系统发生的

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。

In a holistic and systematic view, we discussed the progress mechanism of acute leukemia, found a hypothetic pathway of meningioma progression, and described the network interaction of a set of genes which differentially expressed between androgen independent prostate cancer and androgen dependent prostate cancer significantly and related to hormones.

从系统和整体的角度，对急性白血病的发生发展机制进行了探讨，构建了一条脑膜瘤发生发展的通路，对在前列腺癌中差异表达，且和激素相关的基因的网络相互作用进行了阐述。

The results of DPBMN in n-hexane solution show that there are two non-radiative processes occurring in the local excited state. The decay time constants of ~4 ps and ~ 220 ps are due to vibration relaxation and intersystem crossing processes respectively.

实验结果显示DPBMN分子在非极性溶剂中的区域性激发态(local excited state，LE state)有两个非辐射缓解的过程发生，首先为发生在LE能阶的振动缓解(~ 4 ps)，之后为系统内转换的过程(~ 220 ps)。

The students are required to study and understand the main physiological features of fetuses and the ontogenesis of the most important regulating axises during the fetal development .

中文简介：通过本课程的学习使学生在学习动物胚胎学以及相关课程的基础上，进一步认识动物主要器官或系统的发生发育过程，相关的调控机理；以及动物主要调节轴系的发生和建立。

Based on a systematic field investigation and laboratory experiments, the structures of arthropod communities and the evalution of dominant predatory enemies in cabbage fields of different seasons were studied. The main results were as follows:1 The structures and their dynamics of arthropod communities in cabbage fields1.1 Species composition and population dynamics of each species of the arthropodcommunities in the cabbage fieldsThe research results showed that the occurrence of Pieris rapae in spring cabbage fields was relatively grave.

本文在田间系统调查和室内试验的基础上，对不同季节甘蓝田节肢动物群落结构及捕食性天敌优势种的评价进行了研究，主要结果如下：1甘蓝田节肢动物群落结构及其动态1.1节肢动物群落物种构成和各种群数量动态研究结果表明，春甘蓝田菜青虫的发生比较严重，菜青虫在调查期间种群数量呈上升趋势，5月初高峰期平均每株甘蓝接近20头；菜蚜与小菜蛾的发生相对较轻，菜蚜在5月中旬有个明显高峰。

The located position and development of the disc was correlative with the development of other floral organs, which might provide insight to delimit Wikstroemia and Daphne based on different floral developmental pattern that might exist between the two genera.

花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性，这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有一定意义。

The located position and development of the disc was correlative with the development of other floral organs, which might provide insight to delimit Wikstroemia and Daphne based on different floral developmental pattern that might exist between the two genera.

花盘的发生和早期发育及其着生位置同其他花部器官的发生和发育式样具有明显的相关性，这种相关性对进一步阐明瑞香属Daphne和荛花属Wikstroemia的系统发育关系具有—定意义。

Based on the simulation data, the effects of clearances, damping coefficient and the rotation speed on the dynamic behaviors are studied: compared with ideal mechanisms, mechanisms with clearances are less stable; as for mechanisms with clearances, when the crank rotates at the speed of 100rad/s, the actual clearances are always above the radium of clearances, axle pin and axle cover keep contact throught the rotation; when the crank rotates at the speed of 20rad/s, mechanisms are in an unstable state, at an angle of about 300, the actual clearances are below the radium of clearances, pairs lose contact, which results in collision between them; with the speed of 20rad/s, when damping coefficient is assumed 175Ns/m, distinct separation and collision happen between pairs; when damping coefficient is assumed 220Ns/m, separation and collision are controlled.

在含间隙机构中，当曲柄以100rad/s转动时，运动副间隙始终大於半径间隙，轴销与轴套始终保持连续接触；当曲柄以低速20rad/s转动时，系统处於极不稳定的震荡状态，在转至300°左右时，运动副间隙小於半径间隙，脱离接触，发生明显的分离碰撞现象。在含间隙机构中，曲柄以低速20rad/s转动，当取法向阻尼系数为175Ns/m时，副元素发生明显的分离碰撞现象；当取法向阻尼系数为220Ns/m时控制了副元素的分离，副元素一直处於连续接触状态。

According to the fault data information and expert"s field knowledge, the system can distinguish the lines and buses which fault occurs in, also judge the line"s fault type and the circuit breakers and relayss action performance and give the maintenance suggestion.

系统能在电网发生故障时，根据故障数据信息和专家领域知识，判别发生故障的线路、母线，线路的故障类型以及断路器、保护的动作性能，并给出维修建议。

Depending on how late in the project the incompatibility is discovered, debugging might take longer than it would have if integration had occurred earlier, program interfaces might have to be changed, or major parts of the system might have to be redesigned and reimplemented.

这种风险的发生取决于项目中的这种不兼容性多久才被发现，由于程序界面已经发生了变化，或者系统的主要部分已经被重新设计和重新实现了，相应的排错工作将非常困难和耗时。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。