传播过程中的噪音在大学英语教学中的表现及排除

课堂教学是对学生实施素质教育的基本途径和主要形式,而素质教育的核心内涵则是“以学生的发展为本”。因而,激活课堂,探索教学是现代教学的当务之急。但是,在课堂中存在着诸多干扰(噪音),这些干扰会严重影响教学效果和效率。文章从传播学中的噪音理论的角度,阐述了英语课堂中学生会产生的语义噪音和物理噪音等,并借鉴传播学的过滤器等理论提出了排除英语课堂噪音的办法。

Resonance, Multi-resonance, and Reverse-resonance Induced by Multiplicative Dichotomous Noise

A constant-potential system driven by multiplicative dichotomous noise and subject to an input oscillatory signal is investigated. Two phenomena of stochastic resonance are observed. One is the response as a function of the noise＇s parameters; the other is that as a function of the input signal frequency. A phenomenon of multi-resonance （there are three or four peaks） is found for the response as a function of a parameter of the noise. A phenomenon of reverse-resonance is found, for which the response of the system to the signal can be weakened by the presence of the noise （there is an optimal minimum）. These results help in studies of the systems with multiplicative dichotomous noise, such as the semiconductor, the proteins motor, the chemical reaction, and so on.

Stochastic Resonance in a Bistable System Subject to Dichotomous Noise

The stochastic resonance phenomenon in a bistable system subject to Markov dichotomous noise （DN） is investigated. Based on the adiabatic elimination and the two-state theories, the explicit expressions for the signal-tonoise ratio （SNR） and the spectral power amplification （SPA） have been obtained. It is shown that two peaks can occur on the curve of SNR versus the intensity of the DN. Moreover, the SNR is a non-monotonic function of the correlation time of the DN. The SPA varies non-monotonously with the strength of the DN. The dependence of the SNR on the frequency and the amplitude of the external periodic signal are discussed. The effect of the external frequency and the correlation time of the DN on the SPA are analyzed.

System Driven by Correlated Gaussian Noises Related with Disorder

A system driven by correlated Gaussian noises related with disorder is investigated. The Fokker-Planck equation （FPE） for the system is derived. Using the FPE derived, some systems driven by correlated Gaussian noises related with disorder can be investigated for Brownian motors, nonequilibrium transition, resonant activation, stochastic resonance, and so on. We only give one example： i.e., using the FPE derived, we study the resonant activation for a single motor protein model with correlated noises related to disorder. Since the correlated noise related to disorder usually exists with the friction, for the temperature, and so on, our results have generic physical meanings for physics, chemistry, biology and other sciences.

Influence of Noises on Remote State Preparation Using GHZ State

Using a quantum channel consisting of a GHZ state exposed to noisy environment,we investigate how toremotely prepare an entangled state and a qubit state,respectively.By solving the master equation in the Lindbladform,the influence of the various types of noises on the GHZ state is first discussed.Then we use the fidelity to describehow close the remotely prepared state and the initial state are.Our results show that the fidelity is a function of thedecoherence rates and the angles of the initial state.It is found that for each of the two RSP schemes,the influence ofthe noise acting simultaneously in x,y,and z directions on the average fidelity is the strongest while the influence of thenoise acting in x or z direction on the average fidelity is relatively weaker.

Probability Density and Statistical Properties for a Three-State Markovian Noise and Escape of Particles for a System Driven by This Noise

A three-state Markovian noise is investigated.Its probability density and statistical properties are obtained. Escape of particles for a system with potential barrier only driven by this noise is investigated.It is shown that,in some circumstances,this noise can make the particles escape over the potential barrier;but in other circumstances,it cannot. Resonant activation phenomenon appears for the system considered by us.

Noise Shielding Using Acoustic Metamaterials

We exploit theoretically a class of rectangular cylindrical devices for noise shielding by using acoustic metamateriais. The function of noise shielding is justified by both the far-field and near-field full-wave simulations based on the finite element method. The enlargement of equivalent acoustic scattering cross sections is revealed to be the physical mechanism for this function. This work makes it possible to design a window with both noise shielding and air flow.

A Network Model on the Processing of Sound Wave

On the base of auditory neural system, the network model on the processing of the sound wave is presented. The mathematic equation of the network is also discussed. In the network model, in addition to the negative feedback of the neural cell in the output layer, the cell in the input layer excites the corresponding cell in the ontput layer meanwhile it inhibits the lateral cells. The network has its advantage on the processing of sound wave. In addition to filter the noise, it can search the significance frequency segments （Barks）. The ＂channel suppresser＂ feature, the special phenomena of the human ear, is explained based on the model. The learning algorithm of the network model is discussed, too. In the end, an example is introduced about the application of the network.

Spring peepers Pseudacris crucifer modify their call structure in response to noise

Acoustic interference can impede effective communication that is important for survival and reproduction of animals. In response to acoustic interference, some animals can improve signalling efficacy by altering the structure of their signals. In this study, we played artificial noise to 46 male spring peepers Pseudacris crucifer, on their breeding grounds, and tested whether the noise affected the duration, call rate, and peak frequency of their advertisement calls. We used two experimental noise treatments that masked either the high- or low-frequency components of an average advertisement call; this allowed us to evaluate whether frogs adaptively shift the peak frequency of their calls away from both types of interference. Our playback treatments caused spring peepers to produce shorter calls, and the high-frequency noise treatment caused them to lower the frequency of their calls immediately after the noise ceased. Call rate did not change in response to playback. Consistent with previous studies, ambient temperature was inversely related to call duration and positively related to call rate. We conclude that noise affects the structure of spring peeper advertisement calls, and that spring peepers therefore have a mechanism for altering signal structure in response to noise. Future studies should test if other types of noise, such as biotic or anthropogenic noise, have similar effects on call structure, and if the observed changes to call structure enhance or impair communication in noisy environments [Current Zoology 60 （4）： 438-448, 2014].