查询词典 pressure point

At the same time, combining with the actual condition of delivery pipeline of our country and some prevalent leak detection and location methods, this paper raised a method, which is based on wavelet analysis and negative- pressure-wave to detect and locate the leakage. Jobs in the paper are as follows:As affected by gas density, pressure, specific heat and pipe material, the velocity of negative-pressure-wave improved depending on the energy conservation. At one time, taking the affection of velocity of gas flow, the location formula was modified in some degree.When locating the leaks with location formula, the iterative approach algorithm was adopted as a new method to increase the location accuracy level of system.Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of At in location formula, accordingly improved the location accuracy.Wavelet is a suitable tool for signal analysis. The distinct character is that the mother-wavelet is of optional. That means choosing different mother-wavelet will get different analysis result. So we studied how to choose mother-wavelet and its scale for signal singularity detection. The method is to choose a wavelet by regularities of the wavelet and the signal.Finally, a plan, which bases on SCADA system for inspection and detection of natural gas leakage, is proposed in the article.

其中，主要进行了以下几方面的工作：针对泄漏产生的负压波在管道中的传播速度受媒介的密度、压力、比热及材质等因素的影响，而非声波在空气中传播的速度，本文利用能量守恒原理，对其进行了修正；考虑到管内气体流速对压力波速的影响，对原始的负压波定位公式进行了一定程度的改进，并在利用定位公式进行泄漏点定位时采用逐步迭代逼近算法，提高了系统的定位精度；利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了降噪处理；并利用小波变换技术对信号奇异点的快速、准确的识别能力，对经上述消噪后的负压波信号进行了奇异点捕捉，精确捕捉的结果提高了定位公式中上下游站点采集到的负压波奇异点的时间差△t的精度，从而进一步提高了定位的精度；考虑到小波变换是一种基波可变的信号分析工具，也就是说，不同的小波基波对信号分析的结果将有很大差别，这势必影响最终的处理结果，因此，我们又对比分析了本课题中小波基及尺度的选择问题，依据规则性系数相似性原理对母小波的选择进行了探索性研究；最后，还提出了基于SCADA的泄漏检测与定位系统的软件开发构想及系统的嵌入方案。

Based on the item of national high technology development project, the thesis studies the reasonable construction pattern of the tunnel portal, incidence of the micro-pressure wave and the the effect of bell-mouthed hood, lacunaris hood and expansile hood on alleviating the micro-pressure wave in the situations of single line and double line, obtains the relationship between the max micro-pressure wave and the velocity of the train as well as the relationship between the max micro-pressure wave and distance of measuring point at the velocity of 100km/h-550km/h, compares the different alleviative effect of the three different hood to max micro-pressure wave and finally proposes the reasonable construction pattern of the tunnel portal.

本文针对国家高技术研究发展计划(863计划)课题"磁浮交通沪杭线越黄浦江隧道的工程技术问题研究"，在单洞单线和单洞双线两种工况下，对隧道洞口的合理结构形式和影响范围，以及洞口喇叭形入口缓冲段、多孔壁入口缓冲段以及隧道出口膨胀室对减缓微压波的作用进行了研究，得到了磁浮列车速度在100km/h～550km/h时隧道出口微压波最大值与速度的关系以及微压波最大值与测点距离的关系，比较了三种不同形式缓冲结构对微压波最大值的减缓效果，提出了隧道洞口的合理结构形式。

Based on the basic solutions of the pressure response of point source in infinite space, pressure responses at any point in a horizontally infinite reservoir are studied.

以无限空间点源压力响应的基本解为基础，研究了水平方向无限大油藏在任意位置的压力响应，从测压点位置、等价压力点、多解性的解决办法等方面探讨了水平分支井的试井解释方法。

To exam the validity of the Bloch-Grüneisen formula at megabar pressures, we use the electrical conductivity data point of ε-iron at relatively low pressure (～40GPa) reported by Keeler as a reference point, a formula for calculating the conductivity of the ε-iron under high-pressure and temperature was deduced via Bloch-Grüneisen,where v is specific volume , T is temperature and σ is electrical conductivity .

