推球

As the complete characteristic curves of reversible pump turbine are often used to calculate the instantaneous parameters, this paper studies the characteristic curve and the wicket closure and opening law in pumped storage plants.Chapter 1 presents the importance and the necessity of this study and reviews the previous related research on hydraulic transient process and valve regulation in pumped storage plants.Chapter 2 analyzes the six collected characteristic curves of reversible pumped turbine and studies their diversification from the point of view of specific speed. The six collected discharge and moment curves with maximum efficiency have been fitted to piecewise continuous curves. This curve-fitting procedure is listed.Chapter 3 takes Liyang Pumped storage plant as an example and analyzes the effect of different characteristic curves on regulation guarantee parameters and the variety of its trochoid during the same operation status.Chapter 4 takes three pumped storage plants with different heads as examples and studies the characteristic of coordinated closure with wicket gate and ball valve and its effect on dynamic pressure in the spiral case, inlet pressure in the draft tube and the rise of rotating speed.Chapter 5 summarizes this paper and point out what should be done in the future research.

由于在过渡过程分析计算中，需要频繁利用可逆式机组的全特性曲线推求机组的瞬时参数，所以本文就特性曲线及关闭规律问题进行了研究，其主要内容如下：第1章，指出本文研究的意义和目的，回顾前人对水力过渡过程、抽水蓄能电站及阀调节的研究成果，在此基础上提出本文的研究内容；第2章，针对收集到的六套特性曲线，从比转速的角度出发来研究可逆式机组特性曲线的变化规律；并对六套曲线的最高效率流量和力矩曲线进行分段拟合，得到各分段函数的具体形式，再通过举例说明最高效率曲线的拟合步骤；第3章，以溧阳抽水蓄能电站为实例，分析讨论不同比转速特性曲线对调保参数造成的影响及对于相同工况其轨迹线的变化；第4章，结合高、中、低三水头段抽水蓄能电站，在导叶直线关闭的基础上，研究导叶与球阀协联关闭规律的特点及对蜗壳动水压力、尾水管进口压力及转速上升造成的影响；第5章，总结全文，提出今后研究的重点和方向。

There are a colony of dung beetles in the forest. They trundle sphere of the dungs working hard everyday.

森林里住着一群勤劳的屎克郞，它们每天推着粪球辛勤地工作着。

They trundle sphere of the dungs working hard everyday .

森林里住着一群勤劳的屎克郞，它们每天推着粪球辛勤地工作着。

On Friday, in a frigidly cold, wind-whipped Yankee Stadium, that something pushed the Yankees to a 5-1 win over the Mariners – and stemmed a three-loss, bad-news streak.

星期五在寒冽风儿呼呼地吹著的洋基球场上，有些事儿发生推引著洋基以五比一击败了水手队，阻挡了三连败和一连串的坏消息。

While your nondominant hand drives forward and gives your shot its power, your dominant hand helps put spin on the ball.

你的辅助手向前推拍并发出击球所需的力量，而主控手使球旋转。

While your nondominant hand driv es forward and gives your shot its power, your dominant han d helps put spin on the ball.

你的辅助手向前推拍并发出击球所需的力量，而主控手使球旋转。

Drawing of the side syndiospecific pressure sphere of axis, as installed in the bucket, in production operation, may drop of liquid water on, plus the fact that after transmission and paerboard paper′s of chaetomium, cards and membership cards make dusting, and so on from pollution caused by the secable set.

侧规不推纸压球的轴心，由于安设在水斗的底下，在出产本质操纵历程洋，不定会滴上水斗液，加之经过负纸不活带来的的纸毛、制卡和会员卡制息喷粉等尘埃的浑浊而导致生锈咬不松。

The exceeding beauty of the earth, in her splender of life, yield a new thought with every petal.

过头L爬a球，伫伊玥o光版囥R里，推一款新想法予逐块花瓣(pan7)按呢生。

A silly one among them who had made a square of dungs. Others move sphere with ease, but he had to go to great lengths to push his square forwards.

其中有一只傻乎乎的屎克郞做了个四四方方的粪球，当别人轻松自如地推着前进时，它却费力得要死。

Manhandling referees, making fascist salutes and scoring spectacular goals was all in a day's work for the forward with the shortest fuse in Italy. West Ham fans adore him, the rest of us worry about his fascination with fascism –"I am a fascist, not a racist," Di Canio said. That's all right then.

手推裁判，行法西斯礼，进怪诞异常的球，他是意大利导火索，但西汉姆的球迷就是崇拜他，其他地方的英国球迷则为他的言论感到困扰：&我是法西斯主义者，但我不是种族主义者！&

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。