不变化

The phase of ω0 frequency fluctuates tempestuously. The resonance peaks of flexural and torsional vibrations response are present at 2/3ω0 1/2ω0 1/3ω0 and 1/4ω0 with three kinds cracked rotor models. Near 1/2ω0 frequency, quasi-periodic and chaotic motions maybe appear. Periodic, quasi-periodic and chaotic motions show on alternately when the rotating speed is near to 2/3ω0.Combined step-by-step integral method with traditional transfer matrix method, an increment transfer matrix method is put forward.

研究结果表明：各种故障情况下，华北电力大学博士学位论文弯振和扭振之间都存在祸合关系，但弯扭祸合振动一般不会威胁机组安全运行：在叶片丢失或滑环飞脱故障时，将产生很大的弯振，同时各转子扭振也将被激发出来，它以工倍频和前三阶固有频率为主；在各种电气故障情况下，各转子都很快被激励出较大幅值的扭振来，相应各转子弯振也发生一定的变化，但它的变化明显滞后于扭振，扭振和扭矩主要以前三阶固有频率为主。

The heat capacity of the cold and hot points of said thermopile together with its mounting and the heat conductivity of said mounting are co-ordinated with each other in such a way that a change in the temperature of the housing causes an equal change in the temperature of the cold and hot points, so that no temperature gradients occur inside the thermopile.

热电堆的冷端和热端及其支撑结构的热容量与支撑结构的热导率相互协调，以便壳体的温度变化引起冷端和热端同等幅度的温度变化。也就是说，所述热电堆中不存在温度梯度。

The results of simulation make clear that the platform is incapable of colliding knightheads, and the variation rate of length of tightwire to obliquity of platform comes near to linearity, when the obliquity of platform varies form 0° to 300°.

仿真结果表明，台面倾角在0°～300°变化时，台面不碰撞立柱，且柔索伸缩长度与台面倾斜角度接近于线性变化。

And this causes a frequency change Δf. The resonant point tracing algorithm describes how to detect Δf. So it can introduce a feedback frequencydifference -Δf through a closed loop to realize the resonant state o In the digitaldetection scenario, using staircase wave to replace saw tooth wave, it can overcome a lot of shortcomings in the analog system. The character of the staircase wave affects the detection precision directly. This thesis analyzes a high precision scenario producing a staircase waveform in detail. It can reduce the number of the bits in D/A converter greatly. This thesis proposes another method to improve the detection precision in case that the A/D converter has comparatively little number of bits, while this method will not increase the cost of the system greatly.

在谐振式光纤陀螺中，环形谐振腔的旋转使得谐振腔的谐振频率发生了变化，从而产生了一个与旋转速度成正比的频率变化值△f，谐振点跟踪算法描述了如何检测出△f，从而可以通过闭环在系统中引入反馈频差-△f，实现光路的谐振状态；在数字闭环检测方案中，用阶梯波作为反馈信号来代替锯齿波，可以克服原来模拟系统中锯齿波的很多缺点，阶梯波的性能直接影响着系统的测量精度，本论文详细分析了一种高精度阶梯波生成方案，使得所需D／A的位数大大降低；本文还分析了A／D转换器对系统测量精度的影响，提出了一种A／D转换器位数较少的情况下提高系统测量精度的措施，同时又不会增加太多的系统成本。

In order to conquer the threshold method's shortages,the threshold function is further improved through the simulation of channel's noise based on the translation invariant wavelet,which makes the threshold...

为了克服阈值法的不足，在平移不变量小波阈值去噪法的基础上，通过仿真低压电力线信道噪声，对阈值函数进一步改进，使阈值的变化与噪声的小波变换随尺度的变化特性相一致。

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。

Along with the fast-changing surrounding, Enterprise"s DRP system has to reengineering constantly. Traditional DRP system don"t have such flexibility that self-changing with external environment, this causes the organiziations structure and operation mode being rigescent and unadaptable, and then make the enterprise finally be wash out.

随着市场环境的迅速变化，企业分销体系需要不断的进行业务流程重组，然而传统的分销系统显然不具备这种应变能力，从而导致企业的组织体系和运作方式僵化，难以适应变化而遭淘汰。

By the changing tendency of N, P, K, we coudle see N, P decreased significantly, especially P, the concentration of which was deficient for Chinese Fir nomal growing, but K nutrients were unnoted. So we suggestted increasing N, P fertilizer for Chinese Fir normal growing and might rise its yield.

由N、P、K的变化趋势可以看出，在杉木生长的整个周期，N、P含量降低明显，特别是P，其含量远低于杉木生长所需要的P含量的临界值，处于严重缺乏状态，K含量变化不明显，因此，建议在生产中增施N、P肥，以保证杉木正常生长，提高产量。

While global warming is undoubtedly an important factor, it does not fully account for these extreme and unusual weather patterns.

全球变暖无疑是气候变化的一个重要因素，但是它却不能完全解释这些异常和极端的天气变化。

The wavelet variance verification also indicates that the first main period of the runoff of mountainous watershed in the Shiyang River Basin is 30years, and 22years and l5years are the second and third period respectively; 3 Then we also compared the total runoff of mountain watershed with climate factors of Wushaoling which station is in the mountain headstream area, such as precipitation and temperature, the data record that the correlation coefficient of annual runoff and precipitation variation over the upper reaches in the Shiyang River Basin is 0.61 ,which indicates precipitation is the main water recharge of the runoff.

石羊河流域出山口年径流的周期变化与乌鞘岭站年降水量和年均气温周期基本上都能在同一周期上下浮动，其中出山口年径流量与乌鞘岭山区年降水量相关系数为0.61，说明地表径流量主要是由山区降水补给；年径流量与山区年均气温变化呈0.28的反相关，说明该流域近50年来出山口径流与山区气温呈反比，即径流量随年均气温上升而减少，相关性暂时不十分明显。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。