为了检验Bloch-Grüneisen公式在兆巴压力冲击压缩下的有效性，本文取Keeler在较低压力下ε相区的一个电导率数据作为参考点，得到了Bloch-Grüneisen公式关于ε-铁在高温高压下电导率的一个解析表达式：σ=〓，这里，比容v的单位是cm〓/g，温度T的单位是K，电导率σ的单位是Ω〓cm〓。

By using the calculated results of EET theory, the local valence electron structure elements of residual chemical bonds of Al-Si and Mg-Al alloy melts, that is, the residual bond structure models, were established. From the viewpoint of effect of pressure on melt structure, the essential reason of deviation phenomenon for maximum solution point and eutectic point in thermodynamics equilibrium phase diagram was analysed. Moreover, under pressure condition, the change of thermodynamics equilibrium phase diagram was macroscopic reflection of microstructure change of alloy melt.

运用固体与分子经验电子理论的计算结果分别建立Al-Si、Mg-Al两种合金熔体的剩余化学键的局域价电子结构基本单元即残余键结构模型，从压力对熔体结构作用的层面，分析热力学平衡相图中最大固溶点和共晶点发生偏移的本质原因，并指出压力作用下热力学平衡相图的变化是合金熔体微观结构信息变化的宏观反映。

Firstly, a signalized point is stuck on a moving object to be tested, a microphone array and two video cameras are arranged, and the video cameras are demarcated to obtain a projection matrix; sound pressure signals of a sound source in the moving object to be tested are obtained by the microphone in an array mode, the dynamic video of the moving object to be tested is obtained and disassembled into an image by the video cameras; the signalized point on the moving object to be tested is identified in the video image and the matched signalized point is treated with three-dimension reconstruction to obtain the spatial location of the moving object to be tested; the sound pressure signals are treated with beam forming treatment to obtain a sound field characteristic function scattergram of the moving object to be tested, the video image is treated with spatial coordinate superposition frame by frame and restored into a dynamic video image.

首先在被测运动物体粘贴标志点，布置传声器阵列和两台摄像机，对摄像机进行标定，得到投影矩阵；传声器阵列获取被测运动物体中声源的声压信号，摄像机获取被测运动物体的动态视频，将动态视频拆解成图像；在视频图像中识别出被测运动物体上的标志点，对匹配后的标志点进行三维重构，获取被测运动物体的空间位置；对声压信号进行波束成型处理，得到被测运动物体的声场特征函数分布图，将其视频图像进行逐帧空间坐标叠加，并还原成动态视频图像。

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。

In order to prove this point, Ratchet inferior lubricative solenoid valve core, manually put it on the oil lubrication, at which point it can be seen rising oil pressure drop, and exceeded the original value; successive pressing the lubricating oil pressure of the solenoid valve, can rise to 0.4 or even more, not by this confirmation oil pressure rise and oil pump surface temperature is too high because the machine cannot be automatically put oil lubrication.

为了证实这一不面，用起子底下润滑电磁阀的阀芯，手不静使其不收油润滑，此时可见油压回落后即上落并超功本来值；不断众次按不静润滑电磁阀后，油压竟可上落至0.4甚至以上，由此不否认油压落不矮和油泵暗地温度功矮的来因在于机械不克不及自不静举行不收油润滑所致。

Root canals of the experimental group were filled with gutta percha point plus Cortisomol paste in lateral pressure way.Root canals of the control group were filled with gutta percha point plus Zinc Oxide-engenol paste in lateral pressure way.

实验组用Cortisomol糊剂加牙胶尖侧压根管充填，对照组用氧化锌糊剂加牙胶尖侧压根管充填。

The contact-point pressure must be within specifications, since low point pressure will allow the points to Bounce and Burn, and high pressure will cause rapid wear of the points, cam, and rubbing Block.

接触压力计：触点压力必须符合技术要求，因为触点压力低会使触点产生跳振和烧毁触点压力高会加快触点凸轮和顶块的磨损。

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。