听水

我从三峡回来好些时了，可我一静下来．依然可以听到那条江的水声——阴柔的、安详的、生生不息的那条江的水声啊……

Testing an improved cymbal hydrophone

Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the cymbal hydrophone was improved. The single ceramic piezoelectric element was replaced with a double one, the radius of the ceramic piezoelectric element was reduced, and a parallel circuit was added. A static analysis of this new structure was developed, and then simulations were made of both the traditional and new hydrophone structure using finite element software. Tests were then conducted in a tank. The results showed that the improved hydrophone has reception in a wider frequency band, reception performance is stable within this frequency band, and sensitivity is still high.

Depth Classification of Underwater Targets Based on Complex Acoustic Intensity of Normal Modes

In order to solve the problem of depth classification of the underwater target in a very low frequency acoustic field, the active component of cross spectra of particle pressure and horizontal velocity （ACCSPPHV） is adopted to distinguish the surface vessel and the underwater target. According to the effective depth of a Pekeris waveguide, the placing depth forecasting equations of passive vertical double vector hydrophones are proposed. Numerical examples show that when the sum of depths of two hydro- phones is the effective depth, the sign distribution of ACCSPPHV has nothing to do with horizontal distance; in addition, the sum of the first critical surface and the second critical surface is equal to the effective depth. By setting the first critical surface less than the difference between the effective water depth and the actual water depth, that is, the second critical surface is greater than the actual depth, the three positive and negative regions of the whole ocean volume are equivalent to two positive and negative regions and therefore the depth classification of the underwater target is obtained. Besides, when the 20 m water depth is taken as the first critical surface in the simulation of underwater targets （40 Hz, 50 Hz, and 60 Hz respectively）, the effectiveness of the algorithm and the cor- reemess of relevant conclusions are verified, and the analysis of the corresponding forecasting performance is conducted.

Influence of array elements’ consistency on SNR of hydrophone array

The influence of array element’s consistency on the hydrophone array’s signal-to-noise ratio (SNR) is studied. The consistency of array elements means the outputs of all the array’s elements are the same, that is to say, the outputs have the same phase and amplitude when their inputs are the same. The relationship between the SNR and the correlation coefficient of signal and the relationship between the SNR and the correlation coefficient of noise are given. Hydrophone array’s gain with the output of elements’ inconsistent phase and amplitude is analyzed theoretically. When the signal is single-frequency, the gain expression of two-elements array is deduced. Then the gain is calculated when the phase difference is 10° and the amplitude difference is 3 dB. The theoretical analysis is verified through simulation. The simulation results show the variation rule of array’s SNR when the consistency changes: the array SNR gain is greatly affected by the consistency of the elements’ output and the gain decreases as the consistency decreases and the gain may be negative when the amplitude response becomes worse.

Method for Measuring Self-noise of Vector Hydrophones

The Vector Hydrophone(VH) is widely used to remotely detect underwater targets. Accurately measuring the self-noise of the VH provides an important basis for evaluating the performance of the detection system in which it is utilized, since the ability to acquire weak signals is determined by the VH self-noise level. To accurately measure the VH self-noise level in actual working conditions, the Dual-channel Transfer Function Method(DTFM) is proposed to reduce ambient background noise interference. In this paper, the underlying principles of DTFM in reducing ambient background noise is analyzed. The numerical simulations to determine the influence of ambient background noise, and the sensitivity difference of the two VHs on the measurement results are studied. The results of measuring the VH self-noise level in a small laboratory water tank by using DTMF indicate that ambient background noise interference can be reduced effectively by employing DTMF, more accurate self-noise level can be obtained as well. The DTMF provides an effective method for accurately measuring the self-noise level of VHs and also provides technical support for the practical application of the VH in underwater acoustics.

Detecting hydrosonic signal using a polarization technique

Some optical fiber hydrophones, such as PGC Mach-Zehnder Interferometer, have a birefringence of single mode optical fibers which induce signal fading. Especially, if two optical beams from the optical arms are orthogonal, the interferomic signal can’t be detected at all. Here a new method is introduced. This is to translate the detected phase difference into a linearly polarized angle, then detect it, so that polarization inducing signal fading will be avoided. In theory, this problem is solved. Furthermore, the effect on measurement results from optical source fluctuation becomes little when using the polarization technique.

