在水下的

The paper elaborates the construction of underwater cofferdam which is based on gravels.

对在砂砾石基础上填筑水下围堰进行了阐述，水下围堰的砂砾石基础采用砂砾石帷幕灌浆进行防渗，从理论、实践等多个方面分析了其可行性。

Two methods of correlation of parasequence are put forward in fan delta and near shore sub-water fan sedimentary environment.

提出了在扇三角洲和近岸水下扇沉积环境中沿物源方向的相序递变对比法和垂直物源方向的侵蚀叠置对比法2种准层序对比模式以及在扇三角洲沉积环境中沿物源方向的扇三角洲前缘亚环境中的层组相变对比模式和近岸水下扇环境中叠置砂体对比模式、相变对比模式、薄砂层对比模式、相似渐变等5种层组对比模式。

Firstly, this paper analyzes the forces acting on hydrobomb's body and empennage respectively. Then the mathematical model of hydrobomb's trajectory in seawater is discussed. Secondly, the simulation program is completed with Matlab.

分析了空投水雷水下无动力运动过程中雷体和尾翼的受力情况，并在运动受力分析的基础上给出了研究其水下散布的数学基础－水下无动力运动弹道仿真数模。

This dissertation's main work and innovations is following: 1. The 6DOF kinematic and dynamic equations of motion for multiple thrusters AUV are derived and presented in a compact form using vector notation. The hydrokinetics of the MTAUV is classified anew. The MTAUV has two kinds of work modes which are cruising and hovering. The fluid dynamical mathematics description of the MTAUV is given anew. 2. The kinetics equations of the MTAUV in the low speed hovering are analyzed and studied.

本文主要的工作和创新点主要有以下几个方面：一、采用矢量参数的形式建立了基于多推进器自主水下航行器的六自由度运动学方程和动力学方程；对基于多推进器自主水下航行器的流体动力进行了重新分类，给出了基于多推进器自主水下航行器在巡航工作模式和悬停工作模式两种不同工作状态下流体动力的数学描述。

20X50y on :50, odds 15m kick underwater, then swim through turn and entire second 25 under on the way back; evens 25 kick under surface, one stroke away from wall turn and hold 15m kick underwater off turn.

前25码，出发时做一个水下15米小幅度蝶泳腿的滑行，然后游完剩下的十米，转身后一口气踢水下25码；再完成25米的回程匀速蝶泳腿后，在距壁一划远的地方开始转身，然后接一次水下15码的小幅度蝶泳腿滑行。

I n the end, embedded motion control system in vx Works and the active diagnosis and fault-tolerant control system are developed in this paper, with the results of simulation and the trial in a lake.

最后探讨了嵌入式运动控制系统，给出水下机器人运动控制系统在vxWorks下的实现，建立水下机器人动态故障诊断与容错控制系统，并给出仿真结果和湖试试验结果。

The model of mine's trajectory is built,and the model of wallop is built.Then the underwater trajectory of the airdropped mine is simulated by Matlab/Simulink.At last,This paper gets the result of simulation and analysis.

在建立了六自由度的水雷水下弹道数学模型和水雷入水击水力计算的数学模型基础上，通过实例对水雷的水下弹道在Matlab/Simulink环境下进行了仿真计算，最后给出相应的仿真结果和分析。

The underwater gun's bore pressure test system is built by experimental equipments and measurement instruments. A lot of experiments are carried out with this test system.

根据水下枪械的特点，组建了水下枪械坡膛压力测量系统，在此基础上做了大量实验。

It is demonstrated that the vehicle can achieve station keeping under the closed loop control of the two proposed methods in the presence of man-made abrupt disturbances and current disturbances.

演示实验表明：在两种视觉悬停方法的闭环控制下，水下机器人能够抵抗恒定水流干扰和人工位置扰动，很好地实现水下悬停作业。

Herakleion and Menouthis were rich and proud cities until something reduced them to rubble and buried them in the mud beneath 30 feet of sea water, French underwater explorer Franck Goddio said at the American Geophysical Union conference

法国水下探险家Franck Goddio在美国地球物理联合会大会上说，一些不明物质使Herakleion城和Menouthis城分化为碎石并被埋到35英尺深的水下，在这之前这两座城市一直十分富足并让人引以为荣的。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。