长信号

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。

As response signal of damped free vibration could be considered as product of the harmonic wave and the unilateral exponential function and the rectangle window, the peak frequency and phase are frequency and phase of the harmonic wave signal is proved in theory in this paper.

针对自由衰减振动信号的连续谱，将其看成无限长谐波信号与单边指数函数及矩形窗的乘积，在理论上证明峰值点的频率和相位就是信号的实际频率和相位。

Results: Although most cases (11/16) were typical and clearly classified on MRI, atypical cases were also observed, such as meningioma of long T1/T2 signal intensity with small cystic foci, and neurinoma of iso intensity and homogenous enhancement without cystic change or enlargement of internal acoustic meatus.

结果：尽管多数神经鞘瘤(5/8)和脑膜瘤(6/8)具有典型的MRI表现特征并仅经MRI即可得到正确鉴别，但部分病例(5/16)为不典型表现者，如脑膜瘤呈长T1长T2信号并伴有囊变，以及神经鞘瘤呈等信号、均匀强化且不伴有囊变或内听道扩大者，鉴别诊断困难。

Making use of the analytical expression,one has researched this laws of the parametric bandwidth vs the wavelength of signal light,pump light and the noncollinear angle through the method of numerical calculation.

结果表明，对于同一抽运光，随着信号光波长的增加，参变带宽将先增加而后减小，即参变带宽存在着最大值；随着抽运光波长的减小，参变带宽将增大；对于同一信号光和抽运光，随着非共线角α的增大，参变带宽Δλ将逐渐增大。

The echolocation signals at flying, foraging behaviors and food types of 4 endemic species in China were studied. The results were described as followed:(1) Rhinolophus rex has long CF-FM signals, low dominant frequency with the range of 26. 8±0.2kHz, which is the lowest in the recorded Rhinolophidae.

2.4种中国特有蝙蝠飞行状态下的回声定位信号和根据回声定位信号推测出捕食策略和食物类型：（1）贵州菊头蝠回声定位信号为长CF-FM型，能量最大处频率非常低，为26.8±0.2kHz，是已有记载的菊头蝠科中回声定位频率最低的。

Results (1) Of 19 cases, 7 showed confluent foci within periventricular white matter and centrum semioval, presenting as massive symmetrically-distributed lesions with long T 1 and long T 2 signal.

结果 (1)脑白质异常信号 7例，主要分布于侧脑室旁的脑白质及半卵圆中心，为大片状长T1、长T2 信号，呈对称分布。

In the experiment, 40 Gb/s DPSK signal was demodulated successfully, and the extinction of the demodulated signal is 14.5 dB.

实验中实现了40 Gb/s差分相移键控信号的解调，解调信号消光比为14.5 dB，温度控制实现了输出结果的长时间稳定，并可在相长干涉和相消干涉之间转换。

By means of the different interference phase formed by light beams with different wavelengths in the same light path difference and the superposing of interference signals of different spectral components, ultimate interference signal is formed.

振动系统产生干涉光路的光程差，形成干涉信号的调制相位差，通过不同光波长在相同光程差条件下形成的不同干涉相位，通过对不同光谱分量的干涉信号叠加，形成最终的干涉信号。

In order to acquire the largest extinction ratio of the converted signal in the cross gain modulation wavelength conversion, the signal wavelength λ pk,s should be longer than the small signal gain peak wavelength of the semiconductor optical amplifier.

增益调制型波长转换中，为得到转换后信号最大的消光比，信号光波长应该比半导体光放大器的小信号增益峰值波长长。

In the paper, by describing the inside and outside widening on curve track scientifically, a new method for computing the co-ordinate location where the fouling point or signal will be installed is presented based on calculating the structure gauge limit in favour of developing the CARYD system, and a new graphical method yielded from the the new principle makes it truely possible for using simple tools to determine the position manully.

通过对曲线内外加宽的几何描述，以建筑接近限界作为计算的最终依据，新的适合于计算机辅助设计的警冲标、信号机的计算方法保证了警冲标、信号机位置的确定、到发线有效长的计算以及咽喉区之间的连接能够自动进行。除此之外，按照新的原理和方法，论文中还提出了一种适合于采用简单绘图工具便可实现警冲标、信号机位置确定的新的图解方法。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。