查询词典 noise

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。

The invention performs pseudo bit error rate statistic by utilizing the message of multi sampling points in each modulation symbol of discretization system, and again performs one-to-one mapping by utilizing corresponding relation between the pseudo bit error rate and the signal-to-noise ratio, thereby obtaining signal-to-noise ratio estimation value.

本发明利用了离散系统每个调制符号中多个采样点的信息进行伪误码率统计，再利用伪误码率与信噪比之间的对应关系进行一一映射，从而得到信噪比估计值。

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。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。