在水下

However, the underwater is more execrable compared with the land or space, and more dangerous for human. So as a replacer underwater robot is being used in practical operations more and more.

然而，水下环境与陆地和空间环境相比更加恶劣，对人类的威胁更大，因此水下机器人作为人的替代者，正在越来越多地在实际水下操作中应用。

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。

Using maximum flooding surface and local explosure erosion surface as the correlation framework surface in the 4-th hierarchical base-level cycles, sand-body in the 3-th hierarchical base-level cycles formed in the 4-th hierarchical base-level cycles may be correlated layer by layer. The law of the sand-body and the characters of reservoir heterogeneity formed in the 4-th hierarchical base-level cycles are discussed. The study shows:①During early period of the 4-th hierarchical base-level cycle rising, subaqueous distributary channel formed, continuously stacked vertically, and migrated in limit range laterally, and channel sand-body stretches farther longitudinally, and lacks interbeds of mud rock and siltsand in sand rock, reservoir heterogeneity is relatively weak.②During mid-period of the 4-th hierarchical base-level cycle rising, subsaqueous distributary channel migrated actively, channel divided and converged strongly to form netted sand-body and sand sheet mainly, but interbeds of mud rock and siltsand increases gradually in sand-body, reservoir heterogeneity increased.③During later period of the 4-th hierarchical base-level rising and early period of the 4-th hierarchical base-level falling, reservoir sand-body was poor, and only form thin sand-body of subsaqueous distributary channel, subsaqeuous creveas and distal mouth bar, sand-bodys are surrounded by mud and silt rock.

进一步采用以第4层次基准面旋回中相当最大湖泛面的相转换面和具有区域性暴露侵蚀作用的层序边界面为等时地层对比框架的边界，对发育于MSC2—MSC4三个第4层次基准面旋回的第3层次基准面旋回内砂体进行了逐层等时对比，探讨第4层次等时地层对比格架内储集砂体发育分布规律，及储集砂体的非均质性特点，研究发现：①第4层次基准面上升初期发育的水下分流河道，砂体呈连续叠置、侧向迁移受限，纵向上呈长距离延伸的带状产出，砂体间泥、粉砂岩夹层少，储层非均质性相对较弱；②在第4层次基准面上升中期发育的水下分流河道侧向迁移活跃，纵向延伸过程中分流汇合作用强烈，以形成网状或席状连片砂体为主，但砂体间泥、粉砂岩夹层逐渐增多，储层非均质性增强；③第4层次基准面上升晚期和下降早期，不利于储集砂体发育，仅出现少量薄的水下分流河道、水下决口扇、远—河口砂坝砂体。

Based on the experiment platform of underwater vehicle control system made by ourselves, an underwater demonstration experiment system is developed with forward-looking cameras and man-made targets. Underwater demonstration experiments with the two station keeping methods are made in an indoor experimental pool.

以自行研制的水下机器人控制系统实验平台为实验载体，利用前视摄像机和水下人工目标，建立了水下演示实验验证系统，并在室内实验水池中，分别实现了两种悬停方法的水下演示实验。

There is a low-head runoff electric station at lower reaches of principal river and the workshop is the style of riverbed. A successful example of dredging tail water riverbed with the blasting technology in an electric power plant is introduced with the measure of drilling dynamite for enhancing dynamoelectric benefit in the paper. The construction process flow, detonating parametric design and the security issues of the underwater demolition are discussed in detail and it will give light to the similar project.

摘 要：位於下游干流上某水电站是一座低水头径流式电站，厂房为河床式，为了提高机发电效益，本文结合了在某电厂用爆破法疏挖尾水河床的成功实例，利用钻孔爆破法对水下爆破进行施工，分别介绍了在该工程中进行水下爆破施工的施工工艺流程、爆破参数的设计以及水下爆破安全校核方面的内容，可供类似爆破工程借鉴。

There is a low-head runoff electric station at lower reaches of principal river and the workshop is the style of riverbed. A successful example of dredging tail water riverbed with the blasting technology in an electric power plant is introduced with the measure of drilling dynamite for enhancing dynamoelectric benefit in the paper. The construction process flow, detonating parametric design and the security issues of the underwater demolition are discussed in detail and it will give light to the similar project.

摘 要：位于下游干流上某水电站是一座低水头径流式电站，厂房为河床式，为了提高机发电效益，本文结合了在某电厂用爆破法疏挖尾水河床的成功实例，利用钻孔爆破法对水下爆破进行施工，分别介绍了在该工程中进行水下爆破施工的施工工艺流程、爆破参数的设计以及水下爆破安全校核方面的内容，可供类似爆破工程借鉴。

The re is a low-head runoff electric station at lower reaches of principal river and the workshop is the style of riverbed. A successful example of dredging tail water riverbed with the blasting technology in an electric power plant is introduced with the measure of drilling dynamite for enhancing dynamoelectric benefit in the paper. The construction process flow, detonating parametric design and the security issues of the underwater demolition are discussed in detail and it will give light to the similar project.

摘 要：位于下游干流上某水电站是一座低水头径流式电站，厂房为河床式，为了提高机发电效益，本文结合了在某电厂用爆破法疏挖尾水河床的成功实例，利用钻孔爆破法对水下爆破进行施工，分别介绍了在该工程中进行水下爆破施工的施工工艺流程、爆破参数的设计以及水下爆破安全校核方面的，可供类似爆破工程借鉴。

The re is a low-head runoff electric station at lower reaches of principal river and the workshop is the style of riverbed. A successful example of dredging tail water riverbed with the blasting technology in an electric power plant is introduced with the measure of drilling dynamite for enhancing dynamoelectric benefit in the paper. The construction process flow, detonating parametric design and the security issues of the underwater demolition are discussed in detail and it will give light to the similar project.

摘 要：位于下游干流上某水电站是一座低水头径流式电站，厂房为河床式，为了提高机发电效益，本文结合了在某电厂用爆破法疏挖尾水河床的成功实例，利用钻孔爆破法对水下爆破进行施工，分别介绍了在该工程中进行水下爆破施工的施工工艺流程、爆破参数的设计以及水下爆破安全校核方面的内容，可供类似爆破工程借鉴。

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。