查询词典 noise-power-ratio

It is an important content of construction ecological campus to raise sound environmental quality, through monitoring for the campus regional present situation of noise pollution and analysis, find out the major noise source that affects the area of campus, put forward the corresponding pollutive countermeasure of prevention, offer basis to found healthy quiet, comfortable ecological campus.

引 言 随着城市社会经济、交通运输的迅速发展，噪声污染问题日益严重，很多院校面临着为学生营造一个安静舒适、自然和谐的学习居住环境的压力。国内一些城市己颁布了生态型住宅小区建设管理办法及技术实施细则，对于高校园区，这一特殊的居住区，一方面要符合生态型住宅小区的

Results The system can produce stable signal of exact frequency according to GBZ49-2002 Diagnostic Criteria of Occupational Noise-induced Hearing Loss to output stability of the frequency and intensity of the audio signal, and the specific context of the noise pre-exposure function with screening of hearing impairment was achieved automatically.

结果：该系统经过标定，能够按照《GBZ49-2002职业性听力损伤诊断标准》输出稳定频率和强度的音频信号，实现听力损伤自动筛查以及特定背景的噪声预暴露功能。

The problem of noise of the fan is studied with the non-linear theory, and pressure pulsation of axial flow fan's inside flow was measured by dynamic pressure sensor, the gas-structure coupled noise of contra-rotating axial flow fan was studied through a

摘要用非线性动力学的理论对风机噪声问题进行了分析，同时运用实验手段测量了轴流风机流场内部流动的压力脉动，从全新的角度研究了对旋风机的气固耦合噪声。

A noise an noys an oyster,but a noisy noise an noys an oyster more!

声音令牡蛎烦恼，但是嘈杂的声音更让牡蛎烦躁不安。

Based on this, aim at the disadvantage on Wigner Distribution and Fractional Fourier Transform that can't restrain noise interference effectively when be used to detect Linear Frequency Modulated signals interfered by heavy noises, we proposed a improved WD. Simulation results show that this method can restrain noise interference effectively and improve the ability of LFM signals detection. On the other hand, in multi-component cases, WD suffers from the cross-terms, which may impair some of the auto-terms. In order to separate original multi-component signals into components and reconstruct them separately, we can use the method of optimal filtering in fractional Fourier domain. But this method also has a problem that if signals have aliasing in the fractional Fourier optimal domain as well, the reconstructed signals will be distorted. In this thesis, a novel method of quasi Fourier transform is proposed in order to solve the problem of multi-component signal reconstruction, and have good results.

在此基础上，针对Wigner分布和分数维傅里叶变换在处理高噪声背景下线性调频信号检测的问题时存在不能有效抑制噪声干扰的缺点，提出了改进Wigner分布的办法，该方法能够抑制噪声，提高信号的检测能力；针对Wigner分布在处理多分量非线性调频信号时存在干扰项的缺点，以及分数域最优滤波方法在处理多分量非线性调频信号分离重构问题时存在的局限性，该局限性表现为在对最优分数域上也有信号分量重叠的情况进行处理时重构信号发生畸变，提出了新颖的类傅里叶变换的方法，该方法对在最优分数域上也有信号分量重叠的情况也能处理，得到的重构信号失真很小。

In this paper, the influence of track stiffness on vibration and noise of highspeed wheel/rail system for slab track is investigated under the excitation of wheel/rail roughness on the basis of wheel/rail noise prediction model.

文献仁1〕在国外轮轨噪声相关研究的基础上，结合机车车辆一轨道藕合动力学原理2〕，提出了列车一轨道多轮对系统的轮轨噪声预测模型。

Rolling noise ; wheel/rail ; high-speed train ; slab track ; noise pollution

滚动噪声；轮/轨；高速列车；板式轨道；噪声污染

The road noise, wind noise and engine sound of LF620 at idle speed and at the speed of 80 km/h on the express way are not clearly audible.

怠速下的620相当安分，即使在高速公路上80 km/h左右时速飞驰时，路噪、风噪和发动机噪声也并不突出。

In order to show the validity of the suggested model of radiated noise sources of ship at shallow wave guide, the radiated noise of a fishery ship was measured.

为了验证浅海波导条件下的船舶辐射噪声源模型，在某浅海海域，测量了一艘渔政船的辐射噪声。

Based on this, cacelled the vibration noise with appropriate weight number and step size.From the research work in this paper,it is shown that the vibration noise can be cancelled effectively and cetain cancellation can be obtained in

同时，研究结果还表明：采用归一化LMS自适应滤波器进行舷侧阵振动噪声抵消的效果优于传统的LMS算法自适应滤波器，更有利于满足实时处理的要求。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。