在传播中

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。

The extracted P-wave is reverse-time extrapolated and imaged with a P-velocity model using a finite difference solution of the scalar wave equation, the extracted S-wave is reverse-time extrapolated and imaged similarly, but with an S-velocity model, and converted S-wave data requires a polarity correction prior to migration to ensure constructive interference between data from adjacent source.

在模型中，每个网格点的纵、横波成像时间，为震源到该网格点的纵波初至时间。利用纵波速度模型和声波传播方程的有限差分解，对反射纵波进行逆时延拓和成像，利用横波速度模型和声波传播方程的有限差分解，对转换横波进行逆时延拓和成像，并在偏移前进行极性校正。

Humanism" carried out in archival information communication is not only meant to follow with interest the audience's daily practical needs of archives and esthetic demands, but also, even more basically, meant to encourage the audience's consciousness and willingness of receiving archival information rather than their involuntariness and utilitarianism. The real essence in the communication effects of archival information lies in developing the audience's high-level esthetic view, archival sensitiveness and "EQ for seizing the value of archival information. On the other hand, the humanity in archival information itself, democracilization in the society and the advances of human spirits have all laid a solid foundation for the development of esthetic culture of archives.

在档案信息传播中贯彻"人本主义"，不仅指关注受众日常功利性的档案需要和审美情趣的要求以及传播者对这些需要和审美情趣的迎合与顺应，更根本性的在于促使受众对档案信息的接受超越实用功利性和工具性行为的限定，上升到一种自觉的境况，培养和引导受众形成较高水准的审美观念，从而增强对档案信息传播的敏感度和把握档案信息意义的"情商"，通过接受档案信息触发美好情绪和有益思考，充实和完善自身，这才是理想的档案信息传播效果应有之义。

Using this theory, the flame structure of gas explosion in a horizontal pipe were studied, and the results show that: the gas explosion flame in a horizontal pipe is much thicker than that calculated from the former explosion theory, the intermediate products in the flame region are in separated state between the higher and lower level, and the cohesive force of the luminous body at lower level is bigger than that of the nonluminous body at higher level, there is a negative pressure region in the flame, and the flame splits easily in its propagating process.

结果表明，a水平管道内瓦斯爆炸传播火焰的厚度比以往理论计算得到的厚度大得多；b火焰区内爆炸中间产物呈上下分离状态，下部明亮发光体的内聚力比上部非发光体的内聚力高；c在火焰区内会出现负压现象；d火焰在传播过程中会发生断裂现象。

An analytical model for tunneling transmission through a high—frequency potential barrier in a ballistic channel is formulated.

不仅是量子波导中的传播态决定其弹道输运的过程，衰减态在电子波传播中的作用也是不可忽略的。

In media communication, information communication refers to its directness, determinacy, purposiveness and functionality, while taste transmission refers to indirectness, implicity, procedural and non-utilitarian.

在媒介传播中，信息传播是直接性、确定性、目的性与功能性的方面，趣味传播是其中间接性、隐含性、过程性与非现实功利性的方面。

On the basis of Firm TRs practice, further studies regarding functions and roles of promulgation in corporate culture reengineering has been carried out.

本文通过对TR设计公司进行企业文化建设实例的研究分析，提高了我们对企业文化在对内、对外传播中重要意义的认识，对传播手段在进行企业文化建设中的所起作用有了崭新的认识。

There was the jellylike medium in which the transverse wave spread. A deformation of the jelly, caused by the rotation of the sphere, moved through the medium.

又有一种胶状的介质，横波就是在这种介质中传播的，由于圆球的转动而引起球面上的胶状物的形变，这种形变在介质中向外传播。

More and more media set up web sites on internet in recent years. They provide news, passages and various services for audience. Electronicpage offers a possibility that anyone may present his or her opinion about everything what amplifies unprecedently the opinion-market function for the traditional media.

近两三年来，众多的报刊社、广播电台、电视台纷纷在因特网上建立网站，利用网络传播的强大功能，为受众提供新的信息通道和各项服务，电子论坛为新闻传播提供了在现实中、在技术上都无法实现的新形式，任何受众都有可以通过电子论坛就任何问题交换信息和发表意见。

One possibility is that it's just this particular combination of the eight parts that makes it spread among people, Webby said. But a more logical explanation is that a small mutation within the individual genetic segments changed things.

有一种可能性是这八个部分恰好组合成了能够在人群中迅速传播的性能，Webby说，但是，一个更合乎逻辑的解释是，基因片段中有一个微小的突变改变了病毒的传播特征。

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。