产生结果

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。

This approach not only inherits the advantages of absolute density based algorithms which can discover arbitrary shape clusters and are insensitive to noises , but also efficiently solves the following common problems: clustering results are very sensitive to the user-deflned parameters, reasonable parameters are hard to be determined, and high density clusters are contained fully in coterminous low density clusters. With this approach, incremental clustering can also be supported effectively by defining the affected sets and seed sets of the updating objects in this approach.

聚类算法的有效性问题主要表现在三个方面：其一，聚类算法大多要求用户输入一定的参数，例如希望产生的簇的数目，而这些参数通常难以确定，特别是针对高维空间中稀疏分布的实际应用数据集，用户几乎无法给出合适的算法参数，因此非专业用户需要与数据分析专家密切配合才能保证获得理想的聚类结果，导致算法的使用极为不便；其二，聚类结果对于输入的参数值过于敏感J，往往参数值的一些轻微变化却产生聚类结果的很大差异；其三，对于高维的实际应用数据集，其数据分布往往是稀疏的、杂乱的，很难为算法选择全局的参数进行准确的聚类分析，使得聚类的质量难以保证。

The results showed:(1)the factors which influence causal judgment were that the cause was the real cause or stimulative,the familiarity of the cause,and the covariation degree of causes with outcomes;(2)the character of questions didn't influence causal judgment;(3)causal judgment in some conditions were in accord with the probabilistic contrast model and the causal model theory,but they couldn't explain causal judgment in all conditions.

例如，在两个刺激同时出现并且之后伴随着一个结果事件出现的情况下，其中一个刺激对结果的作用可能被认为减弱了，另一个刺激被认为更易引起结果事件的产生[1]。多原因相互影响的现象，最初在动物条件反射中观察到，现在也已经在人类因果判断的实验中证实了[2]。研究因果判断中的多原因相互影响这一现象是有理论意义的，因为它证明了因果判断产生的情境重要性。

Achievements which are achieved by scientific research of predecessors are summarized. Some methods of how to generate self-similar process and a few means of estimating self-similar parameter are given. Self-similar traffics are generated by using of ON/OFF model with heavy-tailed distribution and results are given. The results of experiment accord with the theory. This identicalness indicates that the method of getting results by using of ON/OFF model is feasible.

本文总结了前人的研究成果，给出了几种常见产生自相似的方法和几种估计自相似参数的方法，并对ON/OFF模型叠加产生自相似业务进行了仿真实验，得到了实验结果，从实验结果可以看出，仿真结果和理论值比较接近，这说明利用ON/OFF模型叠加产生自相似业务是可行的。

From acoustic wave equation, current continuity equation and boundary conditions, we have solved the interface potential produced by BAWs in interface between piezoelectric solid and semiconductor. The results of YZ LiNb03/n-Si structure with SV wave incidence have been calculated and experimental result has been given. Finally, we have presented some kinds of BAW acoustoelectric convolver structures and analyzed their features.

由声波动方程，边界条件和半导体的电流连续性方程出发，推导出了斜入射体波在压电体/半导体界面产生的界面电势以及通过半导体的作用产生的倍频电势的结果，并且对YZ-LiNb03/n-Si结构，SV波入射的情况进行了计算，给出了部分实验结果，提出了几种可能的体波声电卷积器的结构，并分析了它们各自的特点，理论和实验的结果将为今后这类器件的研制提供依据。

To verify the accuracy of CFD simulations, experiments were carried out. The results of simulations with user defined function of the effects of impeller type and stirring rate on the velocity field were in good agreement with the output of particle image velocity. The oxygen mass transfer model can be used to predict the process of oxygen mass transfer in a vessel, and the logarithmical expression can successfully describe the relation between the oxygen concentration and the dissolution time.

结果表明，(1)采用Fluent软件并结合用户自定义方程(user defined function， UDF)能够很好地模拟出实际搅拌器内流场分布，模拟结果与采用粒子成像技术(particle image velocity， PIV)的实验测量结果相符；(2)采用氧气传质模型能预测氧气在搅拌器内的动态传质过程，同时氧气浓度与溶解时间的对数关系式能较好描述试验搅拌器内氧气动态传质过程；(3)在相同搅拌速度下，圆盘涡轮式搅拌器产生的湍流动能分布范围要大于桨式搅拌器产生的湍流动能，而且湍流动能分布更均匀，湍流强度更大。

But in practical operating, overvoltage caused by reignition of the vacuum switching device frequently appears, and it result in damage of the capacitor bank or the switchgear itself. Ensuring the switchgear against reignition and installing a protective device are two main approaches to avoid the phenomenon. In this paper, a study on overvoltage caused by reignition due to capacitor bank switching with the vacuum switching device and its preventive measures are carried out. The main work which has been done and researches are as follows: 1. The producing mechanism of overvoltage and its influence factor are analyzed. It is pointed out that single-phase reignition is the main reason for damage of the switchgear and two-phase reignition is the main reason for damage of the capacitor bank,so overvoltage of single-phase reignition and two-phase reignition are the emphases of prevention. 2. Analysis of the special working condition of the operating switch for capacitor bank is carried out. It indicates that the vacuum switching device is difficult to realize no-reignition under this operation condition, so it is more practical to adopt protection devices. 3. Analyses of protection effect of RC and MOA and their shortages are carried out. It shows that the two methods can only restrain effectively overvoltage caused by single-phase reignition, and they cannot protect the capacitor bank when reignition of two-phase occurs. 4. The operation principle of G-R damping device is analyzed and discussed emphatically.

