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Because the temperature along the pipeline is not a constant, it changes the velocity of the negative-pressure-wave; the Romberg algorithm of numeric integral and the searching for algorithm are emloyed to locate the leakage.Multi-scale decomposition and reconstruction of wavelet transform is applied 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 Δt in location formula, and the location accuracy is improved.

利用小波变换的多分辨分析和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了消噪处理；并利用小波变换技术对信号奇异点快速、准确的识别能力，对经过消噪处理后的负压波信号进行了奇异点捕捉，准确确定了定位公式中上、下游站点采集到的负压波奇异点的时间差△t，从而提高了定位的精度。

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。

Social economic development has brought about rapid growth of catering industries, competition and pressure as well.

社会经济水平的提高带来了餐饮业的迅猛发展，但也带来了更多的竞争和压力。

Sadly he had been brought up far from the grassy savannas of his homeworld Cathar and out of reach of the galaxy's more prosperous regions.

遗憾的是，他成长的地方远离母星卡瑟的大草原，与银河系较繁荣的区域也相去甚远。

The first time I was brought into contact with MSTC started with the first cathedra about programming technology,which was initiated by MSTC technology department.

第一次近距离接触到MSTC是在编程技术版第一次版聚的时候，那次虽说是版聚但却是MSTC技术部主办的。

This paper deals with the phosphor used in FED, which works based on the principle of special cathodoluminescence. A processing method brought forward is that green phosphor ZnS:Cu,Al coated with a layer of SiO_2 film by sol-gel method.

针对用于FED的荧光粉应该是适合FED特殊工作机理的专用阴极射线激发发光材料，提出一种以绿色荧光粉ZnS：Cu，Al为基质，采用溶胶-凝胶法在其表面包覆一层SiO2薄膜作为FED用荧光粉。

Over the weekend of January 30-31, I brought the cabinet and senior White House staff to Camp David, the presidential retreat in Maryland's Catoctin Mountains.

1月30日和31日是周末，我把内阁成员和白宫高级官员带到了戴维营。戴维营位于马里兰州凯托克廷山中，是总统的度假地。

Based on accumulation of long-term experiences, CATT brought up "Regional Conservation Plan of Historic Area in Tamsui" as follow-up proposition for historic preservation and urban design mechanism.

基於长期的经验累积，於2007年提出「淡水历史风貌区域保存计画--保育型的都市设计计画」，作为后续有关於古迹保存与都市设计机制的建议。

Situated In urban fragmentation, CATT brought up a guideline of actions--"constructing Tamsui cultural map as regional renovation strategy".

在断简残篇的都市处境中，提出「淡水文化地图建构作为地域活化策略」作为行动纲领。

I should not so causticity, still, we all are brought up by eating rubbish.

不过想想也是，大家都是吃屎长大的，何必对人家如此刻薄。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。