunate, requirement for the formation of the Union; that in their silence, the Founders only sought to postpone what they were certain would be slavery's ultimate demise; that this single lapse cannot detract from the genius of the Constitution, which permitted the space for abolitionists to rally and the debate to proceed, and provided the framework by which, after the Civil War had been fought, the Thirteenth, Fourteenth, and Fifteenth Amendments could be passed, and the Union finally perfected.

其他人则表现出更保守、更传统的明智，坚持认为所有对奴隶制度在宪法上的妥协——在《独立宣言》，《五分之三条款》，《逃奴条款》和《进口条款》的原始草案中缺乏废奴主义者的意见和看法，第24届美国国会常常在所有关于奴隶制度问题的辩论中，自己强加给自己规定，要求限制这方面的言论自由。联邦制度和参议院的构成体系是一个必要的联邦组成机构；创建宪法者没有对此发表意见，他们认定奴隶制度终究会终结，而他们只是试图寻求推迟这个进程；这一个小小的失误并不能贬低《美国宪法》的本质，它也为废奴主义者提供了重整旗鼓的空间，使得争论得以继续下去，而且提供了立法框架，通过这个框架，在美国南北战争结束后，第十三、第十四、第十五宪法修正案得以通过，我们的联邦最终得到了完善。

Andy Murray, with Ricky Hatton in the stands, outfought and out-thought Rafael Nadal, who limped out of their Australian Open quarter-final, trailing 3-6, 6-7 (2-7), 0-3 and with his chronically troubled knee throbbing painfully.

伴随着 Ricky Hatton 的在注视，安迪·穆雷以三盘6-3，7-6（7-2），3-0的比分击败了拉斐尔·纳达尔。纳达尔因为膝盖的旧伤复发疼痛难忍，推出了本届澳网的四分之一决赛。

Three times ranking events quarter-finalist having the best season in his career so far, from Nortingham, here comes the "hitman", Michael Holt!

三次打进排名赛的四分之一决赛进入了生涯中最好的赛季。来自诺丁汉，&杀手&来了！迈克尔·霍特！

I was three runs into a seven-run practice session on the quarter-mile course.

要在一个四分之一英里赛场进行的7圈训练赛中跑三圈。

Mitsubishi did not release figures related to either the car's acceleration, top speed, or quarter-mile times.

三菱没有公布有关的数字无论是汽车的加速，最高车速，或四分之一英里倍。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。