急流

The current of the Niagara Falls rushs down cliff to come downstream and new confluent later, continue to roll in gorge buckjump, the with prep above cataract velocity of flow on the reach that in inadequacy 2 kilometers grow is horary the fall that 35.4 kilometers drop to swing and issue 15.8 meters, deduce a world to go up the maddest the the wild, most horrible, most dangerous eddy race, rush again deep the eddy pool of 38, next dragon of a flood dragon turns over, the elder brother that passes east bank Canada this, the Liweisidu of right bank United States, had rushed " devil hole race ", along final " Liweisidu affluent gorge " by enter eastwards on the west install rude lake.

尼亚加拉瀑布的水流冲下悬崖至下游重新汇合之后，在峡谷里继续翻滚腾跃，在不足2公里长的河段上以高于大瀑布的流速每小时35.4公里跌荡而下15.8米的落差，演绎出世界上最狂野。最恐怖。最危险的漩涡急流，又冲进深38的漩涡潭，然后一个蛟龙翻身，经过左岸加拿大的昆斯顿。右岸美国的利维斯顿，冲过"魔鬼洞急流"，沿着最后的"利维斯顿支流峡谷"由西向东进入安大略湖。

But they moved slowly,and all the time the river was carrying them towards the place where the water crashed twenty metres down onto rocks.

但是他们游的很慢，河水始终冲着他们向一个急流漂去，那个急流从20米高的地方掉到下面的岩石上去。

Therefore, the moist potential vorticity analysis associated with the mesoscale convective system was researched in the paper, so as to reveal the moist potential characteristics of mesoscale convective system in typhoon circulation. The results showed that, during the generation stage, convective instability characterized by MPV1 was a favorable condition for forming MCS, while the vorticity which was caused by the slantwise isentropic surface and the vertical shear of the horizontal wind characterized by MPV2 was an inspiring mechanism. The specific process was that, the atmosphere exhibited the feature of strong convective instability at the low level of convection areas and the southeast areas, which included plenty of erratic energy. The slantwise ascended the stream transfer the erratic energy to northwest, where the stratification stability was small. As decreased, the cyclonic vorticity increased. On the other hand, the vorticity caused by the slantwise isentropic surface and the vertical shear of the horizontal wind inspired the release of convective instability and as a result that the MCS formed. During the development stage, the cyclonic vorticity increased quickly with the persistent decreasing of . Meanwhile, the inclination of isentropic linewas bigger than the absolute momentum line at middle level, which exhibited the feature of conditional symmetric instability , then the conditional symmetric instability was forced to release by the vorticity resulted from the slantwise isentropic surface and the vertical shear of horizontal wind, and the MCS developed.

结果表明，在对流形成阶段，MPV1即对流不稳定为MCS的形成提供背景不稳定条件，由MPV2即湿等熵面的倾斜和水平风的垂直切变而引起的涡旋发展作为强迫机制：MCS形成的区域及东南区域中低层是强对流不稳定层，蕴含丰富的不稳定能量，倾斜上升运动把对流不稳定区具有强不稳定能量的暖湿空气向西北中层的中性层结区输送，由于的减小，气旋性涡度增强，有利于形成对流，另一方面，由于湿等熵面倾斜和低空急流加强而引起的涡旋发展作为一种强迫机制激发对流不稳定能量得到释放，从而形成对流；在对流系统地发展阶段，由于低层的对流不稳定性进一步减弱，进一步减小，气旋性涡度进一步增强，有利于MCS的增强，中层等θe 线的倾斜度比绝对动量M 等值线的倾斜度大，对应有条件对称不稳定区域，满足条件对称不稳定条件，在湿等熵面倾斜和台风低空急流作用下引起的涡旋发展强迫对称不稳定能量释放，从而使得对流得以维持和加强。

Both theory and practice analysis illustrate that stronger divergence field results from uneven distributed horizontal wind field on the right when high level current axis slopes. Owing to convectional wind convergence at low level responds to high level divergence and leads to storm.

理论和实际分析均表明：高空急流轴一旦发生倾斜，则由于其出口区水平风场的分布不均匀势必会在倾斜急流轴出口区的右侧产生较强的辐散场，由于对流风的作用，低层辐合必然会对高层辐散产生响应，诱发暴雨发生。

The results showed that erectness of coupling pattern between upper-layer jet and low jet and a divergence area, which came forth in right of upper-layer jet provide favorable surrounding conditions. The most intensive moisture convergence, the strongest ascending movement and the most instable convection stratification all occurred in the rainfall center. The rainstorm occurred at the warm and wet side of the negative value center of the moist potential vorticity and relative MPV, which had certain indicative significance for the forecast of rainstorm areas.