How to Motivate Students to Learn Listening Effectively？

This paper reports a study that used a matched-pair pre-test, post-test control group design to compare the impacts of IL （intensive listening） program and EL （extensive listening） program on the learners＇ listening proficiency based on the 30-day experiment. It is hoped that the study can help Vietnamese learners who study EFL （English as a foreign language） develop a positive attitude towards EL on one hand, and may motivate them to listen for pleasure on the other hand. This study may shed light on how to introduce EL into English foreign language classroom practice and how to maximize the students＇ exposure to suitable listening materials, which has been effectively adapted and reproduced, for the real classroom practice

On Improving Students＇ Listening Proficiency From Correlation Analysis Between English Listening and Other English Skills

Researches have proved that in human beings＇ actual languange communication, listening is the most important part. However, in English learning, listening seems always to be a weakness for many Chinese students. English learning is a systematic process, during which, English listening proficience is influeced by many factors. Therefore, from the systematicness and inner relations in English learning and based on qualitative analysis and quantitative analysis between English listening and other English skills in English listening, this paper tries to give the correlation analysis and accordingly give some suggestions to improve listening proficiency for ESL （English as a second language） learners

An Empirical Study of Listening Comprehension Strategies in Autonomous Learning Environment

This is a report on an empirical study of listening comprehension strategies in autonomous learning environment which was conducted among the second-year non-English majors in Shandong University （Weihai） on the basis of O＇Malley and Chamot＇s theory of learning strategies, dating from September, 2010 to January, 2011. The study aims to verify the teachability of listening comprehension strategies, the enhancement of students＇ awareness of applying these strategies in their listening comprehension pratice and positive effects of listening comprehension strategies cast on students＇ listening comprehension proficiency. Questionnares on listening comprehension strategies were conducted at the beginning and at the end of the research respectively, in addition to the listening comprehension strategies training from the beginning to the end of the research. Besides, there was a interview arranged in the middle of the research. Meanwhile, there were two listening comprehension proficiency tests arranged at the beginning and at the end of the research. According to the results, it can be indicated that the students＇ strategy awareness can be promoted, while their listening proficiency also can be improved by the listening comprehension strategy training.

Influence Of English Movies On College English Listening Teaching

Early in the 20th century, Lin Yutang proposed learning English by watching movies, and made a lot of reasons to do so.Contemporary college students are in contact with the flood of information and cultural exchanges have become increasingly frequent.On campus, it also surges wave of watching English movies, movies not only entertainment, but also can train and inspire students＇ interest and enthusiasm for learning English.Videos spoken dialogue is authentic, students can exercise listening, imitating wonderful dialogue to enhance their listening level, reduce hearing misunderstood.There is no doubt that English is the world＇ s most widely used language, learning English is the mission of every student.Only understand English, we can communicate with the world in English.In this paper, combined with the development status in college English listening teaching, and then explore the role of fihn in college English listening teaching.

Metacognitive Strategy and College English Listening Teaching

Metacognitive strategy, as one of the branches of learning strategy, can help students to consciously plan, monitor and evaluate their language learning, thus facilitate it. As a matter of fact, listeuing has long been regarded as an important linguistic skill to be developed in college English teaching. However, there are still some misunderstandings which exist among teachers and students. With the development of second language acquisition and listening comprehension, it becomes clear that listening is an active process in which the listener negotiates meanings in a conscious way. Therefore, if teachers can train students in metacognitive strategies in college English listening teaching, students can consciously plan, monitor and evaluate the entire listening process and become an active listener, thus improve their listening proficiency.

Classification of Underwater Target Echoes Based on Auditory Perception Characteristics

In underwater target detection, the bottom reverberation has some of the same properties as the target echo, which has a great impact on the performance. It is essential to study the difference between target echo and reverberation. In this paper, based on the unique advantage of human listening ability on objects distinction, the Gammatone filter is taken as the auditory model. In addition, time-frequency perception features and auditory spectral features are extracted for active sonar target echo and bottom reverberation separation. The features of the experimental data have good concentration characteristics in the same class and have a large amount of differences between different classes, which shows that this method can effectively distinguish between the target echo and reverberation.