本文针对真空开关投切电容器组时因重燃而产生的过电压及其防治措施进行了研究，所开展的主要工作和研究结果如下： 1、对过电压的产生机理及其影响因素进行了分析，指出单相重燃是导致开关设备损坏的主要原因，而两相重燃则是导致电容器组损坏的主要原因，因此单相重燃和两相重燃过电压是防护的重点； 2、对电容器组操作开关的特殊运行条件进行了分析，指出在这种运行条件真空开关难于实现不重燃，因此采用保护装置更具有现实意义； 3、对RC与MOA的保护效果和存在的不足进行了分析，指出这两种方法均只能有效抑制单相重燃过电压，而不能在发生两相重燃时保护电容器组； 4、重点对G-R阻尼装置的工作原理进行了分析和讨论，指出该装置接入后线路中将会出现两种频率的高频振荡，而电容器组上的过电压是由这两种振荡共同决定的； 5、根据对上述两种振荡的分析指出存在一个最佳电阻值使得过电压最低，并提出了电容器组电压和最佳电阻值的近似求解方法； 6、使用电气暂态分析软件MATLAB对G-R装置的保护效果进行了仿真计算，证实该装置确实可以有效抑制重燃时的电容器组过电压； 7、根据仿真与近似计算结果的偏差提出了近似计算的修正方法，经过修正后的过电压计算结果与仿真结果吻合较好； 8、对G-R装置中放电装置G与阻尼电阻R的要求进行了分析，指出采用编织电阻和真空间隙可能是最佳选择。

Based on the results from a series of simple shear tests for simulation a reinforced cut -- off slope with steelbars, this paper proposes a calculation method to evaluate the shear resistance and effect of the reinforcing materialsinvoking the theory of the lateral resistance of foundation pile.

本文在综合分析插筋补强土体剪切试验基础上，参考横向受力桩所受剪切力的计算方法，提出了用于评价插筋横向抗剪作用及其产生的补强效果的理论计算方法；并据此计算方法对试验条件下插筋在变形不连续面位置的剪力及由此剪力产生的抗剪补强效果进行了计算；然后将计算结果与试验的实测结果进行了分析对比，结果表明理论计算方法在一定的土体变形范围具有良好的精度和适用性。

The results show that:(1) lower concentration or lower initial pH of citrate solution results in a better desorption efficiency;(2) sparging inert gas or adding surfactants into the liquid can lower the viscosity of the solution and the cavitating threshold, and raise the desorption efficiency of SO2;(3) by comparing the experimental results and theoretical analyses , it was concluded that the experimental results are in accordance with the theoretical analyses.

结果表明：(1)在柠檬酸钠浓度较低，或者柠檬酸钠溶液初始pH值较低的条件下均能产生较好的解吸效果；(2)少量惰性气体的通入或者表面活性剂的加入能够降低溶液黏度，产生空化效应，从而提高了SO2的解吸率；(3)通过对比实验证明解吸结果与理论分析相吻合，其研究结果为SO2的深度解吸提供了技术思路，也为该项技术的工业放大提供了一定的基础数据。

Then, a hypothesis of "double force source" for tectonism is put forward, its main points are: the tectonism is not only the result from the action of tectonic stress, but also the result from the action of "double force source", namely, the tectonic stress and subsurface fluid force including force produced by precipitation, etc.

提出了&双力源&构造变动假设，即构造变动不仅是构造应力作用的结果，而且是构造应力与地下流体力共同作用的结果；二者共同作用因方式不同而产生不同的构造变动；在构造变动孕育与产生过程中，构造应力的作用是第一位的，地下流体力则是调制性的，只有那些能与构造应力增强过程产生力学耦合的地下流体力，才能调制与诱发出构造变动异常并促进构造变动。

I am sure after a few weeks of adaptation and familiarization I will have no difficulty in functioning on a daily basis in an English speaking society or in participating fully in graduate studies.

在大学的三年的学习生活不仅给予我自身的充实，更重要的是磨练和培养了我较强的自觉能力和严谨，踏实的作风以及不怕困难的精神，对未来充满了信心！

As the first volcanoes erupted, one of the gases that bellowed out was steam.

在第一批火山喷发时，喷出的气体之一就是水蒸汽。