结果表明：高低空急流的优势配置，耦合形势的建立以及高空急流右侧的强辐散场的存在为暴雨的发生提供了有利的环境条件；暴雨区中上升运动和水汽辐合均大于周围区域，中低层为对流不稳定层结；暴雨区位于湿位涡和湿相对位涡负值中心附近偏暖湿气流一侧，对暴雨落区预报有一定的指示意义。

Analysis and a numerical simulation study are carried out to investigate the effects of surface fluxes on the development of a long-lived severe squall line that occurred on 12 July 2004 near Shanghai using the RSM-RANAL re-analysis data and WRF model.

使用水平分辨率20km的RSM-RANAL再分析资料和WRF模式，对2004年7月12日影响上海地区的一次飑线过程进行分析和数值模拟，结果表明：(1)雷暴发生区域的西北侧约300km处有一冷锋，地面风场辐合；中低层为一致西南急流，雷暴发生区域上空300h Pa位于西风急流右后侧辐散区中；地面存在明显的温度梯度。

The intensive southwest wind jet stream accompanied by the depression is not only the condition of development and maintenance of low vortex and MCC but also the transportational zone of lots of water vapor and non-stable energy.

在MCC的活动中，低空急流始终与低压相伴，急流中心强度达20m/s，急流轴较为宽广和深厚，指向低涡。在水汽和能量的聚集区，形成MCC。

Integrated analysis of 7 times heavy rain in Yunnan from July 19 to August 2 based on actual observation weather datum and satellite cloud atlas and Doppler radar image. The results show that: high-low southwest jet stream is important effect system. The maintenance of southwest jet stream provides water vapor, momentum, fast transfer of unstable energy for the lasting heavy rain. The further configuration of plateau shear line and southwest jet stream is necessarily condition about 7 times heavy rain. The lasting heavy rain appeared on big value region of 500hPa vapour flux and vapour flux divergence. The shear cloud band and subtropical high cloud band crossed and confluenced in Yunnan on the satellite cloud atlas. The maintenance and intensification of shear cloud hand and periphery cloud band of subtropical high correspond quite well to heavy rain falling region and cloud band distribution.

应用实测气象资料，结合卫星云图与多普勒雷达图像分析，对2007年7月19日到8月2日云南少有的7次强降水过程进行综合分析，结果表明：高低空的西南急流是重要的影响系统，西南急流的维持为持续性强降水过程提供了水汽、动量和不稳定能量的快速传递，高原切变线与西南急流的有利配置，是7次持续性强降水过程必不可少的条件；持续性强降水出现在500hPa水汽通量大值区和水汽通量散度辐合区；卫星云图上切变云带和副高外围云带在云南汇合，切变云带和副高外围云带维持、加强的过程与强降水落区的时空分布对应较好。

Had the Stern of the Ship been fix'd, and the Forepart broken off, I am perswaded I might have made a good Voyage; for by what I found in these two Chests, I had room to suppose, the Ship had a great deal of Wealth on board; and if I may guess by the Course she steer'd, she must have been bound from the Buenos Ayres, or the Rio de la Plata, in the South Part of America, beyond the Brasils, to the Havana, in the Gulph of Mexico, and so perhaps to Spain: She had no doubt a great Treasure in her; but of no use at that time to any body; and what became of the rest of her People, I then knew not.

经过观察，我大受鼓舞，决定第二天早晨乘第一次潮汐出发。我把水手值夜的大衣盖在身上，在独木舟里过了一夜。第二天一早，我就驾舟出发了。最初，我一出海就朝正北驶去，走没多远，就进入了那股向东流动的急流；小舟在急流中向前飞驶，可是流速没有上回岛南边那股急流那么大，所以我尚能掌握住小舟。我以桨代舵，使劲掌握航向，朝那失事的大船飞驶过去。不到两小时，我就到了破船跟前。

Just as I had set my Mast and Sail, and the Boat began to stretch away, I saw even by the Clearness of the Water, some Alteration of the Current was near; for where the Current was so strong, the Water was foul; but perceiving the Water clear, I found the Current abate, and presently I found to the East, at about half a Mile, a Breach of the Sea upon some Rocks; these Rocks I found caus'd the Current to part again, and as the main Stress of it ran away more Southerly, leaving the Rocks to the North-East; so the other return'd by the Repulse of the Rocks, and made a strong Eddy, which run back again to the North-West, with a very sharp Stream.

我刚竖起桅杆张好帜，船就开始向前行驶了。我发现四周水色较清，知道那股急流在附近改变了方向。因为，水急水则浊，水缓水则清，我知道那股急流在这儿已成了强弩之末了。不久我果然发现，在半海里以外，海水打在一些礁石上，浪花四溅。那些礁石把这股急流分成两股，主要的一股继续流向南方，另一股被礁石挡回，形成一股强烈的回流，向西北流回来，水流湍急。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。