The Role of EQ in EFL Students＇ Foreign Language Learning

EQ （Emotional Quotient） is considered a key component in foreign language learning. This study examined the relationship between EFL （English as a Foreign Language） students＇ EQ and learning strategies, English proficiency with EIS （Emotinal Intelligence Scale） and Strategy Inventory for Language Learning as well as students＇ tests in English listening, speaking, reading, and writing. Pearson correlation and regression analysis were applied in the data processing. The subsequent data analysis reveals that there is significant relationship between EFL students＇ EQ and their learning strategies as well as English proficiency. The correlation between EQ and affective strategies and the correlation between EQ and English speaking proficiency are higher than others. The factors which contribute to the correlation are analyzed. Furthermore, it is suggested for EFL teachers to take measures to facilitate students＇ EQ in classroom teaching

A STUDY ON THE EFFECTS OF ANNOTATION ON INCIDENTAL VOCABULARY LEARNING ATTACHED TO LISTENING TASKS

本研究考察注释方式对听力附带词汇习得的效果,设置两个实验组,单项定义注释和多项选择注释组。同时,考察语言水平和理解能力对词汇习得的影响。研究结果表明,语言水平和听力理解只影响词汇知识测验的结果;而注释的方式对词汇知识测验及词汇再认测验均产生影响,且影响最显著。

Near fields scattered by an underwater finite cylindrical baffle

In this work,acoustic vector characteristics of near fields scattered by an underwater finite cylindrical baffle are investigated theoretically and experimentally.The analytic expressions for the scattered pressure and particle velocity are derived using the elastic thin shell theory.Calculations are presented for the scattered near fields of the pressure,the particle velocity and the intensity.It is found that the pressure and the particle velocity fields near the surface of the cylindrical baffle are characterized by complex interference structure,particle velocity directions and the source bearings are not consistent.The phase difference between the pressure and the particle velocity is not zero and the intensity vector does not reflect the sound bearings.It can be noted that the distortions of the fields will make the original vector signal processing method based on the free space assumption be no longer applicable in the presence of the cylindrical baffle.These results can serve as a basis of the application for the acoustic vector sensor on board.

LEARNING STRATEGY TRAINING AND LISTENING PROFICIENCY:AN EMPIRICAL STUDY OF NON-ENGLISH MAJOR UNDERGRADUATES

笔者就语言学习策略培训对学生听力理解的影响进行了实证研究,旨在探求学习策略培训的有效性。研究随机选取大学二年级两个实验班的同学作为研究对象,运用Oxford(1996)学习策略问卷和大学英语四级考试听力部分试题作为研究工具,对经历了15周策略培训的实验班和对照班进行了测试和评估。研究结果表明:学习策略培训对学生听力理解有促进作用,可使学生听力成绩明显提高。文末提出了研究的启示,即教师应充分认识策略培训的重要性,把策略教学融入正常的听力教学中,鼓励学生在听力理解过程中运用学习策略,从而帮助其成为更有效的听力学习者。

Liquid Crystal-Based Hydrophone Arrays

We describe a fiber optic hydrophone array system that could be used for underwater acoustic surveillance applications （e.g. military, counter terrorist, and customs authorities in protecting ports and harbors）, offshore production facilities or coastal approaches as well as various marine applications. In this paper, we propose a new approach to underwater sonar systems using the voltage-controlled liquid crystals and simple multiplexing method. The proposed method permits measurement of sound under water at multiple points along an optical fiber using the low cost components and standard single mode fiber, without complex interferometric measurement techniques, electronics or demodulation software.

Introduction to HUA Xue-gui's Experience in Acupuncture Treatment of Tinnitus and Deafness

Doctor HUA Xue-gui, an associate chief physician in Shanghai Research Institute of Acupuncture and Meridian, has been engaged in clinical practice and scientific research of acupuncture for over 30 years. She has created a set of unique and complete acupuncture modalities for neurotic tinnitus and deafness. The authors are honored to have studied with Doctor HUA and have achieved a lot. Now, Doctor HUA＇s experience is summarized as follows.

Underwater patch near-field acoustical holography based on particle velocity and vector hydrophone array

One-step patch near-field acoustical holography(PNAH) is a powerful tool for identifying noise sources from the partially known sound pressure field.The acoustical property to be reconstructed on the surface of interest is related to the partially measured pressure on the hologram surface in terms of sampling and bandlimiting matrices,which cost more in computation.A one-step procedure based on measuring of the normal component of the particle velocity is described,including the mathematical formulation.The numerical simulation shows that one-step PNAH based on particle velocity can obtain more accurately reconstructed results and it is also less sensitive to noise than the method based on pressure.These findings are confirmed by an underwater near-field acoustical holography experiment conducted with a vector hydrophone array.The experimental results have illustrated the high performance of one-step PNAH based on particle velocity in the reconstruction of sound field and the advantages of a vector hydrophone array in an underwater near-field measurement.