压

This paper combines with pipeline delivery of our countrys actual conditions and other methods of detection and location. To the leakage characteristic of the fault to the long-distance natural gas pipeline, a method is raised, which is on the basis of wavelet and negative-pressure-wave to detect the leakage and locate. Jobs in this paper are as follows:Multi-resolution decomposition and reconstruction of wavelet transform is utilized to filter the noises, which the leakage brings the noises of negative-pressure-wave. The research is worked in the wavelet and wavelet packet filter. The wavelet transform have a fast and accurate recognition capability to signal singularity. This paper chooses wavelet technology to catch the break point of pressure signal.

本文结合我国管道输送的实际情况和目前现有的各种泄漏检测与定位方法，针对天然气长输管线泄漏故障的特点，提出了基于小波分析和负压波相结合的方法检测泄漏并定位，其中主要进行了以下几个方面的工作：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降噪处理，并对小波及小波包优化的降噪效果进行对比性研究；利用小波变换技术对信号奇异点的快速、准确的识别能力，捕捉负压波信号的突变点，从而判断是否有泄漏发生。

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。

Accurate understanding and calculating the total fracturing fluid leak-off coefficient is both key problem to the fracturing design and the important matter to the analysis after fracturing.

准确认识和计算压裂液综合滤失系数，既是压裂施工设计中的一个关键问题，也是压后分析评估的一个核心内容。

Studies show that the result of warm compaction is closely related with temperature and pressure.

研究表明：温压效果与温压温度的选择和温压压力密切相关。

The principle and effect of impact compaction, and its application in rockfill subgrade is introduced in this paper.

并对冲击压实的作用原理，压实功效以及冲击压实在填石路基中的应用作了介绍。

That pursue the good and fast compaction method has been a study subject in the compaction area.

追求好的压实质量、高的压实作业效率一直是压实技术领域里热点研究的问题。

Drum dimensions and rolling speed all have influences on compacting capability of a single drum vibratory compactor.

以及压轮尺寸与碾压速度都影响了单轮振动压路机的压实能力。

In the development of error compensation execution unit, different kinds of piezoelectric ceramic material are compared and selected.

误差补偿执行件的研制中，笔者选择和比较了国内主要压电陶瓷生产厂家的，不同性能的压电陶瓷材料，研制成多种压电微位移器。

The (0,1) placement variables are treated as continuous variables and then rounded after the optimization. The computational formula of the sensitivities of the freevibration frequency with respect to placement variables is derived.

在压电材料组成的桁架结构的自由振动频率优化设计中，提出了压电杆件配置的(0，1)设计变量并将其连续化处理，推导了压电桁架自振频率对该设计变量的灵敏度计算方法。

Methods Retrospectively analysis 32 cases (32 eyes) of primary retinal detachment which had accepted surgery under indirect ophthamoscope with no hand-held condensing lens.

回顾性分析32例32眼原发性视网膜脱离术中局部巩膜抵压法压陷后，不用手持聚光透镜而在间接检眼镜直视下进行巩膜外冷凝、垫压或环扎手术，临床观察统计手术效果。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。